3 changed files with 220 additions and 4 deletions
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/* Copyright 2012 Mozilla Foundation |
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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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* |
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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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* 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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/* globals __non_webpack_require__ */ |
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let fs = __non_webpack_require__('fs'); |
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let utils = require('../shared/util'); |
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let assert = utils.assert; |
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let createPromiseCapability = utils.createPromiseCapability; |
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class PDFNodeStream { |
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constructor(args) { |
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this._path = args.path; |
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this._fullRequest = null; |
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this._rangeRequestReaders = []; |
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} |
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getFullReader() { |
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assert(!this._fullRequest); |
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this._fullRequest = new PDFNodeStreamFullReader(this._path); |
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return this._fullRequest; |
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} |
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getRangeReader(begin, end) { |
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let rangeReader = new PDFNodeStreamRangeReader(this._path, begin, end); |
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this._rangeRequestReaders.push(rangeReader); |
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return rangeReader; |
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} |
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cancelAllRequests(reason) { |
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if (this._fullRequest) { |
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this._fullRequest.cancel(reason); |
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} |
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let readers = this._rangeRequestReaders.slice(0); |
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readers.forEach(function(reader) { |
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reader.cancel(reason); |
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}); |
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} |
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} |
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class PDFNodeStreamFullReader { |
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constructor(path) { |
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this._path = path; |
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this._done = false; |
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this._errored = false; |
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this._reason = null; |
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this.onProgress = null; |
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this._length = null; |
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this._loaded = 0; |
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this._readCapability = createPromiseCapability(); |
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this._headersCapability = createPromiseCapability(); |
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this._fullRequest = fs.createReadStream(path); |
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fs.lstat(this._path, (error, stat) => { |
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if (error) { |
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this._errored = true; |
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this._reason = error; |
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this._headersCapability.reject(error); |
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return; |
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} |
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this._length = stat.size; |
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this._headersCapability.resolve(); |
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}); |
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this._fullRequest.on('readable', () => { |
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this._readCapability.resolve(); |
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}); |
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this._fullRequest.on('end', () => { |
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this._done = true; |
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this._readCapability.resolve(); |
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}); |
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this._fullRequest.on('error', (reason) => { |
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this._errored = true; |
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this._reason = reason; |
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this._readCapability.resolve(); |
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}); |
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} |
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get headersReady() { |
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return this._headersCapability.promise; |
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} |
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get contentLength() { |
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return this._length; |
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} |
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get isRangeSupported() { |
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return true; |
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} |
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get isStreamingSupported() { |
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return true; |
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} |
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read() { |
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return this._readCapability.promise.then(() => { |
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if (this._done) { |
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return Promise.resolve({ value: undefined, done: true, }); |
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} |
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if (this._errored) { |
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return Promise.reject(this._reason); |
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} |
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let chunk = this._fullRequest.read(); |
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if (chunk === null) { |
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this._readCapability = createPromiseCapability(); |
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return this.read(); |
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} |
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this._loaded += chunk.length; |
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if (this.onProgress) { |
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this.onProgress({ |
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loaded: this._loaded, |
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total: this._length, |
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}); |
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} |
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return Promise.resolve({ value: chunk, done: false, }); |
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}); |
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} |
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cancel(reason) { |
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this._fullRequest.close(reason); |
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this._fullRequest.destroy(reason); |
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} |
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} |
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class PDFNodeStreamRangeReader { |
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constructor(path, start, end) { |
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this._path = path; |
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this._done = false; |
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this._errored = false; |
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this._reason = null; |
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this.onProgress = null; |
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this._length = null; |
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this._loaded = 0; |
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this._readCapability = createPromiseCapability(); |
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this._rangeRequest = fs.createReadStream(path, { start, end, }); |
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fs.lstat(this._path, (error, stat) => { |
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if (error) { |
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this._errored = true; |
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this._reason = error; |
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return; |
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} |
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this._length = stat.size; |
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}); |
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this._rangeRequest.on('readable', () => { |
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this._readCapability.resolve(); |
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}); |
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this._rangeRequest.on('end', () => { |
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this._done = true; |
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this._readCapability.resolve(); |
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}); |
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this._rangeRequest.on('error', (reason) => { |
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this._errored = true; |
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this._reason = reason; |
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this._readCapability.resolve(); |
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}); |
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} |
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get isStreamingSupported() { |
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return true; |
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} |
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read() { |
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return this._readCapability.promise.then(() => { |
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if (this._done) { |
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return Promise.resolve({ value: undefined, done: true, }); |
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} |
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if (this._errored) { |
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return Promise.reject(this._reason); |
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} |
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let chunk = this._rangeRequest.read(); |
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if (chunk === null) { |
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this._readCapability = createPromiseCapability(); |
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return this.read(); |
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} |
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this._loaded += chunk.length; |
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if (this.onProgress) { |
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this.onProgress({ |
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loaded: this._loaded, |
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total: this._length, |
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}); |
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} |
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return Promise.resolve({ value: chunk, done: false, }); |
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}); |
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} |
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cancel(reason) { |
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this._fullRequest.cancel(reason); |
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this._fullRequest.destroy(reason); |
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} |
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} |
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exports.PDFNodeStream = PDFNodeStream; |
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