fork of https://github.com/oxigraph/rocksdb and https://github.com/facebook/rocksdb for nextgraph and oxigraph
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
76 lines
2.5 KiB
76 lines
2.5 KiB
// Copyright (c) 2011-present, 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
|
|
#include <string>
|
|
#include "db/merge_context.h"
|
|
#include "rocksdb/env.h"
|
|
#include "rocksdb/types.h"
|
|
|
|
namespace rocksdb {
|
|
class MergeContext;
|
|
|
|
class GetContext {
|
|
public:
|
|
enum GetState {
|
|
kNotFound,
|
|
kFound,
|
|
kDeleted,
|
|
kCorrupt,
|
|
kMerge // saver contains the current merge result (the operands)
|
|
};
|
|
|
|
GetContext(const Comparator* ucmp, const MergeOperator* merge_operator,
|
|
Logger* logger, Statistics* statistics, GetState init_state,
|
|
const Slice& user_key, std::string* ret_value, bool* value_found,
|
|
MergeContext* merge_context, Env* env,
|
|
SequenceNumber* seq = nullptr);
|
|
|
|
void MarkKeyMayExist();
|
|
|
|
// Records this key, value, and any meta-data (such as sequence number and
|
|
// state) into this GetContext.
|
|
//
|
|
// 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);
|
|
|
|
// 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_; }
|
|
|
|
// 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); }
|
|
|
|
private:
|
|
const Comparator* ucmp_;
|
|
const MergeOperator* merge_operator_;
|
|
// the merge operations encountered;
|
|
Logger* logger_;
|
|
Statistics* statistics_;
|
|
|
|
GetState state_;
|
|
Slice user_key_;
|
|
std::string* value_;
|
|
bool* value_found_; // Is value set correctly? Used by KeyMayExist
|
|
MergeContext* merge_context_;
|
|
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_;
|
|
};
|
|
|
|
void replayGetContextLog(const Slice& replay_log, const Slice& user_key,
|
|
GetContext* get_context);
|
|
|
|
} // namespace rocksdb
|
|
|