add try lock

server/src/domain/library/library.service.ts

@@ -13,9 +13,11 @@ import { usePagination, validateCronExpression } from '../domain.util';
 import { IBaseJob, IEntityJob, ILibraryFileJob, ILibraryRefreshJob, JOBS_ASSET_PAGINATION_SIZE, JobName } from '../job';
 
 import {
+  DatabaseLock,
   IAccessRepository,
   IAssetRepository,
   ICryptoRepository,
+  IDatabaseRepository,
   IJobRepository,
   ILibraryRepository,
   IStorageRepository,
@@ -53,6 +55,7 @@ export class LibraryService extends EventEmitter {
     @Inject(ILibraryRepository) private repository: ILibraryRepository,
     @Inject(IStorageRepository) private storageRepository: IStorageRepository,
     @Inject(IUserRepository) private userRepository: IUserRepository,
+    @Inject(IDatabaseRepository) private databaseRepository: IDatabaseRepository,
   ) {
     super();
     this.access = AccessCore.create(accessRepository);
@@ -103,6 +106,7 @@ export class LibraryService extends EventEmitter {
       return false;
     }
 
+    this.databaseRepository.withTryLock(DatabaseLock.LibraryWatch, async () => {
       await this.unwatch(id);
 
       this.logger.log(`Starting to watch library ${library.id} with import path(s) ${library.importPaths}`);
@@ -155,6 +159,7 @@ export class LibraryService extends EventEmitter {
 
       // Wait for the watcher to initialize before returning
       await ready$;
+    });
 
     return true;
   }

server/src/domain/repositories/database.repository.ts

@@ -19,6 +19,7 @@ export enum DatabaseLock {
   Migrations = 200,
   StorageTemplateMigration = 420,
   CLIPDimSize = 512,
+  LibraryWatch = 1337,
 }
 
 export const extName: Record<DatabaseExtension, string> = {
@@ -46,6 +47,7 @@ export interface IDatabaseRepository {
   shouldReindex(name: VectorIndex): Promise<boolean>;
   runMigrations(options?: { transaction?: 'all' | 'none' | 'each' }): Promise<void>;
   withLock<R>(lock: DatabaseLock, callback: () => Promise<R>): Promise<R>;
+  withTryLock<R>(lock: DatabaseLock, callback: () => Promise<R>): Promise<R>;
   isBusy(lock: DatabaseLock): boolean;
   wait(lock: DatabaseLock): Promise<void>;
 }

server/src/infra/repositories/database.repository.ts

@@ -210,6 +210,25 @@ export class DatabaseRepository implements IDatabaseRepository {
     return res as R;
   }
 
+  async withTryLock<R>(lock: DatabaseLock, callback: () => Promise<R>): Promise<R> {
+    let res;
+    const queryRunner = this.dataSource.createQueryRunner();
+    try {
+      const lockAcquired = await this.tryLock(lock, queryRunner);
+      if (lockAcquired) {
+        res = await callback();
+      }
+    } finally {
+      try {
+        await this.releaseLock(lock, queryRunner);
+      } finally {
+        await queryRunner.release();
+      }
+    }
+
+    return res as R;
+  }
+
   isBusy(lock: DatabaseLock): boolean {
     return this.asyncLock.isBusy(DatabaseLock[lock]);
   }
@@ -222,6 +241,10 @@ export class DatabaseRepository implements IDatabaseRepository {
     return queryRunner.query('SELECT pg_advisory_lock($1)', [lock]);
   }
 
+  private async tryLock(lock: DatabaseLock, queryRunner: QueryRunner): Promise<boolean> {
+    return queryRunner.query('SELECT pg_try_advisory_lock($1)', [lock]);
+  }
+
   private async releaseLock(lock: DatabaseLock, queryRunner: QueryRunner): Promise<void> {
     return queryRunner.query('SELECT pg_advisory_unlock($1)', [lock]);
   }