61 lines
1.8 KiB
JavaScript
61 lines
1.8 KiB
JavaScript
//
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// Copyright (c) Microsoft and contributors. All rights reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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//
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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var buffer = require('buffer').Buffer;
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var stream = require('stream');
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var util = require('util');
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var Constants = require('../util/constants');
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var bufferSize = Constants.BlobConstants.DEFAULT_WRITE_BLOCK_SIZE_IN_BYTES;
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function BrowserFileReadStream(file, options) {
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stream.Readable.call(this, options);
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if (!options) {
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options = {};
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}
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this._fileReader = new FileReader(file); // HTML FileReader
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this._file = file;
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this._size = file.size;
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this._highWaterMark = options.highWaterMark || bufferSize;
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this._offset = 0;
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var self = this;
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this._fileReader.onloadend = function (event) {
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var data = event.target.result;
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var buf = buffer.from(data);
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self.push(buf);
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};
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this._fileReader.onerror = function (error) {
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self.emit('error', error);
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};
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}
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util.inherits(BrowserFileReadStream, stream.Readable);
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BrowserFileReadStream.prototype._read = function() {
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if (this._offset >= this._size) {
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this.push(null);
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} else {
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var end = this._offset + this._highWaterMark;
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var slice = this._file.slice(this._offset, end);
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this._fileReader.readAsArrayBuffer(slice);
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this._offset = end;
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}
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};
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module.exports = BrowserFileReadStream; |