From ef667823dd9d0f4d318f48c10263bb5d809b98be Mon Sep 17 00:00:00 2001
From: Tony Jin <tjin@box.com>
Date: Wed, 21 Oct 2015 16:56:27 -0700
Subject: [PATCH] [api-minor] Add an optional param to DocumentInitParameters
 for specifying the range request chunk size to use. Defaults to 2^16 = 65536.

---
 src/core/pdf_manager.js | 6 ++----
 src/core/worker.js      | 4 ++--
 src/display/api.js      | 7 +++++++
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/core/pdf_manager.js b/src/core/pdf_manager.js
index b264fdef9..9ae1b0d4d 100644
--- a/src/core/pdf_manager.js
+++ b/src/core/pdf_manager.js
@@ -19,9 +19,6 @@
 
 'use strict';
 
-// The maximum number of bytes fetched per range request
-var RANGE_CHUNK_SIZE = 65536;
-
 // TODO(mack): Make use of PDFJS.Util.inherit() when it becomes available
 var BasePdfManager = (function BasePdfManagerClosure() {
   function BasePdfManager() {
@@ -153,7 +150,8 @@ var NetworkPdfManager = (function NetworkPdfManagerClosure() {
       disableAutoFetch: args.disableAutoFetch,
       initialData: args.initialData
     };
-    this.streamManager = new ChunkedStreamManager(args.length, RANGE_CHUNK_SIZE,
+    this.streamManager = new ChunkedStreamManager(args.length,
+                                                  args.rangeChunkSize,
                                                   args.url, params);
 
     this.pdfDocument = new PDFDocument(this, this.streamManager.getStream(),
diff --git a/src/core/worker.js b/src/core/worker.js
index 7440534e7..efd716478 100644
--- a/src/core/worker.js
+++ b/src/core/worker.js
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 /* globals PDFJS, createPromiseCapability, LocalPdfManager, NetworkPdfManager,
-           NetworkManager, isInt, RANGE_CHUNK_SIZE, MissingPDFException,
+           NetworkManager, isInt, MissingPDFException,
            UnexpectedResponseException, PasswordException, Promise, warn,
            PasswordResponses, InvalidPDFException, UnknownErrorException,
            XRefParseException, Ref, info, globalScope, error, MessageHandler */
@@ -160,7 +160,7 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
             return;
           }
           source.length = length;
-          if (length <= 2 * RANGE_CHUNK_SIZE) {
+          if (length <= 2 * source.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.
diff --git a/src/display/api.js b/src/display/api.js
index f097bcad6..1c354234e 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -23,6 +23,8 @@
 
 'use strict';
 
+var DEFAULT_RANGE_CHUNK_SIZE = 65536; // 2^16 = 65536
+
 /**
  * The maximum allowed image size in total pixels e.g. width * height. Images
  * above this value will not be drawn. Use -1 for no limit.
@@ -217,6 +219,9 @@ PDFJS.isEvalSupported = (PDFJS.isEvalSupported === undefined ?
  * @property {number}     length - The PDF file length. It's used for progress
  *   reports and range requests operations.
  * @property {PDFDataRangeTransport} range
+ * @property {number}     rangeChunkSize - Optional parameter to specify
+ *   maximum number of bytes fetched per range request. The default value is
+ *   2^16 = 65536.
  */
 
 /**
@@ -326,6 +331,8 @@ PDFJS.getDocument = function getDocument(src,
     params[key] = source[key];
   }
 
+  params.rangeChunkSize = source.rangeChunkSize || DEFAULT_RANGE_CHUNK_SIZE;
+
   workerInitializedCapability = createPromiseCapability();
   transport = new WorkerTransport(workerInitializedCapability, source.range);
   workerInitializedCapability.promise.then(function transportInitialized() {