Bug 996310 - Change readArrayBuffer to return the number of bytes rea…

…d. r=bsmedberg
Brli · Apr 29, 2014 · 0e26fbe · 0e26fbe
1 parent b94c682
commit 0e26fbe
Show file tree

Hide file tree

Showing 3 changed files with 13 additions and 10 deletions.
diff --git a/xpcom/io/nsBinaryStream.cpp b/xpcom/io/nsBinaryStream.cpp
@@ -814,9 +814,10 @@ nsBinaryInputStream::ReadByteArray(uint32_t aLength, uint8_t** aResult)
 }
 
 NS_IMETHODIMP
-nsBinaryInputStream::ReadArrayBuffer(uint32_t aLength,
-                                     JS::Handle<JS::Value> aBuffer,
-                                     JSContext* aCx)
++nsBinaryInputStream::ReadArrayBuffer(uint32_t aLength,
+                                      JS::HandleValue aBuffer,
+                                      JSContext* aCx,
+                                      uint32_t *rLength)
 {
   if (!aBuffer.isObject()) {
     return NS_ERROR_FAILURE;
@@ -831,14 +832,11 @@ nsBinaryInputStream::ReadArrayBuffer(uint32_t aLength,
     return NS_ERROR_FAILURE;
   }
 
-  uint32_t bytesRead;
-  nsresult rv = Read(reinterpret_cast<char*>(data), aLength, &bytesRead);
+  nsresult rv = Read(reinterpret_cast<char*>(data), aLength, rLength);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
-  if (bytesRead != aLength) {
-    return NS_ERROR_FAILURE;
-  }
+
   return NS_OK;
 }
 

diff --git a/xpcom/io/nsIBinaryInputStream.idl b/xpcom/io/nsIBinaryInputStream.idl
@@ -76,10 +76,10 @@ interface nsIBinaryInputStream : nsIInputStream {
      * Note: passing view.buffer, where view is an ArrayBufferView of an
      *       ArrayBuffer, is not valid unless view.byteOffset == 0.
      *
-     * @throws NS_ERROR_FAILURE if it can't read aLength bytes
+     * @return The number of bytes actually read into aArrayBuffer.
      */
     [implicit_jscontext]
-    void readArrayBuffer(in uint32_t aLength, in jsval aArrayBuffer);
+    unsigned long readArrayBuffer(in uint32_t aLength, in jsval aArrayBuffer);
 };
 
 %{C++

diff --git a/xpcom/tests/unit/test_streams.js b/xpcom/tests/unit/test_streams.js
@@ -32,6 +32,7 @@ function test_binary_streams() {
   const HelloArray = Array.map(HelloStr, function(c) {return c.charCodeAt(0)});
   var countObj = {};
   var msg = {};
+  var buffer = ArrayBuffer(HelloArray.length);
 
   // Test reading immediately after writing.
   os.writeBoolean(true);
@@ -72,6 +73,10 @@ function test_binary_streams() {
   do_check_eq(typeof msg, typeof HelloArray);
   do_check_eq(msg.toSource(), HelloArray.toSource());
   do_check_eq(is.available(), 0);
+  os.writeByteArray(HelloArray, HelloArray.length);
+  do_check_eq(is.readArrayBuffer(buffer.byteLength, buffer), HelloArray.length);
+  do_check_eq([b for (b of Uint8Array(buffer))].toSource(), HelloArray.toSource());
+  do_check_eq(is.available(), 0);
 
   // Test writing in one big chunk.
   os.writeBoolean(true);