| // Copyright 2011 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_PARSING_DUPLICATE_FINDER_H_ |
| #define V8_PARSING_DUPLICATE_FINDER_H_ |
| |
| #include "src/base/hashmap.h" |
| #include "src/collector.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // DuplicateFinder discovers duplicate symbols. |
| class DuplicateFinder { |
| public: |
| DuplicateFinder() : backing_store_(16), map_(&Match) {} |
| |
| bool AddOneByteSymbol(Vector<const uint8_t> key); |
| bool AddTwoByteSymbol(Vector<const uint16_t> key); |
| |
| private: |
| bool AddSymbol(Vector<const uint8_t> key, bool is_one_byte); |
| // Backs up the key and its length in the backing store. |
| // The backup is stored with a base 127 encoding of the |
| // length (plus a bit saying whether the string is one byte), |
| // followed by the bytes of the key. |
| uint8_t* BackupKey(Vector<const uint8_t> key, bool is_one_byte); |
| |
| // Compare two encoded keys (both pointing into the backing store) |
| // for having the same base-127 encoded lengths and representation. |
| // and then having the same 'length' bytes following. |
| static bool Match(void* first, void* second); |
| |
| // Creates a hash from a sequence of bytes. |
| static uint32_t Hash(Vector<const uint8_t> key, bool is_one_byte); |
| |
| // Backing store used to store strings used as hashmap keys. |
| SequenceCollector<unsigned char> backing_store_; |
| base::CustomMatcherHashMap map_; |
| }; |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_PARSING_DUPLICATE_FINDER_H_ |