Merge pull request #8712 from mukulmishra18/node_stream

Adds node.js logic for networking tasks for PDF.js

examples/node/getinfo.js

@@ -17,11 +17,10 @@ var pdfjsLib = require('pdfjs-dist');
 
 // Loading file from file system into typed array
 var pdfPath = process.argv[2] || '../../web/compressed.tracemonkey-pldi-09.pdf';
-var data = new Uint8Array(fs.readFileSync(pdfPath));
 
 // Will be using promises to load document, pages and misc data instead of
 // callback.
-pdfjsLib.getDocument(data).then(function (doc) {
+pdfjsLib.getDocument(pdfPath).then(function (doc) {
   var numPages = doc.numPages;
   console.log('# Document Loaded');
   console.log('Number of Pages: ' + numPages);

src/display/network.js

@@ -14,11 +14,11 @@
  */
 
 import {
-  assert, createPromiseCapability, isInt, MissingPDFException,
+  assert, createPromiseCapability, MissingPDFException,
   UnexpectedResponseException
 } from '../shared/util';
 import globalScope from '../shared/global_scope';
-import { setPDFNetworkStreamClass } from './api';
+import { validateRangeRequestCapabilities } from './network_utils';
 
 if (typeof PDFJSDev !== 'undefined' && PDFJSDev.test('FIREFOX || MOZCENTRAL')) {
   throw new Error('Module "./network" shall not ' +
@@ -352,56 +352,29 @@ function PDFNetworkStreamFullRequestReader(manager, options) {
 }
 
 PDFNetworkStreamFullRequestReader.prototype = {
-  _validateRangeRequestCapabilities: function
-      PDFNetworkStreamFullRequestReader_validateRangeRequestCapabilities() {
-
-    if (this._disableRange) {
-      return false;
-    }
-
-    var networkManager = this._manager;
-    if (!networkManager.isHttp) {
-      return false;
-    }
-    var fullRequestXhrId = this._fullRequestId;
-    var fullRequestXhr = networkManager.getRequestXhr(fullRequestXhrId);
-    if (fullRequestXhr.getResponseHeader('Accept-Ranges') !== 'bytes') {
-      return false;
-    }
-
-    var contentEncoding =
-      fullRequestXhr.getResponseHeader('Content-Encoding') || 'identity';
-    if (contentEncoding !== 'identity') {
-      return false;
-    }
-
-    var length = fullRequestXhr.getResponseHeader('Content-Length');
-    length = parseInt(length, 10);
-    if (!isInt(length)) {
-      return false;
-    }
-
-    this._contentLength = length; // setting right content length
-
-    if (length <= 2 * this._rangeChunkSize) {
-      // The file size is smaller than the size of two chunks, so it does
-      // not make any sense to abort the request and retry with a range
-      // request.
-      return false;
-    }
-
-    return true;
-  },
-
   _onHeadersReceived:
       function PDFNetworkStreamFullRequestReader_onHeadersReceived() {
+    var fullRequestXhrId = this._fullRequestId;
+    var fullRequestXhr = this._manager.getRequestXhr(fullRequestXhrId);
 
-    if (this._validateRangeRequestCapabilities()) {
+    let { allowRangeRequests, suggestedLength, } =
+      validateRangeRequestCapabilities({
+        getResponseHeader: (name) => {
+          return fullRequestXhr.getResponseHeader(name);
+        },
+        isHttp: this._manager.isHttp,
+        rangeChunkSize: this._rangeChunkSize,
+        disableRange: this._disableRange,
+      });
+
+    // Setting right content length.
+    this._contentLength = suggestedLength || this._contentLength;
+
+    if (allowRangeRequests) {
       this._isRangeSupported = true;
     }
 
     var networkManager = this._manager;
-    var fullRequestXhrId = this._fullRequestId;
     if (networkManager.isStreamingRequest(fullRequestXhrId)) {
       // We can continue fetching when progressive loading is enabled,
       // and we don't need the autoFetch feature.
@@ -594,8 +567,6 @@ PDFNetworkStreamRangeRequestReader.prototype = {
   },
 };
 
-setPDFNetworkStreamClass(PDFNetworkStream);
-
 export {
   PDFNetworkStream,
   NetworkManager,

src/display/network_utils.js

@@ -0,0 +1,57 @@
+/* Copyright 2012 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.
+ */
+
+import { assert, isInt } from '../shared/util';
+
+function validateRangeRequestCapabilities({ getResponseHeader, isHttp,
+                                            rangeChunkSize, disableRange, }) {
+  assert(rangeChunkSize > 0);
+  let returnValues = {
+    allowRangeRequests: false,
+    suggestedLength: undefined,
+  };
+  if (disableRange || !isHttp) {
+    return returnValues;
+  }
+  if (getResponseHeader('Accept-Ranges') !== 'bytes') {
+    return returnValues;
+  }
+
+  let contentEncoding = getResponseHeader('Content-Encoding') || 'identity';
+  if (contentEncoding !== 'identity') {
+    return returnValues;
+  }
+
+  let length = getResponseHeader('Content-Length');
+  length = parseInt(length, 10);
+  if (!isInt(length)) {
+    return returnValues;
+  }
+
+  returnValues.suggestedLength = length;
+  if (length <= 2 * rangeChunkSize) {
+    // The file size is smaller than the size of two chunks, so it does
+    // not make any sense to abort the request and retry with a range
+    // request.
+    return returnValues;
+  }
+
+  returnValues.allowRangeRequests = true;
+  return returnValues;
+}
+
+export {
+  validateRangeRequestCapabilities,
+};

src/display/node_stream.js

@@ -0,0 +1,383 @@
+/* Copyright 2012 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.
+ */
+/* globals __non_webpack_require__ */
+
+let fs = __non_webpack_require__('fs');
+let http = __non_webpack_require__('http');
+let https = __non_webpack_require__('https');
+let url = __non_webpack_require__('url');
+
+import { assert, createPromiseCapability } from '../shared/util';
+import { validateRangeRequestCapabilities } from './network_utils';
+
+class PDFNodeStream {
+  constructor(options) {
+    this.options = options;
+    this.source = options.source;
+    this.url = url.parse(this.source.url);
+    this.isHttp = this.url.protocol === 'http:' ||
+                  this.url.protocol === 'https:';
+    // Check if url refers to filesystem.
+    this.isFsUrl = this.url.protocol === 'file:' || !this.url.host;
+    this.httpHeaders = (this.isHttp && this.source.httpHeaders) || {};
+
+    this._fullRequest = null;
+    this._rangeRequestReaders = [];
+  }
+
+  getFullReader() {
+    assert(!this._fullRequest);
+    this._fullRequest = this.isFsUrl ?
+      new PDFNodeStreamFsFullReader(this) :
+      new PDFNodeStreamFullReader(this);
+    return this._fullRequest;
+  }
+
+  getRangeReader(start, end) {
+    let rangeReader = this.isFsUrl ?
+      new PDFNodeStreamFsRangeReader(this, start, end) :
+      new PDFNodeStreamRangeReader(this, start, end);
+    this._rangeRequestReaders.push(rangeReader);
+    return rangeReader;
+  }
+
+  cancelAllRequests(reason) {
+    if (this._fullRequest) {
+      this._fullRequest.cancel(reason);
+    }
+
+    let readers = this._rangeRequestReaders.slice(0);
+    readers.forEach(function(reader) {
+      reader.cancel(reason);
+    });
+  }
+}
+
+class BaseFullReader {
+  constructor(stream) {
+    this._url = stream.url;
+    this._done = false;
+    this._errored = false;
+    this._reason = null;
+    this.onProgress = null;
+    this._contentLength = stream.source.length; // optional
+    this._loaded = 0;
+
+    this._disableRange = stream.options.disableRange || false;
+    this._rangeChunkSize = stream.source.rangeChunkSize;
+    if (!this._rangeChunkSize && !this._disableRange) {
+      this._disableRange = true;
+    }
+
+    this._isStreamingSupported = !stream.source.disableStream;
+    this._isRangeSupported = !stream.options.disableRange;
+
+    this._readableStream = null;
+    this._readCapability = createPromiseCapability();
+    this._headersCapability = createPromiseCapability();
+  }
+
+  get headersReady() {
+    return this._headersCapability.promise;
+  }
+
+  get contentLength() {
+    return this._contentLength;
+  }
+
+  get isRangeSupported() {
+    return this._isRangeSupported;
+  }
+
+  get isStreamingSupported() {
+    return this._isStreamingSupported;
+  }
+
+  read() {
+    return this._readCapability.promise.then(() => {
+      if (this._done) {
+        return Promise.resolve({ value: undefined, done: true, });
+      }
+      if (this._errored) {
+        return Promise.reject(this._reason);
+      }
+
+      let chunk = this._readableStream.read();
+      if (chunk === null) {
+        this._readCapability = createPromiseCapability();
+        return this.read();
+      }
+      this._loaded += chunk.length;
+      if (this.onProgress) {
+        this.onProgress({
+          loaded: this._loaded,
+          total: this._contentLength,
+        });
+      }
+      // Ensure that `read()` method returns ArrayBuffer.
+      let buffer = new Uint8Array(chunk).buffer;
+      return Promise.resolve({ value: buffer, done: false, });
+    });
+  }
+
+  cancel(reason) {
+    // Call `this._error()` method when cancel is called
+    // before _readableStream is set.
+    if (!this._readableStream) {
+      this._error(reason);
+      return;
+    }
+    this._readableStream.destroy(reason);
+  }
+
+  _error(reason) {
+    this._errored = true;
+    this._reason = reason;
+    this._readCapability.resolve();
+  }
+
+  _setReadableStream(readableStream) {
+    this._readableStream = readableStream;
+    readableStream.on('readable', () => {
+      this._readCapability.resolve();
+    });
+
+    readableStream.on('end', () => {
+      // Destroy readable to minimize resource usage.
+      readableStream.destroy();
+      this._done = true;
+      this._readCapability.resolve();
+    });
+
+    readableStream.on('error', (reason) => {
+      this._error(reason);
+    });
+
+    // Destroy ReadableStream if already in errored state.
+    if (this._errored) {
+      this._readableStream.destroy(this._reason);
+    }
+  }
+}
+
+class BaseRangeReader {
+  constructor(stream) {
+    this._url = stream.url;
+    this._done = false;
+    this._errored = false;
+    this._reason = null;
+    this.onProgress = null;
+    this._loaded = 0;
+    this._readableStream = null;
+    this._readCapability = createPromiseCapability();
+
+    this._isStreamingSupported = !stream.source.disableStream;
+  }
+
+  get isStreamingSupported() {
+    return this._isStreamingSupported;
+  }
+
+  read() {
+    return this._readCapability.promise.then(() => {
+      if (this._done) {
+        return Promise.resolve({ value: undefined, done: true, });
+      }
+      if (this._errored) {
+        return Promise.reject(this._reason);
+      }
+
+      let chunk = this._readableStream.read();
+      if (chunk === null) {
+        this._readCapability = createPromiseCapability();
+        return this.read();
+      }
+      this._loaded += chunk.length;
+      if (this.onProgress) {
+        this.onProgress({ loaded: this._loaded, });
+      }
+      // Ensure that `read()` method returns ArrayBuffer.
+      let buffer = new Uint8Array(chunk).buffer;
+      return Promise.resolve({ value: buffer, done: false, });
+    });
+  }
+
+  cancel(reason) {
+    // Call `this._error()` method when cancel is called
+    // before _readableStream is set.
+    if (!this._readableStream) {
+      this._error(reason);
+      return;
+    }
+    this._readableStream.destroy(reason);
+  }
+
+  _error(reason) {
+    this._errored = true;
+    this._reason = reason;
+    this._readCapability.resolve();
+  }
+
+  _setReadableStream(readableStream) {
+    this._readableStream = readableStream;
+    readableStream.on('readable', () => {
+      this._readCapability.resolve();
+    });
+
+    readableStream.on('end', () => {
+      // Destroy readableStream to minimize resource usage.
+      readableStream.destroy();
+      this._done = true;
+      this._readCapability.resolve();
+    });
+
+    readableStream.on('error', (reason) => {
+      this._error(reason);
+    });
+
+    // Destroy readableStream if already in errored state.
+    if (this._errored) {
+      this._readableStream.destroy(this._reason);
+    }
+  }
+}
+
+function createRequestOptions(url, headers) {
+  return {
+    protocol: url.protocol,
+    auth: url.auth,
+    host: url.hostname,
+    port: url.port,
+    path: url.path,
+    method: 'GET',
+    headers,
+  };
+}
+
+class PDFNodeStreamFullReader extends BaseFullReader {
+  constructor(stream) {
+    super(stream);
+
+    let handleResponse = (response) => {
+      this._headersCapability.resolve();
+      this._setReadableStream(response);
+
+      let { allowRangeRequests, suggestedLength, } =
+      validateRangeRequestCapabilities({
+        getResponseHeader: (name) => {
+          // Make sure that headers name are in lower case, as mentioned
+          // here: https://nodejs.org/api/http.html#http_message_headers.
+          return this._readableStream.headers[name.toLowerCase()];
+        },
+        isHttp: stream.isHttp,
+        rangeChunkSize: this._rangeChunkSize,
+        disableRange: this._disableRange,
+      });
+
+      if (allowRangeRequests) {
+        this._isRangeSupported = true;
+      }
+      // Setting right content length.
+      this._contentLength = suggestedLength;
+    };
+
+    this._request = null;
+    if (this._url.protocol === 'http:') {
+      this._request = http.request(createRequestOptions(
+        this._url, stream.httpHeaders), handleResponse);
+    } else {
+      this._request = https.request(createRequestOptions(
+        this._url, stream.httpHeaders), handleResponse);
+    }
+
+    this._request.on('error', (reason) => {
+      this._errored = true;
+      this._reason = reason;
+      this._headersCapability.reject(reason);
+    });
+    // Note: `request.end(data)` is used to write `data` to request body
+    // and notify end of request. But one should always call `request.end()`
+    // even if there is no data to write -- (to notify the end of request).
+    this._request.end();
+  }
+}
+
+class PDFNodeStreamRangeReader extends BaseRangeReader {
+  constructor(stream, start, end) {
+    super(stream);
+
+    this._httpHeaders = {};
+    for (let property in stream.httpHeaders) {
+      let value = stream.httpHeaders[property];
+      if (typeof value === 'undefined') {
+        continue;
+      }
+      this._httpHeaders[property] = value;
+    }
+    this._httpHeaders['Range'] = `bytes=${start}-${end - 1}`;
+
+    this._request = null;
+    if (this._url.protocol === 'http:') {
+      this._request = http.request(createRequestOptions(
+        this._url, this._httpHeaders), (response) => {
+          this._setReadableStream(response);
+        });
+    } else {
+      this._request = https.request(createRequestOptions(
+        this._url, this._httpHeaders), (response) => {
+          this._setReadableStream(response);
+        });
+    }
+
+    this._request.on('error', (reason) => {
+      this._errored = true;
+      this._reason = reason;
+    });
+    this._request.end();
+  }
+}
+
+class PDFNodeStreamFsFullReader extends BaseFullReader {
+  constructor(stream) {
+    super(stream);
+
+    this._setReadableStream(fs.createReadStream(this._url.path));
+
+    fs.lstat(this._url.path, (error, stat) => {
+      if (error) {
+        this._errored = true;
+        this._reason = error;
+        this._headersCapability.reject(error);
+        return;
+      }
+      // Setting right content length.
+      this._contentLength = stat.size;
+      this._headersCapability.resolve();
+    });
+  }
+}
+
+class PDFNodeStreamFsRangeReader extends BaseRangeReader {
+  constructor(stream, start, end) {
+    super(stream);
+
+    this._setReadableStream(
+      fs.createReadStream(this._url.path, { start, end: end - 1, }));
+  }
+}
+
+export {
+  PDFNodeStream,
+};

src/pdf.js

@@ -31,7 +31,13 @@ var pdfjsDisplaySVG = require('./display/svg.js');
 
 if (typeof PDFJSDev === 'undefined' ||
     !PDFJSDev.test('FIREFOX || MOZCENTRAL')) {
-  require('./display/network.js');
+  if (pdfjsSharedUtil.isNodeJS()) {
+    var PDFNodeStream = require('./display/node_stream.js').PDFNodeStream;
+    pdfjsDisplayAPI.setPDFNetworkStreamClass(PDFNodeStream);
+  } else {
+    var PDFNetworkStream = require('./display/network.js').PDFNetworkStream;
+    pdfjsDisplayAPI.setPDFNetworkStreamClass(PDFNetworkStream);
+  }
 }
 
 exports.PDFJS = pdfjsDisplayGlobal.PDFJS;

test/unit/clitests.json

@@ -15,6 +15,7 @@
     "fonts_spec.js",
     "function_spec.js",
     "murmurhash3_spec.js",
+    "node_stream_spec.js",
     "parser_spec.js",
     "primitives_spec.js",
     "stream_spec.js",

test/unit/jasmine-boot.js

@@ -43,6 +43,8 @@
 function initializePDFJS(callback) {
   Promise.all([
     'pdfjs/display/global',
+    'pdfjs/display/api',
+    'pdfjs/display/network',
     'pdfjs-test/unit/annotation_spec',
     'pdfjs-test/unit/api_spec',
     'pdfjs-test/unit/bidi_spec',
@@ -72,7 +74,11 @@ function initializePDFJS(callback) {
     return SystemJS.import(moduleName);
   })).then(function (modules) {
     var displayGlobal = modules[0];
+    var displayApi = modules[1];
+    var PDFNetworkStream = modules[2].PDFNetworkStream;
 
+    // Set network stream class for unit tests.
+    displayApi.setPDFNetworkStreamClass(PDFNetworkStream);
     // Configure the worker.
     displayGlobal.PDFJS.workerSrc = '../../build/generic/build/pdf.worker.js';
     // Opt-in to using the latest API.

test/unit/node_stream_spec.js

@@ -0,0 +1,234 @@
+/* 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.
+ */
+/* globals __non_webpack_require__ */
+
+import { assert, isNodeJS } from '../../src/shared/util';
+import { PDFNodeStream } from '../../src/display/node_stream';
+
+// Make sure that we only running this script is Node.js environments.
+assert(isNodeJS());
+
+let path = __non_webpack_require__('path');
+let url = __non_webpack_require__('url');
+let http = __non_webpack_require__('http');
+let fs = __non_webpack_require__('fs');
+
+describe('node_stream', function() {
+  let server = null;
+  let port = null;
+  let pdf = url.parse(encodeURI('file://' + path.join(process.cwd(),
+                      './test/pdfs/tracemonkey.pdf'))).href;
+  let pdfLength = 1016315;
+
+  beforeAll((done) => {
+    // Create http server to serve pdf data for tests.
+    server = http.createServer((request, response) => {
+      let filePath = process.cwd() + '/test/pdfs' + request.url;
+      fs.lstat(filePath, (error, stat) => {
+        if (error) {
+          response.writeHead(404);
+          response.end(`File ${request.url} not found!`);
+          return;
+        }
+        if (!request.headers['range']) {
+          let contentLength = stat.size;
+          let stream = fs.createReadStream(filePath);
+          response.writeHead(200, {
+            'Content-Type': 'application/pdf',
+            'Content-Length': contentLength,
+            'Accept-Ranges': 'bytes',
+          });
+          stream.pipe(response);
+        } else {
+          let [start, end] =
+            request.headers['range'].split('=')[1].split('-').map((x) => {
+              return Number(x);
+            });
+          let stream = fs.createReadStream(filePath, { start, end, });
+          response.writeHead(206, {
+            'Content-Type': 'application/pdf',
+          });
+          stream.pipe(response);
+        }
+      });
+    }).listen(0); /* Listen on a random free port */
+    port = server.address().port;
+    done();
+  });
+
+  afterAll((done) => {
+    // Close the server from accepting new connections after all test finishes.
+    server.close();
+    done();
+  });
+
+  it('read both http(s) and filesystem pdf files', function(done) {
+    let stream1 = new PDFNodeStream({
+      source: {
+        url: `http://127.0.0.1:${port}/tracemonkey.pdf`,
+        rangeChunkSize: 65536,
+        disableStream: true,
+      },
+      disableRange: true,
+    });
+
+    let stream2 = new PDFNodeStream({
+      source: {
+        url: pdf,
+        rangeChunkSize: 65536,
+        disableStream: true,
+      },
+      disableRange: true,
+    });
+
+    let fullReader1 = stream1.getFullReader();
+    let fullReader2 = stream2.getFullReader();
+
+    let isStreamingSupported1, isRangeSupported1;
+    let promise1 = fullReader1.headersReady.then(() => {
+      isStreamingSupported1 = fullReader1.isStreamingSupported;
+      isRangeSupported1 = fullReader1.isRangeSupported;
+    });
+
+    let isStreamingSupported2, isRangeSupported2;
+    let promise2 = fullReader2.headersReady.then(() => {
+      isStreamingSupported2 = fullReader2.isStreamingSupported;
+      isRangeSupported2 = fullReader2.isRangeSupported;
+    });
+
+    let len1 = 0, len2 = 0;
+    let read1 = function () {
+      return fullReader1.read().then(function (result) {
+        if (result.done) {
+          return;
+        }
+        len1 += result.value.byteLength;
+        return read1();
+      });
+    };
+    let read2 = function () {
+      return fullReader2.read().then(function (result) {
+        if (result.done) {
+          return;
+        }
+        len2 += result.value.byteLength;
+        return read2();
+      });
+    };
+
+    let readPromise = Promise.all([read1(), read2(), promise1, promise2]);
+    readPromise.then((result) => {
+      expect(isStreamingSupported1).toEqual(false);
+      expect(isRangeSupported1).toEqual(false);
+      expect(isStreamingSupported2).toEqual(false);
+      expect(isRangeSupported2).toEqual(false);
+      expect(len1).toEqual(pdfLength);
+      expect(len1).toEqual(len2);
+      done();
+    }).catch((reason) => {
+      done.fail(reason);
+    });
+  });
+
+  it('read custom ranges for both http(s) and filesystem urls',
+      function(done) {
+    let rangeSize = 32768;
+    let stream1 = new PDFNodeStream({
+      source: {
+        url: `http://127.0.0.1:${port}/tracemonkey.pdf`,
+        length: pdfLength,
+        rangeChunkSize: rangeSize,
+        disableStream: true,
+      },
+      disableRange: false,
+    });
+    let stream2 = new PDFNodeStream({
+      source: {
+        url: pdf,
+        length: pdfLength,
+        rangeChunkSize: rangeSize,
+        disableStream: true,
+      },
+      disableRange: false,
+    });
+
+    let fullReader1 = stream1.getFullReader();
+    let fullReader2 = stream2.getFullReader();
+
+    let isStreamingSupported1, isRangeSupported1, fullReaderCancelled1;
+    let isStreamingSupported2, isRangeSupported2, fullReaderCancelled2;
+
+    let promise1 = fullReader1.headersReady.then(function () {
+      isStreamingSupported1 = fullReader1.isStreamingSupported;
+      isRangeSupported1 = fullReader1.isRangeSupported;
+      // we shall be able to close the full reader without issues
+      fullReader1.cancel('Don\'t need full reader');
+      fullReaderCancelled1 = true;
+    });
+
+    let promise2 = fullReader2.headersReady.then(function () {
+      isStreamingSupported2 = fullReader2.isStreamingSupported;
+      isRangeSupported2 = fullReader2.isRangeSupported;
+      fullReader2.cancel('Don\'t need full reader');
+      fullReaderCancelled2 = true;
+    });
+
+    // Skipping fullReader results, requesting something from the PDF end.
+    let tailSize = (pdfLength % rangeSize) || rangeSize;
+
+    let range11Reader = stream1.getRangeReader(pdfLength - tailSize - rangeSize,
+                                             pdfLength - tailSize);
+    let range12Reader = stream1.getRangeReader(pdfLength - tailSize, pdfLength);
+
+    let range21Reader = stream2.getRangeReader(pdfLength - tailSize - rangeSize,
+                                             pdfLength - tailSize);
+    let range22Reader = stream2.getRangeReader(pdfLength - tailSize, pdfLength);
+
+    let result11 = { value: 0, }, result12 = { value: 0, };
+    let result21 = { value: 0, }, result22 = { value: 0, };
+
+    let read = function (reader, lenResult) {
+      return reader.read().then(function (result) {
+        if (result.done) {
+          return;
+        }
+        lenResult.value += result.value.byteLength;
+        return read(reader, lenResult);
+      });
+    };
+
+    let readPromises = Promise.all([read(range11Reader, result11),
+                                    read(range12Reader, result12),
+                                    read(range21Reader, result21),
+                                    read(range22Reader, result22),
+                                    promise1, promise2]);
+
+    readPromises.then(function () {
+      expect(result11.value).toEqual(rangeSize);
+      expect(result12.value).toEqual(tailSize);
+      expect(result21.value).toEqual(rangeSize);
+      expect(result22.value).toEqual(tailSize);
+      expect(isStreamingSupported1).toEqual(false);
+      expect(isRangeSupported1).toEqual(true);
+      expect(fullReaderCancelled1).toEqual(true);
+      expect(isStreamingSupported2).toEqual(false);
+      expect(isRangeSupported2).toEqual(true);
+      expect(fullReaderCancelled2).toEqual(true);
+      done();
+    }).catch(function (reason) {
+      done.fail(reason);
+    });
+  });
+});