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/target_database_evict_test.go

@@ -17,85 +17,109 @@ import (
 	"sneak.berlin/go/webhooker/internal/delivery"
 )
 
-// evictTestEngine builds an engine backed by a temporary data
-// directory and returns it along with that directory.
-func evictTestEngine(t *testing.T) (*delivery.Engine, string) {
+// deliverTo archives one event to a database target, leaving the
+// target's writer cached with its handle open.
+func deliverTo(
+	t *testing.T, env *archiveEnv, tgt *database.Target,
+) {
 	t.Helper()
 
-	dataDir := t.TempDir()
-
-	eng := delivery.NewTestEngineWithDB(
-		nil,
-		database.NewTestWebhookDBManager(dataDir),
-		archiveTestLogger(),
-		&http.Client{Timeout: 5 * time.Second},
-		1,
-	)
-
-	return eng, dataDir
-}
-
-// TestEvictWebhook_ClosesAndRemovesWriter proves that evicting
-// a webhook drops its archive writer from the registry and
-// closes the open archive handle, rather than leaving both
-// alive for the process lifetime.
-func TestEvictWebhook_ClosesAndRemovesWriter(t *testing.T) {
-	t.Parallel()
-
-	eng, dataDir := evictTestEngine(t)
-
 	webhookDB := testWebhookDB(t)
 	event := seedEvent(t, webhookDB, `{"archived":true}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
 
-	eng.ExportDeliverDatabase(webhookDB, d)
-
-	webhookID := event.WebhookID
-
-	require.True(
-		t, eng.ExportHasArchiveWriter(webhookID),
-		"a delivery should have cached an archive writer",
-	)
-	require.True(
-		t, eng.ExportArchiveHandleOpen(webhookID),
-		"the writer should hold an open handle after a write",
+	env.eng.ExportDeliverDatabase(
+		webhookDB, seedDatabaseTargetDelivery(t, webhookDB, event, tgt),
 	)
+}
 
-	eng.EvictWebhook(webhookID)
+// TestEvictWebhook_ClosesAndRemovesWriter proves that evicting
+// a webhook drops the archive writers of its database targets
+// from the registry and closes their open handles, rather than
+// leaving them alive for the process lifetime, and leaves another
+// webhook's writer alone.
+func TestEvictWebhook_ClosesAndRemovesWriter(t *testing.T) {
+	t.Parallel()
 
-	assert.False(
-		t, eng.ExportHasArchiveWriter(webhookID),
-		"eviction should remove the registry entry",
-	)
-	assert.False(
-		t, eng.ExportArchiveHandleOpen(webhookID),
-		"eviction should close the archive handle",
-	)
+	env := setupArchiveTest(t)
+	first := env.seedDatabaseTarget(t, "")
+	second := env.addDatabaseTarget(t, first.WebhookID, "")
+	other := env.seedDatabaseTarget(t, "")
 
-	archivePath := filepath.Join(
-		dataDir, fmt.Sprintf("archive-%s.db", webhookID),
+	for _, tgt := range []*database.Target{first, second, other} {
+		deliverTo(t, env, tgt)
+
+		require.True(
+			t, env.eng.ExportArchiveHandleOpen(tgt.ID),
+			"the writer should hold an open handle after a write",
+		)
+	}
+
+	env.eng.EvictWebhook(first.WebhookID)
+
+	for _, tgt := range []*database.Target{first, second} {
+		assert.False(
+			t, env.eng.ExportHasArchiveWriter(tgt.ID),
+			"eviction should remove the registry entry",
+		)
+		assert.False(
+			t, env.eng.ExportArchiveHandleOpen(tgt.ID),
+			"eviction should close the archive handle",
+		)
+		assert.FileExists(
+			t, env.archivePath(tgt),
+			"eviction must not delete the archive file",
+		)
+	}
+
+	assert.True(
+		t, env.eng.ExportArchiveHandleOpen(other.ID),
+		"another webhook's writer must be left alone",
 	)
+}
+
+// TestEvictTarget_LeavesOtherTargets proves that evicting one
+// database target leaves the writer of another target of the same
+// webhook in place.
+func TestEvictTarget_LeavesOtherTargets(t *testing.T) {
+	t.Parallel()
+
+	env := setupArchiveTest(t)
+	doomed := env.seedDatabaseTarget(t, "")
+	kept := env.addDatabaseTarget(t, doomed.WebhookID, "")
+
+	deliverTo(t, env, doomed)
+	deliverTo(t, env, kept)
+
+	env.eng.EvictTarget(doomed.ID)
+
+	assert.False(t, env.eng.ExportHasArchiveWriter(doomed.ID))
 	assert.FileExists(
-		t, archivePath,
+		t, env.archivePath(doomed),
 		"eviction must not delete the archive file",
 	)
+	assert.True(
+		t, env.eng.ExportArchiveHandleOpen(kept.ID),
+		"the other target's writer must be left alone",
+	)
 }
 
 // TestEvictWebhook_UnknownWebhookIsNoOp proves eviction is safe
-// for the common case of a webhook that never had a database
-// target, and that repeating it does not panic.
+// for the common case of a webhook or target that never had an
+// archive writer, and that repeating it does not panic.
 func TestEvictWebhook_UnknownWebhookIsNoOp(t *testing.T) {
 	t.Parallel()
 
-	eng, _ := evictTestEngine(t)
+	env := setupArchiveTest(t)
 
 	assert.NotPanics(t, func() {
-		eng.EvictWebhook("no-such-webhook")
-		eng.EvictWebhook("no-such-webhook")
+		env.eng.EvictWebhook("no-such-webhook")
+		env.eng.EvictWebhook("no-such-webhook")
+		env.eng.EvictTarget("no-such-target")
+		env.eng.EvictTarget("no-such-target")
 	})
 
 	assert.False(
-		t, eng.ExportHasArchiveWriter("no-such-webhook"),
+		t, env.eng.ExportHasArchiveWriter("no-such-target"),
 		"eviction must not create a writer",
 	)
 }
@@ -289,17 +313,14 @@ func TestEvictWebhook_RacingWriteDoesNotReopenHandle(
 ) {
 	t.Parallel()
 
-	eng, _ := evictTestEngine(t)
-
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"archived":true}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
 
 	// Prime the registry so the test can hold the very writer the
 	// eviction is about to detach.
-	eng.ExportDeliverDatabase(webhookDB, d)
+	deliverTo(t, env, tgt)
 
-	w := eng.ExportArchiveWriterFor(event.WebhookID)
+	w := env.eng.ExportArchiveWriterFor(tgt.ID)
 	require.NotNil(t, w)
 	require.True(t, w.HandleOpen())
 
@@ -309,7 +330,7 @@ func TestEvictWebhook_RacingWriteDoesNotReopenHandle(
 	// eviction has to contend for the writer's mutex.
 	race.awaitFirstWrite()
 
-	eng.EvictWebhook(event.WebhookID)
+	env.eng.EvictWebhook(tgt.WebhookID)
 
 	sawEvicted, otherErr := race.wait()
 
@@ -324,41 +345,33 @@ func TestEvictWebhook_RacingWriteDoesNotReopenHandle(
 			"been evicted",
 	)
 	assert.False(
-		t, eng.ExportHasArchiveWriter(event.WebhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"the registry entry must stay gone",
 	)
 }
 
 // TestEvictWebhook_LaterDeliveryRecreatesWriter proves eviction
-// does not break archiving for a webhook that is still alive: a
+// does not break archiving for a target that is still alive: a
 // subsequent delivery gets a brand new writer from the registry.
 // It says nothing about the evicted writer itself — that is what
 // TestEvictedWriter_WriteDoesNotReopenFile covers.
 func TestEvictWebhook_LaterDeliveryRecreatesWriter(t *testing.T) {
 	t.Parallel()
 
-	eng, _ := evictTestEngine(t)
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
 
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"archived":true}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
+	deliverTo(t, env, tgt)
+	require.True(t, env.eng.ExportHasArchiveWriter(tgt.ID))
 
-	eng.ExportDeliverDatabase(webhookDB, d)
-	require.True(
-		t, eng.ExportHasArchiveWriter(event.WebhookID),
-	)
+	env.eng.EvictWebhook(tgt.WebhookID)
 
-	eng.EvictWebhook(event.WebhookID)
-
-	// A fresh delivery for the same webhook gets a brand new
+	// A fresh delivery for the same target gets a brand new
 	// writer from the registry, so archiving keeps working.
-	second := seedDatabaseTargetDelivery(
-		t, webhookDB, event, "",
-	)
-	eng.ExportDeliverDatabase(webhookDB, second)
+	deliverTo(t, env, tgt)
 
 	assert.True(
-		t, eng.ExportHasArchiveWriter(event.WebhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"a later delivery should recreate the writer",
 	)
 }
@@ -370,19 +383,16 @@ func TestEvictWebhook_LaterDeliveryRecreatesWriter(t *testing.T) {
 func TestEngineStop_WriteAfterStopIsRefused(t *testing.T) {
 	t.Parallel()
 
-	eng, _ := evictTestEngine(t)
+	env := setupArchiveTest(t)
+	tgt := env.seedDatabaseTarget(t, "")
 
-	webhookDB := testWebhookDB(t)
-	event := seedEvent(t, webhookDB, `{"archived":true}`)
-	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")
+	deliverTo(t, env, tgt)
 
-	eng.ExportDeliverDatabase(webhookDB, d)
-
-	w := eng.ExportArchiveWriterFor(event.WebhookID)
+	w := env.eng.ExportArchiveWriterFor(tgt.ID)
 	require.NotNil(t, w)
 	require.True(t, w.HandleOpen())
 
-	require.NoError(t, eng.ExportStop(context.Background()))
+	require.NoError(t, env.eng.ExportStop(context.Background()))
 
 	err := w.Write(evictTestRow("ev-after-stop"), 0)
 
@@ -395,7 +405,7 @@ func TestEngineStop_WriteAfterStopIsRefused(t *testing.T) {
 		"a refused write must not reopen the archive",
 	)
 	assert.False(
-		t, eng.ExportHasArchiveWriter(event.WebhookID),
+		t, env.eng.ExportHasArchiveWriter(tgt.ID),
 		"the stop should empty the registry",
 	)