Move the archive files into their own package (closes #541)

The SQLite archive files the database target writes are now managed by
internal/archive: file names, rotation, the writer of each target,
pruning, renames, the gzipped JSON export, the idle sweep, and the
rename lock, which was Handlers.renameMu. The database target stays in
internal/delivery and writes through archive.Writers; the engine still
closes the writers when it stops, so the stop order is unchanged. The
handlers take the rename lock from archive.Archives.RenameLock, and
rename and evict through archive.Archives.

Exported names drop their Archive prefix in the new package. The tests
moved with the code; the two that check a delivery's recorded attempt
stay in delivery.

Model: opus-5-5

README.md

@@ -2100,15 +2100,15 @@ writes go on meanwhile, since under WAL a reader never blocks a writer. Until
 the open file is closed its `-wal` cannot be checkpointed past what the download
 reads, so a long download lets that `-wal` grow.
 
-Deleting a webhook releases its archives: the delivery engine's cached archive
-writers are dropped and their file handles closed, so nothing lingers after the
-webhook is gone. The archive **files themselves are deliberately left on disk**.
-Unlike the event database — per-webhook working storage that is hard-deleted
-with the webhook — an archive is long-term storage an operator may still want to
-keep or move away for offline retention, and destroying it as a side effect of
-deleting a webhook would be unrecoverable. Removing an `archive-….db` is the
-operator's call. Deleting a `database` target releases its writer the same way,
-and for the same reason leaves its file alone.
+Deleting a webhook releases its archives: its cached archive writers are dropped
+and their file handles closed, so nothing lingers after the webhook is gone. The
+archive **files themselves are deliberately left on disk**. Unlike the event
+database — per-webhook working storage that is hard-deleted with the webhook —
+an archive is long-term storage an operator may still want to keep or move away
+for offline retention, and destroying it as a side effect of deleting a webhook
+would be unrecoverable. Removing an `archive-….db` is the operator's call.
+Deleting a `database` target releases its writer the same way, and for the same
+reason leaves its file alone.
 
 The **Slack target type** sends webhook events as formatted messages to any
 Slack-compatible incoming webhook URL (works with Slack, Mattermost, and other
@@ -2997,6 +2997,12 @@ webhooker/
 ├── cmd/webhooker/
 │   └── main.go               # Entry point: subcommand dispatch; no args locks DATA_DIR and wires fx
 ├── internal/
+│   ├── archive/
+│   │   ├── archive.go         # The archive writer of each database target, eviction, rename, and the rename lock
+│   │   ├── writer.go          # Archive file lifecycle and pruning
+│   │   ├── rotation.go        # Archive rotation and file names
+│   │   ├── download.go        # Archive download as gzipped JSON
+│   │   └── sweeper.go         # Periodic pruning of idle archives
 │   ├── banner/
 │   │   └── banner.go          # Ruled block for the one credential shown in the clear
 │   ├── resetpw/
@@ -3040,13 +3046,9 @@ webhooker/
 │   │   ├── target.go          # Target interface, Task, Scheduler
 │   │   ├── target_http.go     # HTTP target (retries, circuit breaker)
 │   │   ├── target_slack.go    # Slack/Mattermost incoming-webhook target
-│   │   ├── target_database.go # Database archive target
-│   │   ├── target_database_archive.go  # Archive file lifecycle and pruning
-│   │   ├── target_database_rotation.go # Archive rotation and file names
-│   │   ├── target_database_export.go   # Archive download as gzipped JSON
+│   │   ├── target_database.go # Database archive target, writing through internal/archive
 │   │   ├── target_log.go      # Log target (stdout)
 │   │   ├── target_config_view.go  # Masked target config for templates
-│   │   ├── archive_sweeper.go # Periodic pruning of idle archives
 │   │   ├── queue_depth.go     # Periodic sampler behind the queue-depth gauges
 │   │   ├── url_mask.go        # Strips credentials from *url.Error
 │   │   └── ssrf.go            # SSRF prevention (IP validation, safe HTTP transport)
@@ -3137,14 +3139,16 @@ Components are wired via Uber fx in this order:
 11. `metrics.New` — The delivery collectors, registered on that registry
 12. `middleware.New` — HTTP middleware
 13. `delivery.New` — Event-driven delivery engine
-14. `delivery.NewArchiveSweeper` — Periodic pruning of idle archives
-15. `delivery.Engine` → `delivery.Notifier` — interface bridge
-16. `delivery.Engine` → `delivery.Archives` — interface bridge so deleting or
+14. `archive.NewWriters` — The database targets' archive writers, and the lock
+    every rename of their files runs under
+15. `archive.NewSweeper` — Periodic pruning of idle archives
+16. `delivery.Engine` → `delivery.Notifier` — interface bridge
+17. `archive.Writers` → `archive.Archives` — interface bridge so deleting or
     renaming a webhook or target reaches its archive files
-17. `server.New` — HTTP server and router
+18. `server.New` — HTTP server and router
 
 The server starts via
-`fx.Invoke(func(*server.Server, *delivery.Engine, *database.RetentionReaper, *delivery.ArchiveSweeper) {})`,
+`fx.Invoke(func(*server.Server, *delivery.Engine, *database.RetentionReaper, *archive.Sweeper) {})`,
 which triggers the fx lifecycle hooks in dependency order. The
 `delivery.Notifier` interface allows the webhook handler to send self-contained
 `delivery.Task` slices to the engine without a direct package dependency. Each
@@ -3313,7 +3317,7 @@ order under a **5 second budget** (`fx.StopTimeout` in `cmd/webhooker/main.go`).
 That budget covers the whole sequence, not each hook. The order, read off the fx
 stop-hook log:
 
-1. `ArchiveSweeper`
+1. `archive.Sweeper`
 2. `RetentionReaper`
 3. `server` — the HTTP drain, bounded by `server.ShutdownTimeout` (**3
    seconds**) and by what the hooks before it left, then a Sentry flush if
@@ -3356,7 +3360,7 @@ skipped when that leaves too little to be worth attempting — so a full-length
 drain means Sentry events are dropped rather than the database close being
 skipped.
 
-This does not make the database close unconditional. A slow `ArchiveSweeper` or
+This does not make the database close unconditional. A slow `archive.Sweeper` or
 `RetentionReaper` is enough to cut the shutdown short, not only one that
 consumes the whole budget: what they spend comes out of the drain first, so
 after 2 seconds of theirs a request still in flight gets 1 second to finish, and

cmd/webhooker/main.go

@@ -10,6 +10,7 @@ import (
 
 	"go.uber.org/fx"
 	"go.uber.org/fx/fxevent"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/datadir"
@@ -49,7 +50,7 @@ import (
 // before the server may already have spent.
 //
 // This does not make the database close unconditional: the
-// ArchiveSweeper and RetentionReaper hooks run before the server.
+// archive.Sweeper and RetentionReaper hooks run before the server.
 // What they spend comes out of the drain first, but past 3s it comes
 // out of the reserve, and they can consume the whole budget.
 const stopTimeout = 5 * time.Second
@@ -188,8 +189,8 @@ func newApp() *fx.App {
 		fx.Provide(
 			globals.New,
 			logger.New,
-			// The plain logger the session, the middleware and the
-			// webhook database manager take.
+			// The plain logger the session, the middleware, the
+			// webhook database manager and the archive writers take.
 			func(l *logger.Logger) *slog.Logger { return l.Get() },
 			config.New,
 			database.New,
@@ -208,14 +209,15 @@ func newApp() *fx.App {
 			// disagree about a destination.
 			delivery.NewGuard,
 			delivery.New,
-			delivery.NewArchiveSweeper,
+			archive.NewWriters,
+			archive.NewSweeper,
 			// Wire *delivery.Engine as delivery.Notifier so the
 			// webhook handler can notify the engine of new deliveries.
 			func(e *delivery.Engine) delivery.Notifier { return e },
-			// Wire *delivery.Engine as delivery.Archives so deleting
+			// Wire *archive.Writers as archive.Archives so deleting
 			// or renaming a webhook or target reaches its archive
 			// files.
-			func(e *delivery.Engine) delivery.Archives { return e },
+			func(w *archive.Writers) archive.Archives { return w },
 			// Wire *delivery.Engine as delivery.CircuitBreakers so
 			// the pages can show a target whose deliveries are
 			// paused.
@@ -227,7 +229,7 @@ func newApp() *fx.App {
 				*server.Server,
 				*delivery.Engine,
 				*database.RetentionReaper,
-				*delivery.ArchiveSweeper,
+				*archive.Sweeper,
 			) {
 			},
 		),

cmd/webhooker/main_test.go

@@ -252,7 +252,7 @@ const tailHeadroom = 2 * time.Second
 // can produce, since a shorter drain leaves the flush more room and
 // the worst case is not necessarily at either extreme.
 //
-// Nor does the hook start on a full budget: the ArchiveSweeper and
+// Nor does the hook start on a full budget: the archive.Sweeper and
 // RetentionReaper hooks run before it, and whatever they spent is
 // gone. The outer sweep walks every amount they can spend. Once they
 // have eaten into the headroom themselves, the hook must spend

internal/archive/archive.go

@@ -0,0 +1,454 @@
+// Package archive manages the SQLite archive files the database target
+// writes: how they are named and rotated, the writers that open, write,
+// close and reopen them, pruning the rows past a target's expiry,
+// renaming a target's files and moving them back when that fails, the
+// gzipped JSON export, the idle sweep, and the locks that keep a rename
+// apart from archive writes, from other edits and from exports.
+package archive
+
+import (
+	"fmt"
+	"log/slog"
+	"strings"
+	"sync"
+	"time"
+
+	"go.uber.org/fx"
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// archiveNameMaxLen is how many characters of a webhook or target
+// name an archive file name keeps.
+const archiveNameMaxLen = 40
+
+// Archives is how the handlers keep the database targets' archive
+// files in step with the configuration. Deleting a webhook or a
+// target releases the cached archive writers, whose open file
+// handles would otherwise outlive them; renaming one renames the
+// archive files, which are named for the webhook and the target
+// (see FileName). RenameLock returns the lock every rename runs under
+// (see Writers.RenameLock).
+//
+// It is an interface so that the handlers' tests can stand in for
+// Writers.
+//
+// Neither eviction deletes an archive file. Both are idempotent
+// and are no-ops for a webhook or target with no writer.
+type Archives interface {
+	RenameLock() *sync.Mutex
+	EvictWebhook(webhookID string)
+	EvictTarget(targetID string)
+	Rename(targetID, webhookName, targetName string) error
+}
+
+// WritersParams holds the fx dependencies for Writers.
+type WritersParams struct {
+	fx.In
+
+	Database  *database.Database
+	DBManager *database.WebhookDBManager
+	Logger    *slog.Logger
+}
+
+// Writers holds the archive writer of each database target, and the
+// lock every rename of archive files runs under. The database target
+// writes an event through it, the handlers rename and evict through
+// it, the archive sweeper prunes through it, and the delivery engine
+// evicts every writer when it stops. See archiveWriter for the
+// close/reopen, auto-recreate, and expiry semantics.
+type Writers struct {
+	db    *database.Database
+	dbMgr *database.WebhookDBManager
+	log   *slog.Logger
+
+	// writers holds one archive writer per database target, keyed
+	// by target ID.
+	mu      sync.Mutex
+	writers map[string]*archiveWriter
+
+	// renameMu makes the webhook edit, the target edit and target
+	// creation run one at a time, each held from loading the stored
+	// names through the archive rename, the save and any move back.
+	// Interleaved, one could rename an archive between another's
+	// rename and save, leaving the file named for one edit and the
+	// stored names from the other. An archive download holds it while
+	// it reads the stored names and lists the files they give, and
+	// again for each file while it finds the file under the names
+	// stored then and opens it. RenameLock returns it.
+	renameMu sync.Mutex
+}
+
+// NewWriters builds the archive writers. It opens no archive file:
+// each target's writer is made on its first use.
+func NewWriters(params WritersParams) *Writers {
+	return &Writers{
+		db:    params.Database,
+		dbMgr: params.DBManager,
+		log:   params.Logger,
+	}
+}
+
+// RenameLock implements Archives. It returns the lock every rename of
+// archive files runs under: see renameMu for who holds it and for how
+// long. Archive writes and Rename itself do not take it.
+func (ws *Writers) RenameLock() *sync.Mutex {
+	return &ws.renameMu
+}
+
+// FileName returns the file name of a database target's
+// archive: archive-WEBHOOKNAME-TARGETNAME-TARGETID.db, with both
+// names passed through archiveNamePart. The target ID keeps the
+// name unique when two targets' names come out the same.
+func FileName(webhookName, targetName, targetID string) string {
+	return "archive-" + archiveNamePart(webhookName) + "-" +
+		archiveNamePart(targetName) + "-" + targetID + ".db"
+}
+
+// archiveNamePart makes a webhook or target name safe to put in a
+// file name. It is lowercased; ASCII letters and digits are kept,
+// every other run of characters becomes a single "-", and no "-" is
+// left at either end. It is cut to archiveNameMaxLen characters, and
+// a name with nothing left is "unnamed".
+func archiveNamePart(name string) string {
+	var b strings.Builder
+
+	dash := false
+
+	for _, r := range strings.ToLower(name) {
+		if (r < 'a' || r > 'z') && (r < '0' || r > '9') {
+			dash = b.Len() > 0
+
+			continue
+		}
+
+		if dash {
+			b.WriteByte('-')
+
+			dash = false
+		}
+
+		b.WriteRune(r)
+	}
+
+	part := b.String()
+	if len(part) > archiveNameMaxLen {
+		part = strings.TrimRight(part[:archiveNameMaxLen], "-")
+	}
+
+	if part == "" {
+		return "unnamed"
+	}
+
+	return part
+}
+
+// Write writes the full event of a delivery to a database target as
+// a row into the target's archive database, honouring the optional
+// per-target expiry and rotation parsed from the target config JSON.
+// With rotation, the event goes to the file for the period of its
+// receive time.
+func (ws *Writers) Write(d *database.Delivery) error {
+	webhookID := d.Event.WebhookID
+	if webhookID == "" {
+		return errArchiveMissingWebhookID
+	}
+
+	expiry, err := ParseExpiry(d.Target.Config)
+	if err != nil {
+		return err
+	}
+
+	rotation, err := ParseRotation(d.Target.Config)
+	if err != nil {
+		return err
+	}
+
+	// An event whose stored row was gone before its delivery ran has
+	// no receive time (see delivery's Engine.hydrateEvent), and goes
+	// to the file for now.
+	receivedAt := d.Event.CreatedAt
+	if receivedAt.IsZero() {
+		receivedAt = time.Now()
+	}
+
+	w, err := ws.writerFor(d.TargetID)
+	if err != nil {
+		return err
+	}
+
+	row := archivedEvent{
+		EventID:      d.Event.ID,
+		WebhookID:    webhookID,
+		EntrypointID: d.Event.EntrypointID,
+		Method:       d.Event.Method,
+		RawQuery:     d.Event.RawQuery,
+		Headers:      d.Event.Headers,
+		Body:         d.Event.Body,
+		ContentType:  d.Event.ContentType,
+	}
+
+	return w.write(row, expiry, archivePeriod(rotation, receivedAt))
+}
+
+// Rename implements Archives. It renames every one of a database
+// target's archive files to FileName(webhookName, targetName,
+// targetID), each keeping the period in its name. It goes through the
+// target's writer, so the move holds the lock that the target's
+// archive writes and the idle sweep take, and later writes use the
+// new name. It never replaces a file: if one already has a new name,
+// the error is ErrNameTaken.
+//
+// The writer is created if there is none, and it stays cached. The
+// handlers rename before they save the new name, so until the save
+// the main database still has the old one; a delivery in that window
+// must find this writer rather than build one from the old name.
+func (ws *Writers) Rename(
+	targetID, webhookName, targetName string,
+) error {
+	w, err := ws.writerFor(targetID)
+	if err != nil {
+		return err
+	}
+
+	return w.rename(FileName(webhookName, targetName, targetID))
+}
+
+// EvictTarget implements Archives. It drops a database target's
+// archive writer from the registry and closes its handle, so a
+// deleted target does not leave a writer (and an open archive handle
+// within its debounce window) alive for the process lifetime.
+//
+// The map entry is removed under the registry lock, which is
+// then released before the handle is closed under the writer's
+// own lock: that ordering keeps the registry available to other
+// targets while an in-flight write on this one drains, and
+// closing under the writer's lock means eviction can never race
+// a write.
+//
+// Eviction is idempotent and silent for a target with no writer,
+// which is the common case: only a database target that has
+// received an event or been renamed has one. It never deletes the
+// archive file.
+func (ws *Writers) EvictTarget(targetID string) {
+	ws.mu.Lock()
+
+	w, ok := ws.writers[targetID]
+	if ok {
+		delete(ws.writers, targetID)
+	}
+
+	ws.mu.Unlock()
+
+	if !ok {
+		return
+	}
+
+	w.evict()
+
+	ws.log.Info(
+		"evicted archive writer",
+		"target_id", targetID,
+		"path", w.path,
+	)
+}
+
+// EvictWebhook implements Archives. It evicts, exactly as EvictTarget
+// does, the writer of every database target of a webhook. The archive
+// files themselves are left on disk — they are long-term storage the
+// operator owns.
+func (ws *Writers) EvictWebhook(webhookID string) {
+	ws.mu.Lock()
+
+	var gone []*archiveWriter
+
+	for targetID, w := range ws.writers {
+		if w.webhookID == webhookID {
+			delete(ws.writers, targetID)
+
+			gone = append(gone, w)
+		}
+	}
+
+	ws.mu.Unlock()
+
+	for _, w := range gone {
+		w.evict()
+
+		ws.log.Info(
+			"evicted archive writer",
+			"webhook_id", webhookID,
+			"path", w.path,
+		)
+	}
+}
+
+// EvictAll evicts every cached archive writer, exactly as EvictTarget
+// does for one target. The delivery engine calls it at shutdown, once
+// its workers have returned. Closing the last handle on an archive
+// moves the contents of its -wal into the .db and removes the
+// -wal, so a clean stop leaves each archive as a single file.
+func (ws *Writers) EvictAll() {
+	ws.mu.Lock()
+
+	writers := ws.writers
+	ws.writers = nil
+
+	ws.mu.Unlock()
+
+	for _, w := range writers {
+		w.evict()
+	}
+}
+
+// writerFor returns the archive writer for a database target,
+// creating and caching it on first use. Each target has one writer
+// so its close/reopen debounce state is shared across concurrent
+// deliveries, and so a rename and the idle sweep take the same lock
+// as its writes.
+func (ws *Writers) writerFor(
+	targetID string,
+) (*archiveWriter, error) {
+	ws.mu.Lock()
+	defer ws.mu.Unlock()
+
+	w, ok := ws.writers[targetID]
+	if !ok {
+		var err error
+
+		w, err = ws.newWriter(targetID)
+		if err != nil {
+			return nil, err
+		}
+
+		if ws.writers == nil {
+			ws.writers = make(map[string]*archiveWriter)
+		}
+
+		ws.writers[targetID] = w
+	}
+
+	// A delivery claims the entry: even if the idle sweep created
+	// it moments ago, it now belongs to the registry proper and
+	// the sweep must leave it in place when it finishes.
+	w.sweepOwned = false
+
+	return w, nil
+}
+
+// sweepWriterFor returns the archive writer the idle sweep should
+// prune a target's archive through, together with whether the sweep
+// itself created the registry entry.
+//
+// The sweep must route its prune through the registered writer so
+// the writer's mutex orders it against concurrent writes, but it
+// must never leave a registry entry behind: a sweep that ran
+// concurrently with the target's deletion would otherwise
+// re-create an entry that nothing will ever evict again, which is
+// exactly the leak eviction exists to prevent. An entry the sweep
+// creates is therefore marked sweep-owned and handed back to
+// releaseSweepWriter when the sweep is done.
+func (ws *Writers) sweepWriterFor(
+	targetID string,
+) (*archiveWriter, bool, error) {
+	ws.mu.Lock()
+	defer ws.mu.Unlock()
+
+	w, ok := ws.writers[targetID]
+	if ok {
+		return w, false, nil
+	}
+
+	w, err := ws.newWriter(targetID)
+	if err != nil {
+		return nil, false, err
+	}
+
+	if ws.writers == nil {
+		ws.writers = make(map[string]*archiveWriter)
+	}
+
+	w.sweepOwned = true
+	ws.writers[targetID] = w
+
+	return w, true, nil
+}
+
+// releaseSweepWriter drops a registry entry that the idle sweep
+// created, so a sweep leaves the registry exactly as it found it.
+//
+// The entry is removed only if it is still the very writer the
+// sweep installed and no delivery has claimed it in the meantime
+// (writerFor clears sweepOwned when it hands a writer to the
+// write path). Both conditions are evaluated under the registry
+// lock, so an eviction that raced the sweep — which removes the
+// entry outright — simply finds nothing left to do here, and a
+// delivery that adopted the writer keeps a registered, evictable
+// one.
+func (ws *Writers) releaseSweepWriter(
+	targetID string, w *archiveWriter,
+) {
+	ws.mu.Lock()
+	defer ws.mu.Unlock()
+
+	cur, ok := ws.writers[targetID]
+	if !ok || cur != w || !cur.sweepOwned {
+		return
+	}
+
+	delete(ws.writers, targetID)
+}
+
+// newWriter builds the writer for a database target's archive. Its
+// path is the one Path gives for the webhook and the target as
+// the main database names them now; from then on only rename changes
+// the name the writer uses. It does not touch the archive files.
+func (ws *Writers) newWriter(
+	targetID string,
+) (*archiveWriter, error) {
+	if ws.dbMgr == nil {
+		return nil, errArchiveNoDataDir
+	}
+
+	var target database.Target
+
+	err := ws.db.DB().
+		Preload("Webhook").
+		First(&target, "id = ?", targetID).Error
+	if err != nil {
+		return nil, fmt.Errorf(
+			"loading database target %s: %w", targetID, err,
+		)
+	}
+
+	w := newArchiveWriter(
+		Path(ws.dbMgr, &target.Webhook, &target),
+		ws.log,
+	)
+	w.webhookID = target.WebhookID
+
+	return w, nil
+}
+
+// sweepArchive prunes one database target's archive of rows older
+// than expiry, without requiring a write. A missing archive file is
+// left missing (see sweepExpired), so a sweep never creates an
+// archive for a target that has never received an event.
+//
+// It also never leaves a registry entry behind: an entry it had
+// to create to reach the writer's mutex is released again once
+// the prune is done, so a sweep racing a target deletion cannot
+// resurrect the writer the eviction just dropped.
+func (ws *Writers) sweepArchive(
+	targetID string, expiry time.Duration,
+) error {
+	w, created, err := ws.sweepWriterFor(targetID)
+	if err != nil {
+		return err
+	}
+
+	if created {
+		defer ws.releaseSweepWriter(targetID, w)
+	}
+
+	return w.sweepExpired(expiry)
+}

internal/archive/archive_test.go

@@ -0,0 +1,773 @@
+package archive_test
+
+import (
+	"database/sql"
+	"fmt"
+	"io/fs"
+	"log/slog"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+	_ "modernc.org/sqlite" // Pure Go SQLite driver.
+	"sneak.berlin/go/webhooker/internal/archive"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/gormlog"
+)
+
+const (
+	// testContentType is the event content type used in tests.
+	testContentType = "application/json"
+
+	// eventQuery is the query string an archived event carries.
+	eventQuery = "a=1&b=2"
+)
+
+func archiveTestLogger() *slog.Logger {
+	return slog.New(slog.NewTextHandler(
+		os.Stderr,
+		&slog.HandlerOptions{Level: slog.LevelDebug},
+	))
+}
+
+// openArchiveDBForRead opens an archive file read-only so a
+// test can inspect the rows the writer persisted.
+func openArchiveDBForRead(
+	t *testing.T, path string,
+) *gorm.DB {
+	t.Helper()
+
+	sqlDB, err := sql.Open(
+		"sqlite",
+		fmt.Sprintf("file:%s?mode=ro", path),
+	)
+	require.NoError(t, err)
+
+	t.Cleanup(func() { _ = sqlDB.Close() })
+
+	gdb, err := gorm.Open(
+		sqlite.Dialector{Conn: sqlDB},
+		&gorm.Config{Logger: gormlog.New(slog.New(slog.DiscardHandler))},
+	)
+	require.NoError(t, err)
+
+	return gdb
+}
+
+// archiveFileSuffixes returns the archive file itself and the
+// SQLite sidecars that accompany an open database. A test that
+// asserts no archive was created has to check all of them.
+func archiveFileSuffixes() []string {
+	return []string{"", "-wal", "-shm"}
+}
+
+// removeArchiveFiles simulates an operator moving the archive
+// away by deleting the SQLite file and its sidecar files.
+func removeArchiveFiles(t *testing.T, path string) {
+	t.Helper()
+
+	for _, suffix := range []string{
+		"", "-wal", "-shm", "-journal",
+	} {
+		err := os.Remove(path + suffix)
+		if err != nil && !os.IsNotExist(err) {
+			t.Fatalf("removing %s%s: %v", path, suffix, err)
+		}
+	}
+}
+
+// assertStoredTime asserts that text, a timestamp as SQLite holds it,
+// is in the form GORM stores created_at in: the layout of
+// time.Time.String, with no " m=+…" monotonic clock reading after it.
+func assertStoredTime(t *testing.T, text string) {
+	t.Helper()
+
+	_, err := time.Parse(
+		"2006-01-02 15:04:05.999999999 -0700 MST", text,
+	)
+	assert.NoError(t, err, "stored as %q", text)
+}
+
+// newEvent returns an event received now with the given body, as the
+// webhook handler stores it.
+func newEvent(body string) database.Event {
+	return database.Event{
+		BaseModel: database.BaseModel{
+			ID:        uuid.New().String(),
+			CreatedAt: time.Now(),
+		},
+		WebhookID:    uuid.New().String(),
+		EntrypointID: uuid.New().String(),
+		Method:       http.MethodPost,
+		Headers:      `{"Content-Type":["application/json"]}`,
+		Body:         body,
+		ContentType:  testContentType,
+	}
+}
+
+// databaseTargetDelivery returns a delivery of event to a database
+// target, as the database target hands it to Writers.Write.
+func databaseTargetDelivery(
+	event database.Event, tgt *database.Target,
+) *database.Delivery {
+	return &database.Delivery{
+		EventID:  event.ID,
+		TargetID: tgt.ID,
+		Event:    event,
+		Target: database.Target{
+			Name:   tgt.Name,
+			Type:   database.TargetTypeDatabase,
+			Config: tgt.Config,
+		},
+	}
+}
+
+func TestArchiveWriter_WritesRow(t *testing.T) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "archive-wh.db")
+	w := archive.NewExportArchiveWriter(
+		path, archiveTestLogger(), 0,
+	)
+
+	row := archive.ExportArchivedEvent{
+		EventID:      "ev-1",
+		WebhookID:    "wh-1",
+		EntrypointID: "ep-1",
+		Method:       "POST",
+		Headers:      `{"X":"Y"}`,
+		Body:         `{"hello":"world"}`,
+		ContentType:  "application/json",
+	}
+
+	require.NoError(t, w.Write(row, 0))
+	assert.FileExists(t, path)
+
+	var got []archive.ExportArchivedEvent
+
+	require.NoError(t, w.DB().Find(&got).Error)
+	require.Len(t, got, 1)
+	assert.Equal(t, "ev-1", got[0].EventID)
+	assert.Equal(t, "wh-1", got[0].WebhookID)
+	assert.Equal(t, "ep-1", got[0].EntrypointID)
+	assert.Equal(t, row.Method, got[0].Method)
+	assert.Equal(t, row.ContentType, got[0].ContentType)
+	assert.JSONEq(t, `{"hello":"world"}`, got[0].Body)
+	assert.False(t, got[0].ArchivedAt.IsZero())
+
+	var archivedAt string
+
+	require.NoError(t, w.DB().Raw(
+		"SELECT CAST(archived_at AS TEXT) FROM archived_events",
+	).Row().Scan(&archivedAt))
+	assertStoredTime(t, archivedAt)
+}
+
+func TestArchiveWriter_RecreatesAfterRemoval(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "archive-wh.db")
+	w := archive.NewExportArchiveWriter(
+		path, archiveTestLogger(), 0,
+	)
+
+	require.NoError(t, w.Write(
+		archive.ExportArchivedEvent{EventID: "a"}, 0,
+	))
+	assert.FileExists(t, path)
+
+	// The operator moves the archive away while the handle is
+	// still open.
+	removeArchiveFiles(t, path)
+	require.NoFileExists(t, path)
+
+	// The next write recreates the file with a fresh schema and
+	// only the new row.
+	require.NoError(t, w.Write(
+		archive.ExportArchivedEvent{EventID: "b"}, 0,
+	))
+	assert.FileExists(t, path)
+
+	var got []archive.ExportArchivedEvent
+
+	require.NoError(t, w.DB().Find(&got).Error)
+	require.Len(t, got, 1)
+	assert.Equal(t, "b", got[0].EventID)
+}
+
+// TestArchiveHandleIsWAL closes the last gap in the durability
+// evidence: the main and per-webhook tiers each assert their journal
+// mode on a live handle, and the archive tier gets its settings from
+// the same code path but nothing checked the running file.
+func TestArchiveHandleIsWAL(t *testing.T) {
+	t.Parallel()
+
+	w := archive.NewExportArchiveWriter(
+		filepath.Join(t.TempDir(), "archive-wal.db"),
+		archiveTestLogger(), 0,
+	)
+
+	require.NoError(t, w.Open(0))
+
+	var mode string
+
+	row := w.DB().Raw("pragma journal_mode").Row()
+	require.NoError(t, row.Scan(&mode))
+	assert.Equal(t, "wal", strings.ToLower(mode))
+
+	var busy string
+
+	row = w.DB().Raw("pragma busy_timeout").Row()
+	require.NoError(t, row.Scan(&busy))
+	assert.Equal(t, "10000", busy)
+}
+
+// TestStatArchive proves Stat finds no file before the first
+// write; after a write still held in the -wal, counts the -wal in the
+// size and takes its later time as the last write; and finds no file
+// again once the file has been moved away.
+func TestStatArchive(t *testing.T) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "archive-wh.db")
+
+	_, err := archive.Stat(path)
+	require.ErrorIs(t, err, fs.ErrNotExist)
+
+	// With the clock stopped, the reopen debounce never passes, so
+	// the handle stays open after the write.
+	stopped := time.Now()
+	w := archive.NewExportArchiveWriter(path, archiveTestLogger(), 0)
+	w.SetNow(func() time.Time { return stopped })
+
+	require.NoError(t, w.Write(archive.ExportArchivedEvent{EventID: "a"}, 0))
+
+	written := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	earlier := written.Add(-time.Hour)
+	require.NoError(t, os.Chtimes(path, earlier, earlier))
+	require.NoError(t, os.Chtimes(path+"-wal", written, written))
+
+	file, err := os.Stat(path)
+	require.NoError(t, err)
+
+	wal, err := os.Stat(path + "-wal")
+	require.NoError(t, err)
+	require.Positive(t, wal.Size())
+
+	got, err := archive.Stat(path)
+	require.NoError(t, err)
+	assert.Equal(t, 1, got.Files)
+	assert.Equal(t, file.Size()+wal.Size(), got.Size)
+	assert.True(t, written.Equal(got.Written), got.Written)
+
+	removeArchiveFiles(t, path)
+
+	_, err = archive.Stat(path)
+	require.ErrorIs(t, err, fs.ErrNotExist)
+}
+
+func TestArchiveWriter_ReopenDebounce(t *testing.T) {
+	t.Parallel()
+
+	const debounce = 2 * time.Second
+
+	path := filepath.Join(t.TempDir(), "archive-wh.db")
+	w := archive.NewExportArchiveWriter(
+		path, archiveTestLogger(), debounce,
+	)
+
+	// The writer measures its reopen debounce on this clock, which
+	// only the test moves, so how long the host takes between
+	// writes cannot change the result.
+	now := time.Now()
+
+	w.SetNow(func() time.Time { return now })
+
+	require.NoError(t, w.Write(
+		archive.ExportArchivedEvent{EventID: "a"}, 0,
+	))
+	require.NoError(t, w.Write(
+		archive.ExportArchivedEvent{EventID: "b"}, 0,
+	))
+
+	// Two writes inside the debounce window trigger only the
+	// initial open — no extra close/reopen.
+	assert.Equal(t, 1, w.Reopens())
+
+	now = now.Add(debounce)
+
+	require.NoError(t, w.Write(
+		archive.ExportArchivedEvent{EventID: "c"}, 0,
+	))
+
+	// A write after the window elapses closes and reopens once.
+	assert.Equal(t, 2, w.Reopens())
+}
+
+func TestArchiveWriter_ExpiryPrune(t *testing.T) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "archive-wh.db")
+	w := archive.NewExportArchiveWriter(
+		path, archiveTestLogger(), 0,
+	)
+
+	require.NoError(t, w.Open(0))
+
+	old := archive.ExportArchivedEvent{
+		EventID:    "old",
+		ArchivedAt: time.Now().Add(-2 * time.Hour),
+	}
+	fresh := archive.ExportArchivedEvent{
+		EventID:    "fresh",
+		ArchivedAt: time.Now(),
+	}
+
+	require.NoError(t, w.DB().Create(&old).Error)
+	require.NoError(t, w.DB().Create(&fresh).Error)
+
+	// Reopening with a one-hour expiry prunes the old row.
+	require.NoError(t, w.Reopen(time.Hour))
+
+	var got []archive.ExportArchivedEvent
+
+	require.NoError(t, w.DB().Find(&got).Error)
+	require.Len(t, got, 1)
+	assert.Equal(t, "fresh", got[0].EventID)
+}
+
+func TestParseArchiveExpiry(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name    string
+		in      string
+		want    time.Duration
+		wantErr bool
+	}{
+		{"empty config", "", 0, false},
+		{"explicit never", `{"expiry":"never"}`, 0, false},
+		{"empty expiry", `{"expiry":""}`, 0, false},
+		{"duration", `{"expiry":"1h"}`, time.Hour, false},
+		{"unparseable", `{"expiry":"nonsense"}`, 0, true},
+		{"zero duration", `{"expiry":"0s"}`, 0, true},
+		{"negative duration", `{"expiry":"-5h"}`, 0, true},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			got, err := archive.ParseExpiry(tc.in)
+			if tc.wantErr {
+				require.Error(t, err)
+
+				return
+			}
+
+			require.NoError(t, err)
+			assert.Equal(t, tc.want, got)
+		})
+	}
+}
+
+func TestValidateArchiveExpiry(t *testing.T) {
+	t.Parallel()
+
+	valid := []string{"", "never", "1h", "720h", "30m"}
+	for _, in := range valid {
+		require.NoError(t,
+			archive.ValidateExpiry(in),
+			"expiry %q should be accepted", in,
+		)
+	}
+
+	invalid := []string{"nonsense", "7d", "-5h", "0s", "0"}
+	for _, in := range invalid {
+		require.Error(t,
+			archive.ValidateExpiry(in),
+			"expiry %q should be rejected", in,
+		)
+	}
+}
+
+// TestArchiveFileName pins the archive file name and the rules
+// that make a webhook or target name safe to put in it.
+func TestArchiveFileName(t *testing.T) {
+	t.Parallel()
+
+	const id = "3f2a1c9e-8d4b-4c1a-9e2f-0a1b2c3d4e5f"
+
+	cases := []struct {
+		name    string
+		webhook string
+		target  string
+		want    string
+	}{
+		{
+			"plain names", "orders", "archive",
+			"archive-orders-archive-" + id + ".db",
+		},
+		{
+			"lowercased", "Orders", "Main Archive",
+			"archive-orders-main-archive-" + id + ".db",
+		},
+		{
+			"a run of other characters is one dash",
+			`a  /\..b`, "c__--d",
+			"archive-a-b-c-d-" + id + ".db",
+		},
+		{
+			"no dash at either end", "  --orders!! ", "(archive)",
+			"archive-orders-archive-" + id + ".db",
+		},
+		{
+			"path separators", "../../etc/passwd", "a/b",
+			"archive-etc-passwd-a-b-" + id + ".db",
+		},
+		{
+			"letters outside ASCII are dropped",
+			"Bestellungen Größe", "café",
+			"archive-bestellungen-gr-e-caf-" + id + ".db",
+		},
+		{
+			"nothing left is unnamed", "", "!!!",
+			"archive-unnamed-unnamed-" + id + ".db",
+		},
+		{
+			"cut to 40 characters", strings.Repeat("a", 50), "x",
+			"archive-" + strings.Repeat("a", 40) + "-x-" + id + ".db",
+		},
+		{
+			"no dash left by the cut",
+			strings.Repeat("a", 39) + " b", "x",
+			"archive-" + strings.Repeat("a", 39) + "-x-" + id + ".db",
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			assert.Equal(
+				t, tc.want,
+				archive.FileName(tc.webhook, tc.target, id),
+			)
+		})
+	}
+}
+
+// TestWrite_EachTargetHasItsOwnArchive proves two
+// database targets of one webhook archive into separate files.
+func TestWrite_EachTargetHasItsOwnArchive(t *testing.T) {
+	t.Parallel()
+
+	env := setupArchiveTest(t)
+	first := env.seedDatabaseTarget(t, "")
+	second := env.addDatabaseTarget(t, first.WebhookID, "")
+
+	event := newEvent(`{"n":1}`)
+
+	for _, tgt := range []*database.Target{first, second} {
+		require.NoError(t, env.writers.Write(
+			databaseTargetDelivery(event, tgt),
+		))
+	}
+
+	require.NotEqual(
+		t, env.archivePath(first), env.archivePath(second),
+	)
+	assert.Equal(
+		t, []string{event.ID},
+		archivedEventIDs(t, env.archivePath(first)),
+	)
+	assert.Equal(
+		t, []string{event.ID},
+		archivedEventIDs(t, env.archivePath(second)),
+	)
+}
+
+// TestRename_MovesTheFile proves a rename moves the archive, rows
+// and all, and that later writes go to the new name.
+func TestRename_MovesTheFile(t *testing.T) {
+	t.Parallel()
+
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
+	oldPath := env.archivePath(tgt)
+
+	first := newEvent(`{"n":1}`)
+	require.NoError(t, env.writers.Write(databaseTargetDelivery(first, tgt)))
+	require.FileExists(t, oldPath)
+
+	require.NoError(
+		t, env.writers.Rename(tgt.ID, "Orders", "Long Term"),
+	)
+
+	newPath := filepath.Join(
+		env.dataDir, "archive-orders-long-term-"+tgt.ID+".db",
+	)
+
+	assert.NoFileExists(t, oldPath)
+	assert.Equal(t, []string{first.ID}, archivedEventIDs(t, newPath))
+
+	second := newEvent(`{"n":2}`)
+	require.NoError(t, env.writers.Write(databaseTargetDelivery(second, tgt)))
+
+	assert.ElementsMatch(
+		t, []string{first.ID, second.ID},
+		archivedEventIDs(t, newPath),
+	)
+	assert.NoFileExists(
+		t, oldPath, "a write after the rename must use the new name",
+	)
+}
+
+// TestRename_NeverReplacesAFile plants a file at the new name, once
+// the .db alone, once a lone -wal and once a lone -shm, and proves
+// each time that the rename is refused, the planted file survives,
+// and the archive keeps its name and its rows.
+func TestRename_NeverReplacesAFile(t *testing.T) {
+	t.Parallel()
+
+	for _, suffix := range archiveFileSuffixes() {
+		t.Run("planted .db"+suffix, func(t *testing.T) {
+			t.Parallel()
+
+			env := setupArchiveTest(t)
+			tgt := env.seedDatabaseTarget(t, "")
+			oldPath := env.archivePath(tgt)
+
+			first := newEvent(`{"n":1}`)
+			require.NoError(
+				t, env.writers.Write(databaseTargetDelivery(first, tgt)),
+			)
+
+			newPath := filepath.Join(
+				env.dataDir, "archive-orders-long-term-"+tgt.ID+".db",
+			)
+			plantedPath := newPath + suffix
+			require.NoError(
+				t, os.WriteFile(plantedPath, []byte("planted"), 0o600),
+			)
+
+			require.ErrorIs(
+				t, env.writers.Rename(tgt.ID, "Orders", "Long Term"),
+				archive.ErrNameTaken,
+			)
+
+			//nolint:gosec // reads the file the test planted under t.TempDir()
+			planted, err := os.ReadFile(plantedPath)
+			require.NoError(t, err)
+			assert.Equal(t, "planted", string(planted))
+
+			second := newEvent(`{"n":2}`)
+			require.NoError(
+				t, env.writers.Write(databaseTargetDelivery(second, tgt)),
+			)
+
+			assert.ElementsMatch(
+				t, []string{first.ID, second.ID},
+				archivedEventIDs(t, oldPath),
+			)
+		})
+	}
+}
+
+// TestRename_BeforeTheNameIsSaved covers the order the handlers
+// use: they rename before they save the new name, so a delivery in
+// between must write under the new name although the main database
+// still has the old one. It also shows that renaming an archive that
+// does not exist yet is not an error.
+func TestRename_BeforeTheNameIsSaved(t *testing.T) {
+	t.Parallel()
+
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
+
+	require.NoError(
+		t, env.writers.Rename(tgt.ID, "Orders", "Archive"),
+	)
+
+	event := newEvent(`{"n":1}`)
+	require.NoError(t, env.writers.Write(databaseTargetDelivery(event, tgt)))
+
+	assert.FileExists(
+		t,
+		filepath.Join(
+			env.dataDir, "archive-orders-archive-"+tgt.ID+".db",
+		),
+	)
+	assert.NoFileExists(t, env.archivePath(tgt))
+}
+
+// TestArchiveWriter_RenameMovesSidecars proves a rename carries
+// the -wal and -shm a crash can leave beside an archive no handle
+// has opened since. SQLite finds them by name, so a -wal left
+// behind would lose the transactions it holds.
+func TestArchiveWriter_RenameMovesSidecars(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	oldPath := filepath.Join(dir, "archive-old.db")
+	newPath := filepath.Join(dir, "archive-new.db")
+
+	for _, suffix := range archiveFileSuffixes() {
+		require.NoError(
+			t, os.WriteFile(oldPath+suffix, []byte(suffix), 0o600),
+		)
+	}
+
+	w := archive.NewExportArchiveWriter(
+		oldPath, archiveTestLogger(), 0,
+	)
+
+	require.NoError(t, w.Rename("archive-new.db"))
+
+	for _, suffix := range archiveFileSuffixes() {
+		assert.NoFileExists(t, oldPath+suffix)
+		assert.FileExists(t, newPath+suffix)
+	}
+
+	assert.Equal(t, newPath, w.Path())
+}
+
+// TestArchiveWriter_RenameMovesBackOnFailure makes the -wal fail to
+// move after the .db has moved, and proves the .db is moved back, so
+// the archive is never split across two names. The new name is 255
+// bytes, the longest a file name may be, so the .db can take it but
+// the -wal, four bytes longer, cannot.
+func TestArchiveWriter_RenameMovesBackOnFailure(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	oldPath := filepath.Join(dir, "archive-old.db")
+	newName := strings.Repeat("a", 252) + ".db"
+
+	for _, suffix := range archiveFileSuffixes() {
+		require.NoError(
+			t, os.WriteFile(oldPath+suffix, []byte(suffix), 0o600),
+		)
+	}
+
+	w := archive.NewExportArchiveWriter(
+		oldPath, archiveTestLogger(), 0,
+	)
+
+	require.Error(t, w.Rename(newName))
+
+	for _, suffix := range archiveFileSuffixes() {
+		assert.FileExists(t, oldPath+suffix)
+	}
+
+	assert.NoFileExists(t, filepath.Join(dir, newName))
+	assert.Equal(t, oldPath, w.Path())
+}
+
+// TestArchiveWriter_RenameMovesBackEveryFile renames a target with a
+// file without a period and a file for a month, and proves that when
+// the month's file fails to move, the file already moved is moved back:
+// both files are under the old name with their rows, and nothing is
+// under the new name. The new name is 251 bytes, so the file without a
+// period, with its -wal and -shm, can take it, but the month's file,
+// eight bytes longer, cannot.
+func TestArchiveWriter_RenameMovesBackEveryFile(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	oldPath := filepath.Join(dir, "archive-old.db")
+	monthPath := filepath.Join(dir, "archive-old-2026-03.db")
+	w := archive.NewExportArchiveWriter(oldPath, archiveTestLogger(), 0)
+
+	require.NoError(t, w.WritePeriod(
+		archive.ExportArchivedEvent{EventID: "in-none"}, 0, "",
+	))
+	require.NoError(t, w.WritePeriod(
+		archive.ExportArchivedEvent{EventID: "in-month"}, 0, "2026-03",
+	))
+
+	require.Error(t, w.Rename(strings.Repeat("a", 248)+".db"))
+
+	assert.Equal(t, []string{"in-none"}, archivedEventIDs(t, oldPath))
+	assert.Equal(t, []string{"in-month"}, archivedEventIDs(t, monthPath))
+
+	entries, err := os.ReadDir(dir)
+	require.NoError(t, err)
+
+	for _, entry := range entries {
+		assert.True(t, strings.HasPrefix(entry.Name(), "archive-old"),
+			"%s is not under the old name", entry.Name())
+	}
+
+	assert.Equal(t, oldPath, w.Path())
+}
+
+// TestRenameLock_HeldByOneEditAtATime holds the rename lock, as an edit
+// does from loading the stored names until it has saved them. While it
+// is held, the edit's rename and an archive write still finish, since
+// neither takes it, and the event ends up under the new name whichever
+// ran first. A second edit waits for the lock until the first lets go.
+func TestRenameLock_HeldByOneEditAtATime(t *testing.T) {
+	t.Parallel()
+
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
+	event := newEvent(`{"n":1}`)
+
+	env.writers.RenameLock().Lock()
+
+	finished := make(chan error, 2)
+
+	go func() {
+		finished <- env.writers.Rename(tgt.ID, "Orders", "Long Term")
+	}()
+	go func() {
+		finished <- env.writers.Write(databaseTargetDelivery(event, tgt))
+	}()
+
+	for range 2 {
+		select {
+		case err := <-finished:
+			require.NoError(t, err)
+		case <-time.After(10 * time.Second):
+			t.Fatal("a rename or a write waited for the rename lock")
+		}
+	}
+
+	newPath := filepath.Join(
+		env.dataDir, "archive-orders-long-term-"+tgt.ID+".db",
+	)
+	assert.Equal(t, []string{event.ID}, archivedEventIDs(t, newPath))
+
+	secondEdit := make(chan struct{})
+
+	go func() {
+		env.writers.RenameLock().Lock()
+		close(secondEdit)
+		env.writers.RenameLock().Unlock()
+	}()
+
+	select {
+	case <-secondEdit:
+		t.Fatal("a second edit took the rename lock while it was held")
+	case <-time.After(100 * time.Millisecond):
+	}
+
+	env.writers.RenameLock().Unlock()
+
+	select {
+	case <-secondEdit:
+	case <-time.After(10 * time.Second):
+		t.Fatal("a second edit did not get the rename lock once released")
+	}
+}

internal/archive/download.go

@@ -1,4 +1,4 @@
-package delivery
+package archive
 
 import (
 	"compress/gzip"
@@ -28,25 +28,25 @@ import (
 const archiveTableQuery = "SELECT count(*) FROM sqlite_master " +
 	"WHERE type = 'table' AND name = 'archived_events'"
 
-// ArchivePath returns where a database target's archive file is: in
+// Path returns where a database target's archive file is: in
 // the data directory, beside the webhook's event database, under the
-// name ArchiveFileName gives it.
-func ArchivePath(
+// name FileName gives it.
+func Path(
 	dbMgr *database.WebhookDBManager,
 	webhook *database.Webhook,
 	target *database.Target,
 ) string {
 	return filepath.Join(
 		filepath.Dir(dbMgr.DBPath(webhook.ID)),
-		ArchiveFileName(webhook.Name, target.Name, target.ID),
+		FileName(webhook.Name, target.Name, target.ID),
 	)
 }
 
-// ArchiveExportFileName returns the name a database target's archive
+// ExportFileName returns the name a database target's archive
 // downloads under:
 // archive-WEBHOOKNAME-TARGETNAME-YYYYMMDDTHHMMSSZ.json.gz, the names
-// made safe as in ArchiveFileName and the time in UTC.
-func ArchiveExportFileName(
+// made safe as in FileName and the time in UTC.
+func ExportFileName(
 	webhookName, targetName string, at time.Time,
 ) string {
 	return "archive-" + archiveNamePart(webhookName) + "-" +
@@ -54,7 +54,7 @@ func ArchiveExportFileName(
 		at.UTC().Format("20060102T150405Z") + ".json.gz"
 }
 
-// ArchiveExport is a database target's archive listed for download. It
+// Export is a database target's archive listed for download. It
 // opens one of the target's files at a time, only when its rows are
 // about to be written out, and closes it before it opens the next, so
 // an export holds at most one file open however many the target has.
@@ -66,7 +66,7 @@ func ArchiveExportFileName(
 // is open, and the export does not see them. SQLite cannot checkpoint
 // a -wal past an open snapshot, so the open file's -wal grows until the
 // export has written that file out.
-type ArchiveExport struct {
+type Export struct {
 	// periods are the periods of the target's files when the export
 	// was listed, "" for the file without one, in the order
 	// archiveFiles lists them.
@@ -77,7 +77,7 @@ type ArchiveExport struct {
 	// between.
 	lock sync.Locker
 
-	// currentPath returns the path ArchivePath gives the target under
+	// currentPath returns the path Path gives the target under
 	// the names stored for it now, which a rename may have changed since
 	// the export was listed.
 	currentPath func() (string, error)
@@ -103,11 +103,12 @@ type exportedName struct {
 	Name string `json:"name"`
 }
 
-// NewArchiveExport lists a database target's archive files for export,
-// given the path ArchivePath gives it (see archiveFiles). It opens none
+// NewExport lists a database target's archive files for export,
+// given the path Path gives it (see archiveFiles). It opens none
 // of them. Its caller holds lock, which every rename of the target's
-// files runs under, from reading the names path is made of until it
-// returns, so the files it lists are the ones those names give.
+// files runs under (Writers.RenameLock returns it), from reading the names
+// path is made of until it returns, so the files it lists are the ones
+// those names give.
 //
 // WriteGzipJSON, called without lock held, finds each file again by its
 // period under the path currentPath gives, holding lock while it does
@@ -115,18 +116,18 @@ type exportedName struct {
 // file. A file that is gone by then, emptied by the sweep or moved
 // away, is skipped. The export never creates a file: with no files, it
 // has no rows.
-func NewArchiveExport(
+func NewExport(
 	path string,
 	lock sync.Locker,
 	currentPath func() (string, error),
 	log *slog.Logger,
-) (*ArchiveExport, error) {
+) (*Export, error) {
 	files, err := archiveFiles(path)
 	if err != nil {
 		return nil, err
 	}
 
-	x := &ArchiveExport{lock: lock, currentPath: currentPath, log: log}
+	x := &Export{lock: lock, currentPath: currentPath, log: log}
 
 	for _, file := range files {
 		x.periods = append(x.periods, file.period)
@@ -199,7 +200,7 @@ func openExportFile(
 // closed once its rows are written, before the next is opened. When it
 // returns, no file is open. After an error the gzip stream is left
 // unfinished, so what was written does not decompress as a whole file.
-func (x *ArchiveExport) WriteGzipJSON(
+func (x *Export) WriteGzipJSON(
 	ctx context.Context,
 	w io.Writer,
 	webhook *database.Webhook,
@@ -228,7 +229,7 @@ func (x *ArchiveExport) WriteGzipJSON(
 // openFile finds the target's archive file for period under the path
 // currentPath gives now, and opens it for the export, holding x.lock
 // for both. For a file that is gone, the error wraps fs.ErrNotExist.
-func (x *ArchiveExport) openFile(
+func (x *Export) openFile(
 	ctx context.Context, period string,
 ) (*exportFile, error) {
 	x.lock.Lock()
@@ -258,7 +259,7 @@ func (f *exportFile) close() error {
 
 // writeJSON writes head with archived_events added as its last key,
 // the rows going into it one at a time.
-func (x *ArchiveExport) writeJSON(
+func (x *Export) writeJSON(
 	ctx context.Context, w io.Writer, head []byte,
 ) error {
 	// head goes out without its closing brace, so that
@@ -286,7 +287,7 @@ func (x *ArchiveExport) writeJSON(
 // writeRows writes the archived rows of each file to w, one per line,
 // separated by commas, opening each file in turn and closing it once
 // its rows are written.
-func (x *ArchiveExport) writeRows(ctx context.Context, w io.Writer) error {
+func (x *Export) writeRows(ctx context.Context, w io.Writer) error {
 	sep := "\n"
 
 	for _, period := range x.periods {

internal/archive/download_test.go

@@ -1,4 +1,4 @@
-package delivery_test
+package archive_test
 
 import (
 	"bufio"
@@ -19,8 +19,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
-	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
 // The webhook and the target the export tests' archives belong to.
@@ -37,7 +37,7 @@ const binaryBody = "\xff\xfe\x00\x01binary\x80"
 // writeExportTo writes export to w as the archive of the export tests'
 // webhook and target, exported at 2026-10-02T12:03:04Z.
 func writeExportTo(
-	t *testing.T, export *delivery.ArchiveExport, w io.Writer,
+	t *testing.T, export *archive.Export, w io.Writer,
 ) error {
 	t.Helper()
 
@@ -57,7 +57,7 @@ func writeExportTo(
 
 // listExport lists the archive at path for export, as the archive of a
 // target whose names do not change.
-func listExport(t *testing.T, path string) *delivery.ArchiveExport {
+func listExport(t *testing.T, path string) *archive.Export {
 	t.Helper()
 
 	return newExport(t, path, &sync.Mutex{}, func() (string, error) {
@@ -73,10 +73,10 @@ func newExport(
 	path string,
 	lock sync.Locker,
 	currentPath func() (string, error),
-) *delivery.ArchiveExport {
+) *archive.Export {
 	t.Helper()
 
-	export, err := delivery.NewArchiveExport(
+	export, err := archive.NewExport(
 		path, lock, currentPath, archiveTestLogger(),
 	)
 	require.NoError(t, err)
@@ -96,7 +96,7 @@ func exportArchive(t *testing.T, path string) map[string]any {
 // decompressed and parsed. Reading to the end makes the gzip reader
 // check that the stream was finished.
 func writeExport(
-	t *testing.T, export *delivery.ArchiveExport,
+	t *testing.T, export *archive.Export,
 ) map[string]any {
 	t.Helper()
 
@@ -157,11 +157,11 @@ func TestArchiveExport_MatchesStoredRows(t *testing.T) {
 	t.Parallel()
 
 	path := filepath.Join(t.TempDir(), "archive.db")
-	w := delivery.NewExportArchiveWriter(path, archiveTestLogger(), 0)
+	w := archive.NewExportArchiveWriter(path, archiveTestLogger(), 0)
 	bodies := []string{`{"order":1}`, "plain text", "", binaryBody}
 
 	for i, body := range bodies {
-		require.NoError(t, w.Write(delivery.ExportArchivedEvent{
+		require.NoError(t, w.Write(archive.ExportArchivedEvent{
 			EventID:      fmt.Sprintf("ev-%d", i),
 			WebhookID:    exportWebhookID,
 			EntrypointID: "ep-1",
@@ -173,7 +173,7 @@ func TestArchiveExport_MatchesStoredRows(t *testing.T) {
 		}, 0))
 	}
 
-	var stored []delivery.ExportArchivedEvent
+	var stored []archive.ExportArchivedEvent
 
 	require.NoError(t, openArchiveDBForRead(t, path).
 		Order("id").Find(&stored).Error)
@@ -201,7 +201,7 @@ func TestArchiveExport_MatchesStoredRows(t *testing.T) {
 // assertExportedRow checks that ev, from an export, holds every column
 // of the stored row.
 func assertExportedRow(
-	t *testing.T, row delivery.ExportArchivedEvent, ev map[string]any,
+	t *testing.T, row archive.ExportArchivedEvent, ev map[string]any,
 ) {
 	t.Helper()
 
@@ -248,7 +248,7 @@ func TestArchiveExport_Empty(t *testing.T) {
 
 	require.NoError(t, os.WriteFile(noTable, nil, 0o600))
 	require.NoError(t,
-		delivery.NewExportArchiveWriter(noRows, archiveTestLogger(), 0).
+		archive.NewExportArchiveWriter(noRows, archiveTestLogger(), 0).
 			Open(0),
 	)
 
@@ -284,18 +284,18 @@ func TestArchiveExport_ReadsOneSnapshot(t *testing.T) {
 	t.Parallel()
 
 	path := filepath.Join(t.TempDir(), "archive.db")
-	w := delivery.NewExportArchiveWriter(path, archiveTestLogger(), 0)
+	w := archive.NewExportArchiveWriter(path, archiveTestLogger(), 0)
 
-	require.NoError(t, w.Write(delivery.ExportArchivedEvent{EventID: "listed"}, 0))
+	require.NoError(t, w.Write(archive.ExportArchivedEvent{EventID: "listed"}, 0))
 
 	opened := &unlockHook{fn: func() {
-		require.NoError(t, w.Write(delivery.ExportArchivedEvent{EventID: "during"}, 0))
+		require.NoError(t, w.Write(archive.ExportArchivedEvent{EventID: "during"}, 0))
 	}}
 	export := newExport(t, path, opened, func() (string, error) {
 		return path, nil
 	})
 
-	require.NoError(t, w.Write(delivery.ExportArchivedEvent{EventID: "before-open"}, 0))
+	require.NoError(t, w.Write(archive.ExportArchivedEvent{EventID: "before-open"}, 0))
 
 	assert.Equal(t,
 		[]string{"listed", "before-open"},
@@ -305,7 +305,7 @@ func TestArchiveExport_ReadsOneSnapshot(t *testing.T) {
 	var stored int64
 
 	require.NoError(t, openArchiveDBForRead(t, path).
-		Model(&delivery.ExportArchivedEvent{}).Count(&stored).Error)
+		Model(&archive.ExportArchivedEvent{}).Count(&stored).Error)
 	assert.Equal(t, int64(3), stored)
 }
 
@@ -318,11 +318,11 @@ func TestArchiveExport_FindsFilesAfterRename(t *testing.T) {
 
 	dir := t.TempDir()
 	path := filepath.Join(dir, "archive-old.db")
-	w := delivery.NewExportArchiveWriter(path, archiveTestLogger(), 0)
+	w := archive.NewExportArchiveWriter(path, archiveTestLogger(), 0)
 
 	for _, period := range []string{"", dayPeriod, hourPeriod} {
 		require.NoError(t, w.WritePeriod(
-			delivery.ExportArchivedEvent{EventID: "in-" + period}, 0, period,
+			archive.ExportArchivedEvent{EventID: "in-" + period}, 0, period,
 		))
 	}
 
@@ -353,19 +353,19 @@ func TestArchiveExport_EveryFileOldestFirst(t *testing.T) {
 	t.Parallel()
 
 	path := filepath.Join(t.TempDir(), "archive-wh.db")
-	w := delivery.NewExportArchiveWriter(path, archiveTestLogger(), 0)
+	w := archive.NewExportArchiveWriter(path, archiveTestLogger(), 0)
 
 	// Written in an order that is not the export's.
 	for _, period := range []string{nextDayPeriod, "", hourPeriod, "2026-03"} {
 		require.NoError(t, w.WritePeriod(
-			delivery.ExportArchivedEvent{EventID: "in-" + period}, 0, period,
+			archive.ExportArchivedEvent{EventID: "in-" + period}, 0, period,
 		))
 	}
 
 	export := listExport(t, path)
 
 	require.NoError(t, w.WritePeriod(
-		delivery.ExportArchivedEvent{EventID: "later"}, 0, "2026-03-06",
+		archive.ExportArchivedEvent{EventID: "later"}, 0, "2026-03-06",
 	))
 
 	events := exportedEvents(t, writeExport(t, export))
@@ -434,13 +434,13 @@ func TestArchiveExport_OneFileOpenAtATime(t *testing.T) {
 	require.NoError(t, err)
 
 	path := filepath.Join(dir, "archive-wh.db")
-	w := delivery.NewExportArchiveWriter(path, archiveTestLogger(), 0)
+	w := archive.NewExportArchiveWriter(path, archiveTestLogger(), 0)
 	random := make([]byte, 36<<10)
 
 	for hour := range 24 {
 		_, _ = rand.Read(random)
 
-		require.NoError(t, w.WritePeriod(delivery.ExportArchivedEvent{
+		require.NoError(t, w.WritePeriod(archive.ExportArchivedEvent{
 			Body: base64.StdEncoding.EncodeToString(random),
 		}, 0, fmt.Sprintf("2026-10-01-%02d", hour)))
 	}
@@ -489,7 +489,7 @@ func exportHeapGrowth(t *testing.T, rows, bodySize int) uint64 {
 	t.Helper()
 
 	path := filepath.Join(t.TempDir(), "archive.db")
-	w := delivery.NewExportArchiveWriter(path, archiveTestLogger(), 0)
+	w := archive.NewExportArchiveWriter(path, archiveTestLogger(), 0)
 
 	// Base64 makes four characters of every three bytes.
 	random := make([]byte, bodySize/4*3)
@@ -497,7 +497,7 @@ func exportHeapGrowth(t *testing.T, rows, bodySize int) uint64 {
 	for range rows {
 		_, _ = rand.Read(random)
 
-		require.NoError(t, w.Write(delivery.ExportArchivedEvent{
+		require.NoError(t, w.Write(archive.ExportArchivedEvent{
 			Body: base64.StdEncoding.EncodeToString(random),
 		}, 0))
 	}
@@ -565,7 +565,7 @@ func TestArchiveExportFileName(t *testing.T) {
 
 	assert.Equal(t,
 		"archive-orders-eu-long-term-archive-20261002T120304Z.json.gz",
-		delivery.ArchiveExportFileName(
+		archive.ExportFileName(
 			exportWebhookName, exportTargetName,
 			time.Date(2026, 10, 2, 14, 3, 4, 0, cest),
 		),

internal/archive/evict_test.go

@@ -1,7 +1,6 @@
-package delivery_test
+package archive_test
 
 import (
-	"context"
 	"errors"
 	"fmt"
 	"net/http"
@@ -13,8 +12,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
-	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
 // deliverTo archives one event to a database target, leaving the
@@ -24,12 +23,9 @@ func deliverTo(
 ) {
 	t.Helper()
 
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"archived":true}`)
+	event := newEvent(`{"archived":true}`)
 
-	env.eng.ExportDeliverDatabase(
-		webhookDB, seedDatabaseTargetDelivery(t, webhookDB, event, tgt),
-	)
+	require.NoError(t, env.writers.Write(databaseTargetDelivery(event, tgt)))
 }
 
 // TestEvictWebhook_ClosesAndRemovesWriter proves that evicting
@@ -49,20 +45,20 @@ func TestEvictWebhook_ClosesAndRemovesWriter(t *testing.T) {
 		deliverTo(t, env, tgt)
 
 		require.True(
-			t, env.eng.ExportArchiveHandleOpen(tgt.ID),
+			t, env.writers.ExportArchiveHandleOpen(tgt.ID),
 			"the writer should hold an open handle after a write",
 		)
 	}
 
-	env.eng.EvictWebhook(first.WebhookID)
+	env.writers.EvictWebhook(first.WebhookID)
 
 	for _, tgt := range []*database.Target{first, second} {
 		assert.False(
-			t, env.eng.ExportHasArchiveWriter(tgt.ID),
+			t, env.writers.ExportHasArchiveWriter(tgt.ID),
 			"eviction should remove the registry entry",
 		)
 		assert.False(
-			t, env.eng.ExportArchiveHandleOpen(tgt.ID),
+			t, env.writers.ExportArchiveHandleOpen(tgt.ID),
 			"eviction should close the archive handle",
 		)
 		assert.FileExists(
@@ -72,7 +68,7 @@ func TestEvictWebhook_ClosesAndRemovesWriter(t *testing.T) {
 	}
 
 	assert.True(
-		t, env.eng.ExportArchiveHandleOpen(other.ID),
+		t, env.writers.ExportArchiveHandleOpen(other.ID),
 		"another webhook's writer must be left alone",
 	)
 }
@@ -90,15 +86,15 @@ func TestEvictTarget_LeavesOtherTargets(t *testing.T) {
 	deliverTo(t, env, doomed)
 	deliverTo(t, env, kept)
 
-	env.eng.EvictTarget(doomed.ID)
+	env.writers.EvictTarget(doomed.ID)
 
-	assert.False(t, env.eng.ExportHasArchiveWriter(doomed.ID))
+	assert.False(t, env.writers.ExportHasArchiveWriter(doomed.ID))
 	assert.FileExists(
 		t, env.archivePath(doomed),
 		"eviction must not delete the archive file",
 	)
 	assert.True(
-		t, env.eng.ExportArchiveHandleOpen(kept.ID),
+		t, env.writers.ExportArchiveHandleOpen(kept.ID),
 		"the other target's writer must be left alone",
 	)
 }
@@ -112,21 +108,21 @@ func TestEvictWebhook_UnknownWebhookIsNoOp(t *testing.T) {
 	env := setupArchiveTest(t)
 
 	assert.NotPanics(t, func() {
-		env.eng.EvictWebhook("no-such-webhook")
-		env.eng.EvictWebhook("no-such-webhook")
-		env.eng.EvictTarget("no-such-target")
-		env.eng.EvictTarget("no-such-target")
+		env.writers.EvictWebhook("no-such-webhook")
+		env.writers.EvictWebhook("no-such-webhook")
+		env.writers.EvictTarget("no-such-target")
+		env.writers.EvictTarget("no-such-target")
 	})
 
 	assert.False(
-		t, env.eng.ExportHasArchiveWriter("no-such-target"),
+		t, env.writers.ExportHasArchiveWriter("no-such-target"),
 		"eviction must not create a writer",
 	)
 }
 
 // evictTestRow builds an archive row for the eviction tests.
-func evictTestRow(eventID string) delivery.ExportArchivedEvent {
-	return delivery.ExportArchivedEvent{
+func evictTestRow(eventID string) archive.ExportArchivedEvent {
+	return archive.ExportArchivedEvent{
 		EventID:   eventID,
 		WebhookID: "wh-evict",
 		Method:    http.MethodPost,
@@ -147,7 +143,7 @@ func TestEvictedWriter_WriteDoesNotReopenFile(t *testing.T) {
 
 	path := filepath.Join(t.TempDir(), "archive-evicted.db")
 
-	w := delivery.NewExportArchiveWriter(
+	w := archive.NewExportArchiveWriter(
 		path, archiveTestLogger(), 0,
 	)
 
@@ -164,7 +160,7 @@ func TestEvictedWriter_WriteDoesNotReopenFile(t *testing.T) {
 	err := w.Write(evictTestRow("ev-2"), 0)
 
 	require.ErrorIs(
-		t, err, delivery.ErrExportArchiveWriterEvicted,
+		t, err, archive.ErrExportArchiveWriterEvicted,
 		"an evicted writer must refuse writes",
 	)
 	assert.NoFileExists(
@@ -187,7 +183,7 @@ func TestEvictedWriter_SweepDoesNotReopenFile(t *testing.T) {
 
 	path := filepath.Join(t.TempDir(), "archive-evicted.db")
 
-	w := delivery.NewExportArchiveWriter(
+	w := archive.NewExportArchiveWriter(
 		path, archiveTestLogger(), 0,
 	)
 
@@ -199,7 +195,7 @@ func TestEvictedWriter_SweepDoesNotReopenFile(t *testing.T) {
 	err := w.SweepExpired(time.Hour)
 
 	require.ErrorIs(
-		t, err, delivery.ErrExportArchiveWriterEvicted,
+		t, err, archive.ErrExportArchiveWriterEvicted,
 		"an evicted writer must refuse an idle sweep",
 	)
 	assert.False(
@@ -230,7 +226,7 @@ const racingWriteGoroutines = 4
 // against a hang, not a timing assumption: the first write after
 // the eviction is refused.
 func startRacingWrites(
-	w *delivery.ExportArchiveWriter,
+	w *archive.ExportArchiveWriter,
 ) *racingWrites {
 	r := &racingWrites{
 		started: make(chan struct{}, racingWriteGoroutines),
@@ -276,7 +272,7 @@ func (r *racingWrites) record(err error) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
-	if errors.Is(err, delivery.ErrExportArchiveWriterEvicted) {
+	if errors.Is(err, archive.ErrExportArchiveWriterEvicted) {
 		r.sawEvicted = true
 
 		return
@@ -320,7 +316,7 @@ func TestEvictWebhook_RacingWriteDoesNotReopenHandle(
 	// eviction is about to detach.
 	deliverTo(t, env, tgt)
 
-	w := env.eng.ExportArchiveWriterFor(tgt.ID)
+	w := env.writers.ExportArchiveWriterFor(tgt.ID)
 	require.NotNil(t, w)
 	require.True(t, w.HandleOpen())
 
@@ -330,7 +326,7 @@ func TestEvictWebhook_RacingWriteDoesNotReopenHandle(
 	// eviction has to contend for the writer's mutex.
 	race.awaitFirstWrite()
 
-	env.eng.EvictWebhook(tgt.WebhookID)
+	env.writers.EvictWebhook(tgt.WebhookID)
 
 	sawEvicted, otherErr := race.wait()
 
@@ -345,7 +341,7 @@ func TestEvictWebhook_RacingWriteDoesNotReopenHandle(
 			"been evicted",
 	)
 	assert.False(
-		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		t, env.writers.ExportHasArchiveWriter(tgt.ID),
 		"the registry entry must stay gone",
 	)
 }
@@ -362,25 +358,25 @@ func TestEvictWebhook_LaterDeliveryRecreatesWriter(t *testing.T) {
 	tgt := env.seedDatabaseTarget(t, "")
 
 	deliverTo(t, env, tgt)
-	require.True(t, env.eng.ExportHasArchiveWriter(tgt.ID))
+	require.True(t, env.writers.ExportHasArchiveWriter(tgt.ID))
 
-	env.eng.EvictWebhook(tgt.WebhookID)
+	env.writers.EvictWebhook(tgt.WebhookID)
 
 	// A fresh delivery for the same target gets a brand new
 	// writer from the registry, so archiving keeps working.
 	deliverTo(t, env, tgt)
 
 	assert.True(
-		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		t, env.writers.ExportHasArchiveWriter(tgt.ID),
 		"a later delivery should recreate the writer",
 	)
 }
 
-// TestEngineStop_WriteAfterStopIsRefused proves the engine's stop
-// closes each archive writer the way deleting its webhook does: a
-// write that reaches a writer after the stop is refused, reopens
-// nothing and adds no row.
-func TestEngineStop_WriteAfterStopIsRefused(t *testing.T) {
+// TestEvictAll_WriteAfterIsRefused proves that EvictAll, which the
+// delivery engine calls when it stops, closes each archive writer the
+// way deleting its webhook does: a write that reaches a writer after
+// it is refused, reopens nothing and adds no row.
+func TestEvictAll_WriteAfterIsRefused(t *testing.T) {
 	t.Parallel()
 
 	env := setupArchiveTest(t)
@@ -388,16 +384,16 @@ func TestEngineStop_WriteAfterStopIsRefused(t *testing.T) {
 
 	deliverTo(t, env, tgt)
 
-	w := env.eng.ExportArchiveWriterFor(tgt.ID)
+	w := env.writers.ExportArchiveWriterFor(tgt.ID)
 	require.NotNil(t, w)
 	require.True(t, w.HandleOpen())
 
-	require.NoError(t, env.eng.ExportStop(context.Background()))
+	env.writers.EvictAll()
 
 	err := w.Write(evictTestRow("ev-after-stop"), 0)
 
 	require.ErrorIs(
-		t, err, delivery.ErrExportArchiveWriterEvicted,
+		t, err, archive.ErrExportArchiveWriterEvicted,
 		"a write after the stop must be refused",
 	)
 	assert.False(
@@ -405,7 +401,7 @@ func TestEngineStop_WriteAfterStopIsRefused(t *testing.T) {
 		"a refused write must not reopen the archive",
 	)
 	assert.False(
-		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		t, env.writers.ExportHasArchiveWriter(tgt.ID),
 		"the stop should empty the registry",
 	)
 

internal/archive/export_test.go

@@ -0,0 +1,280 @@
+package archive
+
+import (
+	"context"
+	"log/slog"
+	"time"
+
+	"go.uber.org/fx"
+	"gorm.io/gorm"
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// ErrExportArchiveWriterEvicted exposes the sentinel returned by
+// an evicted archive writer. It carries the Err prefix rather
+// than this file's usual Export one because it is a sentinel
+// error.
+var ErrExportArchiveWriterEvicted = errArchiveWriterEvicted
+
+// ExportArchivedEvent aliases the archive row type so black-box
+// tests can construct and read archive rows.
+type ExportArchivedEvent = archivedEvent
+
+// ExportArchiveWriter wraps an archiveWriter so black-box tests
+// can exercise the archive file mechanics.
+type ExportArchiveWriter struct {
+	w *archiveWriter
+}
+
+// NewExportArchiveWriter builds an archive writer for tests,
+// optionally overriding the reopen debounce (a non-positive
+// debounce keeps the production default).
+func NewExportArchiveWriter(
+	path string, log *slog.Logger, debounce time.Duration,
+) *ExportArchiveWriter {
+	w := newArchiveWriter(path, log)
+	if debounce > 0 {
+		w.debounce = debounce
+	}
+
+	return &ExportArchiveWriter{w: w}
+}
+
+// Write archives a row through the writer, into the file named
+// without a period.
+func (e *ExportArchiveWriter) Write(
+	row ExportArchivedEvent, expiry time.Duration,
+) error {
+	return e.w.write(row, expiry, "")
+}
+
+// WritePeriod archives a row through the writer, into the file for
+// period.
+func (e *ExportArchiveWriter) WritePeriod(
+	row ExportArchivedEvent, expiry time.Duration, period string,
+) error {
+	return e.w.write(row, expiry, period)
+}
+
+// Open opens the archive file, pruning when expiry is positive.
+func (e *ExportArchiveWriter) Open(expiry time.Duration) error {
+	return e.w.open(e.w.path, expiry)
+}
+
+// Reopen closes and reopens the archive file.
+func (e *ExportArchiveWriter) Reopen(
+	expiry time.Duration,
+) error {
+	return e.w.reopen(e.w.path, expiry)
+}
+
+// SetNow replaces the clock the writer measures its reopen
+// debounce on.
+func (e *ExportArchiveWriter) SetNow(now func() time.Time) {
+	e.w.now = now
+}
+
+// Reopens reports how many times the file has been opened.
+func (e *ExportArchiveWriter) Reopens() int {
+	return e.w.reopens
+}
+
+// DB returns the writer's current open handle for row
+// inspection in tests.
+func (e *ExportArchiveWriter) DB() *gorm.DB {
+	return e.w.db
+}
+
+// Path returns the archive file the writer owns.
+func (e *ExportArchiveWriter) Path() string {
+	return e.w.path
+}
+
+// OpenExisting opens the archive without permitting creation,
+// the way the idle sweep does.
+func (e *ExportArchiveWriter) OpenExisting(
+	expiry time.Duration,
+) error {
+	return e.w.openMode(e.w.path, archiveModeExisting, expiry)
+}
+
+// SweepExpired runs an idle sweep of the archive.
+func (e *ExportArchiveWriter) SweepExpired(
+	expiry time.Duration,
+) error {
+	return e.w.sweepExpired(expiry)
+}
+
+// Evict marks the writer evicted and closes its handle, exactly
+// as leaving the registry does.
+func (e *ExportArchiveWriter) Evict() {
+	e.w.evict()
+}
+
+// Rename gives the archive file a new name in the same directory,
+// as a rename of the webhook or target does.
+func (e *ExportArchiveWriter) Rename(name string) error {
+	return e.w.rename(name)
+}
+
+// HandleOpen reports whether the writer currently holds an open
+// archive handle.
+func (e *ExportArchiveWriter) HandleOpen() bool {
+	e.w.mu.Lock()
+	defer e.w.mu.Unlock()
+
+	return e.w.db != nil
+}
+
+// Same reports whether both wrappers refer to the very same
+// underlying archive writer, so a test can prove a registry entry
+// is the writer it was handed rather than a replacement.
+func (e *ExportArchiveWriter) Same(
+	other *ExportArchiveWriter,
+) bool {
+	return other != nil && e.w == other.w
+}
+
+// ExportArchiveWriterFor returns the archive writer the registry
+// currently caches for a database target, or nil when none is
+// cached. It never creates one, so a test can hold a reference to
+// the very writer an eviction is about to detach.
+func (ws *Writers) ExportArchiveWriterFor(
+	targetID string,
+) *ExportArchiveWriter {
+	ws.mu.Lock()
+	defer ws.mu.Unlock()
+
+	w, ok := ws.writers[targetID]
+	if !ok {
+		return nil
+	}
+
+	return &ExportArchiveWriter{w: w}
+}
+
+// ExportHasArchiveWriter reports whether the registry currently
+// caches an archive writer for a target.
+func (ws *Writers) ExportHasArchiveWriter(
+	targetID string,
+) bool {
+	ws.mu.Lock()
+	defer ws.mu.Unlock()
+
+	_, ok := ws.writers[targetID]
+
+	return ok
+}
+
+// ExportArchiveHandleOpen reports whether the cached archive
+// writer for a target holds an open database handle. It
+// returns false when no writer is cached.
+func (ws *Writers) ExportArchiveHandleOpen(
+	targetID string,
+) bool {
+	ws.mu.Lock()
+	w, ok := ws.writers[targetID]
+	ws.mu.Unlock()
+
+	if !ok {
+		return false
+	}
+
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	return w.db != nil
+}
+
+// ExportEnsureArchiveWriter creates (if needed) and returns the
+// archive file path of the cached writer for a target, so a
+// test can prime the registry the way a delivery would.
+func (ws *Writers) ExportEnsureArchiveWriter(
+	targetID string,
+) (string, error) {
+	w, err := ws.writerFor(targetID)
+	if err != nil {
+		return "", err
+	}
+
+	return w.path, nil
+}
+
+// ExportSweepWriterFor takes a target's registry writer exactly
+// as the idle sweep does, reporting whether the sweep had to
+// create the entry. It lets a test drive the registry through the
+// sweep's own entry point instead of choreographing goroutines.
+func (ws *Writers) ExportSweepWriterFor(
+	targetID string,
+) (*ExportArchiveWriter, bool, error) {
+	w, created, err := ws.sweepWriterFor(targetID)
+	if err != nil {
+		return nil, false, err
+	}
+
+	return &ExportArchiveWriter{w: w}, created, nil
+}
+
+// ExportReleaseSweepWriter releases a sweep-created registry entry
+// exactly as a finished sweep does.
+func (ws *Writers) ExportReleaseSweepWriter(
+	targetID string, w *ExportArchiveWriter,
+) {
+	ws.releaseSweepWriter(targetID, w.w)
+}
+
+// NewTestSweeper builds a Sweeper backed by the given main
+// database and archive writers, without the fx lifecycle.
+// Intended for tests.
+func NewTestSweeper(
+	db *database.Database,
+	writers *Writers,
+	log *slog.Logger,
+) *Sweeper {
+	return &Sweeper{
+		db:       db,
+		writers:  writers,
+		log:      log,
+		interval: time.Hour,
+	}
+}
+
+// ExportSweep runs a single archive sweep synchronously for
+// tests.
+func (s *Sweeper) ExportSweep(ctx context.Context) {
+	s.sweep(ctx)
+}
+
+// ExportStart starts the sweeper's background loop for tests.
+func (s *Sweeper) ExportStart() {
+	s.start()
+}
+
+// ExportRegisterHooks registers the sweeper's real fx lifecycle
+// hooks on a lifecycle supplied by a test, so a test can drive
+// the exact OnStart/OnStop functions the application runs and
+// hand OnStart the kind of context fx actually supplies.
+func (s *Sweeper) ExportRegisterHooks(lc fx.Lifecycle) {
+	s.registerHooks(lc)
+}
+
+// ExportStop stops the sweeper's background loop for tests.
+func (s *Sweeper) ExportStop(ctx context.Context) error {
+	return s.stop(ctx)
+}
+
+// ExportWedgeLoop adds a goroutine to the sweeper's WaitGroup
+// that never observes cancellation and returns only when release
+// is closed. It stands in for a prune stuck on a locked archive.
+func (s *Sweeper) ExportWedgeLoop(
+	release <-chan struct{},
+) {
+	s.wg.Go(func() {
+		<-release
+	})
+}
+
+// ExportSetInterval overrides the sweep interval for tests.
+func (s *Sweeper) ExportSetInterval(d time.Duration) {
+	s.interval = d
+}

internal/archive/rotation.go

@@ -1,4 +1,4 @@
-package delivery
+package archive
 
 import (
 	"encoding/json"
@@ -41,10 +41,10 @@ type archiveFile struct {
 	period string
 }
 
-// ValidateArchiveRotation checks a user-supplied archive rotation for
+// ValidateRotation checks a user-supplied archive rotation for
 // a database target: empty or none (both meaning one file), monthly,
 // daily or hourly.
-func ValidateArchiveRotation(rotation string) error {
+func ValidateRotation(rotation string) error {
 	switch rotation {
 	case "", archiveRotationNone, archiveRotationMonthly,
 		archiveRotationDaily, archiveRotationHourly:
@@ -54,21 +54,21 @@ func ValidateArchiveRotation(rotation string) error {
 	}
 }
 
-// parseArchiveRotation reads the rotation from a database target's
+// ParseRotation reads the rotation from a database target's
 // config JSON. An empty config or an empty rotation is none.
-func parseArchiveRotation(configJSON string) (string, error) {
+func ParseRotation(configJSON string) (string, error) {
 	if configJSON == "" {
 		return archiveRotationNone, nil
 	}
 
-	var cfg databaseTargetConfig
+	var cfg DatabaseTargetConfig
 
 	err := json.Unmarshal([]byte(configJSON), &cfg)
 	if err != nil {
 		return "", fmt.Errorf("parsing database target config: %w", err)
 	}
 
-	err = ValidateArchiveRotation(cfg.Rotation)
+	err = ValidateRotation(cfg.Rotation)
 	if err != nil {
 		return "", err
 	}
@@ -97,7 +97,7 @@ func archivePeriod(rotation string, receivedAt time.Time) string {
 }
 
 // archivePeriodPath returns the path of a database target's archive
-// file for a period: path, as ArchivePath gives it, with "-" and the
+// file for a period: path, as Path gives it, with "-" and the
 // period put before its ".db". The period "" gives path itself.
 func archivePeriodPath(path, period string) string {
 	if period == "" {
@@ -107,28 +107,28 @@ func archivePeriodPath(path, period string) string {
 	return strings.TrimSuffix(path, ".db") + "-" + period + ".db"
 }
 
-// ArchivePathAt returns the archive file a database target writes an
-// event received at receivedAt to: ArchivePath's file, with the
+// PathAt returns the archive file a database target writes an
+// event received at receivedAt to: Path's file, with the
 // period in its name when the target rotates.
-func ArchivePathAt(
+func PathAt(
 	dbMgr *database.WebhookDBManager,
 	webhook *database.Webhook,
 	target *database.Target,
 	receivedAt time.Time,
 ) (string, error) {
-	rotation, err := parseArchiveRotation(target.Config)
+	rotation, err := ParseRotation(target.Config)
 	if err != nil {
 		return "", err
 	}
 
 	return archivePeriodPath(
-		ArchivePath(dbMgr, webhook, target),
+		Path(dbMgr, webhook, target),
 		archivePeriod(rotation, receivedAt),
 	), nil
 }
 
 // archiveFiles lists the database target's archive files that exist,
-// given the path ArchivePath gives it: the file at path, then each
+// given the path Path gives it: the file at path, then each
 // file archivePeriodPath names for path and a period, oldest period
 // first. Which rotation wrote a file does not matter, so the files of
 // an earlier rotation setting are listed too.

internal/archive/rotation_test.go

@@ -1,4 +1,4 @@
-package delivery_test
+package archive_test
 
 import (
 	"os"
@@ -9,9 +9,9 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/database/databasetest"
-	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
 // The archive rotations, and the configs of a daily target and of one
@@ -40,32 +40,30 @@ func periodPath(path, period string) string {
 	return strings.TrimSuffix(path, ".db") + "-" + period + ".db"
 }
 
-// deliverReceivedAt delivers to a database target an event whose
-// receive time is receivedAt, and returns the event's id. The receive
-// time is what decides a rotated archive's file, so setting it is how
-// these tests move the clock across a period boundary.
+// deliverReceivedAt archives, as a delivery to a database target
+// does, an event whose receive time is receivedAt, and returns the
+// event's id. The receive time is what decides a rotated archive's
+// file, so setting it is how these tests move the clock across a
+// period boundary.
 func (env *archiveEnv) deliverReceivedAt(
 	t *testing.T, tgt *database.Target, receivedAt time.Time,
 ) string {
 	t.Helper()
 
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"n":1}`)
+	event := newEvent(`{"n":1}`)
 	event.CreatedAt = receivedAt
 
-	env.eng.ExportDeliverDatabase(
-		webhookDB, seedDatabaseTargetDelivery(t, webhookDB, event, tgt),
-	)
+	require.NoError(t, env.writers.Write(databaseTargetDelivery(event, tgt)))
 
 	return event.ID
 }
 
-// TestDeliverDatabase_RotatesAtEachPeriodBoundary delivers, for each
+// TestWrite_RotatesAtEachPeriodBoundary writes, for each
 // rotation, an event received in the last second of a period and one
 // received in the first second of the next, and checks each lands in
 // the file named for its own period, in UTC. Rotation none keeps both
 // in the one file.
-func TestDeliverDatabase_RotatesAtEachPeriodBoundary(t *testing.T) {
+func TestWrite_RotatesAtEachPeriodBoundary(t *testing.T) {
 	t.Parallel()
 
 	berlin := time.FixedZone("CEST", 2*60*60)
@@ -139,10 +137,10 @@ func TestDeliverDatabase_RotatesAtEachPeriodBoundary(t *testing.T) {
 	})
 }
 
-// TestDeliverDatabase_EventWithoutReceiveTime proves an event whose
+// TestWrite_EventWithoutReceiveTime proves an event whose
 // receive time is not known goes to the file for the time it is
 // archived, rather than to one for the year 1.
-func TestDeliverDatabase_EventWithoutReceiveTime(t *testing.T) {
+func TestWrite_EventWithoutReceiveTime(t *testing.T) {
 	t.Parallel()
 
 	env := setupArchiveTest(t)
@@ -164,10 +162,10 @@ func TestDeliverDatabase_EventWithoutReceiveTime(t *testing.T) {
 	assert.NoFileExists(t, periodPath(path, "0001-01"))
 }
 
-// TestDeliverDatabase_RotationChangeKeepsOldFiles changes a target's
+// TestWrite_RotationChangeKeepsOldFiles changes a target's
 // rotation from none to daily between two events, and checks the
 // second goes to the daily file while the first stays where it was.
-func TestDeliverDatabase_RotationChangeKeepsOldFiles(t *testing.T) {
+func TestWrite_RotationChangeKeepsOldFiles(t *testing.T) {
 	t.Parallel()
 
 	env := setupArchiveTest(t)
@@ -237,7 +235,7 @@ func TestRename_MovesEveryFile(t *testing.T) {
 	first := env.deliverReceivedAt(t, tgt, day)
 	second := env.deliverReceivedAt(t, tgt, day.Add(24*time.Hour))
 
-	require.NoError(t, env.eng.Rename(tgt.ID, "Orders", "Long Term"))
+	require.NoError(t, env.writers.Rename(tgt.ID, "Orders", "Long Term"))
 
 	newPath := filepath.Join(
 		env.dataDir, "archive-orders-long-term-"+tgt.ID+".db",
@@ -283,8 +281,8 @@ func TestRename_NeverReplacesARotatedFile(t *testing.T) {
 	require.NoError(t, os.WriteFile(planted, []byte("planted"), 0o600))
 
 	require.ErrorIs(
-		t, env.eng.Rename(tgt.ID, "Orders", "Long Term"),
-		delivery.ErrArchiveNameTaken,
+		t, env.writers.Rename(tgt.ID, "Orders", "Long Term"),
+		archive.ErrNameTaken,
 	)
 
 	assert.FileExists(t, periodPath(oldPath, dayPeriod))
@@ -292,7 +290,7 @@ func TestRename_NeverReplacesARotatedFile(t *testing.T) {
 	assert.NoFileExists(t, periodPath(newPath, dayPeriod))
 }
 
-// TestStatArchive_EveryFile proves StatArchive counts and adds up every
+// TestStatArchive_EveryFile proves Stat counts and adds up every
 // one of a target's files, takes the latest write of any of them, and
 // leaves out files whose names only look like the target's.
 func TestStatArchive_EveryFile(t *testing.T) {
@@ -324,7 +322,7 @@ func TestStatArchive_EveryFile(t *testing.T) {
 			os.WriteFile(filepath.Join(dir, other), []byte("x"), 0o600))
 	}
 
-	got, err := delivery.StatArchive(path)
+	got, err := archive.Stat(path)
 	require.NoError(t, err)
 	assert.Equal(t, len(files), got.Files)
 	assert.Equal(t, size, got.Size)
@@ -357,7 +355,7 @@ func TestArchivePathAt(t *testing.T) {
 			Config:    config,
 		}
 
-		got, err := delivery.ArchivePathAt(dbMgr, webhook, target, at)
+		got, err := archive.PathAt(dbMgr, webhook, target, at)
 		require.NoError(t, err, config)
 		assert.Equal(t,
 			filepath.Join(
@@ -367,7 +365,7 @@ func TestArchivePathAt(t *testing.T) {
 		)
 	}
 
-	_, err := delivery.ArchivePathAt(dbMgr, webhook, &database.Target{
+	_, err := archive.PathAt(dbMgr, webhook, &database.Target{
 		Config: weeklyConfig,
 	}, at)
 	require.Error(t, err)
@@ -381,10 +379,10 @@ func TestValidateArchiveRotation(t *testing.T) {
 	for _, ok := range []string{
 		"", rotationNone, rotationMonthly, rotationDaily, rotationHourly,
 	} {
-		require.NoError(t, delivery.ValidateArchiveRotation(ok), ok)
+		require.NoError(t, archive.ValidateRotation(ok), ok)
 	}
 
 	for _, bad := range []string{"weekly", "Daily", "hourly "} {
-		require.Error(t, delivery.ValidateArchiveRotation(bad), bad)
+		require.Error(t, archive.ValidateRotation(bad), bad)
 	}
 }

internal/archive/sweeper.go

@@ -1,4 +1,4 @@
-package delivery
+package archive
 
 import (
 	"context"
@@ -15,18 +15,18 @@ import (
 	"sneak.berlin/go/webhooker/internal/logger"
 )
 
-// ArchiveSweeperParams holds the fx dependencies for the
-// ArchiveSweeper.
-type ArchiveSweeperParams struct {
+// SweeperParams holds the fx dependencies for the
+// Sweeper.
+type SweeperParams struct {
 	fx.In
 
 	Config   *config.Config
 	Database *database.Database
-	Engine   *Engine
+	Writers  *Writers
 	Logger   *logger.Logger
 }
 
-// ArchiveSweeper periodically prunes expired rows from the
+// Sweeper periodically prunes expired rows from the
 // archive databases of database targets that carry a positive
 // expiry.
 //
@@ -40,9 +40,9 @@ type ArchiveSweeperParams struct {
 // It reuses Config.RetentionSweepInterval rather than
 // introducing a second interval: this is a retention sweep with
 // the same semantics as the event retention reaper.
-type ArchiveSweeper struct {
+type Sweeper struct {
 	db       *database.Database
-	eng      *Engine
+	writers  *Writers
 	log      *slog.Logger
 	interval time.Duration
 
@@ -54,16 +54,16 @@ type ArchiveSweeper struct {
 	wg sync.WaitGroup
 }
 
-// NewArchiveSweeper creates the archive sweeper and registers
+// NewSweeper creates the archive sweeper and registers
 // its fx lifecycle hooks. The background sweep loop starts on
 // OnStart and stops cleanly on OnStop via context cancellation.
-func NewArchiveSweeper(
+func NewSweeper(
 	lc fx.Lifecycle,
-	params ArchiveSweeperParams,
-) *ArchiveSweeper {
-	s := &ArchiveSweeper{
+	params SweeperParams,
+) *Sweeper {
+	s := &Sweeper{
 		db:       params.Database,
-		eng:      params.Engine,
+		writers:  params.Writers,
 		log:      params.Logger.Get(),
 		interval: params.Config.RetentionSweepInterval,
 	}
@@ -77,7 +77,7 @@ func NewArchiveSweeper(
 // lifecycle. The start hook's context is deliberately ignored
 // (see start for why the background loop must not inherit it);
 // the stop hook's context is honoured (see stop).
-func (s *ArchiveSweeper) registerHooks(lc fx.Lifecycle) {
+func (s *Sweeper) registerHooks(lc fx.Lifecycle) {
 	lc.Append(fx.Hook{
 		//nolint:contextcheck // Not passing the hook context is
 		// the point: see start.
@@ -103,7 +103,7 @@ func (s *ArchiveSweeper) registerHooks(lc fx.Lifecycle) {
 // goroutine must outlive the startup phase, so its lifetime is
 // bounded by OnStop instead: stop cancels this context and waits
 // on the WaitGroup.
-func (s *ArchiveSweeper) start() {
+func (s *Sweeper) start() {
 	ctx, cancel := context.WithCancel(context.Background())
 	s.cancel = cancel
 
@@ -121,7 +121,7 @@ func (s *ArchiveSweeper) start() {
 // exit, bounded by the stop hook's context: a prune wedged on a
 // locked archive must not hang the process past fx's stop
 // timeout.
-func (s *ArchiveSweeper) stop(ctx context.Context) error {
+func (s *Sweeper) stop(ctx context.Context) error {
 	s.log.Info("archive sweeper stopping")
 
 	if s.cancel != nil {
@@ -140,7 +140,7 @@ func (s *ArchiveSweeper) stop(ctx context.Context) error {
 	return nil
 }
 
-func (s *ArchiveSweeper) run(ctx context.Context) {
+func (s *Sweeper) run(ctx context.Context) {
 	defer s.wg.Done()
 
 	ticker := time.NewTicker(s.interval)
@@ -164,7 +164,7 @@ func (s *ArchiveSweeper) run(ctx context.Context) {
 // A failure for one target is logged and the sweep continues,
 // matching how the write path already treats a prune error as
 // non-fatal.
-func (s *ArchiveSweeper) sweep(ctx context.Context) {
+func (s *Sweeper) sweep(ctx context.Context) {
 	var targets []database.Target
 
 	err := s.db.DB().
@@ -202,8 +202,8 @@ func (s *ArchiveSweeper) sweep(ctx context.Context) {
 // sweepTarget prunes the archive of a single database target.
 // A missing, empty, or "never" expiry parses as a zero duration
 // and is skipped entirely, so those archives are never pruned.
-func (s *ArchiveSweeper) sweepTarget(target *database.Target) {
-	expiry, err := parseArchiveExpiry(target.Config)
+func (s *Sweeper) sweepTarget(target *database.Target) {
+	expiry, err := ParseExpiry(target.Config)
 	if err != nil {
 		s.log.Error(
 			"archive sweep: invalid database target config",
@@ -219,11 +219,11 @@ func (s *ArchiveSweeper) sweepTarget(target *database.Target) {
 		return
 	}
 
-	if s.eng == nil || s.eng.dbTarget == nil {
+	if s.writers == nil {
 		return
 	}
 
-	err = s.eng.dbTarget.sweepArchive(target.ID, expiry)
+	err = s.writers.sweepArchive(target.ID, expiry)
 	if err == nil {
 		return
 	}

internal/archive/sweeper_test.go

@@ -1,4 +1,4 @@
-package delivery_test
+package archive_test
 
 import (
 	"bytes"
@@ -16,14 +16,15 @@ import (
 	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/fx"
 	"gorm.io/driver/sqlite"
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
 	_ "modernc.org/sqlite" // Pure Go SQLite driver.
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/database/databasetest"
 	"sneak.berlin/go/webhooker/internal/db/migrations"
-	"sneak.berlin/go/webhooker/internal/delivery"
 	"sneak.berlin/go/webhooker/internal/gormlog"
 )
 
@@ -37,6 +38,18 @@ const (
 	// sweepConcurrentWrites is how many deliveries the
 	// concurrent write-plus-sweep test races against the sweep.
 	sweepConcurrentWrites = 20
+
+	// hookStopTimeout bounds how long a lifecycle test waits for
+	// the sweeper's OnStop hook to return before declaring the
+	// shutdown hung.
+	hookStopTimeout = 10 * time.Second
+
+	// wedgeStopTimeout is the stop timeout a wedged-shutdown test
+	// hands OnStop, standing in for fx's StopTimeout. The test
+	// asserts only that the hook returns at all, and allows it
+	// hookStopTimeout — forty times this budget — to do so, so no
+	// assertion here races the wall clock.
+	wedgeStopTimeout = 250 * time.Millisecond
 )
 
 // archiveTestWebhookName is the name of every webhook
@@ -45,12 +58,12 @@ const (
 const archiveTestWebhookName = "Sweep Test!"
 
 // archiveEnv bundles the pieces an archive test drives: a main
-// configuration database holding webhooks and targets, a delivery
-// engine owning the archive writer registry, the archive sweeper,
-// and the data directory the archive files live in.
+// configuration database holding webhooks and targets, the archive
+// writers, the archive sweeper, and the data directory the archive
+// files live in.
 type archiveEnv struct {
-	sweeper *delivery.ArchiveSweeper
-	eng     *delivery.Engine
+	sweeper *archive.Sweeper
+	writers *archive.Writers
 	mainDB  *database.Database
 	dataDir string
 }
@@ -66,30 +79,28 @@ func setupArchiveTest(t *testing.T) *archiveEnv {
 
 	t.Cleanup(func() { _ = mainDB.Close() })
 
-	eng := delivery.NewTestEngineWithDB(
-		mainDB,
-		databasetest.NewWebhookDBManager(t, dataDir),
-		log,
-		&http.Client{Timeout: 5 * time.Second},
-		1,
-	)
+	writers := archive.NewWriters(archive.WritersParams{
+		Database:  mainDB,
+		DBManager: databasetest.NewWebhookDBManager(t, dataDir),
+		Logger:    log,
+	})
 
 	return &archiveEnv{
-		sweeper: delivery.NewTestArchiveSweeper(
-			mainDB, eng, log,
+		sweeper: archive.NewTestSweeper(
+			mainDB, writers, log,
 		),
-		eng:     eng,
+		writers: writers,
 		mainDB:  mainDB,
 		dataDir: dataDir,
 	}
 }
 
-// archivePath returns where the engine keeps a database target's
+// archivePath returns where the writers keep a database target's
 // archive file, for the names seedDatabaseTarget gave it.
 func (env *archiveEnv) archivePath(tgt *database.Target) string {
 	return filepath.Join(
 		env.dataDir,
-		delivery.ArchiveFileName(
+		archive.FileName(
 			archiveTestWebhookName, tgt.Name, tgt.ID,
 		),
 	)
@@ -177,7 +188,7 @@ func seedArchiveFile(
 	require.NoError(t, migrations.Apply(gdb, migrations.Archive))
 
 	for i, at := range archivedAt {
-		row := delivery.ExportArchivedEvent{
+		row := archive.ExportArchivedEvent{
 			EventID:    fmt.Sprintf("ev-%d", i),
 			WebhookID:  webhookID,
 			Method:     http.MethodPost,
@@ -197,7 +208,7 @@ func archivedEventIDs(
 ) []string {
 	t.Helper()
 
-	var rows []delivery.ExportArchivedEvent
+	var rows []archive.ExportArchivedEvent
 
 	rdb := openArchiveDBForRead(t, path)
 	require.NoError(t, rdb.Order("event_id").Find(&rows).Error)
@@ -234,7 +245,7 @@ func countArchivedRows(path string) (int64, error) {
 
 	var count int64
 
-	err = gdb.Model(&delivery.ExportArchivedEvent{}).
+	err = gdb.Model(&archive.ExportArchivedEvent{}).
 		Count(&count).Error
 	if err != nil {
 		return 0, err
@@ -243,6 +254,55 @@ func countArchivedRows(path string) (int64, error) {
 	return count, nil
 }
 
+// recordingLifecycle is a minimal fx.Lifecycle that records the
+// hooks a component registers, so a test can invoke the real
+// OnStart/OnStop functions with a context of its choosing.
+type recordingLifecycle struct {
+	hooks []fx.Hook
+}
+
+func (l *recordingLifecycle) Append(h fx.Hook) {
+	l.hooks = append(l.hooks, h)
+}
+
+// requireStopHookExpires drives hook.OnStop with a stop context
+// that expires while a wedged goroutine is still running, and
+// requires the hook to return the deadline error naming
+// component instead of blocking on the WaitGroup forever.
+func requireStopHookExpires(
+	t *testing.T, hook fx.Hook, component string,
+) {
+	t.Helper()
+
+	stopCtx, cancel := context.WithTimeout(
+		context.Background(), wedgeStopTimeout,
+	)
+	defer cancel()
+
+	var stopErr error
+
+	stopped := make(chan struct{})
+
+	go func() {
+		defer close(stopped)
+
+		stopErr = hook.OnStop(stopCtx)
+	}()
+
+	select {
+	case <-stopped:
+	case <-time.After(hookStopTimeout):
+		t.Fatal(
+			"OnStop did not return: it discarded the stop " +
+				"context and is waiting on a wedged goroutine " +
+				"that will never observe cancellation",
+		)
+	}
+
+	require.ErrorIs(t, stopErr, context.DeadlineExceeded)
+	require.ErrorContains(t, stopErr, component)
+}
+
 // TestArchiveSweeper_LoopOutlivesStartHookContext is the
 // regression test for a sweeper that never swept. fx calls
 // OnStart with a context carrying the application's start
@@ -326,16 +386,16 @@ func TestArchiveSweep_DoesNotResurrectEvictedWriter(
 	// the deletion path does. The target row is deliberately left
 	// in place: this is the tick that listed the target before
 	// the deletion committed.
-	_, err := env.eng.ExportEnsureArchiveWriter(tgt.ID)
+	_, err := env.writers.ExportEnsureArchiveWriter(tgt.ID)
 	require.NoError(t, err)
 
-	env.eng.EvictTarget(tgt.ID)
-	require.False(t, env.eng.ExportHasArchiveWriter(tgt.ID))
+	env.writers.EvictTarget(tgt.ID)
+	require.False(t, env.writers.ExportHasArchiveWriter(tgt.ID))
 
 	env.sweeper.ExportSweep(context.Background())
 
 	assert.False(
-		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		t, env.writers.ExportHasArchiveWriter(tgt.ID),
 		"a sweep must never re-register a writer for a target "+
 			"whose registry entry has already been released",
 	)
@@ -358,7 +418,7 @@ func TestArchiveSweep_LeavesNoRegistryEntry(t *testing.T) {
 		time.Now().Add(-time.Minute),
 	)
 
-	require.False(t, env.eng.ExportHasArchiveWriter(tgt.ID))
+	require.False(t, env.writers.ExportHasArchiveWriter(tgt.ID))
 
 	env.sweeper.ExportSweep(context.Background())
 
@@ -367,7 +427,7 @@ func TestArchiveSweep_LeavesNoRegistryEntry(t *testing.T) {
 		"the sweep must still prune an idle archive",
 	)
 	assert.False(
-		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		t, env.writers.ExportHasArchiveWriter(tgt.ID),
 		"the sweep must release the registry entry it created",
 	)
 }
@@ -389,24 +449,22 @@ func TestArchiveSweep_KeepsWriterAdoptedByDelivery(
 		t, tgt, time.Now().Add(-48*time.Hour),
 	)
 
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"n":1}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, tgt)
+	d := databaseTargetDelivery(newEvent(`{"n":1}`), tgt)
 
 	env.sweeper.ExportSweep(context.Background())
-	require.False(t, env.eng.ExportHasArchiveWriter(tgt.ID))
+	require.False(t, env.writers.ExportHasArchiveWriter(tgt.ID))
 
-	env.eng.ExportDeliverDatabase(webhookDB, d)
+	require.NoError(t, env.writers.Write(d))
 
 	assert.True(
-		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		t, env.writers.ExportHasArchiveWriter(tgt.ID),
 		"a delivery's writer must stay registered",
 	)
 
 	env.sweeper.ExportSweep(context.Background())
 
 	assert.True(
-		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		t, env.writers.ExportHasArchiveWriter(tgt.ID),
 		"a sweep must not drop a writer a delivery owns",
 	)
 }
@@ -445,7 +503,7 @@ func TestArchiveSweep_KeepsWriterAdoptedDuringSweep(
 		t, tgt, time.Now().Add(-48*time.Hour),
 	)
 
-	sweepWriter, created, err := env.eng.ExportSweepWriterFor(
+	sweepWriter, created, err := env.writers.ExportSweepWriterFor(
 		tgt.ID,
 	)
 	require.NoError(t, err)
@@ -455,36 +513,34 @@ func TestArchiveSweep_KeepsWriterAdoptedDuringSweep(
 	)
 
 	// The delivery lands mid-sweep and adopts the entry.
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"n":1}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, tgt)
+	d := databaseTargetDelivery(newEvent(`{"n":1}`), tgt)
 
-	env.eng.ExportDeliverDatabase(webhookDB, d)
+	require.NoError(t, env.writers.Write(d))
 
-	adopted := env.eng.ExportArchiveWriterFor(tgt.ID)
+	adopted := env.writers.ExportArchiveWriterFor(tgt.ID)
 	require.NotNil(t, adopted)
 	require.True(
 		t, sweepWriter.Same(adopted),
 		"the delivery must have adopted the sweep's writer",
 	)
 	require.True(
-		t, env.eng.ExportArchiveHandleOpen(tgt.ID),
+		t, env.writers.ExportArchiveHandleOpen(tgt.ID),
 		"the delivery leaves the archive handle open",
 	)
 
 	// The sweep finishes.
-	env.eng.ExportReleaseSweepWriter(tgt.ID, sweepWriter)
+	env.writers.ExportReleaseSweepWriter(tgt.ID, sweepWriter)
 
 	require.True(
-		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		t, env.writers.ExportHasArchiveWriter(tgt.ID),
 		"a writer adopted by a delivery during a sweep must "+
 			"stay registered, or its open handle is unreachable",
 	)
 
-	env.eng.EvictTarget(tgt.ID)
+	env.writers.EvictTarget(tgt.ID)
 
 	assert.False(
-		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		t, env.writers.ExportHasArchiveWriter(tgt.ID),
 		"the adopted writer must still be evictable",
 	)
 	assert.False(
@@ -548,7 +604,7 @@ func TestArchiveSweep_OpenExistingDoesNotCreateFile(
 	dir := t.TempDir()
 	path := filepath.Join(dir, "archive-absent.db")
 
-	w := delivery.NewExportArchiveWriter(
+	w := archive.NewExportArchiveWriter(
 		path, archiveTestLogger(), 0,
 	)
 
@@ -619,7 +675,7 @@ func TestArchiveSweep_LeavesArchiveClosed(t *testing.T) {
 		t, tgt, time.Now().Add(-48*time.Hour),
 	)
 
-	w := delivery.NewExportArchiveWriter(
+	w := archive.NewExportArchiveWriter(
 		path, archiveTestLogger(), 0,
 	)
 
@@ -659,25 +715,23 @@ func TestArchiveSweep_ClosesHandleOfRegisteredWriter(
 		t, tgt, time.Now().Add(-48*time.Hour),
 	)
 
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"n":1}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, tgt)
+	d := databaseTargetDelivery(newEvent(`{"n":1}`), tgt)
 
-	env.eng.ExportDeliverDatabase(webhookDB, d)
+	require.NoError(t, env.writers.Write(d))
 
 	require.True(
-		t, env.eng.ExportArchiveHandleOpen(tgt.ID),
+		t, env.writers.ExportArchiveHandleOpen(tgt.ID),
 		"the delivery must leave the archive handle open",
 	)
 
 	env.sweeper.ExportSweep(context.Background())
 
 	require.True(
-		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		t, env.writers.ExportHasArchiveWriter(tgt.ID),
 		"the delivery's registry entry must survive the sweep",
 	)
 	assert.False(
-		t, env.eng.ExportArchiveHandleOpen(tgt.ID),
+		t, env.writers.ExportArchiveHandleOpen(tgt.ID),
 		"the sweep must leave the archive closed",
 	)
 }
@@ -693,7 +747,7 @@ func TestArchiveSweep_ClosesHandleBeforeReopening(t *testing.T) {
 
 	path := filepath.Join(t.TempDir(), "archive.db")
 
-	w := delivery.NewExportArchiveWriter(
+	w := archive.NewExportArchiveWriter(
 		path, archiveTestLogger(), 0,
 	)
 
@@ -721,8 +775,8 @@ func TestArchiveSweep_CancelledSweepLogsNoError(t *testing.T) {
 
 	var errorLines bytes.Buffer
 
-	sweeper := delivery.NewTestArchiveSweeper(
-		env.mainDB, env.eng,
+	sweeper := archive.NewTestSweeper(
+		env.mainDB, env.writers,
 		slog.New(slog.NewTextHandler(
 			&errorLines,
 			&slog.HandlerOptions{Level: slog.LevelError},
@@ -766,7 +820,7 @@ func TestArchiveSweep_NeverExpiryUntouched(t *testing.T) {
 			"config %q must keep rows forever", configJSON,
 		)
 		assert.False(
-			t, env.eng.ExportHasArchiveWriter(tgt.ID),
+			t, env.writers.ExportHasArchiveWriter(tgt.ID),
 			"config %q must leave no registry entry behind",
 			configJSON,
 		)
@@ -831,7 +885,7 @@ func archiveTableExists(t *testing.T, path string) bool {
 
 	return openArchiveDBForRead(t, path).
 		Migrator().
-		HasTable(&delivery.ExportArchivedEvent{})
+		HasTable(&archive.ExportArchivedEvent{})
 }
 
 // TestArchiveSweep_DoesNotCreateArchiveFile proves the sweep
@@ -858,7 +912,7 @@ func TestArchiveSweep_DoesNotCreateArchiveFile(t *testing.T) {
 	}
 
 	assert.False(
-		t, env.eng.ExportHasArchiveWriter(tgt.ID),
+		t, env.writers.ExportHasArchiveWriter(tgt.ID),
 		"the sweep must leave no registry entry behind",
 	)
 }
@@ -876,7 +930,7 @@ func TestArchiveSweep_DoesNotCreateAfterWriterExists(
 
 	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 
-	path, err := env.eng.ExportEnsureArchiveWriter(tgt.ID)
+	path, err := env.writers.ExportEnsureArchiveWriter(tgt.ID)
 	require.NoError(t, err)
 	require.NoFileExists(t, path)
 
@@ -923,21 +977,14 @@ func TestArchiveSweep_ConcurrentWrites(t *testing.T) {
 
 	tgt := env.seedDatabaseTarget(t, `{"expiry":"1h"}`)
 
-	webhookDB := testWebhookDB(t)
-
-	// The deliveries are seeded up front, on the test's own
-	// goroutine: the seed helpers assert, and testify assertions
-	// must not run off the test goroutine.
 	deliveries := make(
 		[]*database.Delivery, 0, sweepConcurrentWrites,
 	)
 
 	for range sweepConcurrentWrites {
-		event := seedEvent(t, webhookDB, `{"n":1}`)
-
 		deliveries = append(
 			deliveries,
-			seedDatabaseTargetDelivery(t, webhookDB, event, tgt),
+			databaseTargetDelivery(newEvent(`{"n":1}`), tgt),
 		)
 	}
 
@@ -949,7 +996,7 @@ func TestArchiveSweep_ConcurrentWrites(t *testing.T) {
 		defer wg.Done()
 
 		for _, d := range deliveries {
-			env.eng.ExportDeliverDatabase(webhookDB, d)
+			_ = env.writers.Write(d)
 		}
 	}()
 

internal/archive/writer.go

@@ -1,4 +1,4 @@
-package delivery
+package archive
 
 import (
 	"encoding/json"
@@ -18,9 +18,9 @@ import (
 	"sneak.berlin/go/webhooker/internal/gormlog"
 )
 
-// archiveExpiryNever is the expiry sentinel (and default) that
+// ExpiryNever is the expiry sentinel (and default) that
 // disables pruning so archived rows are kept forever.
-const archiveExpiryNever = "never"
+const ExpiryNever = "never"
 
 // archiveReopenDebounce bounds how often an archive file is
 // closed and reopened. After each write the handle is closed
@@ -71,17 +71,17 @@ var (
 		"archive writer has been evicted",
 	)
 
-	// ErrArchiveNameTaken is returned when an archive cannot be
+	// ErrNameTaken is returned when an archive cannot be
 	// renamed because a file already has the new name. That file may
 	// be an archive with rows of its own, so it is never replaced.
-	ErrArchiveNameTaken = errors.New(
+	ErrNameTaken = errors.New(
 		"a file already has the archive's new name",
 	)
 )
 
-// databaseTargetConfig is the optional per-target JSON config
+// DatabaseTargetConfig is the optional per-target JSON config
 // for a database (archive) target.
-type databaseTargetConfig struct {
+type DatabaseTargetConfig struct {
 	// Expiry is a Go duration (e.g. "720h") after which
 	// archived rows are pruned, or "never" (the default) to
 	// keep them forever.
@@ -112,21 +112,21 @@ type archivedEvent struct {
 	ArchivedAt time.Time `gorm:"index"`
 }
 
-// parseArchiveExpiry reads the optional expiry from a database
+// ParseExpiry reads the optional expiry from a database
 // target's config JSON. An empty config, an empty expiry, or
 // the literal "never" all mean keep forever, returned as a zero
 // duration. Any other value must parse as a positive Go
 // duration; a set-but-invalid value (unparseable, zero, or
 // negative) is an error rather than a silent default, matching
-// ValidateArchiveExpiry at target creation.
-func parseArchiveExpiry(
+// ValidateExpiry at target creation.
+func ParseExpiry(
 	configJSON string,
 ) (time.Duration, error) {
 	if configJSON == "" {
 		return 0, nil
 	}
 
-	var cfg databaseTargetConfig
+	var cfg DatabaseTargetConfig
 
 	err := json.Unmarshal([]byte(configJSON), &cfg)
 	if err != nil {
@@ -135,7 +135,7 @@ func parseArchiveExpiry(
 		)
 	}
 
-	if cfg.Expiry == "" || cfg.Expiry == archiveExpiryNever {
+	if cfg.Expiry == "" || cfg.Expiry == ExpiryNever {
 		return 0, nil
 	}
 
@@ -155,14 +155,14 @@ func parseArchiveExpiry(
 	return dur, nil
 }
 
-// ValidateArchiveExpiry checks a user-supplied archive expiry
+// ValidateExpiry checks a user-supplied archive expiry
 // for a database target at configuration time. Valid values are
 // empty, "never" (both meaning keep forever), or a positive Go
 // duration such as "720h". Anything else is an error, so a bad
 // expiry is rejected when the target is created rather than
 // failing every subsequent delivery.
-func ValidateArchiveExpiry(expiry string) error {
-	if expiry == "" || expiry == archiveExpiryNever {
+func ValidateExpiry(expiry string) error {
+	if expiry == "" || expiry == ExpiryNever {
 		return nil
 	}
 
@@ -171,7 +171,7 @@ func ValidateArchiveExpiry(expiry string) error {
 		return fmt.Errorf(
 			"expiry must be %q or a Go duration "+
 				"such as \"720h\": %w",
-			archiveExpiryNever, err,
+			ExpiryNever, err,
 		)
 	}
 
@@ -194,7 +194,7 @@ func ValidateArchiveExpiry(expiry string) error {
 type archiveWriter struct {
 	mu sync.Mutex
 
-	// path is the target's archive file as ArchivePath names it. A
+	// path is the target's archive file as Path names it. A
 	// target that rotates writes to the files archivePeriodPath names
 	// for path and a period instead.
 	path string
@@ -232,7 +232,7 @@ type archiveWriter struct {
 	// registry proper.
 	//
 	// Unlike every other field here it is guarded by
-	// databaseTarget.mu, not by this writer's mu: it describes the
+	// Writers.mu, not by this writer's mu: it describes the
 	// registry entry rather than the file.
 	sweepOwned bool
 }
@@ -499,7 +499,7 @@ func (w *archiveWriter) sweepFile(
 // the next write creates its file under the new name.
 //
 // If a file already has one of the new names, nothing is moved and
-// the error is ErrArchiveNameTaken. If one file fails to move, those
+// the error is ErrNameTaken. If one file fails to move, those
 // already moved are moved back before the error is returned, so the
 // archive is never split across two names.
 func (w *archiveWriter) rename(name string) error {
@@ -537,7 +537,7 @@ func (w *archiveWriter) rename(name string) error {
 	for _, taken := range to {
 		if fileExists(taken) {
 			return fmt.Errorf(
-				"%w: %s", ErrArchiveNameTaken, filepath.Base(taken),
+				"%w: %s", ErrNameTaken, filepath.Base(taken),
 			)
 		}
 	}
@@ -590,7 +590,7 @@ func (w *archiveWriter) evict() {
 // each row's archived time. It runs on every (re)open, so a
 // steadily written archive is swept by its own write traffic. An
 // archive that goes idle receives no further reopens, which is
-// why ArchiveSweeper exists to drive sweepExpired on a timer.
+// why Sweeper exists to drive sweepExpired on a timer.
 // Failures are logged, not fatal: a prune error must not stop
 // archiving.
 func (w *archiveWriter) prune(expiry time.Duration) {
@@ -617,9 +617,9 @@ func (w *archiveWriter) prune(expiry time.Duration) {
 	}
 }
 
-// ArchiveFileInfo is what the metadata of a database target's archive
+// FileInfo is what the metadata of a database target's archive
 // files says about them.
-type ArchiveFileInfo struct {
+type FileInfo struct {
 	// Files counts the files.
 	Files int
 
@@ -631,18 +631,18 @@ type ArchiveFileInfo struct {
 	Written time.Time
 }
 
-// StatArchive reads the metadata of a database target's archive
-// files, given the path ArchivePath gives it (see archiveFiles), and
+// Stat reads the metadata of a database target's archive
+// files, given the path Path gives it (see archiveFiles), and
 // of their -wal, without opening them. With no files, which is so
 // before the first write and after the operator moved them away, the
 // error wraps fs.ErrNotExist.
-func StatArchive(path string) (ArchiveFileInfo, error) {
+func Stat(path string) (FileInfo, error) {
 	files, err := archiveFiles(path)
 	if err != nil {
-		return ArchiveFileInfo{}, err
+		return FileInfo{}, err
 	}
 
-	var info ArchiveFileInfo
+	var info FileInfo
 
 	for _, file := range files {
 		db, err := os.Stat(file.path)
@@ -651,7 +651,7 @@ func StatArchive(path string) (ArchiveFileInfo, error) {
 		}
 
 		if err != nil {
-			return ArchiveFileInfo{}, err
+			return FileInfo{}, err
 		}
 
 		info.Files++
@@ -667,7 +667,7 @@ func StatArchive(path string) (ArchiveFileInfo, error) {
 		}
 
 		if err != nil {
-			return ArchiveFileInfo{}, err
+			return FileInfo{}, err
 		}
 
 		info.Size += wal.Size()
@@ -678,7 +678,7 @@ func StatArchive(path string) (ArchiveFileInfo, error) {
 	}
 
 	if info.Files == 0 {
-		return ArchiveFileInfo{}, fmt.Errorf(
+		return FileInfo{}, fmt.Errorf(
 			"no archive file for %s: %w", path, fs.ErrNotExist,
 		)
 	}

internal/archive/writer_gormlog_test.go

@@ -1,4 +1,4 @@
-package delivery_test
+package archive_test
 
 import (
 	"bytes"
@@ -14,7 +14,7 @@ import (
 	"github.com/stretchr/testify/require"
 	"gorm.io/gorm"
 	gormlogger "gorm.io/gorm/logger"
-	"sneak.berlin/go/webhooker/internal/delivery"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/middleware"
 )
 
@@ -57,7 +57,7 @@ func (g *gormDefaultBuf) String() string {
 // without exporting production code to carry it, and a logging
 // detector is not worth a production symbol. What it detects is the
 // third gorm.Open in this service, at
-// internal/delivery/target_database_archive.go — the archive writer,
+// internal/archive/writer.go — the archive writer,
 // whose type is unexported, so nothing outside this package can drive
 // it.
 func captureArchiveGORMDefault(t *testing.T) *gormDefaultBuf {
@@ -85,7 +85,7 @@ func captureArchiveGORMDefault(t *testing.T) *gormDefaultBuf {
 // writer's gorm.Open to the adapter.
 //
 // Restore a bare &gorm.Config{} at
-// internal/delivery/target_database_archive.go and this fails: the
+// internal/archive/writer.go and this fails: the
 // default logger prints the fully interpolated SELECT on every
 // ErrRecordNotFound, so the client-chosen event id below arrives whole
 // and unbounded on stdout, answering to no level the operator set.
@@ -100,7 +100,7 @@ func TestArchiveWriter_NeverUsesGORMsDefaultLogger(t *testing.T) {
 
 	gormDefault := captureArchiveGORMDefault(t)
 
-	w := delivery.NewExportArchiveWriter(
+	w := archive.NewExportArchiveWriter(
 		filepath.Join(t.TempDir(), "archive.db"),
 		slog.New(slog.NewTextHandler(
 			&captured, &slog.HandlerOptions{Level: slog.LevelDebug},
@@ -118,7 +118,7 @@ func TestArchiveWriter_NeverUsesGORMsDefaultLogger(t *testing.T) {
 	value := strings.Repeat("\x01", archiveGORMFillBytes) +
 		archiveGORMTailMarker
 
-	var row delivery.ExportArchivedEvent
+	var row archive.ExportArchivedEvent
 
 	err := w.DB().Where("event_id = ?", value).First(&row).Error
 	require.ErrorIs(t, err, gorm.ErrRecordNotFound)

internal/database/sqlite_mode_test.go

@@ -137,7 +137,7 @@ func TestPerWebhookEventDatabaseFilesAreOwnerOnly(t *testing.T) {
 }
 
 // TestArchiveDatabaseFilesAreOwnerOnly covers the archive-*.db tier.
-// internal/delivery builds that path and opens it through OpenSQLite,
+// internal/archive builds that path and opens it through OpenSQLite,
 // the same single open path exercised here, so the mode is settled for
 // all three tiers in one place.
 func TestArchiveDatabaseFilesAreOwnerOnly(t *testing.T) {

internal/db/migrations/archive/001_schema.sql

@@ -1,5 +1,5 @@
 -- Migration 001: the schema of a database target's archive file. The
--- archivedEvent model in internal/delivery must agree with it.
+-- archivedEvent model in internal/archive must agree with it.
 
 CREATE TABLE archived_events (
     id integer PRIMARY KEY AUTOINCREMENT,

internal/delivery/engine.go

@@ -13,6 +13,7 @@ import (
 
 	"go.uber.org/fx"
 	"gorm.io/gorm"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/globals"
 	"sneak.berlin/go/webhooker/internal/lifecycle"
@@ -124,31 +125,11 @@ type Notifier interface {
 	Notify(tasks []Task)
 }
 
-// Archives is how the handlers keep the database targets' archive
-// files in step with the configuration. Deleting a webhook or a
-// target releases the cached archive writers, whose open file
-// handles would otherwise outlive them; renaming one renames the
-// archive files, which are named for the webhook and the target
-// (see ArchiveFileName).
-//
-// It is deliberately separate from Notifier: archiving lifecycle
-// is not notification, and a small interface keeps the handlers
-// package free of any dependency on the engine's internals while
-// staying trivially fakeable in tests.
-//
-// Neither eviction deletes an archive file. Both are idempotent
-// and are no-ops for a webhook or target with no engine state.
-type Archives interface {
-	EvictWebhook(webhookID string)
-	EvictTarget(targetID string)
-	Rename(targetID, webhookName, targetName string) error
-}
-
 // CircuitBreakers is how the handlers read a target's circuit
 // breaker, so the webhook page and the event log can say that
-// deliveries to the target are paused and until when. Like Archives,
-// it keeps the handlers free of the engine's internals and is
-// trivially faked in tests.
+// deliveries to the target are paused and until when. It keeps the
+// handlers free of the engine's internals and is trivially faked in
+// tests.
 type CircuitBreakers interface {
 	StateAndCooldown(targetID string) (CircuitState, time.Duration)
 }
@@ -164,6 +145,7 @@ type EngineParams struct {
 	Logger    *logger.Logger
 	SSRFGuard *Guard
 	Metrics   *metrics.Set
+	Archives  *archive.Writers
 }
 
 // Engine processes queued deliveries in the background
@@ -202,9 +184,10 @@ type Engine struct {
 	httpTarget  *httpTarget
 	slackTarget *slackTarget
 
-	// dbTarget is retained so the engine can reach the archive
-	// writer registry for eviction, renames and the idle sweep.
-	dbTarget *databaseTarget
+	// archives is the database targets' archive writers. The
+	// database target writes each event through them, and stop
+	// closes them.
+	archives *archive.Writers
 
 	// inflight is the set of deliveries this engine currently owns.
 	// Recovery and the sweeps re-dispatch only what it does not
@@ -228,6 +211,7 @@ func New(
 		workers:    defaultWorkers,
 		version:    params.Globals.Version,
 		mtr:        params.Metrics,
+		archives:   params.Archives,
 	}
 
 	e.initTargets(&http.Client{
@@ -272,47 +256,6 @@ func (e *Engine) Notify(tasks []Task) {
 	}
 }
 
-// EvictWebhook implements Archives. The cached archive writer of
-// every database target of the webhook is dropped from the
-// registry and its file handle closed. The archive files
-// themselves are left on disk — they are long-term storage the
-// operator owns.
-func (e *Engine) EvictWebhook(webhookID string) {
-	if e.dbTarget == nil {
-		return
-	}
-
-	e.dbTarget.evictWebhook(webhookID)
-}
-
-// EvictTarget implements Archives. It is EvictWebhook for a single
-// database target, and leaves the archive file on disk the same
-// way.
-func (e *Engine) EvictTarget(targetID string) {
-	if e.dbTarget == nil {
-		return
-	}
-
-	e.dbTarget.evict(targetID)
-}
-
-// Rename implements Archives. It renames every one of a database
-// target's archive files to ArchiveFileName(webhookName, targetName,
-// targetID), each keeping the period in its name, under the lock the
-// target's archive writes and the idle sweep take. It never replaces
-// a file: if one already has a new name, the error is
-// ErrArchiveNameTaken. The caller renames before it saves the new
-// name: see databaseTarget.rename.
-func (e *Engine) Rename(
-	targetID, webhookName, targetName string,
-) error {
-	if e.dbTarget == nil {
-		return nil
-	}
-
-	return e.dbTarget.rename(targetID, webhookName, targetName)
-}
-
 // StateAndCooldown implements CircuitBreakers. It returns the state of
 // the target's circuit breaker and, while the breaker is open, what is
 // left of its cooldown; the cooldown is zero once that has passed and
@@ -466,7 +409,7 @@ func (e *Engine) stop(ctx context.Context) error {
 		return err
 	}
 
-	e.dbTarget.evictAll()
+	e.archives.EvictAll()
 
 	e.log.Info("delivery engine stopped")
 

internal/delivery/engine_lifecycle_test.go

@@ -427,9 +427,9 @@ func TestEngine_StopLeavesLastRetryAttemptRetrying(t *testing.T) {
 
 // deliverToArchive gives the setup's webhook a database target,
 // runs one delivery to it through the running engine, and returns
-// the target's ID and archive file path. The archive writer holds
-// the file open afterwards.
-func deliverToArchive(t *testing.T, s iSetup) (string, string) {
+// the target's archive file path. The archive writer holds the file
+// open afterwards.
+func deliverToArchive(t *testing.T, s iSetup) string {
 	t.Helper()
 
 	iCreateWebhook(t, s.MainDB, s.WebhookID, "hook")
@@ -452,7 +452,7 @@ func deliverToArchive(t *testing.T, s iSetup) (string, string) {
 
 	iWaitForDelivered(t, s.WebhookDB, deliveryID)
 
-	return tgt.ID, filepath.Join(
+	return filepath.Join(
 		filepath.Dir(s.DBMgr.DBPath(s.WebhookID)),
 		"archive-hook-archive-"+tgt.ID+".db",
 	)
@@ -471,7 +471,7 @@ func TestEngine_StopHookClosesArchives(t *testing.T) {
 
 	lc := startEngineViaHook(t, s.Engine)
 
-	_, path := deliverToArchive(t, s)
+	path := deliverToArchive(t, s)
 	require.FileExists(
 		t, path+"-wal",
 		"an open archive should have a -wal for the stop to remove",
@@ -505,21 +505,23 @@ func TestEngine_StopHookTimeoutLeavesArchivesOpen(t *testing.T) {
 
 	lc := startEngineViaHook(t, s.Engine)
 
-	targetID, _ := deliverToArchive(t, s)
+	path := deliverToArchive(t, s)
 
 	release := make(chan struct{})
 
 	t.Cleanup(func() {
 		close(release)
-		s.Engine.EvictWebhook(s.WebhookID)
+		s.Engine.ExportArchives().EvictWebhook(s.WebhookID)
 	})
 
 	s.Engine.ExportWedgeWorker(release)
 
 	requireStopHookExpires(t, lc.hooks[0], "delivery engine")
 
-	require.True(
-		t, s.Engine.ExportArchiveHandleOpen(targetID),
+	// Closing the last handle on an archive removes its -wal, so a
+	// -wal still there is a writer still open.
+	require.FileExists(
+		t, path+"-wal",
 		"a stop that timed out must not close archive writers",
 	)
 }

internal/delivery/export_test.go

@@ -12,16 +12,11 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"go.uber.org/fx"
 	"gorm.io/gorm"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/metrics"
 )
 
-// ErrExportArchiveWriterEvicted exposes the sentinel returned by
-// an evicted archive writer. It carries the Err prefix rather
-// than this file's usual Export one because it is a sentinel
-// error.
-var ErrExportArchiveWriterEvicted = errArchiveWriterEvicted
-
 // Exported constants for test access.
 const (
 	ExportDeliveryChannelSize     = deliveryChannelSize
@@ -399,7 +394,8 @@ func (e *Engine) ExportRetryCh() chan Task {
 }
 
 // NewTestEngine creates an Engine for unit tests without
-// database dependencies.
+// database dependencies. Its archive writers have no data
+// directory, so a delivery to a database target fails.
 func NewTestEngine(
 	log *slog.Logger,
 	client *http.Client,
@@ -411,6 +407,7 @@ func NewTestEngine(
 		retryCh:    make(chan Task, retryChannelSize),
 		workers:    workers,
 		mtr:        metrics.New(prometheus.NewRegistry()),
+		archives:   archive.NewWriters(archive.WritersParams{Logger: log}),
 	}
 	e.initTargets(client)
 
@@ -426,6 +423,7 @@ func NewTestEngineSmallRetry(
 		log:      log,
 		retryCh:  make(chan Task, 1),
 		mtr:      metrics.New(prometheus.NewRegistry()),
+		archives: archive.NewWriters(archive.WritersParams{Logger: log}),
 	}
 	e.initTargets(nil)
 
@@ -433,7 +431,8 @@ func NewTestEngineSmallRetry(
 }
 
 // NewTestEngineWithDB creates an Engine with a real
-// database and dbManager for integration tests.
+// database and dbManager for integration tests, and archive
+// writers of its own over the same two.
 func NewTestEngineWithDB(
 	db *database.Database,
 	dbMgr *database.WebhookDBManager,
@@ -449,12 +448,22 @@ func NewTestEngineWithDB(
 		retryCh:    make(chan Task, retryChannelSize),
 		workers:    workers,
 		mtr:        metrics.New(prometheus.NewRegistry()),
+		archives: archive.NewWriters(archive.WritersParams{
+			Database:  db,
+			DBManager: dbMgr,
+			Logger:    log,
+		}),
 	}
 	e.initTargets(client)
 
 	return e
 }
 
+// ExportArchives returns the engine's archive writers.
+func (e *Engine) ExportArchives() *archive.Writers {
+	return e.archives
+}
+
 // ExportSetMetrics substitutes the engine's metric set, so a test can
 // assert on collectors registered on a registry it holds.
 func (e *Engine) ExportSetMetrics(mtr *metrics.Set) {
@@ -477,273 +486,3 @@ func NewTestCircuitBreaker(
 		cooldown:  cooldown,
 	}
 }
-
-// ExportArchivedEvent aliases the archive row type so black-box
-// tests can construct and read archive rows.
-type ExportArchivedEvent = archivedEvent
-
-// ExportArchiveWriter wraps an archiveWriter so black-box tests
-// can exercise the archive file mechanics.
-type ExportArchiveWriter struct {
-	w *archiveWriter
-}
-
-// NewExportArchiveWriter builds an archive writer for tests,
-// optionally overriding the reopen debounce (a non-positive
-// debounce keeps the production default).
-func NewExportArchiveWriter(
-	path string, log *slog.Logger, debounce time.Duration,
-) *ExportArchiveWriter {
-	w := newArchiveWriter(path, log)
-	if debounce > 0 {
-		w.debounce = debounce
-	}
-
-	return &ExportArchiveWriter{w: w}
-}
-
-// Write archives a row through the writer, into the file named
-// without a period.
-func (e *ExportArchiveWriter) Write(
-	row ExportArchivedEvent, expiry time.Duration,
-) error {
-	return e.w.write(row, expiry, "")
-}
-
-// WritePeriod archives a row through the writer, into the file for
-// period.
-func (e *ExportArchiveWriter) WritePeriod(
-	row ExportArchivedEvent, expiry time.Duration, period string,
-) error {
-	return e.w.write(row, expiry, period)
-}
-
-// Open opens the archive file, pruning when expiry is positive.
-func (e *ExportArchiveWriter) Open(expiry time.Duration) error {
-	return e.w.open(e.w.path, expiry)
-}
-
-// Reopen closes and reopens the archive file.
-func (e *ExportArchiveWriter) Reopen(
-	expiry time.Duration,
-) error {
-	return e.w.reopen(e.w.path, expiry)
-}
-
-// SetNow replaces the clock the writer measures its reopen
-// debounce on.
-func (e *ExportArchiveWriter) SetNow(now func() time.Time) {
-	e.w.now = now
-}
-
-// Reopens reports how many times the file has been opened.
-func (e *ExportArchiveWriter) Reopens() int {
-	return e.w.reopens
-}
-
-// DB returns the writer's current open handle for row
-// inspection in tests.
-func (e *ExportArchiveWriter) DB() *gorm.DB {
-	return e.w.db
-}
-
-// Path returns the archive file the writer owns.
-func (e *ExportArchiveWriter) Path() string {
-	return e.w.path
-}
-
-// OpenExisting opens the archive without permitting creation,
-// the way the idle sweep does.
-func (e *ExportArchiveWriter) OpenExisting(
-	expiry time.Duration,
-) error {
-	return e.w.openMode(e.w.path, archiveModeExisting, expiry)
-}
-
-// SweepExpired runs an idle sweep of the archive.
-func (e *ExportArchiveWriter) SweepExpired(
-	expiry time.Duration,
-) error {
-	return e.w.sweepExpired(expiry)
-}
-
-// Evict marks the writer evicted and closes its handle, exactly
-// as leaving the registry does.
-func (e *ExportArchiveWriter) Evict() {
-	e.w.evict()
-}
-
-// Rename gives the archive file a new name in the same directory,
-// as a rename of the webhook or target does.
-func (e *ExportArchiveWriter) Rename(name string) error {
-	return e.w.rename(name)
-}
-
-// HandleOpen reports whether the writer currently holds an open
-// archive handle.
-func (e *ExportArchiveWriter) HandleOpen() bool {
-	e.w.mu.Lock()
-	defer e.w.mu.Unlock()
-
-	return e.w.db != nil
-}
-
-// Same reports whether both wrappers refer to the very same
-// underlying archive writer, so a test can prove a registry entry
-// is the writer it was handed rather than a replacement.
-func (e *ExportArchiveWriter) Same(
-	other *ExportArchiveWriter,
-) bool {
-	return other != nil && e.w == other.w
-}
-
-// ExportArchiveWriterFor returns the archive writer the registry
-// currently caches for a database target, or nil when none is
-// cached. It never creates one, so a test can hold a reference to
-// the very writer an eviction is about to detach.
-func (e *Engine) ExportArchiveWriterFor(
-	targetID string,
-) *ExportArchiveWriter {
-	e.dbTarget.mu.Lock()
-	defer e.dbTarget.mu.Unlock()
-
-	w, ok := e.dbTarget.writers[targetID]
-	if !ok {
-		return nil
-	}
-
-	return &ExportArchiveWriter{w: w}
-}
-
-// ExportHasArchiveWriter reports whether the database target
-// type currently caches an archive writer for a target.
-func (e *Engine) ExportHasArchiveWriter(
-	targetID string,
-) bool {
-	e.dbTarget.mu.Lock()
-	defer e.dbTarget.mu.Unlock()
-
-	_, ok := e.dbTarget.writers[targetID]
-
-	return ok
-}
-
-// ExportArchiveHandleOpen reports whether the cached archive
-// writer for a target holds an open database handle. It
-// returns false when no writer is cached.
-func (e *Engine) ExportArchiveHandleOpen(
-	targetID string,
-) bool {
-	e.dbTarget.mu.Lock()
-	w, ok := e.dbTarget.writers[targetID]
-	e.dbTarget.mu.Unlock()
-
-	if !ok {
-		return false
-	}
-
-	w.mu.Lock()
-	defer w.mu.Unlock()
-
-	return w.db != nil
-}
-
-// ExportEnsureArchiveWriter creates (if needed) and returns the
-// archive file path of the cached writer for a target, so a
-// test can prime the registry the way a delivery would.
-func (e *Engine) ExportEnsureArchiveWriter(
-	targetID string,
-) (string, error) {
-	w, err := e.dbTarget.writerFor(targetID)
-	if err != nil {
-		return "", err
-	}
-
-	return w.path, nil
-}
-
-// ExportSweepWriterFor takes a target's registry writer exactly
-// as the idle sweep does, reporting whether the sweep had to
-// create the entry. It lets a test drive the registry through the
-// sweep's own entry point instead of choreographing goroutines.
-func (e *Engine) ExportSweepWriterFor(
-	targetID string,
-) (*ExportArchiveWriter, bool, error) {
-	w, created, err := e.dbTarget.sweepWriterFor(targetID)
-	if err != nil {
-		return nil, false, err
-	}
-
-	return &ExportArchiveWriter{w: w}, created, nil
-}
-
-// ExportReleaseSweepWriter releases a sweep-created registry entry
-// exactly as a finished sweep does.
-func (e *Engine) ExportReleaseSweepWriter(
-	targetID string, w *ExportArchiveWriter,
-) {
-	e.dbTarget.releaseSweepWriter(targetID, w.w)
-}
-
-// NewTestArchiveSweeper builds an ArchiveSweeper backed by the
-// given main database and engine, without the fx lifecycle.
-// Intended for tests.
-func NewTestArchiveSweeper(
-	db *database.Database,
-	eng *Engine,
-	log *slog.Logger,
-) *ArchiveSweeper {
-	return &ArchiveSweeper{
-		db:       db,
-		eng:      eng,
-		log:      log,
-		interval: time.Hour,
-	}
-}
-
-// ExportSweep runs a single archive sweep synchronously for
-// tests.
-func (s *ArchiveSweeper) ExportSweep(ctx context.Context) {
-	s.sweep(ctx)
-}
-
-// ExportStart starts the sweeper's background loop for tests.
-func (s *ArchiveSweeper) ExportStart() {
-	s.start()
-}
-
-// ExportRegisterHooks registers the sweeper's real fx lifecycle
-// hooks on a lifecycle supplied by a test, so a test can drive
-// the exact OnStart/OnStop functions the application runs and
-// hand OnStart the kind of context fx actually supplies.
-func (s *ArchiveSweeper) ExportRegisterHooks(lc fx.Lifecycle) {
-	s.registerHooks(lc)
-}
-
-// ExportStop stops the sweeper's background loop for tests.
-func (s *ArchiveSweeper) ExportStop(ctx context.Context) error {
-	return s.stop(ctx)
-}
-
-// ExportWedgeLoop adds a goroutine to the sweeper's WaitGroup
-// that never observes cancellation and returns only when release
-// is closed. It stands in for a prune stuck on a locked archive.
-func (s *ArchiveSweeper) ExportWedgeLoop(
-	release <-chan struct{},
-) {
-	s.wg.Go(func() {
-		<-release
-	})
-}
-
-// ExportSetInterval overrides the sweep interval for tests.
-func (s *ArchiveSweeper) ExportSetInterval(d time.Duration) {
-	s.interval = d
-}
-
-// ExportParseArchiveExpiry exposes parseArchiveExpiry.
-func ExportParseArchiveExpiry(
-	configJSON string,
-) (time.Duration, error) {
-	return parseArchiveExpiry(configJSON)
-}

internal/delivery/inflight_test.go

@@ -2,8 +2,6 @@ package delivery_test
 
 import (
 	"context"
-	"path/filepath"
-	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -66,33 +64,6 @@ func fDrain(e *delivery.Engine) []delivery.Task {
 	}
 }
 
-// TestArchiveHandleIsWAL closes the last gap in the durability
-// evidence: the main and per-webhook tiers each assert their journal
-// mode on a live handle, and the archive tier gets its settings from
-// the same code path but nothing checked the running file.
-func TestArchiveHandleIsWAL(t *testing.T) {
-	t.Parallel()
-
-	w := delivery.NewExportArchiveWriter(
-		filepath.Join(t.TempDir(), "archive-wal.db"),
-		archiveTestLogger(), 0,
-	)
-
-	require.NoError(t, w.Open(0))
-
-	var mode string
-
-	row := w.DB().Raw("pragma journal_mode").Row()
-	require.NoError(t, row.Scan(&mode))
-	assert.Equal(t, "wal", strings.ToLower(mode))
-
-	var busy string
-
-	row = w.DB().Raw("pragma busy_timeout").Row()
-	require.NoError(t, row.Scan(&busy))
-	assert.Equal(t, "10000", busy)
-}
-
 // TestSweepLeavesAQueuedDeliveryAlone is the case the age bound cannot
 // see. The delivery is queued and untouched, so its row is arbitrarily
 // old and still perfectly healthy; only ownership distinguishes it

internal/delivery/target.go

@@ -103,16 +103,13 @@ func (e *Engine) initTargets(client *http.Client) {
 		client:   client,
 	}
 
-	dbT := &databaseTarget{eng: e}
-
 	e.httpTarget = httpT
 	e.slackTarget = slackT
-	e.dbTarget = dbT
 
 	e.targets = map[database.TargetType]Target{
 		database.TargetTypeHTTP:     httpT,
 		database.TargetTypeSlack:    slackT,
-		database.TargetTypeDatabase: dbT,
+		database.TargetTypeDatabase: &databaseTarget{eng: e},
 		database.TargetTypeLog:      &logTarget{eng: e},
 	}
 }

internal/delivery/target_config_edit.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
 )
 
@@ -105,7 +106,7 @@ func databaseConfigForm(
 		return TargetConfigForm{}, nil
 	}
 
-	var cfg databaseTargetConfig
+	var cfg archive.DatabaseTargetConfig
 
 	err := json.Unmarshal([]byte(configJSON), &cfg)
 	if err != nil {
@@ -114,18 +115,18 @@ func databaseConfigForm(
 		)
 	}
 
-	err = ValidateArchiveRotation(cfg.Rotation)
+	err = archive.ValidateRotation(cfg.Rotation)
 	if err != nil {
 		return TargetConfigForm{}, err
 	}
 
 	form := TargetConfigForm{Rotation: cfg.Rotation}
 
-	if cfg.Expiry == "" || cfg.Expiry == archiveExpiryNever {
+	if cfg.Expiry == "" || cfg.Expiry == archive.ExpiryNever {
 		return form, nil
 	}
 
-	err = ValidateArchiveExpiry(cfg.Expiry)
+	err = archive.ValidateExpiry(cfg.Expiry)
 	if err != nil {
 		return TargetConfigForm{}, err
 	}

internal/delivery/target_config_view.go

@@ -5,6 +5,7 @@ import (
 	"strconv"
 	"time"
 
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
 )
 
@@ -200,17 +201,17 @@ func maxAttemptsField(t *database.Target) ConfigField {
 // not one of the four, is reported as unavailable rather than
 // echoed back.
 func databaseConfigFields(configJSON string) []ConfigField {
-	expiry, err := parseArchiveExpiry(configJSON)
+	expiry, err := archive.ParseExpiry(configJSON)
 	if err != nil {
 		return unavailableConfigFields()
 	}
 
-	rotation, err := parseArchiveRotation(configJSON)
+	rotation, err := archive.ParseRotation(configJSON)
 	if err != nil {
 		return unavailableConfigFields()
 	}
 
-	value := archiveExpiryNever
+	value := archive.ExpiryNever
 	if expiry > 0 {
 		value = plainDuration(expiry)
 	}

internal/delivery/target_config_view_test.go

@@ -35,6 +35,17 @@ const (
 	viewMaxAttempts   = "Delivery attempts"
 )
 
+// The archive rotations a database target's settings can name, and
+// the config of one whose rotation is not one of the four.
+const (
+	rotationNone    = "none"
+	rotationMonthly = "monthly"
+	rotationDaily   = "daily"
+	rotationHourly  = "hourly"
+
+	weeklyConfig = `{"rotation":"weekly"}`
+)
+
 func TestMaskedWebhookURL(t *testing.T) {
 	t.Parallel()
 

internal/delivery/target_database.go

@@ -2,83 +2,23 @@ package delivery
 
 import (
 	"context"
-	"fmt"
-	"strings"
-	"sync"
 	"time"
 
 	"gorm.io/gorm"
 	"sneak.berlin/go/webhooker/internal/database"
 )
 
-// archiveNameMaxLen is how many characters of a webhook or target
-// name an archive file name keeps.
-const archiveNameMaxLen = 40
-
 // databaseTarget is a no-retry target that archives the full
 // inbound event into the target's own archive SQLite file, separate
 // from the per-webhook event database. The event is already
 // persisted in the per-webhook event DB by the time delivery runs;
 // the database target additionally writes a durable long-term copy
-// into the file ArchiveFileName names, with a period added when the
-// target rotates (see archivePeriodPath), and then records a single
+// through the engine's archive.Writers, and then records a single
 // attempt whose outcome reflects whether the archive write
-// succeeded. See archiveWriter for the close/reopen, auto-recreate,
-// and expiry semantics.
+// succeeded. Package archive holds everything about the files
+// themselves.
 type databaseTarget struct {
 	eng *Engine
-
-	// writers holds one archive writer per database target, keyed
-	// by target ID.
-	mu      sync.Mutex
-	writers map[string]*archiveWriter
-}
-
-// ArchiveFileName returns the file name of a database target's
-// archive: archive-WEBHOOKNAME-TARGETNAME-TARGETID.db, with both
-// names passed through archiveNamePart. The target ID keeps the
-// name unique when two targets' names come out the same.
-func ArchiveFileName(webhookName, targetName, targetID string) string {
-	return "archive-" + archiveNamePart(webhookName) + "-" +
-		archiveNamePart(targetName) + "-" + targetID + ".db"
-}
-
-// archiveNamePart makes a webhook or target name safe to put in a
-// file name. It is lowercased; ASCII letters and digits are kept,
-// every other run of characters becomes a single "-", and no "-" is
-// left at either end. It is cut to archiveNameMaxLen characters, and
-// a name with nothing left is "unnamed".
-func archiveNamePart(name string) string {
-	var b strings.Builder
-
-	dash := false
-
-	for _, r := range strings.ToLower(name) {
-		if (r < 'a' || r > 'z') && (r < '0' || r > '9') {
-			dash = b.Len() > 0
-
-			continue
-		}
-
-		if dash {
-			b.WriteByte('-')
-
-			dash = false
-		}
-
-		b.WriteRune(r)
-	}
-
-	part := b.String()
-	if len(part) > archiveNameMaxLen {
-		part = strings.TrimRight(part[:archiveNameMaxLen], "-")
-	}
-
-	if part == "" {
-		return "unnamed"
-	}
-
-	return part
 }
 
 // Deliver implements Target. It archives the event, then
@@ -98,7 +38,7 @@ func (t *databaseTarget) Deliver(
 ) {
 	start := time.Now()
 
-	err := t.archive(d)
+	err := t.eng.archives.Write(d)
 
 	elapsed := time.Since(start)
 
@@ -145,308 +85,3 @@ func (t *databaseTarget) Deliver(
 		database.DeliveryStatusDelivered,
 	)
 }
-
-// archive writes the full event as a row into the target's
-// archive database, honouring the optional per-target expiry and
-// rotation parsed from the target config JSON. With rotation, the
-// event goes to the file for the period of its receive time.
-func (t *databaseTarget) archive(d *database.Delivery) error {
-	webhookID := d.Event.WebhookID
-	if webhookID == "" {
-		return errArchiveMissingWebhookID
-	}
-
-	expiry, err := parseArchiveExpiry(d.Target.Config)
-	if err != nil {
-		return err
-	}
-
-	rotation, err := parseArchiveRotation(d.Target.Config)
-	if err != nil {
-		return err
-	}
-
-	// An event whose stored row was gone before its delivery ran has
-	// no receive time (see Engine.hydrateEvent), and goes to the
-	// file for now.
-	receivedAt := d.Event.CreatedAt
-	if receivedAt.IsZero() {
-		receivedAt = time.Now()
-	}
-
-	w, err := t.writerFor(d.TargetID)
-	if err != nil {
-		return err
-	}
-
-	row := archivedEvent{
-		EventID:      d.Event.ID,
-		WebhookID:    webhookID,
-		EntrypointID: d.Event.EntrypointID,
-		Method:       d.Event.Method,
-		RawQuery:     d.Event.RawQuery,
-		Headers:      d.Event.Headers,
-		Body:         d.Event.Body,
-		ContentType:  d.Event.ContentType,
-	}
-
-	return w.write(row, expiry, archivePeriod(rotation, receivedAt))
-}
-
-// writerFor returns the archive writer for a database target,
-// creating and caching it on first use. Each target has one writer
-// so its close/reopen debounce state is shared across concurrent
-// deliveries, and so a rename and the idle sweep take the same lock
-// as its writes.
-func (t *databaseTarget) writerFor(
-	targetID string,
-) (*archiveWriter, error) {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-
-	w, ok := t.writers[targetID]
-	if !ok {
-		var err error
-
-		w, err = t.newWriter(targetID)
-		if err != nil {
-			return nil, err
-		}
-
-		if t.writers == nil {
-			t.writers = make(map[string]*archiveWriter)
-		}
-
-		t.writers[targetID] = w
-	}
-
-	// A delivery claims the entry: even if the idle sweep created
-	// it moments ago, it now belongs to the registry proper and
-	// the sweep must leave it in place when it finishes.
-	w.sweepOwned = false
-
-	return w, nil
-}
-
-// sweepWriterFor returns the archive writer the idle sweep should
-// prune a target's archive through, together with whether the sweep
-// itself created the registry entry.
-//
-// The sweep must route its prune through the registered writer so
-// the writer's mutex orders it against concurrent writes, but it
-// must never leave a registry entry behind: a sweep that ran
-// concurrently with the target's deletion would otherwise
-// re-create an entry that nothing will ever evict again, which is
-// exactly the leak eviction exists to prevent. An entry the sweep
-// creates is therefore marked sweep-owned and handed back to
-// releaseSweepWriter when the sweep is done.
-func (t *databaseTarget) sweepWriterFor(
-	targetID string,
-) (*archiveWriter, bool, error) {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-
-	w, ok := t.writers[targetID]
-	if ok {
-		return w, false, nil
-	}
-
-	w, err := t.newWriter(targetID)
-	if err != nil {
-		return nil, false, err
-	}
-
-	if t.writers == nil {
-		t.writers = make(map[string]*archiveWriter)
-	}
-
-	w.sweepOwned = true
-	t.writers[targetID] = w
-
-	return w, true, nil
-}
-
-// releaseSweepWriter drops a registry entry that the idle sweep
-// created, so a sweep leaves the registry exactly as it found it.
-//
-// The entry is removed only if it is still the very writer the
-// sweep installed and no delivery has claimed it in the meantime
-// (writerFor clears sweepOwned when it hands a writer to the
-// write path). Both conditions are evaluated under the registry
-// lock, so an eviction that raced the sweep — which removes the
-// entry outright — simply finds nothing left to do here, and a
-// delivery that adopted the writer keeps a registered, evictable
-// one.
-func (t *databaseTarget) releaseSweepWriter(
-	targetID string, w *archiveWriter,
-) {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-
-	cur, ok := t.writers[targetID]
-	if !ok || cur != w || !cur.sweepOwned {
-		return
-	}
-
-	delete(t.writers, targetID)
-}
-
-// newWriter builds the writer for a database target's archive. Its
-// path is the one ArchivePath gives for the webhook and the target as
-// the main database names them now; from then on only rename changes
-// the name the writer uses. It does not touch the archive files.
-func (t *databaseTarget) newWriter(
-	targetID string,
-) (*archiveWriter, error) {
-	if t.eng.dbManager == nil {
-		return nil, errArchiveNoDataDir
-	}
-
-	var target database.Target
-
-	err := t.eng.database.DB().
-		Preload("Webhook").
-		First(&target, "id = ?", targetID).Error
-	if err != nil {
-		return nil, fmt.Errorf(
-			"loading database target %s: %w", targetID, err,
-		)
-	}
-
-	w := newArchiveWriter(
-		ArchivePath(t.eng.dbManager, &target.Webhook, &target),
-		t.eng.log,
-	)
-	w.webhookID = target.WebhookID
-
-	return w, nil
-}
-
-// rename moves every one of a database target's archive files to the
-// name for webhookName and targetName. It goes through the target's
-// writer, so the move holds the lock that writes and the idle sweep
-// take, and later writes use the new name.
-//
-// The writer is created if there is none, and it stays cached. The
-// handlers rename before they save the new name, so until the save
-// the main database still has the old one; a delivery in that window
-// must find this writer rather than build one from the old name.
-func (t *databaseTarget) rename(
-	targetID, webhookName, targetName string,
-) error {
-	w, err := t.writerFor(targetID)
-	if err != nil {
-		return err
-	}
-
-	return w.rename(ArchiveFileName(webhookName, targetName, targetID))
-}
-
-// evict drops a database target's archive writer from the registry
-// and closes its handle, so a deleted target does not leave a
-// writer (and an open archive handle within its debounce window)
-// alive for the process lifetime.
-//
-// The map entry is removed under the registry lock, which is
-// then released before the handle is closed under the writer's
-// own lock: that ordering keeps the registry available to other
-// targets while an in-flight write on this one drains, and
-// closing under the writer's lock means eviction can never race
-// a write.
-//
-// Eviction is idempotent and silent for a target with no writer,
-// which is the common case: only a database target that has
-// received an event or been renamed has one. It never deletes the
-// archive file.
-func (t *databaseTarget) evict(targetID string) {
-	t.mu.Lock()
-
-	w, ok := t.writers[targetID]
-	if ok {
-		delete(t.writers, targetID)
-	}
-
-	t.mu.Unlock()
-
-	if !ok {
-		return
-	}
-
-	w.evict()
-
-	t.eng.log.Info(
-		"evicted archive writer",
-		"target_id", targetID,
-		"path", w.path,
-	)
-}
-
-// evictWebhook evicts, exactly as evict does, the writer of every
-// database target of a webhook.
-func (t *databaseTarget) evictWebhook(webhookID string) {
-	t.mu.Lock()
-
-	var gone []*archiveWriter
-
-	for targetID, w := range t.writers {
-		if w.webhookID == webhookID {
-			delete(t.writers, targetID)
-
-			gone = append(gone, w)
-		}
-	}
-
-	t.mu.Unlock()
-
-	for _, w := range gone {
-		w.evict()
-
-		t.eng.log.Info(
-			"evicted archive writer",
-			"webhook_id", webhookID,
-			"path", w.path,
-		)
-	}
-}
-
-// evictAll evicts every cached archive writer, exactly as evict
-// does for one target. The engine calls it at shutdown, once its
-// workers have returned. Closing the last handle on an archive
-// moves the contents of its -wal into the .db and removes the
-// -wal, so a clean stop leaves each archive as a single file.
-func (t *databaseTarget) evictAll() {
-	t.mu.Lock()
-
-	writers := t.writers
-	t.writers = nil
-
-	t.mu.Unlock()
-
-	for _, w := range writers {
-		w.evict()
-	}
-}
-
-// sweepArchive prunes one database target's archive of rows older
-// than expiry, without requiring a write. A missing archive file is
-// left missing (see sweepExpired), so a sweep never creates an
-// archive for a target that has never received an event.
-//
-// It also never leaves a registry entry behind: an entry it had
-// to create to reach the writer's mutex is released again once
-// the prune is done, so a sweep racing a target deletion cannot
-// resurrect the writer the eviction just dropped.
-func (t *databaseTarget) sweepArchive(
-	targetID string, expiry time.Duration,
-) error {
-	w, created, err := t.sweepWriterFor(targetID)
-	if err != nil {
-		return err
-	}
-
-	if created {
-		defer t.releaseSweepWriter(targetID, w)
-	}
-
-	return w.sweepExpired(expiry)
-}

internal/delivery/target_database_test.go

@@ -3,24 +3,65 @@ package delivery_test
 import (
 	"database/sql"
 	"fmt"
-	"io/fs"
 	"log/slog"
+	"net/http"
 	"os"
 	"path/filepath"
-	"strings"
 	"testing"
 	"time"
 
+	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"gorm.io/driver/sqlite"
 	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
 	_ "modernc.org/sqlite" // Pure Go SQLite driver.
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/database/databasetest"
 	"sneak.berlin/go/webhooker/internal/delivery"
 	"sneak.berlin/go/webhooker/internal/gormlog"
 )
 
+// archiveTestWebhookName is the name of every webhook
+// seedDatabaseTarget creates. It is not safe in a file name as it
+// stands, so every archive file name made from it is made safe first.
+const archiveTestWebhookName = "Sweep Test!"
+
+// archiveEnv bundles the pieces a database target test drives: a main
+// configuration database holding webhooks and targets, a delivery
+// engine whose archive writers write into the data directory, and that
+// directory.
+type archiveEnv struct {
+	eng     *delivery.Engine
+	mainDB  *database.Database
+	dataDir string
+}
+
+func setupArchiveTest(t *testing.T) *archiveEnv {
+	t.Helper()
+
+	dataDir := t.TempDir()
+
+	mainDB, err := database.Open(dataDir, slog.New(slog.DiscardHandler))
+	require.NoError(t, err)
+
+	t.Cleanup(func() { _ = mainDB.Close() })
+
+	return &archiveEnv{
+		eng: delivery.NewTestEngineWithDB(
+			mainDB,
+			databasetest.NewWebhookDBManager(t, dataDir),
+			archiveTestLogger(),
+			&http.Client{Timeout: 5 * time.Second},
+			1,
+		),
+		mainDB:  mainDB,
+		dataDir: dataDir,
+	}
+}
+
 func archiveTestLogger() *slog.Logger {
 	return slog.New(slog.NewTextHandler(
 		os.Stderr,
@@ -28,8 +69,85 @@ func archiveTestLogger() *slog.Logger {
 	))
 }
 
+// archivePath returns where the engine keeps a database target's
+// archive file, for the names seedDatabaseTarget gave it.
+func (env *archiveEnv) archivePath(tgt *database.Target) string {
+	return filepath.Join(
+		env.dataDir,
+		archive.FileName(archiveTestWebhookName, tgt.Name, tgt.ID),
+	)
+}
+
+// seedDatabaseTarget creates a webhook with one database target
+// carrying the given target config JSON, and returns the target.
+func (env *archiveEnv) seedDatabaseTarget(
+	t *testing.T, configJSON string,
+) *database.Target {
+	t.Helper()
+
+	wh := &database.Webhook{
+		UserID: uuid.New().String(),
+		Name:   archiveTestWebhookName,
+	}
+	require.NoError(
+		t,
+		env.mainDB.DB().
+			Omit(clause.Associations).
+			Create(wh).Error,
+	)
+
+	tgt := &database.Target{
+		WebhookID:   wh.ID,
+		Name:        "Archive",
+		Type:        database.TargetTypeDatabase,
+		Active:      true,
+		Config:      configJSON,
+		MaxAttempts: 1,
+	}
+	require.NoError(
+		t,
+		env.mainDB.DB().
+			Omit(clause.Associations).
+			Create(tgt).Error,
+	)
+
+	return tgt
+}
+
+// seedDatabaseTargetDelivery seeds a pending delivery of an event
+// to a database target and returns the in-memory delivery the
+// target handler is invoked with.
+func seedDatabaseTargetDelivery(
+	t *testing.T,
+	webhookDB *gorm.DB,
+	event database.Event,
+	tgt *database.Target,
+) *database.Delivery {
+	t.Helper()
+
+	dlv := seedDelivery(
+		t, webhookDB, event.ID, tgt.ID,
+		database.DeliveryStatusPending,
+	)
+
+	d := &database.Delivery{
+		EventID:  event.ID,
+		TargetID: tgt.ID,
+		Status:   database.DeliveryStatusPending,
+		Event:    event,
+		Target: database.Target{
+			Name:   tgt.Name,
+			Type:   database.TargetTypeDatabase,
+			Config: tgt.Config,
+		},
+	}
+	d.ID = dlv.ID
+
+	return d
+}
+
 // openArchiveDBForRead opens an archive file read-only so a
-// test can inspect the rows the writer persisted.
+// test can inspect the rows the database target archived.
 func openArchiveDBForRead(
 	t *testing.T, path string,
 ) *gorm.DB {
@@ -52,26 +170,45 @@ func openArchiveDBForRead(
 	return gdb
 }
 
-// archiveFileSuffixes returns the archive file itself and the
-// SQLite sidecars that accompany an open database. A test that
-// asserts no archive was created has to check all of them.
-func archiveFileSuffixes() []string {
-	return []string{"", "-wal", "-shm"}
+// countArchivedRows counts the rows in an archive file without
+// asserting anything, so it is safe to poll from an
+// assert.Eventually condition (which runs off the test
+// goroutine, where testify assertions must not be used).
+func countArchivedRows(path string) (int64, error) {
+	sqlDB, err := sql.Open(
+		"sqlite", fmt.Sprintf("file:%s?mode=ro", path),
+	)
+	if err != nil {
+		return 0, err
+	}
+
+	defer func() { _ = sqlDB.Close() }()
+
+	gdb, err := gorm.Open(
+		sqlite.Dialector{Conn: sqlDB},
+		&gorm.Config{Logger: gormlog.New(slog.New(slog.DiscardHandler))},
+	)
+	if err != nil {
+		return 0, err
+	}
+
+	var count int64
+
+	err = gdb.Table("archived_events").Count(&count).Error
+	if err != nil {
+		return 0, err
+	}
+
+	return count, nil
 }
 
-// removeArchiveFiles simulates an operator moving the archive
-// away by deleting the SQLite file and its sidecar files.
-func removeArchiveFiles(t *testing.T, path string) {
-	t.Helper()
-
-	for _, suffix := range []string{
-		"", "-wal", "-shm", "-journal",
-	} {
-		err := os.Remove(path + suffix)
-		if err != nil && !os.IsNotExist(err) {
-			t.Fatalf("removing %s%s: %v", path, suffix, err)
-		}
-	}
+// archivedRow is the columns of an archive row these tests read.
+type archivedRow struct {
+	EventID   string
+	WebhookID string
+	Method    string
+	RawQuery  string
+	Body      string
 }
 
 // TestDeliverDatabase_ArchivesEvent verifies that delivering to
@@ -107,9 +244,9 @@ func TestDeliverDatabase_ArchivesEvent(t *testing.T) {
 
 	rdb := openArchiveDBForRead(t, archivePath)
 
-	var rows []delivery.ExportArchivedEvent
+	var rows []archivedRow
 
-	require.NoError(t, rdb.Find(&rows).Error)
+	require.NoError(t, rdb.Table("archived_events").Find(&rows).Error)
 	require.Len(t, rows, 1)
 	assert.Equal(t, event.ID, rows[0].EventID)
 	assert.Equal(t, event.WebhookID, rows[0].WebhookID)
@@ -118,262 +255,6 @@ func TestDeliverDatabase_ArchivesEvent(t *testing.T) {
 	assert.JSONEq(t, `{"archived":true}`, rows[0].Body)
 }
 
-func TestArchiveWriter_WritesRow(t *testing.T) {
-	t.Parallel()
-
-	path := filepath.Join(t.TempDir(), "archive-wh.db")
-	w := delivery.NewExportArchiveWriter(
-		path, archiveTestLogger(), 0,
-	)
-
-	row := delivery.ExportArchivedEvent{
-		EventID:      "ev-1",
-		WebhookID:    "wh-1",
-		EntrypointID: "ep-1",
-		Method:       "POST",
-		Headers:      `{"X":"Y"}`,
-		Body:         `{"hello":"world"}`,
-		ContentType:  "application/json",
-	}
-
-	require.NoError(t, w.Write(row, 0))
-	assert.FileExists(t, path)
-
-	var got []delivery.ExportArchivedEvent
-
-	require.NoError(t, w.DB().Find(&got).Error)
-	require.Len(t, got, 1)
-	assert.Equal(t, "ev-1", got[0].EventID)
-	assert.Equal(t, "wh-1", got[0].WebhookID)
-	assert.Equal(t, "ep-1", got[0].EntrypointID)
-	assert.Equal(t, row.Method, got[0].Method)
-	assert.Equal(t, row.ContentType, got[0].ContentType)
-	assert.JSONEq(t, `{"hello":"world"}`, got[0].Body)
-	assert.False(t, got[0].ArchivedAt.IsZero())
-
-	var archivedAt string
-
-	require.NoError(t, w.DB().Raw(
-		"SELECT CAST(archived_at AS TEXT) FROM archived_events",
-	).Row().Scan(&archivedAt))
-	assertStoredTime(t, archivedAt)
-}
-
-func TestArchiveWriter_RecreatesAfterRemoval(
-	t *testing.T,
-) {
-	t.Parallel()
-
-	path := filepath.Join(t.TempDir(), "archive-wh.db")
-	w := delivery.NewExportArchiveWriter(
-		path, archiveTestLogger(), 0,
-	)
-
-	require.NoError(t, w.Write(
-		delivery.ExportArchivedEvent{EventID: "a"}, 0,
-	))
-	assert.FileExists(t, path)
-
-	// The operator moves the archive away while the handle is
-	// still open.
-	removeArchiveFiles(t, path)
-	require.NoFileExists(t, path)
-
-	// The next write recreates the file with a fresh schema and
-	// only the new row.
-	require.NoError(t, w.Write(
-		delivery.ExportArchivedEvent{EventID: "b"}, 0,
-	))
-	assert.FileExists(t, path)
-
-	var got []delivery.ExportArchivedEvent
-
-	require.NoError(t, w.DB().Find(&got).Error)
-	require.Len(t, got, 1)
-	assert.Equal(t, "b", got[0].EventID)
-}
-
-// TestStatArchive proves StatArchive finds no file before the first
-// write; after a write still held in the -wal, counts the -wal in the
-// size and takes its later time as the last write; and finds no file
-// again once the file has been moved away.
-func TestStatArchive(t *testing.T) {
-	t.Parallel()
-
-	path := filepath.Join(t.TempDir(), "archive-wh.db")
-
-	_, err := delivery.StatArchive(path)
-	require.ErrorIs(t, err, fs.ErrNotExist)
-
-	// With the clock stopped, the reopen debounce never passes, so
-	// the handle stays open after the write.
-	stopped := time.Now()
-	w := delivery.NewExportArchiveWriter(path, archiveTestLogger(), 0)
-	w.SetNow(func() time.Time { return stopped })
-
-	require.NoError(t, w.Write(delivery.ExportArchivedEvent{EventID: "a"}, 0))
-
-	written := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
-	earlier := written.Add(-time.Hour)
-	require.NoError(t, os.Chtimes(path, earlier, earlier))
-	require.NoError(t, os.Chtimes(path+"-wal", written, written))
-
-	file, err := os.Stat(path)
-	require.NoError(t, err)
-
-	wal, err := os.Stat(path + "-wal")
-	require.NoError(t, err)
-	require.Positive(t, wal.Size())
-
-	got, err := delivery.StatArchive(path)
-	require.NoError(t, err)
-	assert.Equal(t, 1, got.Files)
-	assert.Equal(t, file.Size()+wal.Size(), got.Size)
-	assert.True(t, written.Equal(got.Written), got.Written)
-
-	removeArchiveFiles(t, path)
-
-	_, err = delivery.StatArchive(path)
-	require.ErrorIs(t, err, fs.ErrNotExist)
-}
-
-func TestArchiveWriter_ReopenDebounce(t *testing.T) {
-	t.Parallel()
-
-	const debounce = 2 * time.Second
-
-	path := filepath.Join(t.TempDir(), "archive-wh.db")
-	w := delivery.NewExportArchiveWriter(
-		path, archiveTestLogger(), debounce,
-	)
-
-	// The writer measures its reopen debounce on this clock, which
-	// only the test moves, so how long the host takes between
-	// writes cannot change the result.
-	now := time.Now()
-
-	w.SetNow(func() time.Time { return now })
-
-	require.NoError(t, w.Write(
-		delivery.ExportArchivedEvent{EventID: "a"}, 0,
-	))
-	require.NoError(t, w.Write(
-		delivery.ExportArchivedEvent{EventID: "b"}, 0,
-	))
-
-	// Two writes inside the debounce window trigger only the
-	// initial open — no extra close/reopen.
-	assert.Equal(t, 1, w.Reopens())
-
-	now = now.Add(debounce)
-
-	require.NoError(t, w.Write(
-		delivery.ExportArchivedEvent{EventID: "c"}, 0,
-	))
-
-	// A write after the window elapses closes and reopens once.
-	assert.Equal(t, 2, w.Reopens())
-}
-
-func TestArchiveWriter_ExpiryPrune(t *testing.T) {
-	t.Parallel()
-
-	path := filepath.Join(t.TempDir(), "archive-wh.db")
-	w := delivery.NewExportArchiveWriter(
-		path, archiveTestLogger(), 0,
-	)
-
-	require.NoError(t, w.Open(0))
-
-	old := delivery.ExportArchivedEvent{
-		EventID:    "old",
-		ArchivedAt: time.Now().Add(-2 * time.Hour),
-	}
-	fresh := delivery.ExportArchivedEvent{
-		EventID:    "fresh",
-		ArchivedAt: time.Now(),
-	}
-
-	require.NoError(t, w.DB().Create(&old).Error)
-	require.NoError(t, w.DB().Create(&fresh).Error)
-
-	// Reopening with a one-hour expiry prunes the old row.
-	require.NoError(t, w.Reopen(time.Hour))
-
-	var got []delivery.ExportArchivedEvent
-
-	require.NoError(t, w.DB().Find(&got).Error)
-	require.Len(t, got, 1)
-	assert.Equal(t, "fresh", got[0].EventID)
-}
-
-func TestParseArchiveExpiry(t *testing.T) {
-	t.Parallel()
-
-	cases := []struct {
-		name    string
-		in      string
-		want    time.Duration
-		wantErr bool
-	}{
-		{"empty config", "", 0, false},
-		{"explicit never", `{"expiry":"never"}`, 0, false},
-		{"empty expiry", `{"expiry":""}`, 0, false},
-		{"duration", `{"expiry":"1h"}`, time.Hour, false},
-		{"unparseable", `{"expiry":"nonsense"}`, 0, true},
-		{"zero duration", `{"expiry":"0s"}`, 0, true},
-		{"negative duration", `{"expiry":"-5h"}`, 0, true},
-	}
-
-	for _, tc := range cases {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			got, err := delivery.ExportParseArchiveExpiry(tc.in)
-			if tc.wantErr {
-				require.Error(t, err)
-
-				return
-			}
-
-			require.NoError(t, err)
-			assert.Equal(t, tc.want, got)
-		})
-	}
-}
-
-// seedDatabaseTargetDelivery seeds a pending delivery of an event
-// to a database target and returns the in-memory delivery the
-// target handler is invoked with.
-func seedDatabaseTargetDelivery(
-	t *testing.T,
-	webhookDB *gorm.DB,
-	event database.Event,
-	tgt *database.Target,
-) *database.Delivery {
-	t.Helper()
-
-	dlv := seedDelivery(
-		t, webhookDB, event.ID, tgt.ID,
-		database.DeliveryStatusPending,
-	)
-
-	d := &database.Delivery{
-		EventID:  event.ID,
-		TargetID: tgt.ID,
-		Status:   database.DeliveryStatusPending,
-		Event:    event,
-		Target: database.Target{
-			Name:   tgt.Name,
-			Type:   database.TargetTypeDatabase,
-			Config: tgt.Config,
-		},
-	}
-	d.ID = dlv.ID
-
-	return d
-}
-
 // TestDeliverDatabase_ArchiveFailureFailsDelivery verifies that
 // an archive error (here: an unparseable expiry in the target
 // config) fails the delivery loudly: the attempt is recorded as
@@ -423,348 +304,3 @@ func TestDeliverDatabase_ArchiveFailureFailsDelivery(
 		"no archive file should exist for a failed config",
 	)
 }
-
-func TestValidateArchiveExpiry(t *testing.T) {
-	t.Parallel()
-
-	valid := []string{"", "never", "1h", "720h", "30m"}
-	for _, in := range valid {
-		require.NoError(t,
-			delivery.ValidateArchiveExpiry(in),
-			"expiry %q should be accepted", in,
-		)
-	}
-
-	invalid := []string{"nonsense", "7d", "-5h", "0s", "0"}
-	for _, in := range invalid {
-		require.Error(t,
-			delivery.ValidateArchiveExpiry(in),
-			"expiry %q should be rejected", in,
-		)
-	}
-}
-
-// TestArchiveFileName pins the archive file name and the rules
-// that make a webhook or target name safe to put in it.
-func TestArchiveFileName(t *testing.T) {
-	t.Parallel()
-
-	const id = "3f2a1c9e-8d4b-4c1a-9e2f-0a1b2c3d4e5f"
-
-	cases := []struct {
-		name    string
-		webhook string
-		target  string
-		want    string
-	}{
-		{
-			"plain names", "orders", "archive",
-			"archive-orders-archive-" + id + ".db",
-		},
-		{
-			"lowercased", "Orders", "Main Archive",
-			"archive-orders-main-archive-" + id + ".db",
-		},
-		{
-			"a run of other characters is one dash",
-			`a  /\..b`, "c__--d",
-			"archive-a-b-c-d-" + id + ".db",
-		},
-		{
-			"no dash at either end", "  --orders!! ", "(archive)",
-			"archive-orders-archive-" + id + ".db",
-		},
-		{
-			"path separators", "../../etc/passwd", "a/b",
-			"archive-etc-passwd-a-b-" + id + ".db",
-		},
-		{
-			"letters outside ASCII are dropped",
-			"Bestellungen Größe", "café",
-			"archive-bestellungen-gr-e-caf-" + id + ".db",
-		},
-		{
-			"nothing left is unnamed", "", "!!!",
-			"archive-unnamed-unnamed-" + id + ".db",
-		},
-		{
-			"cut to 40 characters", strings.Repeat("a", 50), "x",
-			"archive-" + strings.Repeat("a", 40) + "-x-" + id + ".db",
-		},
-		{
-			"no dash left by the cut",
-			strings.Repeat("a", 39) + " b", "x",
-			"archive-" + strings.Repeat("a", 39) + "-x-" + id + ".db",
-		},
-	}
-
-	for _, tc := range cases {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			assert.Equal(
-				t, tc.want,
-				delivery.ArchiveFileName(tc.webhook, tc.target, id),
-			)
-		})
-	}
-}
-
-// TestDeliverDatabase_EachTargetHasItsOwnArchive proves two
-// database targets of one webhook archive into separate files.
-func TestDeliverDatabase_EachTargetHasItsOwnArchive(t *testing.T) {
-	t.Parallel()
-
-	env := setupArchiveTest(t)
-	first := env.seedDatabaseTarget(t, "")
-	second := env.addDatabaseTarget(t, first.WebhookID, "")
-
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"n":1}`)
-
-	for _, tgt := range []*database.Target{first, second} {
-		env.eng.ExportDeliverDatabase(
-			webhookDB,
-			seedDatabaseTargetDelivery(t, webhookDB, event, tgt),
-		)
-	}
-
-	require.NotEqual(
-		t, env.archivePath(first), env.archivePath(second),
-	)
-	assert.Equal(
-		t, []string{event.ID},
-		archivedEventIDs(t, env.archivePath(first)),
-	)
-	assert.Equal(
-		t, []string{event.ID},
-		archivedEventIDs(t, env.archivePath(second)),
-	)
-}
-
-// TestRename_MovesTheFile proves a rename moves the archive, rows
-// and all, and that later writes go to the new name.
-func TestRename_MovesTheFile(t *testing.T) {
-	t.Parallel()
-
-	env := setupArchiveTest(t)
-	tgt := env.seedDatabaseTarget(t, "")
-	oldPath := env.archivePath(tgt)
-
-	webhookDB := testWebhookDB(t)
-	first := seedEvent(t, webhookDB, `{"n":1}`)
-	env.eng.ExportDeliverDatabase(
-		webhookDB, seedDatabaseTargetDelivery(t, webhookDB, first, tgt),
-	)
-	require.FileExists(t, oldPath)
-
-	require.NoError(
-		t, env.eng.Rename(tgt.ID, "Orders", "Long Term"),
-	)
-
-	newPath := filepath.Join(
-		env.dataDir, "archive-orders-long-term-"+tgt.ID+".db",
-	)
-
-	assert.NoFileExists(t, oldPath)
-	assert.Equal(t, []string{first.ID}, archivedEventIDs(t, newPath))
-
-	second := seedEvent(t, webhookDB, `{"n":2}`)
-	env.eng.ExportDeliverDatabase(
-		webhookDB,
-		seedDatabaseTargetDelivery(t, webhookDB, second, tgt),
-	)
-
-	assert.ElementsMatch(
-		t, []string{first.ID, second.ID},
-		archivedEventIDs(t, newPath),
-	)
-	assert.NoFileExists(
-		t, oldPath, "a write after the rename must use the new name",
-	)
-}
-
-// TestRename_NeverReplacesAFile plants a file at the new name, once
-// the .db alone, once a lone -wal and once a lone -shm, and proves
-// each time that the rename is refused, the planted file survives,
-// and the archive keeps its name and its rows.
-func TestRename_NeverReplacesAFile(t *testing.T) {
-	t.Parallel()
-
-	for _, suffix := range archiveFileSuffixes() {
-		t.Run("planted .db"+suffix, func(t *testing.T) {
-			t.Parallel()
-
-			env := setupArchiveTest(t)
-			tgt := env.seedDatabaseTarget(t, "")
-			oldPath := env.archivePath(tgt)
-
-			webhookDB := testWebhookDB(t)
-			first := seedEvent(t, webhookDB, `{"n":1}`)
-			env.eng.ExportDeliverDatabase(
-				webhookDB,
-				seedDatabaseTargetDelivery(t, webhookDB, first, tgt),
-			)
-
-			newPath := filepath.Join(
-				env.dataDir, "archive-orders-long-term-"+tgt.ID+".db",
-			)
-			plantedPath := newPath + suffix
-			require.NoError(
-				t, os.WriteFile(plantedPath, []byte("planted"), 0o600),
-			)
-
-			require.ErrorIs(
-				t, env.eng.Rename(tgt.ID, "Orders", "Long Term"),
-				delivery.ErrArchiveNameTaken,
-			)
-
-			//nolint:gosec // reads the file the test planted under t.TempDir()
-			planted, err := os.ReadFile(plantedPath)
-			require.NoError(t, err)
-			assert.Equal(t, "planted", string(planted))
-
-			second := seedEvent(t, webhookDB, `{"n":2}`)
-			env.eng.ExportDeliverDatabase(
-				webhookDB,
-				seedDatabaseTargetDelivery(t, webhookDB, second, tgt),
-			)
-
-			assert.ElementsMatch(
-				t, []string{first.ID, second.ID},
-				archivedEventIDs(t, oldPath),
-			)
-		})
-	}
-}
-
-// TestRename_BeforeTheNameIsSaved covers the order the handlers
-// use: they rename before they save the new name, so a delivery in
-// between must write under the new name although the main database
-// still has the old one. It also shows that renaming an archive that
-// does not exist yet is not an error.
-func TestRename_BeforeTheNameIsSaved(t *testing.T) {
-	t.Parallel()
-
-	env := setupArchiveTest(t)
-	tgt := env.seedDatabaseTarget(t, "")
-
-	require.NoError(
-		t, env.eng.Rename(tgt.ID, "Orders", "Archive"),
-	)
-
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"n":1}`)
-	env.eng.ExportDeliverDatabase(
-		webhookDB, seedDatabaseTargetDelivery(t, webhookDB, event, tgt),
-	)
-
-	assert.FileExists(
-		t,
-		filepath.Join(
-			env.dataDir, "archive-orders-archive-"+tgt.ID+".db",
-		),
-	)
-	assert.NoFileExists(t, env.archivePath(tgt))
-}
-
-// TestArchiveWriter_RenameMovesSidecars proves a rename carries
-// the -wal and -shm a crash can leave beside an archive no handle
-// has opened since. SQLite finds them by name, so a -wal left
-// behind would lose the transactions it holds.
-func TestArchiveWriter_RenameMovesSidecars(t *testing.T) {
-	t.Parallel()
-
-	dir := t.TempDir()
-	oldPath := filepath.Join(dir, "archive-old.db")
-	newPath := filepath.Join(dir, "archive-new.db")
-
-	for _, suffix := range archiveFileSuffixes() {
-		require.NoError(
-			t, os.WriteFile(oldPath+suffix, []byte(suffix), 0o600),
-		)
-	}
-
-	w := delivery.NewExportArchiveWriter(
-		oldPath, archiveTestLogger(), 0,
-	)
-
-	require.NoError(t, w.Rename("archive-new.db"))
-
-	for _, suffix := range archiveFileSuffixes() {
-		assert.NoFileExists(t, oldPath+suffix)
-		assert.FileExists(t, newPath+suffix)
-	}
-
-	assert.Equal(t, newPath, w.Path())
-}
-
-// TestArchiveWriter_RenameMovesBackOnFailure makes the -wal fail to
-// move after the .db has moved, and proves the .db is moved back, so
-// the archive is never split across two names. The new name is 255
-// bytes, the longest a file name may be, so the .db can take it but
-// the -wal, four bytes longer, cannot.
-func TestArchiveWriter_RenameMovesBackOnFailure(t *testing.T) {
-	t.Parallel()
-
-	dir := t.TempDir()
-	oldPath := filepath.Join(dir, "archive-old.db")
-	newName := strings.Repeat("a", 252) + ".db"
-
-	for _, suffix := range archiveFileSuffixes() {
-		require.NoError(
-			t, os.WriteFile(oldPath+suffix, []byte(suffix), 0o600),
-		)
-	}
-
-	w := delivery.NewExportArchiveWriter(
-		oldPath, archiveTestLogger(), 0,
-	)
-
-	require.Error(t, w.Rename(newName))
-
-	for _, suffix := range archiveFileSuffixes() {
-		assert.FileExists(t, oldPath+suffix)
-	}
-
-	assert.NoFileExists(t, filepath.Join(dir, newName))
-	assert.Equal(t, oldPath, w.Path())
-}
-
-// TestArchiveWriter_RenameMovesBackEveryFile renames a target with a
-// file without a period and a file for a month, and proves that when
-// the month's file fails to move, the file already moved is moved back:
-// both files are under the old name with their rows, and nothing is
-// under the new name. The new name is 251 bytes, so the file without a
-// period, with its -wal and -shm, can take it, but the month's file,
-// eight bytes longer, cannot.
-func TestArchiveWriter_RenameMovesBackEveryFile(t *testing.T) {
-	t.Parallel()
-
-	dir := t.TempDir()
-	oldPath := filepath.Join(dir, "archive-old.db")
-	monthPath := filepath.Join(dir, "archive-old-2026-03.db")
-	w := delivery.NewExportArchiveWriter(oldPath, archiveTestLogger(), 0)
-
-	require.NoError(t, w.WritePeriod(
-		delivery.ExportArchivedEvent{EventID: "in-none"}, 0, "",
-	))
-	require.NoError(t, w.WritePeriod(
-		delivery.ExportArchivedEvent{EventID: "in-month"}, 0, "2026-03",
-	))
-
-	require.Error(t, w.Rename(strings.Repeat("a", 248)+".db"))
-
-	assert.Equal(t, []string{"in-none"}, archivedEventIDs(t, oldPath))
-	assert.Equal(t, []string{"in-month"}, archivedEventIDs(t, monthPath))
-
-	entries, err := os.ReadDir(dir)
-	require.NoError(t, err)
-
-	for _, entry := range entries {
-		assert.True(t, strings.HasPrefix(entry.Name(), "archive-old"),
-			"%s is not under the old name", entry.Name())
-	}
-
-	assert.Equal(t, oldPath, w.Path())
-}

internal/handlers/archive_rotation_test.go

@@ -12,8 +12,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
-	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
 // rotationNone is the archive rotation that keeps one file.
@@ -181,7 +181,7 @@ func TestArchiveFileView_Rotated(t *testing.T) {
 		`{"rotation":"daily"}`,
 	)
 
-	path := delivery.ArchivePath(env.dbMgr, &webhook, target)
+	path := archive.Path(env.dbMgr, &webhook, target)
 	stem := strings.TrimSuffix(path, ".db")
 	written := time.Date(2026, 10, 2, 9, 0, 0, 0, time.UTC)
 

internal/handlers/gormlogbound_test.go

@@ -374,7 +374,7 @@ func assertFloodBounded(t *testing.T, label, out string) {
 // this service's three gorm.Open sites: the main database behind the
 // two unauthenticated lookups, and the per-webhook database the
 // WebhookDBManager opens. The third, the archive writer, is pinned in
-// internal/delivery, where its type lives.
+// internal/archive, where its type lives.
 //
 // What each assertion is worth, since two of the three would pass
 // against a service that had never been fixed if the capture were set

internal/handlers/handlers.go

@@ -10,11 +10,11 @@ import (
 	"html/template"
 	"log/slog"
 	"net/http"
-	"sync"
 	"sync/atomic"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"go.uber.org/fx"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/delivery"
@@ -65,7 +65,7 @@ type HandlersParams struct {
 	Session         *session.Session
 	Middleware      *middleware.Middleware
 	Notifier        delivery.Notifier
-	Archives        delivery.Archives
+	Archives        archive.Archives
 	CircuitBreakers delivery.CircuitBreakers
 	SSRFGuard       *delivery.Guard
 	Metrics         *metrics.Set
@@ -83,7 +83,7 @@ type Handlers struct {
 	session   *session.Session
 	mw        *middleware.Middleware
 	notifier  delivery.Notifier
-	archives  delivery.Archives
+	archives  archive.Archives
 	breakers  delivery.CircuitBreakers
 	mtr       *metrics.Set
 	templates map[string]*template.Template
@@ -93,17 +93,6 @@ type Handlers struct {
 	// is one delivery will actually attempt.
 	ssrf *delivery.Guard
 
-	// renameMu makes the webhook edit, the target edit and target
-	// creation run one at a time, each held from loading the stored
-	// names through the archive rename, the save and any move back.
-	// Interleaved, one could rename an archive between another's
-	// rename and save, leaving the file named for one edit and the
-	// stored names from the other. An archive download holds it while
-	// it reads the stored names and lists the files they give, and
-	// again for each file while it finds the file under the names
-	// stored then and opens it.
-	renameMu sync.Mutex
-
 	// dummyVerifications counts the equivalent-cost verifications
 	// charged for usernames that do not exist. It exists so a test
 	// can prove that path runs without measuring wall-clock time.

internal/handlers/handlers_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/stretchr/testify/require"
 	"go.uber.org/fx"
 	"go.uber.org/fx/fxtest"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/delivery"
@@ -55,12 +56,14 @@ func (n *recordingNotifier) Tasks() []delivery.Task {
 	return out
 }
 
-// recordingArchives is a delivery.Archives that records what it
+// recordingArchives is an archive.Archives that records what it
 // was asked to do, so a test can prove that a deletion or rename
-// path reached the delivery engine. After FailRenames, every
+// path reached the archive writers. After FailRenames, every
 // rename of that target fails with the given error. After
 // BlockNextRename, the next rename is recorded and then waits.
+// RenameLock returns a plain mutex, as in archive.Writers.
 type recordingArchives struct {
+	renameMu       sync.Mutex
 	mu             sync.Mutex
 	evicted        []string
 	evictedTargets []string
@@ -73,10 +76,10 @@ type recordingArchives struct {
 // errInjectedRename is the failure a test hands FailRenames.
 var errInjectedRename = errors.New("injected rename failure")
 
-// errNameTaken is what the delivery engine returns when a file
+// errNameTaken is what the archive writers return when a file
 // already has an archive's new name, here archive-taken.db.
 var errNameTaken = fmt.Errorf(
-	"%w: archive-taken.db", delivery.ErrArchiveNameTaken,
+	"%w: archive-taken.db", archive.ErrNameTaken,
 )
 
 // archiveRename is one recorded Rename call.
@@ -86,6 +89,10 @@ type archiveRename struct {
 	TargetName  string
 }
 
+func (r *recordingArchives) RenameLock() *sync.Mutex {
+	return &r.renameMu
+}
+
 func (r *recordingArchives) EvictWebhook(webhookID string) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
@@ -265,7 +272,7 @@ func newTestAppWithConfig(
 			func() *recordingArchives {
 				return &recordingArchives{}
 			},
-			func(r *recordingArchives) delivery.Archives {
+			func(r *recordingArchives) archive.Archives {
 				return r
 			},
 			func() *testCircuitBreakers {

internal/handlers/source_delete_test.go

@@ -16,8 +16,8 @@ import (
 	"github.com/stretchr/testify/require"
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
-	"sneak.berlin/go/webhooker/internal/delivery"
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/session"
 )
@@ -180,7 +180,7 @@ func failSaveOnTable(
 }
 
 // archivePathFor returns the archive database path the
-// delivery engine would use for a database target: beside the
+// archive writers would use for a database target: beside the
 // webhook's event database in the data directory.
 func archivePathFor(
 	t *testing.T,
@@ -192,7 +192,7 @@ func archivePathFor(
 
 	return filepath.Join(
 		filepath.Dir(mgr.DBPath(wh.ID)),
-		delivery.ArchiveFileName(wh.Name, tgt.Name, tgt.ID),
+		archive.FileName(wh.Name, tgt.Name, tgt.ID),
 	)
 }
 
@@ -228,9 +228,9 @@ func postRequest(
 }
 
 // TestHandleSourceDelete_EvictsArchiveWriter proves that
-// deleting a webhook reaches the delivery engine and releases
-// the webhook's archive writers, exercised through the real
-// deletion handler rather than by calling the engine directly.
+// deleting a webhook releases the webhook's archive writers,
+// exercised through the real deletion handler rather than by
+// calling the archive writers directly.
 func TestHandleSourceDelete_EvictsArchiveWriter(t *testing.T) {
 	t.Parallel()
 
@@ -290,7 +290,7 @@ func TestHandleSourceDelete_KeepsArchiveFile(t *testing.T) {
 	wh := seedWebhook(t, db)
 	tgt := seedTarget(t, db, wh.ID, database.TargetTypeDatabase)
 
-	// Place an archive file where the delivery engine would.
+	// Place an archive file where the archive writers would.
 	archivePath := archivePathFor(t, mgr, wh, tgt)
 	require.NoError(
 		t,

internal/handlers/target_create.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 
 	"github.com/go-chi/chi"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
@@ -27,8 +28,8 @@ func (h *Handlers) HandleTargetCreate() http.HandlerFunc {
 
 		sourceID := chi.URLParam(r, "sourceID")
 
-		h.renameMu.Lock()
-		defer h.renameMu.Unlock()
+		h.archives.RenameLock().Lock()
+		defer h.archives.RenameLock().Unlock()
 
 		var webhook database.Webhook
 
@@ -361,12 +362,12 @@ func buildDatabaseTargetConfig(
 ) (string, string, error) {
 	expiry = strings.TrimSpace(expiry)
 
-	err := delivery.ValidateArchiveExpiry(expiry)
+	err := archive.ValidateExpiry(expiry)
 	if err != nil {
 		return "", fmt.Sprintf("Invalid archive expiry: %v", err), nil
 	}
 
-	err = delivery.ValidateArchiveRotation(rotation)
+	err = archive.ValidateRotation(rotation)
 	if err != nil {
 		return "", fmt.Sprintf("Invalid archive rotation: %v", err), nil
 	}

internal/handlers/target_download.go

@@ -6,8 +6,8 @@ import (
 	"net/http"
 	"time"
 
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
-	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
 // downloadWriteTimeout is how long one write of a download may wait
@@ -16,7 +16,7 @@ const downloadWriteTimeout = 60 * time.Second
 
 // HandleTargetDownload serves a database target's archive as one
 // gzipped JSON file, named for the webhook, the target and the time;
-// see delivery.ArchiveExport.WriteGzipJSON for what it holds. Other
+// see archive.Export.WriteGzipJSON for what it holds. Other
 // target types have no archive and are a 404.
 //
 // A download runs for as long as the client keeps reading: it reads
@@ -37,7 +37,7 @@ func (h *Handlers) HandleTargetDownload() http.HandlerFunc {
 		w.Header().Set("Content-Type", "application/gzip")
 		w.Header().Set(
 			"Content-Disposition",
-			`attachment; filename="`+delivery.ArchiveExportFileName(
+			`attachment; filename="`+archive.ExportFileName(
 				webhook.Name, target.Name, now,
 			)+`"`,
 		)
@@ -82,17 +82,17 @@ func (d downloadWriter) Write(b []byte) (int, error) {
 // listTargetArchive lists the archive files of the request's database
 // target for export. It reports false once it has written the response.
 //
-// It holds renameMu, which every archive rename runs under, while it
-// reads the stored names and lists the files, so the files it lists
-// are the ones those names give. It lets go before the export is
-// streamed, which takes renameMu again for each file only while it
+// It holds the rename lock, which every archive rename runs under,
+// while it reads the stored names and lists the files, so the files it
+// lists are the ones those names give. It lets go before the export is
+// streamed, which takes the lock again for each file only while it
 // finds the file under the names stored then and opens it.
 func (h *Handlers) listTargetArchive(
 	w http.ResponseWriter,
 	r *http.Request,
-) (database.Webhook, *database.Target, *delivery.ArchiveExport, bool) {
-	h.renameMu.Lock()
-	defer h.renameMu.Unlock()
+) (database.Webhook, *database.Target, *archive.Export, bool) {
+	h.archives.RenameLock().Lock()
+	defer h.archives.RenameLock().Unlock()
 
 	webhook, target, ok := h.ownedTarget(w, r)
 	if !ok {
@@ -105,9 +105,9 @@ func (h *Handlers) listTargetArchive(
 		return database.Webhook{}, nil, nil, false
 	}
 
-	export, err := delivery.NewArchiveExport(
-		delivery.ArchivePath(h.dbMgr, &webhook, target),
-		&h.renameMu,
+	export, err := archive.NewExport(
+		archive.Path(h.dbMgr, &webhook, target),
+		h.archives.RenameLock(),
 		func() (string, error) {
 			return h.storedArchivePath(webhook.ID, target.ID)
 		},
@@ -122,9 +122,9 @@ func (h *Handlers) listTargetArchive(
 	return webhook, target, export, true
 }
 
-// storedArchivePath returns the path delivery.ArchivePath gives a
+// storedArchivePath returns the path archive.Path gives a
 // database target under the names stored for it and its webhook now.
-// Its caller holds renameMu. A webhook or target deleted since is still
+// Its caller holds the rename lock. A webhook or target deleted since is still
 // found, since deleting one leaves its archive files under their names.
 func (h *Handlers) storedArchivePath(
 	webhookID, targetID string,
@@ -143,5 +143,5 @@ func (h *Handlers) storedArchivePath(
 		return "", err
 	}
 
-	return delivery.ArchivePath(h.dbMgr, &webhook, &target), nil
+	return archive.Path(h.dbMgr, &webhook, &target), nil
 }

internal/handlers/target_download_test.go

@@ -21,9 +21,9 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/database"
-	"sneak.berlin/go/webhooker/internal/delivery"
 	"sneak.berlin/go/webhooker/internal/middleware/middlewaretest"
 )
 
@@ -223,8 +223,8 @@ func TestHandleTargetDownload_FindsFilesAfterRename(t *testing.T) {
 
 	env := setupSourceTest(t)
 	wh := seedWebhookWithRetention(t, env.db, 7)
-	archive := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
-	oldPath := delivery.ArchivePath(env.dbMgr, &wh, archive)
+	target := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
+	oldPath := archive.Path(env.dbMgr, &wh, target)
 
 	month := func(path string) string {
 		return strings.TrimSuffix(path, ".db") + "-2026-10.db"
@@ -233,19 +233,19 @@ func TestHandleTargetDownload_FindsFilesAfterRename(t *testing.T) {
 	seedArchive(t, oldPath, 1, 16)
 	seedArchive(t, month(oldPath), 1, 16)
 
-	sw, downloaded := startStalledDownload(t, env, wh.ID, archive.ID)
+	sw, downloaded := startStalledDownload(t, env, wh.ID, target.ID)
 
 	require.Equal(t,
-		http.StatusSeeOther, renameTarget(env, wh.ID, archive.ID).Code,
+		http.StatusSeeOther, renameTarget(env, wh.ID, target.ID).Code,
 	)
 
 	// The test's archives record a rename without moving any file, so
-	// the files are moved here, as the delivery engine moves them.
+	// the files are moved here, as the archive writers move them.
 	var renamed database.Target
 
-	require.NoError(t, env.db.DB().First(&renamed, "id = ?", archive.ID).Error)
+	require.NoError(t, env.db.DB().First(&renamed, "id = ?", target.ID).Error)
 
-	newPath := delivery.ArchivePath(env.dbMgr, &wh, &renamed)
+	newPath := archive.Path(env.dbMgr, &wh, &renamed)
 
 	require.NoError(t, os.Rename(oldPath, newPath))
 	require.NoError(t, os.Rename(month(oldPath), month(newPath)))
@@ -355,16 +355,16 @@ func TestHandleTargetDownload_OutlastsTheRequestLimit(t *testing.T) {
 
 	env := setupSourceTest(t)
 	wh := seedWebhookWithRetention(t, env.db, 7)
-	archive := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
+	target := seedTarget(t, env.db, wh.ID, database.TargetTypeDatabase)
 	seedArchive(
-		t, delivery.ArchivePath(env.dbMgr, &wh, archive), rows, bodySize,
+		t, archive.Path(env.dbMgr, &wh, target), rows, bodySize,
 	)
 
 	srv, accessLog := limitedServer(t, env, limit)
 
 	req, err := http.NewRequestWithContext(
 		t.Context(), http.MethodGet,
-		srv.URL+downloadPath(wh.ID, archive.ID), nil,
+		srv.URL+downloadPath(wh.ID, target.ID), nil,
 	)
 	require.NoError(t, err)
 

internal/handlers/target_edit.go

@@ -6,6 +6,7 @@ import (
 	"strconv"
 
 	"github.com/go-chi/chi"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
@@ -96,8 +97,8 @@ func (h *Handlers) HandleTargetEdit() http.HandlerFunc {
 // HandleTargetEditSubmit handles the target edit form submission.
 func (h *Handlers) HandleTargetEditSubmit() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		h.renameMu.Lock()
-		defer h.renameMu.Unlock()
+		h.archives.RenameLock().Lock()
+		defer h.archives.RenameLock().Unlock()
 
 		webhook, target, ok := h.ownedTarget(w, r)
 		if !ok {
@@ -157,7 +158,7 @@ func (h *Handlers) applyTargetEdit(
 	}
 
 	// A new name renames the archive file before it is saved (see
-	// delivery.Engine.Rename). If either step fails, it goes back to
+	// archive.Writers.Rename). If either step fails, it goes back to
 	// the name that is still stored.
 	err = h.renameTargetArchive(
 		target, webhook.Name, target.Name, edited.Name,
@@ -178,7 +179,7 @@ func (h *Handlers) applyTargetEdit(
 			)
 		}
 
-		if errors.Is(err, delivery.ErrArchiveNameTaken) {
+		if errors.Is(err, archive.ErrNameTaken) {
 			h.renderTargetEdit(
 				w, r, webhook, target, in,
 				"Not saved: "+err.Error()+

internal/handlers/target_list.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/dustin/go-humanize"
 	"gorm.io/gorm"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
@@ -242,7 +243,7 @@ func readTargetDeliveries(
 func (h *Handlers) archiveFileView(
 	webhook *database.Webhook, target *database.Target, now time.Time,
 ) *ArchiveFileView {
-	current, err := delivery.ArchivePathAt(h.dbMgr, webhook, target, now)
+	current, err := archive.PathAt(h.dbMgr, webhook, target, now)
 	if err != nil {
 		return h.archiveUnreadable(&ArchiveFileView{}, target, err)
 	}
@@ -254,8 +255,8 @@ func (h *Handlers) archiveFileView(
 		view.Note = "not created yet"
 	}
 
-	files, err := delivery.StatArchive(
-		delivery.ArchivePath(h.dbMgr, webhook, target),
+	files, err := archive.Stat(
+		archive.Path(h.dbMgr, webhook, target),
 	)
 
 	switch {

internal/handlers/target_list_test.go

@@ -10,8 +10,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
-	"sneak.berlin/go/webhooker/internal/delivery"
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/logger"
 	"sneak.berlin/go/webhooker/internal/session"
@@ -38,10 +38,10 @@ func TestHandleSourceDetail_ShowsArchiveFile(t *testing.T) {
 	t.Cleanup(app.RequireStop)
 
 	wh := seedWebhook(t, db)
-	archive := seedTarget(t, db, wh.ID, database.TargetTypeDatabase)
+	target := seedTarget(t, db, wh.ID, database.TargetTypeDatabase)
 	seedTarget(t, db, wh.ID, database.TargetTypeLog)
 
-	path := delivery.ArchivePath(dbMgr, wh, archive)
+	path := archive.Path(dbMgr, wh, target)
 
 	body := renderSourceDetailPage(t, h, sess, wh.ID)
 	assert.Equal(t, 1, strings.Count(body, "Archive file:"))

internal/handlers/webhook_delete.go

@@ -77,8 +77,8 @@ func (h *Handlers) deleteWebhookResources(
 		"user_id", userID,
 	)
 
-	// Release the delivery engine's per-webhook archiving state
-	// so a deleted webhook's archive writer (and any handle open
+	// Release the webhook's archive writers so a deleted
+	// webhook's archive writer (and any handle open
 	// within its debounce window) does not linger for the
 	// process lifetime. The archive file itself is deliberately
 	// left on disk; see evictArchiveWriter.
@@ -150,9 +150,9 @@ func (h *Handlers) commitWebhookDeletion(
 	return tx.Commit().Error
 }
 
-// evictArchiveWriter asks the delivery engine to drop the cached
-// archive writers of a webhook's database targets, closing their
-// archive file handles.
+// evictArchiveWriter asks the archive writers to drop the cached
+// writers of a webhook's database targets, closing their archive
+// file handles.
 //
 // The archive database files are NOT deleted. Unlike the event
 // database — which is per-webhook working storage and is

internal/handlers/webhook_edit.go

@@ -6,8 +6,8 @@ import (
 	"strconv"
 
 	"github.com/go-chi/chi"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/database"
-	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
 // HandleSourceEdit shows the form to edit a webhook.
@@ -59,8 +59,8 @@ func (h *Handlers) HandleSourceEditSubmit() http.HandlerFunc {
 
 		sourceID := chi.URLParam(r, "sourceID")
 
-		h.renameMu.Lock()
-		defer h.renameMu.Unlock()
+		h.archives.RenameLock().Lock()
+		defer h.archives.RenameLock().Unlock()
 
 		var webhook database.Webhook
 
@@ -130,7 +130,7 @@ func (h *Handlers) applyWebhookEdit(
 	edited.RetentionDays = retentionDays
 
 	// A new name renames the archive files before it is saved (see
-	// delivery.Engine.Rename). If either step fails, the same targets'
+	// archive.Writers.Rename). If either step fails, the same targets'
 	// archives go back to the name that is still stored, without
 	// reading the main database again.
 	targets, err := h.renameWebhookArchives(
@@ -150,7 +150,7 @@ func (h *Handlers) applyWebhookEdit(
 			)
 		}
 
-		if errors.Is(err, delivery.ErrArchiveNameTaken) {
+		if errors.Is(err, archive.ErrNameTaken) {
 			h.renderWebhookEdit(
 				w, r, webhook, name, description, retention,
 				"Not saved: "+err.Error()+

internal/resetpw/resetpw_test.go

@@ -10,6 +10,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -17,6 +18,7 @@ import (
 	"github.com/stretchr/testify/require"
 	"go.uber.org/fx"
 	"go.uber.org/fx/fxtest"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/datadir"
@@ -133,7 +135,13 @@ type noopNotifier struct{}
 
 func (n *noopNotifier) Notify([]delivery.Task) {}
 
-type noopArchives struct{}
+type noopArchives struct {
+	renameMu sync.Mutex
+}
+
+func (n *noopArchives) RenameLock() *sync.Mutex {
+	return &n.renameMu
+}
 
 func (n *noopArchives) EvictWebhook(string) {}
 
@@ -183,7 +191,7 @@ func newServerApp(
 			healthcheck.New,
 			session.New,
 			func() delivery.Notifier { return &noopNotifier{} },
-			func() delivery.Archives { return &noopArchives{} },
+			func() archive.Archives { return &noopArchives{} },
 			func() delivery.CircuitBreakers {
 				return &noopCircuitBreakers{}
 			},

internal/server/routes_test.go

@@ -11,6 +11,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -20,6 +21,7 @@ import (
 	"go.uber.org/fx"
 	"go.uber.org/fx/fxtest"
 	"gorm.io/gorm/clause"
+	"sneak.berlin/go/webhooker/internal/archive"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/delivery"
@@ -50,10 +52,16 @@ type noopNotifier struct{}
 
 func (n *noopNotifier) Notify([]delivery.Task) {}
 
-// noopArchives satisfies handlers.New's delivery.Archives
+// noopArchives satisfies handlers.New's archive.Archives
 // dependency. No test here checks what gets evicted or renamed, so
-// it records nothing.
-type noopArchives struct{}
+// it records nothing. Its rename lock is a plain mutex.
+type noopArchives struct {
+	renameMu sync.Mutex
+}
+
+func (e *noopArchives) RenameLock() *sync.Mutex {
+	return &e.renameMu
+}
 
 func (e *noopArchives) EvictWebhook(string) {}
 
@@ -138,7 +146,7 @@ func newTestEnvWithConfig(
 			healthcheck.New,
 			session.New,
 			func() delivery.Notifier { return &noopNotifier{} },
-			func() delivery.Archives { return &noopArchives{} },
+			func() archive.Archives { return &noopArchives{} },
 			func() delivery.CircuitBreakers {
 				return &noopCircuitBreakers{}
 			},