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/delivery/engine_lifecycle_test.go

@@ -2,7 +2,6 @@ package delivery_test
 
 import (
 	"context"
-	"fmt"
 	"path/filepath"
 	"testing"
 	"time"
@@ -10,6 +9,7 @@ import (
 	"github.com/google/uuid"
 	"github.com/stretchr/testify/require"
 	"go.uber.org/fx"
+	"gorm.io/gorm/clause"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
@@ -272,22 +272,35 @@ func TestEngine_StopHookHonoursStopTimeout(t *testing.T) {
 	requireStopHookExpires(t, lc.hooks[0], "delivery engine")
 }
 
-// deliverToArchive runs one delivery to a database target through
-// the running engine and returns the webhook's archive file path.
-// The archive writer holds the file open afterwards.
-func deliverToArchive(t *testing.T, s iSetup) string {
+// 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) {
 	t.Helper()
 
+	iCreateWebhook(t, s.MainDB, s.WebhookID, "hook")
+
+	tgt := &database.Target{
+		WebhookID: s.WebhookID,
+		Name:      "archive",
+		Type:      database.TargetTypeDatabase,
+	}
+	require.NoError(
+		t, s.MainDB.Omit(clause.Associations).Create(tgt).Error,
+	)
+
 	deliveryID, task := seedLogTask(t, s)
+	task.TargetID = tgt.ID
 	task.TargetType = database.TargetTypeDatabase
 
 	s.Engine.Notify([]delivery.Task{task})
 
 	iWaitForDelivered(t, s.WebhookDB, deliveryID)
 
-	return filepath.Join(
+	return tgt.ID, filepath.Join(
 		filepath.Dir(s.DBMgr.DBPath(s.WebhookID)),
-		fmt.Sprintf("archive-%s.db", s.WebhookID),
+		"archive-hook-archive-"+tgt.ID+".db",
 	)
 }
 
@@ -304,7 +317,7 @@ 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",
@@ -338,7 +351,7 @@ func TestEngine_StopHookTimeoutLeavesArchivesOpen(t *testing.T) {
 
 	lc := startEngineViaHook(t, s.Engine)
 
-	deliverToArchive(t, s)
+	targetID, _ := deliverToArchive(t, s)
 
 	release := make(chan struct{})
 
@@ -352,7 +365,7 @@ func TestEngine_StopHookTimeoutLeavesArchivesOpen(t *testing.T) {
 	requireStopHookExpires(t, lc.hooks[0], "delivery engine")
 
 	require.True(
-		t, s.Engine.ExportArchiveHandleOpen(s.WebhookID),
+		t, s.Engine.ExportArchiveHandleOpen(targetID),
 		"a stop that timed out must not close archive writers",
 	)
 }