chromium/net/third_party/quiche/src/quiche/http2/decoder/decode_buffer.h

// Copyright 2016 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.

#ifndef QUICHE_HTTP2_DECODER_DECODE_BUFFER_H_
#define QUICHE_HTTP2_DECODER_DECODE_BUFFER_H_

// DecodeBuffer provides primitives for decoding various integer types found in
// HTTP/2 frames. It wraps a byte array from which we can read and decode
// serialized HTTP/2 frames, or parts thereof. DecodeBuffer is intended only for
// stack allocation, where the caller is typically going to use the DecodeBuffer
// instance as part of decoding the entire buffer before returning to its own
// caller.

#include <stddef.h>

#include <algorithm>
#include <cstdint>

#include "absl/strings/string_view.h"
#include "quiche/common/platform/api/quiche_export.h"
#include "quiche/common/platform/api/quiche_logging.h"

namespace http2 {
class DecodeBufferSubset;

class QUICHE_EXPORT DecodeBuffer { … };

// DecodeBufferSubset is used when decoding a known sized chunk of data, which
// starts at base->cursor(), and continues for subset_len, which may be
// entirely in |base|, or may extend beyond it (hence the MinLengthRemaining
// in the constructor).
// There are two benefits to using DecodeBufferSubset: it ensures that the
// cursor of |base| is advanced when the subset's destructor runs, and it
// ensures that the consumer of the subset can't go beyond the subset which
// it is intended to decode.
// There must be only a single DecodeBufferSubset at a time for a base
// DecodeBuffer, though they can be nested (i.e. a DecodeBufferSubset's
// base may itself be a DecodeBufferSubset). This avoids the AdvanceCursor
// being called erroneously.
class QUICHE_EXPORT DecodeBufferSubset : public DecodeBuffer { … };

}  // namespace http2

#endif  // QUICHE_HTTP2_DECODER_DECODE_BUFFER_H_