Start moving non-platform libraries from lib/ to pkg/ .

lib/logging/logging.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-/**
- * Provides APIs for debugging and error logging. This library introduces
- * abstractions similar to those used in other languages, such as the Closure JS
- * Logger and java.util.logging.Logger.
- */
-#library('logging');
-
-/**
- * Whether to allow fine-grain logging and configuration of loggers in a
- * hierarchy. When false, all logging is merged in the root logger.
- */
-bool hierarchicalLoggingEnabled = false;
-
-/**
- * Level for the root-logger. This will be the level of all loggers if
- * [hierarchicalLoggingEnabled] is false.
- */
-Level _rootLevel = Level.INFO;
-
-
-/**
- * Use a [Logger] to log debug messages. [Logger]s are named using a
- * hierarchical dot-separated name convention.
- */
-class Logger {
-  /** Simple name of this logger. */
-  final String name;
-
-  /** The full name of this logger, which includes the parent's full name. */
-  String get fullName() =>
-      (parent == null || parent.name == '') ? name : '${parent.fullName}.$name';
-
-  /** Parent of this logger in the hierarchy of loggers. */
-  final Logger parent;
-
-  /** Logging [Level] used for entries generated on this logger. */
-  Level _level;
-
-  /** Children in the hierarchy of loggers, indexed by their simple names. */
-  Map<String, Logger> children;
-
-  /** Handlers used to process log entries in this logger. */
-  List<LoggerHandler> _handlers;
-
-  /**
-   * Singleton constructor. Calling `new Logger(name)` will return the same
-   * actual instance whenever it is called with the same string name.
-   */
-  factory Logger(String name) {
-    if (name.startsWith('.')) {
-      throw new IllegalArgumentException("name shouldn't start with a '.'");
-    }
-    if (_loggers == null) _loggers = <Logger>{};
-    if (_loggers.containsKey(name)) return _loggers[name];
-
-    // Split hierarchical names (separated with '.').
-    int dot = name.lastIndexOf('.');
-    Logger parent = null;
-    String thisName;
-    if (dot == -1) {
-      if (name != '') parent = new Logger('');
-      thisName = name;
-    } else {
-      parent = new Logger(name.substring(0, dot));
-      thisName = name.substring(dot + 1);
-    }
-    final res = new Logger._internal(thisName, parent);
-    _loggers[name] = res;
-    return res;
-  }
-
-  Logger._internal(this.name, this.parent)
-      : children = new Map<String, Logger>() {
-    if (parent != null) parent.children[name] = this;
-  }
-
-  /**
-   * Effective level considering the levels established in this logger's parents
-   * (when [hierarchicalLoggingEnabled] is true).
-   */
-  Level get level() {
-    if (hierarchicalLoggingEnabled) {
-      if (_level != null) return _level;
-      if (parent != null) return parent.level;
-    }
-    return _rootLevel;
-  }
-
-  /** Override the level for this particular [Logger] and its children. */
-  Level set level(value) {
-    if (hierarchicalLoggingEnabled && parent != null) {
-      _level = value;
-    } else {
-      if (parent != null) {
-        throw new UnsupportedOperationException(
-            'Please set "hierarchicalLoggingEnabled" to true if you want to '
-            'change the level on a non-root logger.');
-      }
-      _rootLevel = value;
-    }
-  }
-
-  /**
-   * Returns an event manager for this [Logger]. You can listen for log messages
-   * by adding a [LoggerHandler] to an event from the event manager, for
-   * instance:
-   *    logger.on.record.add((record) { ... });
-   */
-  LoggerEvents get on() => new LoggerEvents(this);
-
-  /** Adds a handler to listen whenever a log record is added to this logger. */
-  void _addHandler(LoggerHandler handler) {
-    if (hierarchicalLoggingEnabled || parent == null) {
-      if (_handlers == null) {
-        _handlers = new List<LoggerHandler>();
-      }
-      _handlers.add(handler);
-    } else {
-      root._addHandler(handler);
-    }
-  }
-
-  /** Remove a previously added handler. */
-  void _removeHandler(LoggerHandler handler) {
-    if (hierarchicalLoggingEnabled || parent == null) {
-      if (_handlers == null) return;
-      int index = _handlers.indexOf(handler);
-      if (index != -1) _handlers.removeRange(index, 1);
-    } else {
-      root._removeHandler(handler);
-    }
-  }
-
-  /** Removes all handlers previously added to this logger. */
-  void _clearHandlers() {
-    if (hierarchicalLoggingEnabled || parent == null) {
-      _handlers = null;
-    } else {
-      root._clearHandlers();
-    }
-  }
-
-  /** Whether a message for [value]'s level is loggable in this logger. */
-  bool isLoggable(Level value) => (value >= level);
-
-  /**
-   * Adds a log record for a [message] at a particular [logLevel] if
-   * `isLoggable(logLevel)` is true. Use this method to create log entries for
-   * user-defined levels. To record a message at a predefined level (e.g.
-   * [Level.INFO], [Level.WARNING], etc) you can use their specialized methods
-   * instead (e.g. [info], [warning], etc).
-   */
-  // TODO(sigmund): add support for logging exceptions.
-  void log(Level logLevel, String message) {
-    if (isLoggable(logLevel)) {
-      var record = new LogRecord(logLevel, message, fullName);
-      if (hierarchicalLoggingEnabled) {
-        var target = this;
-        while (target != null) {
-          target._publish(record);
-          target = target.parent;
-        }
-      } else {
-        root._publish(record);
-      }
-    }
-  }
-
-  /** Log message at level [Level.FINEST]. */
-  void finest(String message) => log(Level.FINEST, message);
-
-  /** Log message at level [Level.FINER]. */
-  void finer(String message) => log(Level.FINER, message);
-
-  /** Log message at level [Level.FINE]. */
-  void fine(String message) => log(Level.FINE, message);
-
-  /** Log message at level [Level.CONFIG]. */
-  void config(String message) => log(Level.CONFIG, message);
-
-  /** Log message at level [Level.INFO]. */
-  void info(String message) => log(Level.INFO, message);
-
-  /** Log message at level [Level.WARNING]. */
-  void warning(String message) => log(Level.WARNING, message);
-
-  /** Log message at level [Level.SEVERE]. */
-  void severe(String message) => log(Level.SEVERE, message);
-
-  /** Log message at level [Level.SHOUT]. */
-  void shout(String message) => log(Level.SHOUT, message);
-
-  void _publish(LogRecord record) {
-    if (_handlers != null) {
-      _handlers.forEach((h) => h(record));
-    }
-  }
-
-  /** Top-level root [Logger]. */
-  static get root() => new Logger('');
-
-  /** All [Logger]s in the system. */
-  static Map<String, Logger> _loggers;
-}
-
-
-/** Handler callback to process log entries as they are added to a [Logger]. */
-typedef void LoggerHandler(LogRecord);
-
-
-/** Event manager for a [Logger] (holds events that a [Logger] can fire). */
-class LoggerEvents {
-  final Logger _logger;
-
-  LoggerEvents(this._logger);
-
-  /** Event fired when a log record is added to a [Logger]. */
-  LoggerHandlerList get record() => new LoggerHandlerList(_logger);
-}
-
-
-/** List of handlers that will be called on a logger event. */
-class LoggerHandlerList {
-  Logger _logger;
-
-  LoggerHandlerList(this._logger);
-
-  void add(LoggerHandler handler) => _logger._addHandler(handler);
-  void remove(LoggerHandler handler) => _logger._removeHandler(handler);
-  void clear() => _logger._clearHandlers();
-}
-
-
-/**
- * [Level]s to control logging output. Logging can be enabled to include all
- * levels above certain [Level]. [Level]s are ordered using an integer
- * value [Level.value]. The predefined [Level] constants below are sorted as
- * follows (in descending order): [Level.SHOUT], [Level.SEVERE],
- * [Level.WARNING], [Level.INFO], [Level.CONFIG], [Level.FINE], [Level.FINER],
- * [Level.FINEST], and [Level.ALL].
- *
- * We recommend using one of the predefined logging levels. If you define your
- * own level, make sure you use a value between those used in [Level.ALL] and
- * [Level.OFF].
- */
-class Level implements Comparable, Hashable {
-
-  // TODO(sigmund): mark name/value as 'const' when the language supports it.
-  final String name;
-
-  /**
-   * Unique value for this level. Used to order levels, so filtering can exclude
-   * messages whose level is under certain value.
-   */
-  final int value;
-
-  const Level(this.name, this.value);
-
-  /** Special key to turn on logging for all levels ([value] = 0). */
-  static final Level ALL = const Level('ALL', 0);
-
-  /** Special key to turn off all logging ([value] = 2000). */
-  static final Level OFF = const Level('OFF', 2000);
-
-  /** Key for highly detailed tracing ([value] = 300). */
-  static final Level FINEST = const Level('FINEST', 300);
-
-  /** Key for fairly detailed tracing ([value] = 400). */
-  static final Level FINER = const Level('FINER', 400);
-
-  /** Key for tracing information ([value] = 500). */
-  static final Level FINE = const Level('FINE', 500);
-
-  /** Key for static configuration messages ([value] = 700). */
-  static final Level CONFIG = const Level('CONFIG', 700);
-
-  /** Key for informational messages ([value] = 800). */
-  static final Level INFO = const Level('INFO', 800);
-
-  /** Key for potential problems ([value] = 900). */
-  static final Level WARNING = const Level('WARNING', 900);
-
-  /** Key for serious failures ([value] = 1000). */
-  static final Level SEVERE = const Level('SEVERE', 1000);
-
-  /** Key for extra debugging loudness ([value] = 1200). */
-  static final Level SHOUT = const Level('SHOUT', 1200);
-
-  bool operator ==(Level other) => other != null && value == other.value;
-  bool operator <(Level other) => value < other.value;
-  bool operator <=(Level other) => value <= other.value;
-  bool operator >(Level other) => value > other.value;
-  bool operator >=(Level other) => value >= other.value;
-  int compareTo(Level other) => value - other.value;
-  int hashCode() => value;
-  String toString() => name;
-}
-
-
-/**
- * A log entry representation used to propagate information from [Logger] to
- * individual [Handler]s.
- */
-class LogRecord {
-  final Level level;
-  final String message;
-
-  /** Logger where this record is stored. */
-  final String loggerName;
-
-  /** Time when this record was created. */
-  final Date time;
-
-  /** Unique sequence number greater than all log records created before it. */
-  final int sequenceNumber;
-
-  static int _nextNumber = 0;
-
-  /** Associated exception (if any) when recording errors messages. */
-  Exception exception;
-
-  /** Associated exception message (if any) when recording errors messages. */
-  String exceptionText;
-
-  LogRecord(
-      this.level, this.message, this.loggerName,
-      [time, this.exception, this.exceptionText]) :
-    this.time = (time == null) ? new Date.now() : time,
-    this.sequenceNumber = LogRecord._nextNumber++;
-}