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// Copyright 2011 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview A wrapper for the HTML5 FileWriter object.
*
* When adding or modifying functionality in this namespace, be sure to update
* the mock counterparts in goog.testing.fs.
*
*/
goog.provide('goog.fs.FileWriter');
goog.require('goog.fs.Error');
goog.require('goog.fs.FileSaver');
/**
* An object for monitoring the saving of files, as well as other fine-grained
* writing operations.
*
* This should not be instantiated directly. Instead, it should be accessed via
* {@link goog.fs.FileEntry#createWriter}.
*
* @param {!FileWriter} writer The underlying FileWriter object.
* @constructor
* @extends {goog.fs.FileSaver}
*/
goog.fs.FileWriter = function(writer) {
goog.base(this, writer);
/**
* The underlying FileWriter object.
*
* @type {!FileWriter}
* @private
*/
this.writer_ = writer;
};
goog.inherits(goog.fs.FileWriter, goog.fs.FileSaver);
/**
* @return {number} The byte offset at which the next write will occur.
*/
goog.fs.FileWriter.prototype.getPosition = function() {
return this.writer_.position;
};
/**
* @return {number} The length of the file.
*/
goog.fs.FileWriter.prototype.getLength = function() {
return this.writer_.length;
};
/**
* Write data to the file.
*
* @param {!Blob} blob The data to write.
*/
goog.fs.FileWriter.prototype.write = function(blob) {
try {
this.writer_.write(blob);
} catch (e) {
throw new goog.fs.Error(e.code, 'writing file');
}
};
/**
* Set the file position at which the next write will occur.
*
* @param {number} offset An absolute byte offset into the file.
*/
goog.fs.FileWriter.prototype.seek = function(offset) {
try {
this.writer_.seek(offset);
} catch (e) {
throw new goog.fs.Error(e.code, 'seeking in file');
}
};
/**
* Changes the length of the file to that specified.
*
* @param {number} size The new size of the file, in bytes.
*/
goog.fs.FileWriter.prototype.truncate = function(size) {
try {
this.writer_.truncate(size);
} catch (e) {
throw new goog.fs.Error(e.code, 'truncating file');
}
};
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