blob: f69dec9ecfbb8f97130e8cd206e5c30e36caa07a [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <memory>
#include <string>
#include <vector>
#include "base/memory/scoped_ptr.h"
#include "base/memory/scoped_vector.h"
namespace cobalt {
namespace speech {
// Models a chunk-oriented byte buffer. The term chunk is herein defined as an
// arbitrary sequence of bytes that is preceeded by N header bytes, indicating
// its size. Data may be appended to the buffer with no particular respect of
// chunks boundaries. However, chunks can be extracted (FIFO) only when their
// content (according to their header) is fully available in the buffer.
// The current implementation support only 4 byte Big Endian headers.
// Empty chunks (i.e. the sequence 00 00 00 00) are NOT allowed.
// E.g. 00 00 00 04 xx xx xx xx 00 00 00 02 yy yy 00 00 00 04 zz zz zz zz
// [----- CHUNK 1 -------] [--- CHUNK 2 ---] [------ CHUNK 3 ------]
class ChunkedByteBuffer {
// Appends |length| bytes starting from |start| to the buffer.
void Append(const uint8_t* start, size_t length);
// Appends bytes contained in the |string| to the buffer.
void Append(const std::string& string);
// Checks whether one or more complete chunks are available in the buffer.
bool HasChunks() const;
// If enough data is available, reads and removes the first complete chunk
// from the buffer. Returns a NULL pointer if no complete chunk is available.
scoped_ptr<std::vector<uint8_t> > PopChunk();
// Clears all the content of the buffer.
void Clear();
// Returns the number of raw bytes (including headers) present.
size_t GetTotalLength() const { return total_bytes_stored_; }
struct Chunk {
std::vector<uint8_t> header;
scoped_ptr<std::vector<uint8_t> > content;
size_t ExpectedContentLength() const;
ScopedVector<Chunk> chunks_;
scoped_ptr<Chunk> partial_chunk_;
size_t total_bytes_stored_;
} // namespace speech
} // namespace cobalt