feat: basic shape of file handler; noop logger always returns the same instance

Author: segfaultmedaddy

lib/handlers.dart

@@ -9,6 +9,9 @@
 library strlog.handlers;
 
 export 'src/handlers/console_handler.dart';
+export 'src/handlers/file_handler/noop.dart'
+    if (dart.libary.io) 'src/handlers/file_handler/io.dart';
+export 'src/handlers/file_handler/policy.dart';
 export 'src/handlers/memory_handler.dart';
 export 'src/handlers/multi_handler.dart';
 export 'src/handlers/stream_handler.dart';

lib/src/handlers/console_handler.dart

@@ -12,14 +12,16 @@ class ConsoleHandler extends Handler {
   final Formatter _formatter;
   Filter? _filter;
 
-  /// Sets records filterer.
+  /// Sets records filter.
   ///
-  /// Set filterer behaves the same way as a [Logger] filter.
+  /// Set filter behaves the same way as a [Logger] filter.
   set filter(Filter filter) => _filter = filter;
 
   @override
   void handle(Record record) {
-    if (_filter != null && !_filter!(record)) {
+    final filter = _filter;
+    final shouldFilter = filter != null && !filter(record);
+    if (shouldFilter) {
       return;
     }
 

lib/src/handlers/file_handler/io.dart

@@ -0,0 +1,60 @@
+import 'dart:io' show BytesBuilder;
+import 'dart:typed_data' show Uint8List;
+
+import 'package:file/file.dart' show File, FileSystem, IOSink;
+import 'package:file/local.dart' show LocalFileSystem;
+import 'package:strlog/formatters.dart' show Formatter;
+import 'package:strlog/strlog.dart' show Handler, Record, Filter;
+
+import './policy.dart';
+
+const _localFs = LocalFileSystem();
+
+// [FileHandler] writes log records to the file via [fs].
+class FileHandler extends Handler {
+  FileHandler(this._policy, {required Formatter formatter, FileSystem? fs})
+      : _formatter = formatter,
+        _fs = fs ?? _localFs,
+        _buffer = BytesBuilder(copy: false),
+        _stateMask = 0;
+
+  final FileRotationPolicy _policy;
+  final Formatter _formatter;
+  Filter? _filter;
+
+  final FileSystem _fs;
+  final BytesBuilder _buffer;
+  IOSink? _sink;
+  int _stateMask; // controls lifecyrcle of the file
+
+  /// Sets records filter.
+  ///
+  /// Set filter behaves the same way as a [Logger] filter.
+  set filter(Filter? filter) => _filter = filter;
+
+  void _rotate() {}
+
+  void _tick() {
+    if (_policy.shouldRotate()) {
+      return _rotate();
+    }
+
+    while (_buffer.isNotEmpty) {
+      final bytes = _buffer.takeBytes();
+
+      _sink?.write(bytes);
+    }
+  }
+
+  @override
+  void handle(Record record) {
+    final filter = _filter;
+    final shouldFilter = filter != null && !filter(record);
+    if (shouldFilter) {
+      return;
+    }
+
+    _buffer.add(Uint8List.fromList(_formatter(record)));
+    _tick();
+  }
+}

lib/src/handlers/file_handler/noop.dart

@@ -0,0 +1,8 @@
+import 'package:strlog/strlog.dart' show Handler, Record;
+
+class FileHandler extends Handler {
+  FileHandler();
+
+  @override
+  void handle(Record record) {/* noop */}
+}

lib/src/handlers/file_handler/policy.dart

@@ -0,0 +1,39 @@
+abstract class FileRotationPolicy {
+  // [FileRotationPolicy.never] creates a never rotating policy.
+  //
+  // [FileHandler] with the policy will never rotate a file, effectively
+  // writting the data to the same file until the end of the application
+  // lifetime.
+  const factory FileRotationPolicy.never() = _NeverFileRotationPolicy;
+
+  // [FileRotationPolicy.interval] creates a interval based rotation policy.
+  //
+  // [FileHandler] with the policy will rotate a logging file each [duration].
+  const factory FileRotationPolicy.interval(Duration duration) =
+      _IntervalFileRotationPolicy;
+
+  bool shouldRotate();
+}
+
+// [_NeverFileRotationPolicy] never rotates file.
+class _NeverFileRotationPolicy implements FileRotationPolicy {
+  const _NeverFileRotationPolicy();
+
+  @override
+  bool shouldRotate() => false;
+}
+
+// [_intervalFileRotationPolicy] rotates a file each [duration].
+class _IntervalFileRotationPolicy implements FileRotationPolicy {
+  const _IntervalFileRotationPolicy(this.duration);
+
+  final Duration duration;
+
+  @override
+  bool shouldRotate() {
+    final now = DateTime.now();
+    final diff = now.difference(DateTime.now());
+
+    return diff.inMilliseconds < duration.inMilliseconds;
+  }
+}

lib/src/handlers/multi_handler.dart

@@ -23,9 +23,9 @@ class MultiHandler extends Handler {
 
   final StreamController<Record> _controller;
 
-  /// Sets records filterer.
+  /// Sets records filter.
   ///
-  /// Set filterer behaves the same way as a [Logger] filter.
+  /// Set filter behaves the same way as a [Logger] filter.
   set filter(Filter filter) => _filter = filter;
 
   @override

lib/src/handlers/stream_handler.dart

@@ -8,24 +8,26 @@ import 'package:strlog/strlog.dart' show Handler, Record, Filter;
 /// Each log record is formatted using the `formatter` before
 /// submitting it to the downstream.
 class StreamHandler extends Handler {
-  StreamHandler(this._stream, {required Formatter formatter})
+  StreamHandler(this._sink, {required Formatter formatter})
       : _formatter = formatter;
 
+  final StreamSink<List<int>> _sink;
   final Formatter _formatter;
-  final StreamSink<List<int>> _stream;
   Filter? _filter;
 
-  /// Sets records filterer.
+  /// Sets records filter.
   ///
-  /// Set filterer behaves the same way as a [Logger] filter.
+  /// Set filter behaves the same way as a [Logger] filter.
   set filter(Filter? filter) => _filter = filter;
 
   @override
   void handle(Record record) {
-    if (_filter != null && !_filter!(record)) {
+    final filter = _filter;
+    final shouldFilter = filter != null && !filter(record);
+    if (shouldFilter) {
       return;
     }
 
-    _stream.add(_formatter(record));
+    _sink.add(_formatter(record));
   }
 }

lib/src/logger.dart

@@ -41,7 +41,7 @@ abstract interface class Logger implements Interface {
   factory Logger.detached([String? name]) => LoggerImpl.detached(name);
 
   /// Creates a new noop logger which never emits logs or delegates records to handlers.
-  factory Logger.noop([String? name]) => NoopLogger(name);
+  factory Logger.noop() => NoopLogger();
 
   /// Retrieves or creates a logger with the given [name].
   ///

lib/src/noop_logger.dart

@@ -13,11 +13,12 @@ final class NoopTimer implements Timer {
 }
 
 final class NoopLogger with LoggerBase {
-  NoopLogger([this.name]);
+  factory NoopLogger() => _logger;
+  NoopLogger._();
 
   Level? _level;
 
-  static final NoopLogger _logger = NoopLogger();
+  static final NoopLogger _logger = NoopLogger._();
   static final NoopTimer _timer = NoopTimer();
 
   @override
@@ -29,43 +30,30 @@ final class NoopLogger with LoggerBase {
   Level get level => _level ?? Level.info;
 
   @override
-  final String? name;
+  String? get name => null;
 
   @override
   @pragma('vm:prefer-inline')
   Interface withFields([Iterable<Field>? fields]) => _logger;
 
   @override
-  set handler(Handler? handler) {
-    // noop
-  }
+  set handler(Handler? handler) {/* noop */}
 
   @override
-  set filter(Filter? handler) {
-    // noop
-  }
+  set filter(Filter? handler) {/* noop */}
 
   @override
   Timer startTimer(String message, {Level level = Level.debug}) => _timer;
 
   @override
-  void log(Level level, String message, [Iterable<Field>? fields]) {
-    // noop
-  }
+  void log(Level level, String message, [Iterable<Field>? fields]) {/* noop */}
 
   @override
   String toString() {
     final buffer = StringBuffer();
 
     buffer.write('NoopLogger(');
 
-    if (name != null) {
-      buffer
-        ..write('name=')
-        ..write(name)
-        ..write(', ');
-    }
-
     buffer
       ..write('level=')
       ..write(level.name)

pubspec.yaml

@@ -18,6 +18,7 @@ environment:
 
 dependencies:
   meta: ^1.15.0
+  file: ^7.0.1
 
 dev_dependencies:
   test: ^1.25.8