// Copyright 2016 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_WASM_SIGNATURE_MAP_H_ #define V8_WASM_SIGNATURE_MAP_H_ #include <map> #include "src/signature.h" #include "src/wasm/wasm-opcodes.h" namespace v8 { namespace internal { namespace wasm { // A signature map canonicalizes signatures into a range of indices so that // two different {FunctionSig} instances with the same contents map to the // same index. class V8_EXPORT_PRIVATE SignatureMap { public: // Allow default construction and move construction (because we have vectors // of objects containing SignatureMaps), but disallow copy or assign. It's // too easy to get security bugs by accidentally updating a copy of the map. SignatureMap(); SignatureMap(SignatureMap&&) = default; // Gets the index for a signature, assigning a new index if necessary. uint32_t FindOrInsert(FunctionSig* sig); // Gets the index for a signature, returning {-1} if not found. int32_t Find(FunctionSig* sig) const; private: // TODO(wasm): use a hashmap instead of an ordered map? struct CompareFunctionSigs { bool operator()(FunctionSig* a, FunctionSig* b) const; }; uint32_t next_ = 0; // TODO(wasm): performance-critical, replace with a reader-writer lock std::unique_ptr<base::Mutex> mutex_; std::map<FunctionSig*, uint32_t, CompareFunctionSigs> map_; DISALLOW_COPY_AND_ASSIGN(SignatureMap); }; } // namespace wasm } // namespace internal } // namespace v8 #endif // V8_WASM_SIGNATURE_MAP_H_