fix(server): deal with unexpected updates (#4064)

apps/server/src/modules/doc/manager.ts

@@ -67,8 +67,17 @@ export class DocManager implements OnModuleInit, OnModuleDestroy {
   protected recoverDoc(...updates: Buffer[]): Doc {
     const doc = new Doc();
 
-    updates.forEach(update => {
+    updates.forEach((update, i) => {
-      applyUpdate(doc, update);
+      try {
+        if (update.length) {
+          applyUpdate(doc, update);
+        }
+      } catch (e) {
+        this.logger.error(
+          `Failed to apply updates, index: ${i}`,
+          updates.map(u => u.toString('hex'))
+        );
+      }
     });
 
     return doc;

apps/server/src/modules/doc/redis-manager.ts

@@ -105,6 +105,8 @@ export class RedisDocManager extends DocManager {
       .catch(() => null); // safe;
 
     if (!lockResult) {
+      // we failed to acquire the lock, put the pending doc back to queue.
+      await this.redis.sadd(pending, pendingDoc).catch(() => null); // safe
       return;
     }
 
@@ -141,7 +143,10 @@ export class RedisDocManager extends DocManager {
           this.logger.error('Failed to remove merged updates from Redis', e);
         });
     } catch (e) {
-      this.logger.error('Failed to merge updates with snapshot', e);
+      this.logger.error(
+        `Failed to merge updates with snapshot for ${pendingDoc}`,
+        e
+      );
       await this.redis.sadd(pending, `${workspaceId}:${id}`).catch(() => null); // safe
     } finally {
       await this.redis.del(lockKey);

apps/server/src/modules/workspaces/resolver.ts

@@ -326,13 +326,15 @@ export class WorkspaceResolver {
       },
     });
 
-    await this.prisma.snapshot.create({
+    if (buffer.length) {
-      data: {
+      await this.prisma.snapshot.create({
-        id: workspace.id,
+        data: {
-        workspaceId: workspace.id,
+          id: workspace.id,
-        blob: buffer,
+          workspaceId: workspace.id,
-      },
+          blob: buffer,
-    });
+        },
+      });
+    }
 
     return workspace;
   }