mirror of
https://github.com/facebook/rocksdb.git
synced 2024-12-01 16:15:59 +00:00
9b58c73c7c
Summary: It only covers Open() with default column family right now Test Plan: make release Reviewers: igor, yhchiang, sdong Reviewed By: sdong Subscribers: leveldb Differential Revision: https://reviews.facebook.net/D22467
72 lines
2.3 KiB
C++
72 lines
2.3 KiB
C++
// 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 <string>
|
|
#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<RandomAccessFile>&& file, uint64_t file_size,
|
|
unique_ptr<TableReader>* 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(const 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
|