mirror of https://github.com/facebook/rocksdb.git
112 lines
3.7 KiB
C++
112 lines
3.7 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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#pragma once
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#include <string>
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#include "db/merge_context.h"
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#include "db/range_del_aggregator.h"
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#include "db/read_callback.h"
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#include "rocksdb/env.h"
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#include "rocksdb/statistics.h"
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#include "rocksdb/types.h"
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#include "table/block.h"
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namespace rocksdb {
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class MergeContext;
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class PinnedIteratorsManager;
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class GetContext {
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public:
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enum GetState {
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kNotFound,
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kFound,
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kDeleted,
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kCorrupt,
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kMerge, // saver contains the current merge result (the operands)
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kBlobIndex,
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};
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uint64_t tickers_value[Tickers::TICKER_ENUM_MAX] = {0};
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GetContext(const Comparator* ucmp, const MergeOperator* merge_operator,
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Logger* logger, Statistics* statistics, GetState init_state,
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const Slice& user_key, PinnableSlice* value, bool* value_found,
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MergeContext* merge_context, RangeDelAggregator* range_del_agg,
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Env* env, SequenceNumber* seq = nullptr,
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PinnedIteratorsManager* _pinned_iters_mgr = nullptr,
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ReadCallback* callback = nullptr, bool* is_blob_index = nullptr);
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void MarkKeyMayExist();
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// Records this key, value, and any meta-data (such as sequence number and
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// state) into this GetContext.
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//
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// If the parsed_key matches the user key that we are looking for, sets
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// mathced to true.
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//
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// Returns True if more keys need to be read (due to merges) or
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// False if the complete value has been found.
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bool SaveValue(const ParsedInternalKey& parsed_key, const Slice& value,
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bool* matched, Cleanable* value_pinner = nullptr);
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// Simplified version of the previous function. Should only be used when we
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// know that the operation is a Put.
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void SaveValue(const Slice& value, SequenceNumber seq);
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GetState State() const { return state_; }
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RangeDelAggregator* range_del_agg() { return range_del_agg_; }
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PinnedIteratorsManager* pinned_iters_mgr() { return pinned_iters_mgr_; }
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// If a non-null string is passed, all the SaveValue calls will be
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// logged into the string. The operations can then be replayed on
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// another GetContext with replayGetContextLog.
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void SetReplayLog(std::string* replay_log) { replay_log_ = replay_log; }
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// Do we need to fetch the SequenceNumber for this key?
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bool NeedToReadSequence() const { return (seq_ != nullptr); }
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bool sample() const { return sample_; }
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bool CheckCallback(SequenceNumber seq) {
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if (callback_) {
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return callback_->IsCommitted(seq);
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}
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return true;
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}
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void RecordCounters(Tickers ticker, size_t val);
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private:
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const Comparator* ucmp_;
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const MergeOperator* merge_operator_;
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// the merge operations encountered;
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Logger* logger_;
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Statistics* statistics_;
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GetState state_;
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Slice user_key_;
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PinnableSlice* pinnable_val_;
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bool* value_found_; // Is value set correctly? Used by KeyMayExist
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MergeContext* merge_context_;
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RangeDelAggregator* range_del_agg_;
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Env* env_;
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// If a key is found, seq_ will be set to the SequenceNumber of most recent
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// write to the key or kMaxSequenceNumber if unknown
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SequenceNumber* seq_;
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std::string* replay_log_;
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// Used to temporarily pin blocks when state_ == GetContext::kMerge
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PinnedIteratorsManager* pinned_iters_mgr_;
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ReadCallback* callback_;
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bool sample_;
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bool* is_blob_index_;
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};
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void replayGetContextLog(const Slice& replay_log, const Slice& user_key,
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GetContext* get_context,
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Cleanable* value_pinner = nullptr);
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} // namespace rocksdb
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