fbd2dafc9f
Summary: Add the MultiGet API to allow prefetching. With file size of 1.5G, I configured it to have 0.9 hash ratio that can fill With 115M keys and result in 2 hash functions, the lookup QPS is ~4.9M/s vs. 3M/s for Get(). It is tricky to set the parameters right. Since files size is determined by power-of-two factor, that means # of keys is fixed in each file. With big file size (thus smaller # of files), we will have more chance to waste lot of space in the last file - lower space utilization as a result. Using smaller file size can improve the situation, but that harms lookup speed. Test Plan: db_bench Reviewers: yhchiang, sdong, igor Reviewed By: sdong Subscribers: leveldb Differential Revision: https://reviews.facebook.net/D23673
100 lines
3.6 KiB
C++
100 lines
3.6 KiB
C++
// Copyright (c) 2014, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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#pragma once
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#ifndef ROCKSDB_LITE
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#include "db/db_impl.h"
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#include <vector>
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#include <string>
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namespace rocksdb {
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class CompactedDBImpl : public DBImpl {
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public:
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CompactedDBImpl(const DBOptions& options, const std::string& dbname);
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virtual ~CompactedDBImpl();
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static Status Open(const Options& options, const std::string& dbname,
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DB** dbptr);
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// Implementations of the DB interface
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using DB::Get;
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virtual Status Get(const ReadOptions& options,
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ColumnFamilyHandle* column_family, const Slice& key,
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std::string* value) override;
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using DB::MultiGet;
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virtual std::vector<Status> MultiGet(
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const ReadOptions& options,
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const std::vector<ColumnFamilyHandle*>&,
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const std::vector<Slice>& keys, std::vector<std::string>* values)
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override;
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using DBImpl::Put;
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virtual Status Put(const WriteOptions& options,
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ColumnFamilyHandle* column_family, const Slice& key,
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const Slice& value) override {
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return Status::NotSupported("Not supported in compacted db mode.");
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}
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using DBImpl::Merge;
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virtual Status Merge(const WriteOptions& options,
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ColumnFamilyHandle* column_family, const Slice& key,
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const Slice& value) override {
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return Status::NotSupported("Not supported in compacted db mode.");
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}
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using DBImpl::Delete;
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virtual Status Delete(const WriteOptions& options,
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ColumnFamilyHandle* column_family,
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const Slice& key) override {
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return Status::NotSupported("Not supported in compacted db mode.");
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}
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virtual Status Write(const WriteOptions& options,
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WriteBatch* updates) override {
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return Status::NotSupported("Not supported in compacted db mode.");
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}
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using DBImpl::CompactRange;
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virtual Status CompactRange(ColumnFamilyHandle* column_family,
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const Slice* begin, const Slice* end,
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bool reduce_level = false, int target_level = -1,
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uint32_t target_path_id = 0) override {
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return Status::NotSupported("Not supported in compacted db mode.");
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}
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virtual Status DisableFileDeletions() override {
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return Status::NotSupported("Not supported in compacted db mode.");
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}
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virtual Status EnableFileDeletions(bool force) override {
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return Status::NotSupported("Not supported in compacted db mode.");
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}
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virtual Status GetLiveFiles(std::vector<std::string>&,
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uint64_t* manifest_file_size,
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bool flush_memtable = true) override {
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return Status::NotSupported("Not supported in compacted db mode.");
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}
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using DBImpl::Flush;
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virtual Status Flush(const FlushOptions& options,
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ColumnFamilyHandle* column_family) override {
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return Status::NotSupported("Not supported in compacted db mode.");
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}
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private:
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friend class DB;
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inline size_t FindFile(const Slice& key);
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Status Init(const Options& options);
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ColumnFamilyData* cfd_;
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Version* version_;
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const Comparator* user_comparator_;
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FileLevel files_;
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Statistics* statistics_;
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Logger* info_log_;
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// No copying allowed
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CompactedDBImpl(const CompactedDBImpl&);
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void operator=(const CompactedDBImpl&);
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};
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}
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#endif // ROCKSDB_LITE
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