Add a flush operations to IOSink

sdk/lib/io/file.dart

 // Copyright (c) 2013, 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.
 
 part of dart.io;
 
 /**
  * FileMode describes the modes in which a file can be opened.
  */
 class FileMode {
@@ skipping 231 matching lines @@
   /**
    * Write a list of bytes to a file.
    *
    * Opens the file, writes the list of bytes to it, and closes the file.
    * Returns a [:Future<File>:] that completes with this [File] object once
    * the entire operation has completed.
    *
    * By default [writeAsBytes] creates the file for writing and truncates the
    * file if it already exists. In order to append the bytes to an existing
    * file, pass [FileMode.APPEND] as the optional mode parameter.
+   *
+   * If the argument [flush] is set to `true`, the data written will be
+   * flushed to the file system before the returned future completes.
    */
-  Future<File> writeAsBytes(List<int> bytes, {FileMode mode: FileMode.WRITE});
+  Future<File> writeAsBytes(List<int> bytes,
+                            {FileMode mode: FileMode.WRITE,
+                             bool flush: false});
 
   /**
    * Synchronously write a list of bytes to a file.
    *
    * Opens the file, writes the list of bytes to it and closes the file.
    *
    * By default [writeAsBytesSync] creates the file for writing and truncates
    * the file if it already exists. In order to append the bytes to an existing
    * file, pass [FileMode.APPEND] as the optional mode parameter.
    *
+   * If the [flush] argument is set to `true` data written will be
+   * flushed to the file system before returning.
+   *
    * Throws a [FileSystemException] if the operation fails.
    */
-  void writeAsBytesSync(List<int> bytes, {FileMode mode: FileMode.WRITE});
+  void writeAsBytesSync(List<int> bytes,
+                        {FileMode mode: FileMode.WRITE,
+                         bool flush: false});
 
   /**
    * Write a string to a file.
    *
    * Opens the file, writes the string in the given encoding, and closes the
    * file. Returns a [:Future<File>:] that completes with this [File] object
    * once the entire operation has completed.
    *
    * By default [writeAsString] creates the file for writing and truncates the
    * file if it already exists. In order to append the bytes to an existing
    * file, pass [FileMode.APPEND] as the optional mode parameter.
+   *
+   * If the argument [flush] is set to `true`, the data written will be
+   * flushed to the file system before the returned future completes.
+   *
    */
   Future<File> writeAsString(String contents,
                              {FileMode mode: FileMode.WRITE,
-                              Encoding encoding: UTF8});
+                              Encoding encoding: UTF8,
+                              bool flush: false});
 
   /**
    * Synchronously write a string to a file.
    *
    * Opens the file, writes the string in the given encoding, and closes the
    * file.
    *
    * By default [writeAsStringSync] creates the file for writing and
    * truncates the file if it already exists. In order to append the bytes
    * to an existing file, pass [FileMode.APPEND] as the optional mode
    * parameter.
    *
+   * If the [flush] argument is set to `true` data written will be
+   * flushed to the file system before returning.
+   *
    * Throws a [FileSystemException] if the operation fails.
    */
   void writeAsStringSync(String contents,
                          {FileMode mode: FileMode.WRITE,
-                          Encoding encoding: UTF8});
+                          Encoding encoding: UTF8,
+                          bool flush: false});
 
   /**
    * Get the path of the file.
    */
   String get path;
 }
 
 
 /**
  * [RandomAccessFile] provides random access to the data in a
@@ skipping 216 matching lines @@
       }
     } else if (osError != null) {
       sb.write(": osError");
       if (path != null) {
         sb.write(", path = $path");
       }
     }
     return sb.toString();
   }
 }