6 changed files with 270 additions and 20 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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import { assert, createPromiseCapability } from '../shared/util'; |
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import { |
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createResponseStatusError, validateRangeRequestCapabilities, |
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validateResponseStatus |
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} from './network_utils'; |
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function createFetchOptions(headers, withCredentials) { |
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return { |
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method: 'GET', |
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headers, |
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mode: 'cors', |
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credentials: withCredentials ? 'omit' : 'include', |
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redirect: 'follow', |
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}; |
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} |
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class PDFFetchStream { |
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constructor(options) { |
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this.options = options; |
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this.source = options.source; |
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this.isHttp = /^https?:/i.test(this.source.url); |
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this.httpHeaders = (this.isHttp && this.source.httpHeaders) || {}; |
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this._fullRequestReader = null; |
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this._rangeRequestReaders = []; |
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} |
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getFullReader() { |
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assert(!this._fullRequestReader); |
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this._fullRequestReader = new PDFFetchStreamReader(this); |
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return this._fullRequestReader; |
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} |
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getRangeReader(begin, end) { |
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let reader = new PDFFetchStreamRangeReader(this, begin, end); |
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this._rangeRequestReaders.push(reader); |
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return reader; |
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} |
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cancelAllRequests(reason) { |
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if (this._fullRequestReader) { |
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this._fullRequestReader.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 PDFFetchStreamReader { |
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constructor(stream) { |
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this._stream = stream; |
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this._reader = null; |
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this._loaded = 0; |
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this._withCredentials = stream.source.withCredentials; |
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this._contentLength = this._stream.source.length; |
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this._headersCapability = createPromiseCapability(); |
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this._disableRange = this._stream.options.disableRange; |
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this._rangeChunkSize = this._stream.source.rangeChunkSize; |
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if (!this._rangeChunkSize && !this._disableRange) { |
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this._disableRange = true; |
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} |
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this._isRangeSupported = !this._stream.options.disableRange; |
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this._isStreamingSupported = !this._stream.source.disableStream; |
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this._headers = new Headers(); |
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for (let property in this._stream.httpHeaders) { |
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let value = this._stream.httpHeaders[property]; |
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if (typeof value === 'undefined') { |
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continue; |
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} |
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this._headers.append(property, value); |
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} |
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let url = this._stream.source.url; |
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fetch(url, createFetchOptions(this._headers, this._withCredentials)). |
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then((response) => { |
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if (!validateResponseStatus(response.status, this._stream.isHttp)) { |
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throw createResponseStatusError(response.status, url); |
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} |
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this._headersCapability.resolve(); |
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this._reader = response.body.getReader(); |
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let { allowRangeRequests, suggestedLength, } = |
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validateRangeRequestCapabilities({ |
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getResponseHeader: (name) => { |
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return response.headers.get(name); |
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}, |
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isHttp: this._stream.isHttp, |
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rangeChunkSize: this._rangeChunkSize, |
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disableRange: this._disableRange, |
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}); |
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this._contentLength = suggestedLength; |
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this._isRangeSupported = allowRangeRequests; |
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}).catch(this._headersCapability.reject); |
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this.onProgress = null; |
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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._contentLength; |
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} |
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get isRangeSupported() { |
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return this._isRangeSupported; |
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} |
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get isStreamingSupported() { |
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return this._isStreamingSupported; |
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} |
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read() { |
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return this._headersCapability.promise.then(() => { |
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return this._reader.read().then(({ value, done, }) => { |
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if (done) { |
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return Promise.resolve({ value, done, }); |
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} |
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this._loaded += value.byteLength; |
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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._contentLength, |
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}); |
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} |
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let buffer = new Uint8Array(value).buffer; |
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return Promise.resolve({ value: buffer, done: false, }); |
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}); |
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}); |
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} |
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cancel(reason) { |
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if (this._reader) { |
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this._reader.cancel(reason); |
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} |
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} |
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} |
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class PDFFetchStreamRangeReader { |
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constructor(stream, begin, end) { |
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this._stream = stream; |
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this._reader = null; |
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this._loaded = 0; |
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this._withCredentials = stream.source.withCredentials; |
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this._readCapability = createPromiseCapability(); |
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this._isStreamingSupported = !stream.source.disableStream; |
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this._headers = new Headers(); |
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for (let property in this._stream.httpHeaders) { |
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let value = this._stream.httpHeaders[property]; |
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if (typeof value === 'undefined') { |
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continue; |
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} |
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this._headers.append(property, value); |
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} |
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let rangeStr = begin + '-' + (end - 1); |
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this._headers.append('Range', 'bytes=' + rangeStr); |
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let url = this._stream.source.url; |
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fetch(url, createFetchOptions(this._headers, this._withCredentials)). |
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then((response) => { |
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if (!validateResponseStatus(response.status, this._stream.isHttp)) { |
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throw createResponseStatusError(response.status, url); |
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} |
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this._readCapability.resolve(); |
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this._reader = response.body.getReader(); |
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}); |
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this.onProgress = null; |
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} |
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get isStreamingSupported() { |
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return this._isStreamingSupported; |
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} |
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read() { |
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return this._readCapability.promise.then(() => { |
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return this._reader.read().then(({ value, done, }) => { |
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if (done) { |
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return Promise.resolve({ value, done, }); |
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} |
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this._loaded += value.byteLength; |
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if (this.onProgress) { |
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this.onProgress({ loaded: this._loaded, }); |
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} |
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let buffer = new Uint8Array(value).buffer; |
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return Promise.resolve({ value: buffer, done: false, }); |
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}); |
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}); |
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} |
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cancel(reason) { |
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if (this._reader) { |
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this._reader.cancel(reason); |
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} |
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} |
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} |
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export { |
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PDFFetchStream, |
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}; |
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