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// Copyright 2017 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 COMPONENTS_SERVICES_HEAP_PROFILING_STREAM_PARSER_H_
#define COMPONENTS_SERVICES_HEAP_PROFILING_STREAM_PARSER_H_
#include "base/callback.h"
#include "base/containers/circular_deque.h"
#include "base/macros.h"
#include "base/synchronization/lock.h"
#include "components/services/heap_profiling/receiver.h"
#include "components/services/heap_profiling/stream_receiver.h"
namespace heap_profiling {
// Parses a memory stream. Refcounted via StreamReceiver.
class StreamParser : public StreamReceiver {
public:
// Both receivers must either outlive this class or live until
// DisconnectReceivers is called.
explicit StreamParser(Receiver* receiver);
// For tear-down, resets both receivers so they will not be called.
void DisconnectReceivers();
// StreamReceiver implementation.
bool OnStreamData(std::unique_ptr<char[]> data, size_t sz) override;
void OnStreamComplete() override;
base::Lock* GetLock() { return &lock_; }
// Returns true if this stream has encountered a fatal parse error.
bool has_error() const { return error_; }
private:
struct Block {
Block(std::unique_ptr<char[]> d, size_t s);
Block(Block&& other) noexcept;
~Block();
std::unique_ptr<char[]> data;
size_t size;
};
enum ReadStatus {
READ_OK, // Read OK.
READ_ERROR, // Fatal error, don't send more data.
READ_NO_DATA // Not enough data, try again when we get more
};
~StreamParser() override;
// Returns true if the given number of bytes are available now.
bool AreBytesAvailable(size_t count) const;
// Returns false if not enough bytes are available. On failure, the dest
// buffer will be in an undefined state (it may be written partially).
bool PeekBytes(size_t count, void* dest) const;
bool ReadBytes(size_t count, void* dest);
void ConsumeBytes(size_t count); // Bytes must be available.
ReadStatus ParseHeader();
ReadStatus ParseAlloc();
ReadStatus ParseFree();
ReadStatus ParseBarrier();
ReadStatus ParseStringMapping();
void SetErrorState();
// Not owned by this class.
Receiver* receiver_;
base::circular_deque<Block> blocks_;
bool received_header_ = false;
bool error_ = false;
// Current offset into blocks_[0] of the next packet to process.
size_t block_zero_offset_ = 0;
// This lock must be acquired anytime the stream is being parsed. This
// prevents concurrent access to data structures used by both the parser and
// the memory dumper.
base::Lock lock_;
DISALLOW_COPY_AND_ASSIGN(StreamParser);
};
} // namespace heap_profiling
#endif // COMPONENTS_SERVICES_HEAP_PROFILING_STREAM_PARSER_H_