Move the disableAutoFetch option from the global PDFJS object and into getDocument instead

One additional complication with removing this option from the global `PDFJS` object, is that the viewer currently needs to check `disableAutoFetch` in a couple of places. To address this I'm thus proposing adding a getter in `PDFDocumentProxy`, to allow checking the *actually* used values for a particular `getDocument` invocation.

src/display/api.js

@@ -18,7 +18,7 @@ import {
   assert, createPromiseCapability, getVerbosityLevel, info, InvalidPDFException,
   isArrayBuffer, isNum, isSameOrigin, MessageHandler, MissingPDFException,
   NativeImageDecoding, PageViewport, PasswordException, setVerbosityLevel,
-  stringToBytes, UnexpectedResponseException, UnknownErrorException,
+  shadow, stringToBytes, UnexpectedResponseException, UnknownErrorException,
   unreachable, Util, warn
 } from '../shared/util';
 import {
@@ -164,6 +164,12 @@ function setPDFNetworkStreamFactory(pdfNetworkStreamFactory) {
  *   converted to OpenType fonts and loaded via font face rules. If disabled,
  *   fonts will be rendered using a built-in font renderer that constructs the
  *   glyphs with primitive path commands. The default value is `false`.
+ * @property {boolean} disableAutoFetch - (optional) Disable pre-fetching of PDF
+ *   file data. When range requests are enabled PDF.js will automatically keep
+ *   fetching more data even if it isn't needed to display the current page.
+ *   The default value is `false`.
+ *   NOTE: It is also necessary to disable streaming, see above,
+ *         in order for disabling of pre-fetching to work correctly.
  */
 
 /**
@@ -266,6 +272,10 @@ function getDocument(src) {
     params.disableFontFace = false;
   }
 
+  if (typeof params.disableAutoFetch !== 'boolean') {
+    params.disableAutoFetch = false;
+  }
+
   // Set the main-thread verbosity level.
   setVerbosityLevel(params.verbosity);
 
@@ -333,7 +343,6 @@ function _fetchDocument(worker, source, pdfDataRangeTransport, docId) {
     typeof PDFJSDev !== 'undefined' ? PDFJSDev.eval('BUNDLE_VERSION') : null;
 
   source.disableRange = getDefaultSetting('disableRange');
-  source.disableAutoFetch = getDefaultSetting('disableAutoFetch');
   source.disableStream = getDefaultSetting('disableStream');
   if (pdfDataRangeTransport) {
     source.length = pdfDataRangeTransport.length;
@@ -683,6 +692,10 @@ var PDFDocumentProxy = (function PDFDocumentProxyClosure() {
     destroy: function PDFDocumentProxy_destroy() {
       return this.loadingTask.destroy();
     },
+
+    get loadingParams() {
+      return this.transport.loadingParams;
+    },
   };
   return PDFDocumentProxy;
 })();
@@ -2116,6 +2129,13 @@ var WorkerTransport = (function WorkerTransportClosure() {
         this.fontLoader.clear();
       });
     },
+
+    get loadingParams() {
+      let params = this._params;
+      return shadow(this, 'loadingParams', {
+        disableAutoFetch: params.disableAutoFetch,
+      });
+    },
   };
   return WorkerTransport;
 

src/display/dom_utils.js

@@ -336,8 +336,6 @@ function getDefaultSetting(id) {
   switch (id) {
     case 'pdfBug':
       return globalSettings ? globalSettings.pdfBug : false;
-    case 'disableAutoFetch':
-      return globalSettings ? globalSettings.disableAutoFetch : false;
     case 'disableStream':
       return globalSettings ? globalSettings.disableStream : false;
     case 'disableRange':

src/display/global.js

@@ -82,18 +82,6 @@ PDFJS.disableRange = (PDFJS.disableRange === undefined ?
 PDFJS.disableStream = (PDFJS.disableStream === undefined ?
                        false : PDFJS.disableStream);
 
-/**
- * Disable pre-fetching of PDF file data. When range requests are enabled
- * PDF.js will automatically keep fetching more data even if it isn't needed
- * to display the current page. This default behavior can be disabled.
- *
- * NOTE: It is also necessary to disable streaming, see above,
- *       in order for disabling of pre-fetching to work correctly.
- * @var {boolean}
- */
-PDFJS.disableAutoFetch = (PDFJS.disableAutoFetch === undefined ?
-                          false : PDFJS.disableAutoFetch);
-
 /**
  * Enables special hooks for debugging PDF.js.
  * @var {boolean}