1 files changed, 61 insertions, 0 deletions
diff --git a/dom/media/ByteWriter.h b/dom/media/ByteWriter.h
new file mode 100644
index 0000000000..cc7f5ecf3f
--- /dev/null
+++ b/dom/media/ByteWriter.h
@@ -0,0 +1,61 @@
+/* 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/. */
+
+#ifndef BYTE_WRITER_H_
+#define BYTE_WRITER_H_
+
+#include "mozilla/EndianUtils.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+
+template <typename Endianess>
+class ByteWriter {
+ public:
+  explicit ByteWriter(nsTArray<uint8_t>& aData) : mPtr(aData) {}
+  ~ByteWriter() = default;
+
+  [[nodiscard]] bool WriteU8(uint8_t aByte) { return Write(&aByte, 1); }
+
+  [[nodiscard]] bool WriteU16(uint16_t aShort) {
+    uint8_t c[2];
+    Endianess::writeUint16(&c[0], aShort);
+    return Write(&c[0], 2);
+  }
+
+  [[nodiscard]] bool WriteU32(uint32_t aLong) {
+    uint8_t c[4];
+    Endianess::writeUint32(&c[0], aLong);
+    return Write(&c[0], 4);
+  }
+
+  [[nodiscard]] bool Write32(int32_t aLong) {
+    uint8_t c[4];
+    Endianess::writeInt32(&c[0], aLong);
+    return Write(&c[0], 4);
+  }
+
+  [[nodiscard]] bool WriteU64(uint64_t aLongLong) {
+    uint8_t c[8];
+    Endianess::writeUint64(&c[0], aLongLong);
+    return Write(&c[0], 8);
+  }
+
+  [[nodiscard]] bool Write64(int64_t aLongLong) {
+    uint8_t c[8];
+    Endianess::writeInt64(&c[0], aLongLong);
+    return Write(&c[0], 8);
+  }
+
+  [[nodiscard]] bool Write(const uint8_t* aSrc, size_t aCount) {
+    return mPtr.AppendElements(aSrc, aCount, mozilla::fallible);
+  }
+
+ private:
+  nsTArray<uint8_t>& mPtr;
+};
+
+}  // namespace mozilla
+
+#endif