// Copyright 2020 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_BUILTINS_PROFILE_DATA_READER_H_ #define V8_BUILTINS_PROFILE_DATA_READER_H_ #include <cstddef> #include <cstdint> #include <vector> namespace v8 { namespace internal { class ProfileDataFromFile { public: // A hash of the function's Graph before scheduling. Allows us to avoid using // profiling data if the function has been changed. int hash() const { return hash_; } // Returns how many times the block with the given ID was executed during // profiling. uint32_t GetCounter(size_t block_id) const { // The profile data is allowed to omit blocks which were never hit, so be // careful to avoid out-of-bounds access. return block_id < block_counts_by_id_.size() ? block_counts_by_id_[block_id] : 0; } // Load basic block profiling data for the builtin with the given name, if // such data exists. The returned vector is indexed by block ID, and its // values are the number of times each block was executed while profiling. static const ProfileDataFromFile* TryRead(const char* name); protected: int hash_ = 0; // How many times each block was executed, indexed by block ID. This vector // may be shorter than the total number of blocks; any omitted block should be // treated as a zero. std::vector<uint32_t> block_counts_by_id_; }; // The following strings can't be static members of ProfileDataFromFile until // C++ 17; see https://stackoverflow.com/q/8016780/839379 . So for now we use a // namespace. namespace ProfileDataFromFileConstants { // Any line in a v8.log beginning with this string represents a basic block // counter. static constexpr char kBlockCounterMarker[] = "block"; // Any line in a v8.log beginning with this string represents the hash of the // function Graph for a builtin. static constexpr char kBuiltinHashMarker[] = "builtin_hash"; } // namespace ProfileDataFromFileConstants } // namespace internal } // namespace v8 #endif // V8_BUILTINS_PROFILE_DATA_READER_H_