// Copyright (c) 2014, Facebook, Inc. All rights reserved. // This source code is licensed under the BSD-style license found in the // LICENSE file in the root directory of this source tree. An additional grant // of patent rights can be found in the PATENTS file in the same directory. #pragma once #ifndef ROCKSDB_LITE #include #include "rocksdb/table.h" #include "util/murmurhash.h" namespace rocksdb { const uint32_t kCuckooMurmurSeedMultiplier = 816922183; static inline uint64_t CuckooHash( const Slice& user_key, uint32_t hash_cnt, uint64_t table_size_minus_one, uint64_t (*get_slice_hash)(const Slice&, uint32_t, uint64_t)) { #ifndef NDEBUG // This part is used only in unit tests. if (get_slice_hash != nullptr) { return get_slice_hash(user_key, hash_cnt, table_size_minus_one + 1); } #endif return MurmurHash(user_key.data(), user_key.size(), kCuckooMurmurSeedMultiplier * hash_cnt) & table_size_minus_one; } // Cuckoo Table is designed for applications that require fast point lookups // but not fast range scans. // // Some assumptions: // - Key length and Value length are fixed. // - Does not support Snapshot. // - Does not support Merge operations. class CuckooTableFactory : public TableFactory { public: CuckooTableFactory(double hash_table_ratio, uint32_t max_search_depth, uint32_t cuckoo_block_size) : hash_table_ratio_(hash_table_ratio), max_search_depth_(max_search_depth), cuckoo_block_size_(cuckoo_block_size) {} ~CuckooTableFactory() {} const char* Name() const override { return "CuckooTable"; } Status NewTableReader( const Options& options, const EnvOptions& soptions, const InternalKeyComparator& internal_comparator, unique_ptr&& file, uint64_t file_size, unique_ptr* table) const override; TableBuilder* NewTableBuilder(const Options& options, const InternalKeyComparator& icomparator, WritableFile* file, CompressionType compression_type) const override; // Sanitizes the specified DB Options. Status SanitizeDBOptions(DBOptions* db_opts) const override { return Status::OK(); } std::string GetPrintableTableOptions() const override; private: const double hash_table_ratio_; const uint32_t max_search_depth_; const uint32_t cuckoo_block_size_; }; } // namespace rocksdb #endif // ROCKSDB_LITE