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rocksdb/utilities/ttl/db_ttl.h

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4.4 KiB

// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#ifndef LEVELDB_UTILITIES_TTL_DB_TTL_H_
#define LEVELDB_UTILITIES_TTL_DB_TTL_H_
#include "include/leveldb/db.h"
#include "include/leveldb/compaction_filter.h"
#include "db/db_impl.h"
namespace leveldb {
class DBWithTTL : public DB, CompactionFilter {
public:
DBWithTTL(const int32_t ttl,
const Options& options,
const std::string& dbname,
Status& st,
bool read_only);
virtual ~DBWithTTL();
virtual Status Put(const WriteOptions& o,
const Slice& key,
const Slice& val);
virtual Status Get(const ReadOptions& options,
const Slice& key,
std::string* value);
virtual std::vector<Status> MultiGet(const ReadOptions& options,
const std::vector<Slice>& keys,
std::vector<std::string>* values);
virtual bool KeyMayExist(const Slice& key);
virtual Status Delete(const WriteOptions& wopts, const Slice& key);
virtual Status Merge(const WriteOptions& options,
const Slice& key,
const Slice& value);
virtual Status Write(const WriteOptions& opts, WriteBatch* updates);
virtual Iterator* NewIterator(const ReadOptions& opts);
virtual const Snapshot* GetSnapshot();
virtual void ReleaseSnapshot(const Snapshot* snapshot);
virtual bool GetProperty(const Slice& property, std::string* value);
virtual void GetApproximateSizes(const Range* r, int n, uint64_t* sizes);
virtual void CompactRange(const Slice* begin, const Slice* end,
bool reduce_level = false);
virtual int NumberLevels();
virtual int MaxMemCompactionLevel();
virtual int Level0StopWriteTrigger();
virtual Status Flush(const FlushOptions& fopts);
virtual Status DisableFileDeletions();
virtual Status EnableFileDeletions();
virtual Status GetLiveFiles(std::vector<std::string>& vec, uint64_t* mfs);
virtual SequenceNumber GetLatestSequenceNumber();
virtual Status GetUpdatesSince(SequenceNumber seq_number,
unique_ptr<TransactionLogIterator>* iter);
// Simulate a db crash, no elegant closing of database.
void TEST_Destroy_DBWithTtl();
// The following two methods are for CompactionFilter
virtual bool Filter(int level,
const Slice& key,
const Slice& old_val,
std::string* new_val,
bool* value_changed) const override;
virtual const char* Name() const override;
static bool IsStale(const Slice& value, int32_t ttl);
static Status AppendTS(const Slice& val, std::string& val_with_ts);
static Status SanityCheckTimestamp(const Slice& str);
static Status StripTS(std::string* str);
static Status GetCurrentTime(int32_t& curtime);
static const int32_t kTSLength = sizeof(int32_t); // size of timestamp
static const int32_t kMinTimestamp = 1368146402; // 05/09/2013:5:40PM GMT-8
static const int32_t kMaxTimestamp = 2147483647; // 01/18/2038:7:14PM GMT-8
private:
DB* db_;
int32_t ttl_;
};
class TtlIterator : public Iterator {
public:
explicit TtlIterator(Iterator* iter)
: iter_(iter) {
assert(iter_);
}
~TtlIterator() {
delete iter_;
}
bool Valid() const {
return iter_->Valid();
}
void SeekToFirst() {
iter_->SeekToFirst();
}
void SeekToLast() {
iter_->SeekToLast();
}
void Seek(const Slice& target) {
iter_->Seek(target);
}
void Next() {
iter_->Next();
}
void Prev() {
iter_->Prev();
}
Slice key() const {
return iter_->key();
}
int32_t timestamp() const {
return DecodeFixed32(
iter_->value().data() + iter_->value().size() - DBWithTTL::kTSLength);
}
Slice value() const {
//TODO: handle timestamp corruption like in general iterator semantics
assert(DBWithTTL::SanityCheckTimestamp(iter_->value()).ok());
Slice trimmed_value = iter_->value();
trimmed_value.size_ -= DBWithTTL::kTSLength;
return trimmed_value;
}
Status status() const {
return iter_->status();
}
private:
Iterator* iter_;
};
}
#endif // LEVELDB_UTILITIES_TTL_DB_TTL_H_