Merge pull request #15916 from Snuffleupagus/fetch-transfer

[api-minor] Enabling transferring of data fetched with the `PDFFetchStream` implementation

src/display/api.js

@@ -192,9 +192,7 @@ if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("PRODUCTION")) {
  * @property {boolean} [transferPdfData] - Determines if we can transfer
  *   TypedArrays used for loading the PDF file, utilized together with:
  *    - The `data`-option, for the `getDocument` function.
- *    - The `initialData`-option, for the `PDFDataRangeTransport` constructor.
+ *    - The `PDFDataTransportStream` implementation.
- *    - The `chunk`-option, for the `PDFDataTransportStream._onReceiveData`
- *      method.
  *   This will help reduce main-thread memory usage, however it will take
  *   ownership of the TypedArrays. The default value is `false`.
  * @property {boolean} [isEvalSupported] - Determines if we can evaluate strings
@@ -2499,7 +2497,7 @@ class WorkerTransport {
               return;
             }
             assert(
-              isArrayBuffer(value),
+              value instanceof ArrayBuffer,
               "GetReader - expected an ArrayBuffer."
             );
             // Enqueue data chunk into sink, and transfer it
@@ -2585,7 +2583,7 @@ class WorkerTransport {
               return;
             }
             assert(
-              isArrayBuffer(value),
+              value instanceof ArrayBuffer,
               "GetRangeReader - expected an ArrayBuffer."
             );
             sink.enqueue(new Uint8Array(value), 1, [value]);

src/display/fetch_stream.js

@@ -17,6 +17,7 @@ import {
   AbortException,
   assert,
   createPromiseCapability,
+  warn,
 } from "../shared/util.js";
 import {
   createResponseStatusError,
@@ -54,6 +55,17 @@ function createHeaders(httpHeaders) {
   return headers;
 }
 
+function getArrayBuffer(val) {
+  if (val instanceof Uint8Array) {
+    return val.buffer;
+  }
+  if (val instanceof ArrayBuffer) {
+    return val;
+  }
+  warn(`getArrayBuffer - unexpected data format: ${val}`);
+  return new Uint8Array(val).buffer;
+}
+
 /** @implements {IPDFStream} */
 class PDFFetchStream {
   constructor(source) {
@@ -195,8 +207,7 @@ class PDFFetchStreamReader {
       total: this._contentLength,
     });
 
-    const buffer = new Uint8Array(value).buffer;
+    return { value: getArrayBuffer(value), done: false };
-    return { value: buffer, done: false };
   }
 
   cancel(reason) {
@@ -254,8 +265,7 @@ class PDFFetchStreamRangeReader {
     this._loaded += value.byteLength;
     this.onProgress?.({ loaded: this._loaded });
 
-    const buffer = new Uint8Array(value).buffer;
+    return { value: getArrayBuffer(value), done: false };
-    return { value: buffer, done: false };
   }
 
   cancel(reason) {

src/display/network.js

@@ -38,8 +38,7 @@ function getArrayBuffer(xhr) {
   if (typeof data !== "string") {
     return data;
   }
-  const array = stringToBytes(data);
+  return stringToBytes(data).buffer;
-  return array.buffer;
 }
 
 class NetworkManager {