| // Copyright 2012 the V8 project 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 V8_SNAPSHOT_SOURCE_SINK_H_ |
| #define V8_SNAPSHOT_SOURCE_SINK_H_ |
| |
| #include "src/base/logging.h" |
| #include "src/utils.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| /** |
| * Source to read snapshot and builtins files from. |
| * |
| * Note: Memory ownership remains with callee. |
| */ |
| class SnapshotByteSource FINAL { |
| public: |
| SnapshotByteSource(const byte* array, int length); |
| ~SnapshotByteSource(); |
| |
| bool HasMore() { return position_ < length_; } |
| |
| int Get() { |
| DCHECK(position_ < length_); |
| return data_[position_++]; |
| } |
| |
| int32_t GetUnalignedInt(); |
| |
| void Advance(int by) { position_ += by; } |
| |
| void CopyRaw(byte* to, int number_of_bytes); |
| |
| inline int GetInt() { |
| // This way of variable-length encoding integers does not suffer from branch |
| // mispredictions. |
| uint32_t answer = GetUnalignedInt(); |
| int bytes = (answer & 3) + 1; |
| Advance(bytes); |
| uint32_t mask = 0xffffffffu; |
| mask >>= 32 - (bytes << 3); |
| answer &= mask; |
| answer >>= 2; |
| return answer; |
| } |
| |
| bool GetBlob(const byte** data, int* number_of_bytes); |
| |
| bool AtEOF(); |
| |
| int position() { return position_; } |
| |
| private: |
| const byte* data_; |
| int length_; |
| int position_; |
| |
| DISALLOW_COPY_AND_ASSIGN(SnapshotByteSource); |
| }; |
| |
| |
| /** |
| * Sink to write snapshot files to. |
| * |
| * Subclasses must implement actual storage or i/o. |
| */ |
| class SnapshotByteSink { |
| public: |
| SnapshotByteSink() {} |
| explicit SnapshotByteSink(int initial_size) : data_(initial_size) {} |
| |
| ~SnapshotByteSink() {} |
| |
| void Put(byte b, const char* description) { data_.Add(b); } |
| |
| void PutSection(int b, const char* description) { |
| DCHECK_LE(b, kMaxUInt8); |
| Put(static_cast<byte>(b), description); |
| } |
| |
| void PutInt(uintptr_t integer, const char* description); |
| void PutRaw(byte* data, int number_of_bytes, const char* description); |
| void PutBlob(byte* data, int number_of_bytes, const char* description); |
| int Position() { return data_.length(); } |
| |
| const List<byte>& data() const { return data_; } |
| |
| private: |
| List<byte> data_; |
| }; |
| |
| } // namespace v8::internal |
| } // namespace v8 |
| |
| #endif // V8_SNAPSHOT_SOURCE_SINK_H_ |