diff -r 000000000000 -r 6474c204b198 content/media/EncodedBufferCache.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/media/EncodedBufferCache.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,74 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "EncodedBufferCache.h"
+#include "nsAnonymousTemporaryFile.h"
+#include "nsDOMFile.h"
+#include "prio.h"
+
+namespace mozilla {
+
+void
+EncodedBufferCache::AppendBuffer(nsTArray<uint8_t> & aBuf)
+{
+  MutexAutoLock lock(mMutex);
+  mDataSize += aBuf.Length();
+
+  mEncodedBuffers.AppendElement()->SwapElements(aBuf);
+
+  if (!mTempFileEnabled && mDataSize > mMaxMemoryStorage) {
+    nsresult rv = NS_OpenAnonymousTemporaryFile(&mFD);
+    if (!NS_FAILED(rv)) {
+      mTempFileEnabled = true;
+    }
+  }
+
+  if (mTempFileEnabled) {
+    // has created temporary file, write buffer in it
+    for (uint32_t i = 0; i < mEncodedBuffers.Length(); i++) {
+      int64_t amount = PR_Write(mFD, mEncodedBuffers.ElementAt(i).Elements(), mEncodedBuffers.ElementAt(i).Length());
+      if (amount <  mEncodedBuffers.ElementAt(i).Length()) {
+        NS_WARNING("Failed to write media cache block!");
+      }
+    }
+    mEncodedBuffers.Clear();
+  }
+
+}
+
+already_AddRefed<nsIDOMBlob>
+EncodedBufferCache::ExtractBlob(const nsAString &aContentType)
+{
+  MutexAutoLock lock(mMutex);
+  nsCOMPtr<nsIDOMBlob> blob;
+  if (mTempFileEnabled) {
+    // generate new temporary file to write
+    blob = new nsDOMTemporaryFileBlob(mFD, 0, mDataSize, aContentType);
+    // fallback to memory blob
+    mTempFileEnabled = false;
+    mDataSize = 0;
+    mFD = nullptr;
+  } else {
+    void* blobData = moz_malloc(mDataSize);
+    NS_ASSERTION(blobData, "out of memory!!");
+
+    if (blobData) {
+      for (uint32_t i = 0, offset = 0; i < mEncodedBuffers.Length(); i++) {
+        memcpy((uint8_t*)blobData + offset, mEncodedBuffers.ElementAt(i).Elements(),
+               mEncodedBuffers.ElementAt(i).Length());
+        offset += mEncodedBuffers.ElementAt(i).Length();
+      }
+      blob = new nsDOMMemoryFile(blobData, mDataSize,
+                                 aContentType);
+      mEncodedBuffers.Clear();
+    } else
+      return nullptr;
+  }
+  mDataSize = 0;
+  return blob.forget();
+}
+
+} //end namespace