rocksdb/utilities/merge_operators/uint64add.cc
Yueh-Hsuan Chiang 6afafa3694 Apply InfoLogLevel to the logs in utilities/merge_operators/uint64add.cc
Summary:
Apply InfoLogLevel to the logs and add missing copy-right information
to  utilities/merge_operators/uint64add.cc.

Test Plan: make

Reviewers: ljin, sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27897
2014-10-29 17:10:21 -07:00

72 lines
2 KiB
C++

// Copyright (c) 2013, 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.
#include <memory>
#include "rocksdb/env.h"
#include "rocksdb/merge_operator.h"
#include "rocksdb/slice.h"
#include "util/coding.h"
#include "utilities/merge_operators.h"
using namespace rocksdb;
namespace { // anonymous namespace
// A 'model' merge operator with uint64 addition semantics
// Implemented as an AssociativeMergeOperator for simplicity and example.
class UInt64AddOperator : public AssociativeMergeOperator {
public:
virtual bool Merge(const Slice& key,
const Slice* existing_value,
const Slice& value,
std::string* new_value,
Logger* logger) const override {
uint64_t orig_value = 0;
if (existing_value){
orig_value = DecodeInteger(*existing_value, logger);
}
uint64_t operand = DecodeInteger(value, logger);
assert(new_value);
new_value->clear();
PutFixed64(new_value, orig_value + operand);
return true; // Return true always since corruption will be treated as 0
}
virtual const char* Name() const override {
return "UInt64AddOperator";
}
private:
// Takes the string and decodes it into a uint64_t
// On error, prints a message and returns 0
uint64_t DecodeInteger(const Slice& value, Logger* logger) const {
uint64_t result = 0;
if (value.size() == sizeof(uint64_t)) {
result = DecodeFixed64(value.data());
} else if (logger != nullptr) {
// If value is corrupted, treat it as 0
Log(InfoLogLevel::ERROR_LEVEL, logger,
"uint64 value corruption, size: %zu > %zu",
value.size(), sizeof(uint64_t));
}
return result;
}
};
}
namespace rocksdb {
std::shared_ptr<MergeOperator> MergeOperators::CreateUInt64AddOperator() {
return std::make_shared<UInt64AddOperator>();
}
}