mirror of
https://github.com/facebook/rocksdb.git
synced 2024-11-26 16:30:56 +00:00
320 lines
9.2 KiB
C++
320 lines
9.2 KiB
C++
// 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 "leveldb/db.h"
|
|
#include "leveldb/env.h"
|
|
#include "leveldb/compaction_filter.h"
|
|
#include "leveldb/merge_operator.h"
|
|
#include "utilities/utility_db.h"
|
|
#include "db/db_impl.h"
|
|
|
|
namespace leveldb {
|
|
|
|
class DBWithTTL : public StackableDB {
|
|
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(ReadOptions& options,
|
|
const Slice& key,
|
|
std::string* value,
|
|
bool* value_found = nullptr);
|
|
|
|
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();
|
|
|
|
virtual DB* GetRawDB() {
|
|
return db_;
|
|
}
|
|
|
|
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 uint32_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_;
|
|
unique_ptr<MergeOperator> ttl_merge_op_;
|
|
unique_ptr<CompactionFilter> ttl_comp_filter_;
|
|
};
|
|
|
|
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_;
|
|
};
|
|
|
|
class TtlCompactionFilter : public CompactionFilter {
|
|
|
|
public:
|
|
TtlCompactionFilter(int32_t ttl, const CompactionFilter* comp_filter)
|
|
: ttl_(ttl),
|
|
user_comp_filter_(comp_filter) {
|
|
// Unlike the merge operator, compaction filter is necessary for TTL, hence
|
|
// this would be called even if user doesn't specify any compaction-filter
|
|
}
|
|
|
|
virtual bool Filter(int level,
|
|
const Slice& key,
|
|
const Slice& old_val,
|
|
std::string* new_val,
|
|
bool* value_changed) const override {
|
|
if (DBWithTTL::IsStale(old_val, ttl_)) {
|
|
return true;
|
|
}
|
|
if (user_comp_filter_ == nullptr) {
|
|
return false;
|
|
}
|
|
assert(old_val.size() >= DBWithTTL::kTSLength);
|
|
Slice old_val_without_ts(old_val.data(),
|
|
old_val.size() - DBWithTTL::kTSLength);
|
|
if (user_comp_filter_->Filter(level, key, old_val_without_ts, new_val,
|
|
value_changed)) {
|
|
return true;
|
|
}
|
|
if (*value_changed) {
|
|
new_val->append(old_val.data() + old_val.size() - DBWithTTL::kTSLength,
|
|
DBWithTTL::kTSLength);
|
|
}
|
|
return false;
|
|
}
|
|
|
|
virtual const char* Name() const override {
|
|
return "Delete By TTL";
|
|
}
|
|
|
|
private:
|
|
int32_t ttl_;
|
|
const CompactionFilter* user_comp_filter_;
|
|
};
|
|
|
|
class TtlMergeOperator : public MergeOperator {
|
|
|
|
public:
|
|
explicit TtlMergeOperator(const MergeOperator* merge_op)
|
|
: user_merge_op_(merge_op) {
|
|
assert(merge_op);
|
|
}
|
|
|
|
virtual bool Merge(const Slice& key,
|
|
const Slice* existing_value,
|
|
const std::deque<std::string>& operands,
|
|
std::string* new_value,
|
|
Logger* logger) const override {
|
|
const uint32_t ts_len = DBWithTTL::kTSLength;
|
|
if (existing_value && existing_value->size() < ts_len) {
|
|
Log(logger, "Error: Could not remove timestamp from existing value.");
|
|
return false;
|
|
// TODO: Change Merge semantics and add a counter here
|
|
}
|
|
|
|
// Extract time-stamp from each operand to be passed to user_merge_op_
|
|
std::deque<std::string> operands_without_ts;
|
|
for (auto it = operands.begin(); it != operands.end(); ++it) {
|
|
if (it->size() < ts_len) {
|
|
Log(logger, "Error: Could not remove timestamp from operand value.");
|
|
return false;
|
|
}
|
|
operands_without_ts.push_back(it->substr(0, it->size() - ts_len));
|
|
}
|
|
|
|
// Apply the user merge operator (store result in *new_value)
|
|
if (existing_value) {
|
|
Slice existing_value_without_ts(existing_value->data(),
|
|
existing_value->size() - ts_len);
|
|
user_merge_op_->Merge(key, &existing_value_without_ts,
|
|
operands_without_ts, new_value, logger);
|
|
} else {
|
|
user_merge_op_->Merge(key, nullptr, operands_without_ts, new_value,
|
|
logger);
|
|
}
|
|
|
|
// Augment the *new_value with the ttl time-stamp
|
|
int32_t curtime;
|
|
if (!DBWithTTL::GetCurrentTime(curtime).ok()) {
|
|
Log(logger, "Error: Could not get current time to be attached internally "
|
|
"to the new value.");
|
|
return false;
|
|
} else {
|
|
char ts_string[ts_len];
|
|
EncodeFixed32(ts_string, curtime);
|
|
new_value->append(ts_string, ts_len);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
virtual bool PartialMerge(const Slice& key,
|
|
const Slice& left_operand,
|
|
const Slice& right_operand,
|
|
std::string* new_value,
|
|
Logger* logger) const override {
|
|
const uint32_t ts_len = DBWithTTL::kTSLength;
|
|
|
|
if (left_operand.size() < ts_len || right_operand.size() < ts_len) {
|
|
Log(logger, "Error: Could not remove timestamp from value.");
|
|
return false;
|
|
//TODO: Change Merge semantics and add a counter here
|
|
}
|
|
|
|
// Apply the user partial-merge operator (store result in *new_value)
|
|
assert(new_value);
|
|
Slice left_without_ts(left_operand.data(), left_operand.size() - ts_len);
|
|
Slice right_without_ts(right_operand.data(), right_operand.size() - ts_len);
|
|
user_merge_op_->PartialMerge(key, left_without_ts, right_without_ts,
|
|
new_value, logger);
|
|
|
|
// Augment the *new_value with the ttl time-stamp
|
|
int32_t curtime;
|
|
if (!DBWithTTL::GetCurrentTime(curtime).ok()) {
|
|
Log(logger, "Error: Could not get current time to be attached internally "
|
|
"to the new value.");
|
|
return false;
|
|
} else {
|
|
char ts_string[ts_len];
|
|
EncodeFixed32(ts_string, curtime);
|
|
new_value->append(ts_string, ts_len);
|
|
return true;
|
|
}
|
|
|
|
}
|
|
|
|
virtual const char* Name() const override {
|
|
return "Merge By TTL";
|
|
}
|
|
|
|
private:
|
|
const MergeOperator* user_merge_op_;
|
|
};
|
|
|
|
}
|
|
#endif // LEVELDB_UTILITIES_TTL_DB_TTL_H_
|