pdfjs-dist/lib/core/worker.js

/* Copyright 2017 Mozilla Foundation
 *
 * 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.
 */
'use strict';
var sharedUtil = require('../shared/util.js');
var corePrimitives = require('./primitives.js');
var corePdfManager = require('./pdf_manager.js');
var UNSUPPORTED_FEATURES = sharedUtil.UNSUPPORTED_FEATURES;
var InvalidPDFException = sharedUtil.InvalidPDFException;
var MessageHandler = sharedUtil.MessageHandler;
var MissingPDFException = sharedUtil.MissingPDFException;
var UnexpectedResponseException = sharedUtil.UnexpectedResponseException;
var PasswordException = sharedUtil.PasswordException;
var UnknownErrorException = sharedUtil.UnknownErrorException;
var XRefParseException = sharedUtil.XRefParseException;
var arrayByteLength = sharedUtil.arrayByteLength;
var arraysToBytes = sharedUtil.arraysToBytes;
var assert = sharedUtil.assert;
var createPromiseCapability = sharedUtil.createPromiseCapability;
var info = sharedUtil.info;
var warn = sharedUtil.warn;
var setVerbosityLevel = sharedUtil.setVerbosityLevel;
var isNodeJS = sharedUtil.isNodeJS;
var Ref = corePrimitives.Ref;
var LocalPdfManager = corePdfManager.LocalPdfManager;
var NetworkPdfManager = corePdfManager.NetworkPdfManager;
var WorkerTask = function WorkerTaskClosure() {
 function WorkerTask(name) {
  this.name = name;
  this.terminated = false;
  this._capability = createPromiseCapability();
 }
 WorkerTask.prototype = {
  get finished() {
   return this._capability.promise;
  },
  finish: function () {
   this._capability.resolve();
  },
  terminate: function () {
   this.terminated = true;
  },
  ensureNotTerminated: function () {
   if (this.terminated) {
    throw new Error('Worker task was terminated');
   }
  }
 };
 return WorkerTask;
}();
var PDFWorkerStream = function PDFWorkerStreamClosure() {
 function PDFWorkerStream(params, msgHandler) {
  this._queuedChunks = [];
  var initialData = params.initialData;
  if (initialData && initialData.length > 0) {
   this._queuedChunks.push(initialData);
  }
  this._msgHandler = msgHandler;
  this._isRangeSupported = !params.disableRange;
  this._isStreamingSupported = !params.disableStream;
  this._contentLength = params.length;
  this._fullRequestReader = null;
  this._rangeReaders = [];
  msgHandler.on('OnDataRange', this._onReceiveData.bind(this));
  msgHandler.on('OnDataProgress', this._onProgress.bind(this));
 }
 PDFWorkerStream.prototype = {
  _onReceiveData: function PDFWorkerStream_onReceiveData(args) {
   if (args.begin === undefined) {
    if (this._fullRequestReader) {
     this._fullRequestReader._enqueue(args.chunk);
    } else {
     this._queuedChunks.push(args.chunk);
    }
   } else {
    var found = this._rangeReaders.some(function (rangeReader) {
     if (rangeReader._begin !== args.begin) {
      return false;
     }
     rangeReader._enqueue(args.chunk);
     return true;
    });
    assert(found);
   }
  },
  _onProgress: function PDFWorkerStream_onProgress(evt) {
   if (this._rangeReaders.length > 0) {
    var firstReader = this._rangeReaders[0];
    if (firstReader.onProgress) {
     firstReader.onProgress({ loaded: evt.loaded });
    }
   }
  },
  _removeRangeReader: function PDFWorkerStream_removeRangeReader(reader) {
   var i = this._rangeReaders.indexOf(reader);
   if (i >= 0) {
    this._rangeReaders.splice(i, 1);
   }
  },
  getFullReader: function PDFWorkerStream_getFullReader() {
   assert(!this._fullRequestReader);
   var queuedChunks = this._queuedChunks;
   this._queuedChunks = null;
   return new PDFWorkerStreamReader(this, queuedChunks);
  },
  getRangeReader: function PDFWorkerStream_getRangeReader(begin, end) {
   var reader = new PDFWorkerStreamRangeReader(this, begin, end);
   this._msgHandler.send('RequestDataRange', {
    begin: begin,
    end: end
   });
   this._rangeReaders.push(reader);
   return reader;
  },
  cancelAllRequests: function PDFWorkerStream_cancelAllRequests(reason) {
   if (this._fullRequestReader) {
    this._fullRequestReader.cancel(reason);
   }
   var readers = this._rangeReaders.slice(0);
   readers.forEach(function (rangeReader) {
    rangeReader.cancel(reason);
   });
  }
 };
 function PDFWorkerStreamReader(stream, queuedChunks) {
  this._stream = stream;
  this._done = false;
  this._queuedChunks = queuedChunks || [];
  this._requests = [];
  this._headersReady = Promise.resolve();
  stream._fullRequestReader = this;
  this.onProgress = null;
 }
 PDFWorkerStreamReader.prototype = {
  _enqueue: function PDFWorkerStreamReader_enqueue(chunk) {
   if (this._done) {
    return;
   }
   if (this._requests.length > 0) {
    var requestCapability = this._requests.shift();
    requestCapability.resolve({
     value: chunk,
     done: false
    });
    return;
   }
   this._queuedChunks.push(chunk);
  },
  get headersReady() {
   return this._headersReady;
  },
  get isRangeSupported() {
   return this._stream._isRangeSupported;
  },
  get isStreamingSupported() {
   return this._stream._isStreamingSupported;
  },
  get contentLength() {
   return this._stream._contentLength;
  },
  read: function PDFWorkerStreamReader_read() {
   if (this._queuedChunks.length > 0) {
    var chunk = this._queuedChunks.shift();
    return Promise.resolve({
     value: chunk,
     done: false
    });
   }
   if (this._done) {
    return Promise.resolve({
     value: undefined,
     done: true
    });
   }
   var requestCapability = createPromiseCapability();
   this._requests.push(requestCapability);
   return requestCapability.promise;
  },
  cancel: function PDFWorkerStreamReader_cancel(reason) {
   this._done = true;
   this._requests.forEach(function (requestCapability) {
    requestCapability.resolve({
     value: undefined,
     done: true
    });
   });
   this._requests = [];
  }
 };
 function PDFWorkerStreamRangeReader(stream, begin, end) {
  this._stream = stream;
  this._begin = begin;
  this._end = end;
  this._queuedChunk = null;
  this._requests = [];
  this._done = false;
  this.onProgress = null;
 }
 PDFWorkerStreamRangeReader.prototype = {
  _enqueue: function PDFWorkerStreamRangeReader_enqueue(chunk) {
   if (this._done) {
    return;
   }
   if (this._requests.length === 0) {
    this._queuedChunk = chunk;
   } else {
    var requestsCapability = this._requests.shift();
    requestsCapability.resolve({
     value: chunk,
     done: false
    });
    this._requests.forEach(function (requestCapability) {
     requestCapability.resolve({
      value: undefined,
      done: true
     });
    });
    this._requests = [];
   }
   this._done = true;
   this._stream._removeRangeReader(this);
  },
  get isStreamingSupported() {
   return false;
  },
  read: function PDFWorkerStreamRangeReader_read() {
   if (this._queuedChunk) {
    return Promise.resolve({
     value: this._queuedChunk,
     done: false
    });
   }
   if (this._done) {
    return Promise.resolve({
     value: undefined,
     done: true
    });
   }
   var requestCapability = createPromiseCapability();
   this._requests.push(requestCapability);
   return requestCapability.promise;
  },
  cancel: function PDFWorkerStreamRangeReader_cancel(reason) {
   this._done = true;
   this._requests.forEach(function (requestCapability) {
    requestCapability.resolve({
     value: undefined,
     done: true
    });
   });
   this._requests = [];
   this._stream._removeRangeReader(this);
  }
 };
 return PDFWorkerStream;
}();
var PDFNetworkStream;
function setPDFNetworkStreamClass(cls) {
 PDFNetworkStream = cls;
}
var WorkerMessageHandler = {
 setup: function wphSetup(handler, port) {
  var testMessageProcessed = false;
  handler.on('test', function wphSetupTest(data) {
   if (testMessageProcessed) {
    return;
   }
   testMessageProcessed = true;
   if (!(data instanceof Uint8Array)) {
    handler.send('test', 'main', false);
    return;
   }
   var supportTransfers = data[0] === 255;
   handler.postMessageTransfers = supportTransfers;
   var xhr = new XMLHttpRequest();
   var responseExists = 'response' in xhr;
   try {
    xhr.responseType;
   } catch (e) {
    responseExists = false;
   }
   if (!responseExists) {
    handler.send('test', false);
    return;
   }
   handler.send('test', {
    supportTypedArray: true,
    supportTransfers: supportTransfers
   });
  });
  handler.on('configure', function wphConfigure(data) {
   setVerbosityLevel(data.verbosity);
  });
  handler.on('GetDocRequest', function wphSetupDoc(data) {
   return WorkerMessageHandler.createDocumentHandler(data, port);
  });
 },
 createDocumentHandler: function wphCreateDocumentHandler(docParams, port) {
  var pdfManager;
  var terminated = false;
  var cancelXHRs = null;
  var WorkerTasks = [];
  var docId = docParams.docId;
  var docBaseUrl = docParams.docBaseUrl;
  var workerHandlerName = docParams.docId + '_worker';
  var handler = new MessageHandler(workerHandlerName, docId, port);
  handler.postMessageTransfers = docParams.postMessageTransfers;
  function ensureNotTerminated() {
   if (terminated) {
    throw new Error('Worker was terminated');
   }
  }
  function startWorkerTask(task) {
   WorkerTasks.push(task);
  }
  function finishWorkerTask(task) {
   task.finish();
   var i = WorkerTasks.indexOf(task);
   WorkerTasks.splice(i, 1);
  }
  function loadDocument(recoveryMode) {
   var loadDocumentCapability = createPromiseCapability();
   var parseSuccess = function parseSuccess() {
    var numPagesPromise = pdfManager.ensureDoc('numPages');
    var fingerprintPromise = pdfManager.ensureDoc('fingerprint');
    var encryptedPromise = pdfManager.ensureXRef('encrypt');
    Promise.all([
     numPagesPromise,
     fingerprintPromise,
     encryptedPromise
    ]).then(function onDocReady(results) {
     var doc = {
      numPages: results[0],
      fingerprint: results[1],
      encrypted: !!results[2]
     };
     loadDocumentCapability.resolve(doc);
    }, parseFailure);
   };
   var parseFailure = function parseFailure(e) {
    loadDocumentCapability.reject(e);
   };
   pdfManager.ensureDoc('checkHeader', []).then(function () {
    pdfManager.ensureDoc('parseStartXRef', []).then(function () {
     pdfManager.ensureDoc('parse', [recoveryMode]).then(parseSuccess, parseFailure);
    }, parseFailure);
   }, parseFailure);
   return loadDocumentCapability.promise;
  }
  function getPdfManager(data, evaluatorOptions) {
   var pdfManagerCapability = createPromiseCapability();
   var pdfManager;
   var source = data.source;
   if (source.data) {
    try {
     pdfManager = new LocalPdfManager(docId, source.data, source.password, evaluatorOptions, docBaseUrl);
     pdfManagerCapability.resolve(pdfManager);
    } catch (ex) {
     pdfManagerCapability.reject(ex);
    }
    return pdfManagerCapability.promise;
   }
   var pdfStream;
   try {
    if (source.chunkedViewerLoading) {
     pdfStream = new PDFWorkerStream(source, handler);
    } else {
     assert(PDFNetworkStream, 'pdfjs/core/network module is not loaded');
     pdfStream = new PDFNetworkStream(data);
    }
   } catch (ex) {
    pdfManagerCapability.reject(ex);
    return pdfManagerCapability.promise;
   }
   var fullRequest = pdfStream.getFullReader();
   fullRequest.headersReady.then(function () {
    if (!fullRequest.isStreamingSupported || !fullRequest.isRangeSupported) {
     fullRequest.onProgress = function (evt) {
      handler.send('DocProgress', {
       loaded: evt.loaded,
       total: evt.total
      });
     };
    }
    if (!fullRequest.isRangeSupported) {
     return;
    }
    var disableAutoFetch = source.disableAutoFetch || fullRequest.isStreamingSupported;
    pdfManager = new NetworkPdfManager(docId, pdfStream, {
     msgHandler: handler,
     url: source.url,
     password: source.password,
     length: fullRequest.contentLength,
     disableAutoFetch: disableAutoFetch,
     rangeChunkSize: source.rangeChunkSize
    }, evaluatorOptions, docBaseUrl);
    pdfManagerCapability.resolve(pdfManager);
    cancelXHRs = null;
   }).catch(function (reason) {
    pdfManagerCapability.reject(reason);
    cancelXHRs = null;
   });
   var cachedChunks = [], loaded = 0;
   var flushChunks = function () {
    var pdfFile = arraysToBytes(cachedChunks);
    if (source.length && pdfFile.length !== source.length) {
     warn('reported HTTP length is different from actual');
    }
    try {
     pdfManager = new LocalPdfManager(docId, pdfFile, source.password, evaluatorOptions, docBaseUrl);
     pdfManagerCapability.resolve(pdfManager);
    } catch (ex) {
     pdfManagerCapability.reject(ex);
    }
    cachedChunks = [];
   };
   var readPromise = new Promise(function (resolve, reject) {
    var readChunk = function (chunk) {
     try {
      ensureNotTerminated();
      if (chunk.done) {
       if (!pdfManager) {
        flushChunks();
       }
       cancelXHRs = null;
       return;
      }
      var data = chunk.value;
      loaded += arrayByteLength(data);
      if (!fullRequest.isStreamingSupported) {
       handler.send('DocProgress', {
        loaded: loaded,
        total: Math.max(loaded, fullRequest.contentLength || 0)
       });
      }
      if (pdfManager) {
       pdfManager.sendProgressiveData(data);
      } else {
       cachedChunks.push(data);
      }
      fullRequest.read().then(readChunk, reject);
     } catch (e) {
      reject(e);
     }
    };
    fullRequest.read().then(readChunk, reject);
   });
   readPromise.catch(function (e) {
    pdfManagerCapability.reject(e);
    cancelXHRs = null;
   });
   cancelXHRs = function () {
    pdfStream.cancelAllRequests('abort');
   };
   return pdfManagerCapability.promise;
  }
  function setupDoc(data) {
   function onSuccess(doc) {
    ensureNotTerminated();
    handler.send('GetDoc', { pdfInfo: doc });
   }
   function onFailure(e) {
    if (e instanceof PasswordException) {
     var task = new WorkerTask('PasswordException: response ' + e.code);
     startWorkerTask(task);
     handler.sendWithPromise('PasswordRequest', e).then(function (data) {
      finishWorkerTask(task);
      pdfManager.updatePassword(data.password);
      pdfManagerReady();
     }).catch(function (ex) {
      finishWorkerTask(task);
      handler.send('PasswordException', ex);
     }.bind(null, e));
    } else if (e instanceof InvalidPDFException) {
     handler.send('InvalidPDF', e);
    } else if (e instanceof MissingPDFException) {
     handler.send('MissingPDF', e);
    } else if (e instanceof UnexpectedResponseException) {
     handler.send('UnexpectedResponse', e);
    } else {
     handler.send('UnknownError', new UnknownErrorException(e.message, e.toString()));
    }
   }
   function pdfManagerReady() {
    ensureNotTerminated();
    loadDocument(false).then(onSuccess, function loadFailure(ex) {
     ensureNotTerminated();
     if (!(ex instanceof XRefParseException)) {
      onFailure(ex);
      return;
     }
     pdfManager.requestLoadedStream();
     pdfManager.onLoadedStream().then(function () {
      ensureNotTerminated();
      loadDocument(true).then(onSuccess, onFailure);
     });
    }, onFailure);
   }
   ensureNotTerminated();
   var evaluatorOptions = {
    forceDataSchema: data.disableCreateObjectURL,
    maxImageSize: data.maxImageSize === undefined ? -1 : data.maxImageSize,
    disableFontFace: data.disableFontFace,
    disableNativeImageDecoder: data.disableNativeImageDecoder
   };
   getPdfManager(data, evaluatorOptions).then(function (newPdfManager) {
    if (terminated) {
     newPdfManager.terminate();
     throw new Error('Worker was terminated');
    }
    pdfManager = newPdfManager;
    handler.send('PDFManagerReady', null);
    pdfManager.onLoadedStream().then(function (stream) {
     handler.send('DataLoaded', { length: stream.bytes.byteLength });
    });
   }).then(pdfManagerReady, onFailure);
  }
  handler.on('GetPage', function wphSetupGetPage(data) {
   return pdfManager.getPage(data.pageIndex).then(function (page) {
    var rotatePromise = pdfManager.ensure(page, 'rotate');
    var refPromise = pdfManager.ensure(page, 'ref');
    var userUnitPromise = pdfManager.ensure(page, 'userUnit');
    var viewPromise = pdfManager.ensure(page, 'view');
    return Promise.all([
     rotatePromise,
     refPromise,
     userUnitPromise,
     viewPromise
    ]).then(function (results) {
     return {
      rotate: results[0],
      ref: results[1],
      userUnit: results[2],
      view: results[3]
     };
    });
   });
  });
  handler.on('GetPageIndex', function wphSetupGetPageIndex(data) {
   var ref = new Ref(data.ref.num, data.ref.gen);
   var catalog = pdfManager.pdfDocument.catalog;
   return catalog.getPageIndex(ref);
  });
  handler.on('GetDestinations', function wphSetupGetDestinations(data) {
   return pdfManager.ensureCatalog('destinations');
  });
  handler.on('GetDestination', function wphSetupGetDestination(data) {
   return pdfManager.ensureCatalog('getDestination', [data.id]);
  });
  handler.on('GetPageLabels', function wphSetupGetPageLabels(data) {
   return pdfManager.ensureCatalog('pageLabels');
  });
  handler.on('GetAttachments', function wphSetupGetAttachments(data) {
   return pdfManager.ensureCatalog('attachments');
  });
  handler.on('GetJavaScript', function wphSetupGetJavaScript(data) {
   return pdfManager.ensureCatalog('javaScript');
  });
  handler.on('GetOutline', function wphSetupGetOutline(data) {
   return pdfManager.ensureCatalog('documentOutline');
  });
  handler.on('GetMetadata', function wphSetupGetMetadata(data) {
   return Promise.all([
    pdfManager.ensureDoc('documentInfo'),
    pdfManager.ensureCatalog('metadata')
   ]);
  });
  handler.on('GetData', function wphSetupGetData(data) {
   pdfManager.requestLoadedStream();
   return pdfManager.onLoadedStream().then(function (stream) {
    return stream.bytes;
   });
  });
  handler.on('GetStats', function wphSetupGetStats(data) {
   return pdfManager.pdfDocument.xref.stats;
  });
  handler.on('GetAnnotations', function wphSetupGetAnnotations(data) {
   return pdfManager.getPage(data.pageIndex).then(function (page) {
    return pdfManager.ensure(page, 'getAnnotationsData', [data.intent]);
   });
  });
  handler.on('RenderPageRequest', function wphSetupRenderPage(data) {
   var pageIndex = data.pageIndex;
   pdfManager.getPage(pageIndex).then(function (page) {
    var task = new WorkerTask('RenderPageRequest: page ' + pageIndex);
    startWorkerTask(task);
    var pageNum = pageIndex + 1;
    var start = Date.now();
    page.getOperatorList(handler, task, data.intent, data.renderInteractiveForms).then(function (operatorList) {
     finishWorkerTask(task);
     info('page=' + pageNum + ' - getOperatorList: time=' + (Date.now() - start) + 'ms, len=' + operatorList.totalLength);
    }, function (e) {
     finishWorkerTask(task);
     if (task.terminated) {
      return;
     }
     handler.send('UnsupportedFeature', { featureId: UNSUPPORTED_FEATURES.unknown });
     var minimumStackMessage = 'worker.js: while trying to getPage() and getOperatorList()';
     var wrappedException;
     if (typeof e === 'string') {
      wrappedException = {
       message: e,
       stack: minimumStackMessage
      };
     } else if (typeof e === 'object') {
      wrappedException = {
       message: e.message || e.toString(),
       stack: e.stack || minimumStackMessage
      };
     } else {
      wrappedException = {
       message: 'Unknown exception type: ' + typeof e,
       stack: minimumStackMessage
      };
     }
     handler.send('PageError', {
      pageNum: pageNum,
      error: wrappedException,
      intent: data.intent
     });
    });
   });
  }, this);
  handler.on('GetTextContent', function wphExtractText(data) {
   var pageIndex = data.pageIndex;
   var normalizeWhitespace = data.normalizeWhitespace;
   var combineTextItems = data.combineTextItems;
   return pdfManager.getPage(pageIndex).then(function (page) {
    var task = new WorkerTask('GetTextContent: page ' + pageIndex);
    startWorkerTask(task);
    var pageNum = pageIndex + 1;
    var start = Date.now();
    return page.extractTextContent(task, normalizeWhitespace, combineTextItems).then(function (textContent) {
     finishWorkerTask(task);
     info('text indexing: page=' + pageNum + ' - time=' + (Date.now() - start) + 'ms');
     return textContent;
    }, function (reason) {
     finishWorkerTask(task);
     if (task.terminated) {
      return;
     }
     throw reason;
    });
   });
  });
  handler.on('Cleanup', function wphCleanup(data) {
   return pdfManager.cleanup();
  });
  handler.on('Terminate', function wphTerminate(data) {
   terminated = true;
   if (pdfManager) {
    pdfManager.terminate();
    pdfManager = null;
   }
   if (cancelXHRs) {
    cancelXHRs();
   }
   var waitOn = [];
   WorkerTasks.forEach(function (task) {
    waitOn.push(task.finished);
    task.terminate();
   });
   return Promise.all(waitOn).then(function () {
    handler.destroy();
    handler = null;
   });
  });
  handler.on('Ready', function wphReady(data) {
   setupDoc(docParams);
   docParams = null;
  });
  return workerHandlerName;
 }
};
function initializeWorker() {
 var handler = new MessageHandler('worker', 'main', self);
 WorkerMessageHandler.setup(handler, self);
 handler.send('ready', null);
}
if (typeof window === 'undefined' && !isNodeJS()) {
 initializeWorker();
}
exports.setPDFNetworkStreamClass = setPDFNetworkStreamClass;
exports.WorkerTask = WorkerTask;
exports.WorkerMessageHandler = WorkerMessageHandler;