From eda6572c87ca2a364c285b150ecea52293ea2b1c Mon Sep 17 00:00:00 2001
From: Jonathan Jogenfors <jonathan@jogenfors.se>
Date: Thu, 29 Feb 2024 18:50:05 +0100
Subject: [PATCH] use global library watch lock

---
 server/src/domain/library/library.service.ts | 110 ++++++++++---------
 1 file changed, 58 insertions(+), 52 deletions(-)

diff --git a/server/src/domain/library/library.service.ts b/server/src/domain/library/library.service.ts
index eb80a94886..f81d0d3ba6 100644
--- a/server/src/domain/library/library.service.ts
+++ b/server/src/domain/library/library.service.ts
@@ -70,8 +70,16 @@ export class LibraryService extends EventEmitter {
 
   async init() {
     const config = await this.configCore.getConfig();
+
     const { watch, scan } = config.library;
-    this.watchLibraries = watch.enabled;
+    this.watchLibraries = false;
+    if (watch.enabled) {
+      this.databaseRepository.withTryLock(DatabaseLock.LibraryWatch, async () => {
+        // This ensures that library watching only occurs in one microservice
+        // TODO: we could make the lock be per-library instead of global
+        this.watchLibraries = true;
+      });
+    }
     this.jobRepository.addCronJob(
       'libraryScan',
       scan.cronExpression,
@@ -106,61 +114,59 @@ export class LibraryService extends EventEmitter {
       return false;
     }
 
-    this.databaseRepository.withTryLock(DatabaseLock.LibraryWatch, async () => {
-      await this.unwatch(id);
+    await this.unwatch(id);
 
-      this.logger.log(`Starting to watch library ${library.id} with import path(s) ${library.importPaths}`);
+    this.logger.log(`Starting to watch library ${library.id} with import path(s) ${library.importPaths}`);
 
-      const matcher = picomatch(`**/*{${mimeTypes.getSupportedFileExtensions().join(',')}}`, {
-        nocase: true,
-        ignore: library.exclusionPatterns,
-      });
-
-      let _resolve: () => void;
-      const ready$ = new Promise<void>((resolve) => (_resolve = resolve));
-
-      this.watchers[id] = this.storageRepository.watch(
-        library.importPaths,
-        {
-          usePolling: false,
-          ignoreInitial: true,
-        },
-        {
-          onReady: () => _resolve(),
-          onAdd: async (path) => {
-            this.logger.debug(`File add event received for ${path} in library ${library.id}}`);
-            if (matcher(path)) {
-              await this.scanAssets(library.id, [path], library.ownerId, false);
-            }
-            this.emit('add', path);
-          },
-          onChange: async (path) => {
-            this.logger.debug(`Detected file change for ${path} in library ${library.id}`);
-            if (matcher(path)) {
-              // Note: if the changed file was not previously imported, it will be imported now.
-              await this.scanAssets(library.id, [path], library.ownerId, false);
-            }
-            this.emit('change', path);
-          },
-          onUnlink: async (path) => {
-            this.logger.debug(`Detected deleted file at ${path} in library ${library.id}`);
-            const asset = await this.assetRepository.getByLibraryIdAndOriginalPath(library.id, path);
-            if (asset && matcher(path)) {
-              await this.assetRepository.save({ id: asset.id, isOffline: true });
-            }
-            this.emit('unlink', path);
-          },
-          onError: (error) => {
-            // TODO: should we log, or throw an exception?
-            this.logger.error(`Library watcher for library ${library.id} encountered error: ${error}`);
-          },
-        },
-      );
-
-      // Wait for the watcher to initialize before returning
-      await ready$;
+    const matcher = picomatch(`**/*{${mimeTypes.getSupportedFileExtensions().join(',')}}`, {
+      nocase: true,
+      ignore: library.exclusionPatterns,
     });
 
+    let _resolve: () => void;
+    const ready$ = new Promise<void>((resolve) => (_resolve = resolve));
+
+    this.watchers[id] = this.storageRepository.watch(
+      library.importPaths,
+      {
+        usePolling: false,
+        ignoreInitial: true,
+      },
+      {
+        onReady: () => _resolve(),
+        onAdd: async (path) => {
+          this.logger.debug(`File add event received for ${path} in library ${library.id}}`);
+          if (matcher(path)) {
+            await this.scanAssets(library.id, [path], library.ownerId, false);
+          }
+          this.emit('add', path);
+        },
+        onChange: async (path) => {
+          this.logger.debug(`Detected file change for ${path} in library ${library.id}`);
+          if (matcher(path)) {
+            // Note: if the changed file was not previously imported, it will be imported now.
+            await this.scanAssets(library.id, [path], library.ownerId, false);
+          }
+          this.emit('change', path);
+        },
+        onUnlink: async (path) => {
+          this.logger.debug(`Detected deleted file at ${path} in library ${library.id}`);
+          const asset = await this.assetRepository.getByLibraryIdAndOriginalPath(library.id, path);
+          if (asset && matcher(path)) {
+            await this.assetRepository.save({ id: asset.id, isOffline: true });
+          }
+          this.emit('unlink', path);
+        },
+        onError: (error) => {
+          // TODO: should we log, or throw an exception?
+          this.logger.error(`Library watcher for library ${library.id} encountered error: ${error}`);
+        },
+      },
+    );
+
+    // Wait for the watcher to initialize before returning
+    await ready$;
+
     return true;
   }