Leave initial request open until the viewer is ready to switch to range requests.

extensions/firefox/components/PdfStreamConverter.js

@@ -439,9 +439,12 @@ var RangedChromeActions = (function RangedChromeActionsClosure() {
    * This is for range requests
    */
   function RangedChromeActions(
-              domWindow, contentDispositionFilename, originalRequest) {
+              domWindow, contentDispositionFilename, originalRequest,
+              dataListener) {
 
     ChromeActions.call(this, domWindow, contentDispositionFilename);
+    this.dataListener = dataListener;
+    this.originalRequest = originalRequest;
 
     this.pdfUrl = originalRequest.URI.spec;
     this.contentLength = originalRequest.contentLength;
@@ -487,11 +490,15 @@ var RangedChromeActions = (function RangedChromeActionsClosure() {
   proto.constructor = RangedChromeActions;
 
   proto.initPassiveLoading = function RangedChromeActions_initPassiveLoading() {
+    this.originalRequest.cancel(Cr.NS_BINDING_ABORTED);
+    this.originalRequest = null;
     this.domWindow.postMessage({
       pdfjsLoadAction: 'supportsRangedLoading',
       pdfUrl: this.pdfUrl,
-      length: this.contentLength
+      length: this.contentLength,
+      data: this.dataListener.getData()
     }, '*');
+    this.dataListener = null;
 
     return true;
   };
@@ -692,8 +699,8 @@ PdfStreamConverter.prototype = {
    * 1. asyncConvertData stores the listener
    * 2. onStartRequest creates a new channel, streams the viewer
    * 3. If range requests are supported:
-   *      3.1. Suspends and cancels the request so we can issue range
-   *          requests instead.
+   *      3.1. Leave the request open until the viewer is ready to switch to
+   *           range requests.
    *
    *    If range rquests are not supported:
    *      3.1. Read the stream as it's loaded in onDataAvailable to send
@@ -779,18 +786,12 @@ PdfStreamConverter.prototype = {
     PdfJsTelemetry.onViewerIsUsed();
     PdfJsTelemetry.onDocumentSize(aRequest.contentLength);
 
-    if (!rangeRequest) {
-      // Creating storage for PDF data
-      var contentLength = aRequest.contentLength;
-      this.dataListener = new PdfDataListener(contentLength);
-      this.binaryStream = Cc['@mozilla.org/binaryinputstream;1']
-                          .createInstance(Ci.nsIBinaryInputStream);
-    } else {
-      // Suspend the request so we're not consuming any of the stream,
-      // but we can't cancel the request yet. Otherwise, the original
-      // listener will think we do not want to go the new PDF url
-      aRequest.suspend();
-    }
+
+    // Creating storage for PDF data
+    var contentLength = aRequest.contentLength;
+    this.dataListener = new PdfDataListener(contentLength);
+    this.binaryStream = Cc['@mozilla.org/binaryinputstream;1']
+                        .createInstance(Ci.nsIBinaryInputStream);
 
     // Create a new channel that is viewer loaded as a resource.
     var ioService = Services.io;
@@ -816,12 +817,8 @@ PdfStreamConverter.prototype = {
         var domWindow = getDOMWindow(channel);
         var actions;
         if (rangeRequest) {
-          // We are going to be issuing range requests, so cancel the
-          // original request
-          aRequest.resume();
-          aRequest.cancel(Cr.NS_BINDING_ABORTED);
-          actions = new RangedChromeActions(domWindow,
-              contentDispositionFilename, aRequest);
+          actions = new RangedChromeActions(
+              domWindow, contentDispositionFilename, aRequest, dataListener);
         } else {
           actions = new StandardChromeActions(
               domWindow, contentDispositionFilename, dataListener);

src/core/chunked_stream.js

@@ -30,6 +30,7 @@ var ChunkedStream = (function ChunkedStreamClosure() {
     this.numChunksLoaded = 0;
     this.numChunks = Math.ceil(length / chunkSize);
     this.manager = manager;
+    this.initialDataLength = 0;
   }
 
   // required methods for a stream. if a particular stream does not
@@ -77,11 +78,26 @@ var ChunkedStream = (function ChunkedStreamClosure() {
       }
     },
 
+    onReceiveInitialData: function (data) {
+      this.bytes.set(data);
+      this.initialDataLength = data.length;
+      var endChunk = this.end === data.length ?
+                     this.numChunks : Math.floor(data.length / this.chunkSize);
+      for (var i = 0; i < endChunk; i++) {
+        this.loadedChunks[i] = true;
+        ++this.numChunksLoaded;
+      }
+    },
+
     ensureRange: function ChunkedStream_ensureRange(begin, end) {
       if (begin >= end) {
         return;
       }
 
+      if (end <= this.initialDataLength) {
+        return;
+      }
+
       var chunkSize = this.chunkSize;
       var beginChunk = Math.floor(begin / chunkSize);
       var endChunk = Math.floor((end - 1) / chunkSize) + 1;
@@ -243,10 +259,25 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
     this.callbacksByRequest = {};
 
     this.loadedStream = new Promise();
+    if (args.initialData) {
+      this.setInitialData(args.initialData);
+    }
   }
 
   ChunkedStreamManager.prototype = {
 
+    setInitialData: function ChunkedStreamManager_setInitialData(data) {
+      this.stream.onReceiveInitialData(data);
+      if (this.stream.allChunksLoaded()) {
+        this.loadedStream.resolve(this.stream);
+      } else if (this.msgHandler) {
+        this.msgHandler.send('DocProgress', {
+          loaded: data.length,
+          total: this.length
+        });
+      }
+    },
+
     onLoadedStream: function ChunkedStreamManager_getLoadedStream() {
       return this.loadedStream;
     },

src/core/pdf_manager.js

@@ -139,7 +139,8 @@ var NetworkPdfManager = (function NetworkPdfManagerClosure() {
       msgHandler: msgHandler,
       httpHeaders: args.httpHeaders,
       chunkedViewerLoading: args.chunkedViewerLoading,
-      disableAutoFetch: args.disableAutoFetch
+      disableAutoFetch: args.disableAutoFetch,
+      initialData: args.initialData
     };
     this.streamManager = new ChunkedStreamManager(args.length, CHUNK_SIZE,
                                                   args.url, params);

src/display/api.js

@@ -98,6 +98,9 @@ PDFJS.pdfBug = PDFJS.pdfBug === undefined ? false : PDFJS.pdfBug;
  *  - data  - A typed array with PDF data.
  *  - httpHeaders - Basic authentication headers.
  *  - password - For decrypting password-protected PDFs.
+ *  - initialData - A typed array with the first portion or all of the pdf data.
+ *                  Used by the extension since some data is already loaded
+ *                  before the switch to range requests. 
  *
  * @param {object} pdfDataRangeTransport is optional. It is used if you want
  * to manually serve range requests for data in the PDF. See viewer.js for

web/viewer.js

@@ -445,7 +445,8 @@ var PDFView = {
       switch (args.pdfjsLoadAction) {
         case 'supportsRangedLoading':
           PDFView.open(args.pdfUrl, 0, undefined, pdfDataRangeTransport, {
-            length: args.length
+            length: args.length,
+            initialData: args.data
           });
           break;
         case 'range':