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