Improve logging options

Author: renefloor

flutter_cache_manager/lib/flutter_cache_manager.dart

@@ -2,6 +2,7 @@ export 'src/cache_manager.dart';
 export 'src/cache_managers/cache_managers.dart';
 export 'src/compat/file_fetcher.dart';
 export 'src/config/config.dart';
+export 'src/logger.dart';
 export 'src/result/result.dart';
 export 'src/storage/cache_info_repositories/cache_info_repositories.dart';
 export 'src/web/file_service.dart';

flutter_cache_manager/lib/src/cache_manager.dart

@@ -6,6 +6,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter_cache_manager/flutter_cache_manager.dart';
 import 'package:flutter_cache_manager/src/cache_managers/base_cache_manager.dart';
 import 'package:flutter_cache_manager/src/cache_store.dart';
+import 'package:flutter_cache_manager/src/logger.dart';
 import 'package:flutter_cache_manager/src/result/download_progress.dart';
 import 'package:flutter_cache_manager/src/result/file_info.dart';
 import 'package:flutter_cache_manager/src/result/file_response.dart';
@@ -23,6 +24,8 @@ import 'config/config.dart';
 /// Basic cache manager implementation, which should be used as a single
 /// instance.
 class CacheManager implements BaseCacheManager {
+  static CacheManagerLogLevel logLevel = CacheManagerLogLevel.none;
+
   /// Creates a new instance of a cache manager. This can be used to retrieve
   /// files from the cache or download them online. The http headers are used
   /// for the maximum age of the files. The BaseCacheManager should only be
@@ -130,8 +133,9 @@ class CacheManager implements BaseCacheManager {
         withProgress = false;
       }
     } catch (e) {
-      print(
-          'CacheManager: Failed to load cached file for $url with error:\n$e');
+      cacheLogger.log(
+          'CacheManager: Failed to load cached file for $url with error:\n$e',
+          CacheManagerLogLevel.debug);
     }
     if (cacheFile == null || cacheFile.validTill.isBefore(DateTime.now())) {
       try {
@@ -145,11 +149,9 @@ class CacheManager implements BaseCacheManager {
           }
         }
       } catch (e) {
-        assert(() {
-          print(
-              'CacheManager: Failed to download file from $url with error:\n$e');
-          return true;
-        }());
+        cacheLogger.log(
+            'CacheManager: Failed to download file from $url with error:\n$e',
+            CacheManagerLogLevel.debug);
         if (cacheFile == null && streamController.hasListener) {
           streamController.addError(e);
         }

flutter_cache_manager/lib/src/cache_store.dart

@@ -4,6 +4,8 @@ import 'package:flutter_cache_manager/src/config/config.dart';
 import 'package:flutter_cache_manager/src/storage/file_system/file_system.dart';
 import 'package:pedantic/pedantic.dart';
 
+import '../flutter_cache_manager.dart';
+import 'logger.dart';
 import 'result/file_info.dart';
 import 'storage/cache_info_repositories/cache_info_repository.dart';
 import 'storage/cache_object.dart';
@@ -41,6 +43,9 @@ class CacheStore {
       return null;
     }
     final file = await fileSystem.createFile(cacheObject.relativePath);
+    cacheLogger.log(
+        'CacheManager: Loaded $key from cache', CacheManagerLogLevel.verbose);
+
     return FileInfo(
       file,
       FileSource.Cache,

flutter_cache_manager/lib/src/logger.dart

@@ -0,0 +1,18 @@
+import '../flutter_cache_manager.dart';
+
+CacheLogger cacheLogger = CacheLogger();
+
+enum CacheManagerLogLevel {
+  none,
+  warning,
+  debug,
+  verbose,
+}
+
+class CacheLogger {
+  void log(String message, CacheManagerLogLevel level) {
+    if (CacheManager.logLevel.index >= level.index) {
+      print(message);
+    }
+  }
+}

flutter_cache_manager/lib/src/storage/cache_info_repositories/cache_info_repository.dart

@@ -1,5 +1,6 @@
 import 'dart:async';
 
+import 'package:flutter_cache_manager/src/logger.dart';
 import 'package:flutter_cache_manager/src/storage/cache_object.dart';
 
 /// Base class for cache info repositories
@@ -58,7 +59,10 @@ extension MigrationExtension on CacheInfoRepository {
     var cacheObjects = await previousRepository.getAllObjects();
     await _putAll(cacheObjects);
     var isClosed = await previousRepository.close();
-    if (!isClosed) print('Deleting an open repository while migrating.');
+    if (!isClosed) {
+      cacheLogger.log('Deleting an open repository while migrating.',
+          CacheManagerLogLevel.warning);
+    }
     await previousRepository.deleteDataFile();
   }
 

flutter_cache_manager/lib/src/web/web_helper.dart

@@ -16,6 +16,8 @@ import 'package:pedantic/pedantic.dart';
 import 'package:rxdart/rxdart.dart';
 import 'package:uuid/uuid.dart';
 
+import '../logger.dart';
+
 ///Flutter Cache Manager
 ///Copyright (c) 2019 Rene Floor
 ///Released under MIT License.
@@ -60,6 +62,8 @@ class WebHelper {
       _queue.add(QueueItem(url, key, authHeaders));
       return;
     }
+    cacheLogger.log(
+        'CacheManager: Downloading $url', CacheManagerLogLevel.verbose);
 
     concurrentCalls++;
     var subject = _memCache[key]!;