1 files changed, 59 insertions, 0 deletions
diff --git a/dom/media/mp4/BufferStream.cpp b/dom/media/mp4/BufferStream.cpp
new file mode 100644
index 0000000000..c2fa40cb8a
--- /dev/null
+++ b/dom/media/mp4/BufferStream.cpp
@@ -0,0 +1,59 @@
+/* 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 "BufferStream.h"
+#include "MediaData.h"
+#include "MediaResource.h"
+#include <algorithm>
+
+namespace mozilla {
+
+BufferStream::BufferStream()
+    : mStartOffset(0), mData(new mozilla::MediaByteBuffer) {}
+
+BufferStream::BufferStream(mozilla::MediaByteBuffer* aBuffer)
+    : mStartOffset(0), mData(aBuffer) {}
+
+BufferStream::~BufferStream() = default;
+
+/*virtual*/
+bool BufferStream::ReadAt(int64_t aOffset, void* aData, size_t aLength,
+                          size_t* aBytesRead) {
+  if (aOffset < mStartOffset || aOffset > mStartOffset + mData->Length()) {
+    return false;
+  }
+  *aBytesRead =
+      std::min(aLength, size_t(mStartOffset + mData->Length() - aOffset));
+  memcpy(aData, mData->Elements() + aOffset - mStartOffset, *aBytesRead);
+  return true;
+}
+
+/*virtual*/
+bool BufferStream::CachedReadAt(int64_t aOffset, void* aData, size_t aLength,
+                                size_t* aBytesRead) {
+  return ReadAt(aOffset, aData, aLength, aBytesRead);
+}
+
+/*virtual*/
+bool BufferStream::Length(int64_t* aLength) {
+  *aLength = mStartOffset + mData->Length();
+  return true;
+}
+
+/* virtual */
+void BufferStream::DiscardBefore(int64_t aOffset) {
+  if (aOffset > mStartOffset) {
+    mData->RemoveElementsAt(0, aOffset - mStartOffset);
+    mStartOffset = aOffset;
+  }
+}
+
+bool BufferStream::AppendBytes(const uint8_t* aData, size_t aLength) {
+  return mData->AppendElements(aData, aLength, fallible);
+}
+
+MediaByteRange BufferStream::GetByteRange() {
+  return MediaByteRange(mStartOffset, mStartOffset + mData->Length());
+}
+}  // namespace mozilla