Name each database target's archive for its webhook and target (closes #376)

Each database target now has its own archive file,
archive-WEBHOOKNAME-TARGETNAME-TARGETID.db, instead of one
archive-WEBHOOKID.db per webhook. delivery.ArchiveFileName builds the
name.

A change of webhook or target name renames its archive files under the
archive writer's lock, before the new name is saved, and back again if
the save fails. Webhook edits, target edits and target creation run one
at a time, so no two of them interleave. A rename never replaces a
file, and one that fails part way moves back what it moved. Deleting a
target evicts only that target's writer. Archive files are never
deleted, and nothing looks for files under the old name.

Model: opus-5-5

internal/handlers/source_delete_test.go

@@ -15,6 +15,7 @@ import (
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
 	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/delivery"
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/session"
 )
@@ -79,6 +80,10 @@ func seedTarget(
 // from a delete statement.
 var errInjectedDelete = errors.New("injected delete failure")
 
+// errInjectedSave is the failure failSaveOnTable reports from a
+// save of an existing row.
+var errInjectedSave = errors.New("injected save failure")
+
 // seedEntrypoint inserts an entrypoint for a webhook.
 func seedEntrypoint(
 	t *testing.T,
@@ -146,19 +151,42 @@ func failDeleteOnTable(
 	)
 }
 
+// failSaveOnTable is failDeleteOnTable for saves: every update of
+// an existing row in the named table fails.
+func failSaveOnTable(
+	t *testing.T,
+	db *database.Database,
+	table string,
+) {
+	t.Helper()
+
+	require.NoError(t, db.DB().Callback().Update().
+		Before("gorm:update").
+		Register(
+			"test:fail_save_"+table,
+			func(tx *gorm.DB) {
+				if tx.Statement.Table == table {
+					_ = tx.AddError(errInjectedSave)
+				}
+			},
+		),
+	)
+}
+
 // archivePathFor returns the archive database path the
-// delivery engine would use for a webhook: beside the webhook's
-// event database in the data directory.
+// delivery engine would use for a database target: beside the
+// webhook's event database in the data directory.
 func archivePathFor(
 	t *testing.T,
 	mgr *database.WebhookDBManager,
-	webhookID string,
+	wh *database.Webhook,
+	tgt *database.Target,
 ) string {
 	t.Helper()
 
 	return filepath.Join(
-		filepath.Dir(mgr.DBPath(webhookID)),
-		"archive-"+webhookID+".db",
+		filepath.Dir(mgr.DBPath(wh.ID)),
+		delivery.ArchiveFileName(wh.Name, tgt.Name, tgt.ID),
 	)
 }
 
@@ -195,8 +223,8 @@ func postRequest(
 
 // TestHandleSourceDelete_EvictsArchiveWriter proves that
 // deleting a webhook reaches the delivery engine and releases
-// the webhook's archive writer, exercised through the real
-// deletion handler rather than by calling the evictor directly.
+// the webhook's archive writers, exercised through the real
+// deletion handler rather than by calling the engine directly.
 func TestHandleSourceDelete_EvictsArchiveWriter(t *testing.T) {
 	t.Parallel()
 
@@ -204,7 +232,7 @@ func TestHandleSourceDelete_EvictsArchiveWriter(t *testing.T) {
 		h    *handlers.Handlers
 		sess *session.Session
 		db   *database.Database
-		ev   *recordingEvictor
+		ev   *recordingArchives
 	)
 
 	app := newTestApp(t, &h, &sess, &db, &ev)
@@ -254,9 +282,10 @@ func TestHandleSourceDelete_KeepsArchiveFile(t *testing.T) {
 	t.Cleanup(app.RequireStop)
 
 	wh := seedWebhook(t, db)
+	tgt := seedTarget(t, db, wh.ID, database.TargetTypeDatabase)
 
 	// Place an archive file where the delivery engine would.
-	archivePath := archivePathFor(t, mgr, wh.ID)
+	archivePath := archivePathFor(t, mgr, wh, tgt)
 	require.NoError(
 		t,
 		writeArchivePlaceholder(archivePath),
@@ -437,68 +466,17 @@ func TestHandleSourceDelete_RemovesConfigAndEventDatabase(
 	)
 }
 
-// TestHandleTargetDelete_EvictsWhenLastDatabaseTargetGone
-// proves that removing the last database target releases the
-// archive writer.
-func TestHandleTargetDelete_EvictsWhenLastDatabaseTargetGone(
-	t *testing.T,
-) {
+// TestHandleTargetDelete_EvictsThatTarget proves that deleting a
+// database target releases that target's archive writer and no
+// other: the webhook's other database target keeps its own.
+func TestHandleTargetDelete_EvictsThatTarget(t *testing.T) {
 	t.Parallel()
 
 	var (
 		h    *handlers.Handlers
 		sess *session.Session
 		db   *database.Database
-		ev   *recordingEvictor
-	)
-
-	app := newTestApp(t, &h, &sess, &db, &ev)
-	app.RequireStart()
-
-	t.Cleanup(app.RequireStop)
-
-	wh := seedWebhook(t, db)
-	tgt := seedTarget(
-		t, db, wh.ID, database.TargetTypeDatabase,
-	)
-
-	cookies := authenticatedCookies(
-		t, sess, deleteTestUserID, deleteTestUsername,
-	)
-
-	req := postRequest(
-		"/hook/"+wh.ID+"/targets/"+tgt.ID+"/delete",
-		cookies,
-		map[string]string{
-			paramSourceID: wh.ID,
-			paramTargetID: tgt.ID,
-		},
-	)
-	w := httptest.NewRecorder()
-
-	h.HandleTargetDelete().ServeHTTP(w, req)
-
-	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Equal(
-		t, []string{wh.ID}, ev.Evicted(),
-		"removing the last database target should evict",
-	)
-}
-
-// TestHandleTargetDelete_KeepsWriterWhenDatabaseTargetRemains
-// proves that deleting one of several database targets leaves
-// the still-needed archive writer alone: the surviving target
-// keeps archiving to the same file, so the writer must stay.
-func TestHandleTargetDelete_KeepsWriterWhenDatabaseTargetRemains(
-	t *testing.T,
-) {
-	t.Parallel()
-
-	var (
-		h    *handlers.Handlers
-		sess *session.Session
-		db   *database.Database
-		ev   *recordingEvictor
+		ev   *recordingArchives
 	)
 
 	app := newTestApp(t, &h, &sess, &db, &ev)
@@ -529,17 +507,17 @@ func TestHandleTargetDelete_KeepsWriterWhenDatabaseTargetRemains(
 	h.HandleTargetDelete().ServeHTTP(w, req)
 
 	require.Equal(t, http.StatusSeeOther, w.Code)
-	assert.Empty(
-		t, ev.Evicted(),
-		"a second database target still needs the writer",
+	assert.Equal(
+		t, []string{doomed.ID}, ev.EvictedTargets(),
+		"deleting a database target should evict its writer",
 	)
+	assert.Empty(t, ev.Evicted(), "the webhook is not deleted")
 }
 
-// TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted proves
-// that deleting a target of an unrelated type leaves a
-// still-needed archive writer alone: the webhook's database
-// target is untouched, so its writer must stay.
-func TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted(
+// TestHandleTargetDelete_IgnoresAnotherWebhooksTarget proves that
+// a target id from the URL that is not a target of the webhook
+// deletes nothing and so evicts nothing.
+func TestHandleTargetDelete_IgnoresAnotherWebhooksTarget(
 	t *testing.T,
 ) {
 	t.Parallel()
@@ -548,7 +526,7 @@ func TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted(
 		h    *handlers.Handlers
 		sess *session.Session
 		db   *database.Database
-		ev   *recordingEvictor
+		ev   *recordingArchives
 	)
 
 	app := newTestApp(t, &h, &sess, &db, &ev)
@@ -557,19 +535,20 @@ func TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted(
 	t.Cleanup(app.RequireStop)
 
 	wh := seedWebhook(t, db)
-	seedTarget(t, db, wh.ID, database.TargetTypeDatabase)
-	other := seedTarget(t, db, wh.ID, database.TargetTypeLog)
+	elsewhere := seedTarget(
+		t, db, seedWebhook(t, db).ID, database.TargetTypeDatabase,
+	)
 
 	cookies := authenticatedCookies(
 		t, sess, deleteTestUserID, deleteTestUsername,
 	)
 
 	req := postRequest(
-		"/hook/"+wh.ID+"/targets/"+other.ID+"/delete",
+		"/hook/"+wh.ID+"/targets/"+elsewhere.ID+"/delete",
 		cookies,
 		map[string]string{
 			paramSourceID: wh.ID,
-			paramTargetID: other.ID,
+			paramTargetID: elsewhere.ID,
 		},
 	)
 	w := httptest.NewRecorder()
@@ -578,7 +557,7 @@ func TestHandleTargetDelete_KeepsWriterWhenOtherTypeDeleted(
 
 	require.Equal(t, http.StatusSeeOther, w.Code)
 	assert.Empty(
-		t, ev.Evicted(),
-		"a surviving database target must keep its writer",
+		t, ev.EvictedTargets(),
+		"another webhook's target must not be evicted",
 	)
 }