fix: history may duplicate on concurrency (#14487)

#### PR Dependency Tree


* **PR #14487** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Bug Fixes**
* Enhanced history record creation to prevent duplicate entries in
concurrent scenarios.

* **Tests**
  * Added validation for idempotent history record creation.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/core/doc/adapters/workspace.ts

@@ -276,22 +276,16 @@ export class PgWorkspaceDocStorageAdapter extends DocStorageAdapter {
         return false;
       }
 
-      try {
-        await this.models.history.create(
-          {
-            spaceId: snapshot.spaceId,
-            docId: snapshot.docId,
-            timestamp: snapshot.timestamp,
-            blob: Buffer.from(snapshot.bin),
-            editorId: snapshot.editor,
-          },
-          historyMaxAge
-        );
-      } catch (e) {
-        // safe to ignore
-        // only happens when duplicated history record created in multi processes
-        this.logger.error('Failed to create history record', e);
-      }
+      await this.models.history.create(
+        {
+          spaceId: snapshot.spaceId,
+          docId: snapshot.docId,
+          timestamp: snapshot.timestamp,
+          blob: Buffer.from(snapshot.bin),
+          editorId: snapshot.editor,
+        },
+        historyMaxAge
+      );
 
       metrics.doc
         .counter('history_created_counter', {

packages/backend/server/src/models/__tests__/history.spec.ts

@@ -74,6 +74,27 @@ test('should create a history record', async t => {
   });
 });
 
+test('should not fail on duplicated history record', async t => {
+  const snapshot = {
+    spaceId: workspace.id,
+    docId: randomUUID(),
+    blob: Uint8Array.from([1, 2, 3]),
+    timestamp: Date.now(),
+    editorId: user.id,
+  };
+
+  const created1 = await t.context.history.create(snapshot, 1000);
+  const created2 = await t.context.history.create(snapshot, 1000);
+  t.deepEqual(created1.timestamp, snapshot.timestamp);
+  t.deepEqual(created2.timestamp, snapshot.timestamp);
+
+  const histories = await t.context.history.findMany(
+    snapshot.spaceId,
+    snapshot.docId
+  );
+  t.is(histories.length, 1);
+});
+
 test('should return null when history timestamp not match', async t => {
   const snapshot = {
     spaceId: workspace.id,

packages/backend/server/src/models/history.ts

@@ -33,22 +33,33 @@ export class HistoryModel extends BaseModel {
    * Create a doc history with a max age.
    */
   async create(snapshot: Doc, maxAge: number): Promise<DocHistorySimple> {
-    const row = await this.db.snapshotHistory.create({
-      select: {
-        timestamp: true,
-        createdByUser: { select: publicUserSelect },
+    const timestamp = new Date(snapshot.timestamp);
+    const expiredAt = new Date(Date.now() + maxAge);
+
+    // This method may be called concurrently by multiple processes for the same
+    // (workspaceId, docId, timestamp). Using upsert avoids duplicate key errors
+    // that would otherwise abort the surrounding transaction.
+    const row = await this.db.snapshotHistory.upsert({
+      where: {
+        workspaceId_id_timestamp: {
+          workspaceId: snapshot.spaceId,
+          id: snapshot.docId,
+          timestamp,
+        },
       },
-      data: {
+      select: { timestamp: true, createdByUser: { select: publicUserSelect } },
+      create: {
         workspaceId: snapshot.spaceId,
         id: snapshot.docId,
-        timestamp: new Date(snapshot.timestamp),
+        timestamp,
         blob: snapshot.blob,
         createdBy: snapshot.editorId,
-        expiredAt: new Date(Date.now() + maxAge),
+        expiredAt,
       },
+      update: { expiredAt },
     });
     this.logger.debug(
-      `Created history ${row.timestamp} for ${snapshot.docId} in ${snapshot.spaceId}`
+      `Upserted history ${row.timestamp} for ${snapshot.docId} in ${snapshot.spaceId}`
     );
     return {
       timestamp: row.timestamp.getTime(),