| // 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_BASE_HASHMAP_ENTRY_H_ |
| #define V8_BASE_HASHMAP_ENTRY_H_ |
| |
| #include <cstdint> |
| |
| namespace v8 { |
| namespace base { |
| |
| // HashMap entries are (key, value, hash) triplets, with a boolean indicating if |
| // they are an empty entry. Some clients may not need to use the value slot |
| // (e.g. implementers of sets, where the key is the value). |
| template <typename Key, typename Value> |
| struct TemplateHashMapEntry { |
| Key key; |
| Value value; |
| uint32_t hash; // The full hash value for key |
| |
| TemplateHashMapEntry(Key key, Value value, uint32_t hash) |
| : key(key), value(value), hash(hash), exists_(true) {} |
| |
| bool exists() const { return exists_; } |
| |
| void clear() { exists_ = false; } |
| |
| private: |
| bool exists_; |
| }; |
| |
| // Specialization for pointer-valued keys |
| template <typename Key, typename Value> |
| struct TemplateHashMapEntry<Key*, Value> { |
| Key* key; |
| Value value; |
| uint32_t hash; // The full hash value for key |
| |
| TemplateHashMapEntry(Key* key, Value value, uint32_t hash) |
| : key(key), value(value), hash(hash) {} |
| |
| bool exists() const { return key != nullptr; } |
| |
| void clear() { key = nullptr; } |
| }; |
| |
| // TODO(leszeks): There could be a specialisation for void values (e.g. for |
| // sets), which omits the value field |
| |
| } // namespace base |
| } // namespace v8 |
| |
| #endif // V8_BASE_HASHMAP_ENTRY_H_ |