rocksdb/db/merge_operator.cc
Deon Nicholas e1346968d8 Merge operator fixes part 1.
Summary:
-Added null checks and revisions to DBIter::MergeValuesNewToOld()
-Added DBIter test to stringappend_test
-Major fix with Merge and TTL
More plans for fixes later.

Test Plan:
-make clean; make stringappend_test -j 32; ./stringappend_test
-make all check;

Reviewers: haobo, emayanke, vamsi, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12315
2013-08-19 11:42:47 -07:00

52 lines
1.4 KiB
C++

/**
* Back-end implementation details specific to the Merge Operator.
*
* @author Deon Nicholas (dnicholas@fb.com)
* Copyright 2013 Facebook
*/
#include "leveldb/merge_operator.h"
namespace leveldb {
// Given a "real" merge from the library, call the user's
// associative merge function one-by-one on each of the operands.
// NOTE: It is assumed that the client's merge-operator will handle any errors.
bool AssociativeMergeOperator::FullMerge(
const Slice& key,
const Slice* existing_value,
const std::deque<std::string>& operand_list,
std::string* new_value,
Logger* logger) const {
// Simply loop through the operands
Slice temp_existing;
std::string temp_value;
for (const auto& operand : operand_list) {
Slice value(operand);
if (!Merge(key, existing_value, value, &temp_value, logger)) {
return false;
}
swap(temp_value, *new_value);
temp_existing = Slice(*new_value);
existing_value = &temp_existing;
}
// The result will be in *new_value. All merges succeeded.
return true;
}
// Call the user defined simple merge on the operands;
// NOTE: It is assumed that the client's merge-operator will handle any errors.
bool AssociativeMergeOperator::PartialMerge(
const Slice& key,
const Slice& left_operand,
const Slice& right_operand,
std::string* new_value,
Logger* logger) const {
return Merge(key, &left_operand, right_operand, new_value, logger);
}
} // namespace leveldb