rocksdb/utilities/ttl/db_ttl.cc

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// 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.
#include "utilities/ttl/db_ttl.h"
#include "db/filename.h"
#include "util/coding.h"
#include "include/rocksdb/env.h"
#include "include/rocksdb/iterator.h"
namespace rocksdb {
void DBWithTTL::SanitizeOptions(int32_t ttl, Options* options) {
if (options->compaction_filter) {
options->compaction_filter =
new TtlCompactionFilter(ttl, options->compaction_filter);
} else {
options->compaction_filter_factory =
std::shared_ptr<CompactionFilterFactory>(new TtlCompactionFilterFactory(
ttl, options->compaction_filter_factory));
}
if (options->merge_operator) {
options->merge_operator.reset(
new TtlMergeOperator(options->merge_operator));
}
}
// Open the db inside DBWithTTL because options needs pointer to its ttl
DBWithTTL::DBWithTTL(DB* db) : StackableDB(db) {}
DBWithTTL::~DBWithTTL() {
delete GetOptions().compaction_filter;
}
Status UtilityDB::OpenTtlDB(
const Options& options,
const std::string& dbname,
StackableDB** dbptr,
int32_t ttl,
bool read_only) {
Status st;
Options options_to_open = options;
DBWithTTL::SanitizeOptions(ttl, &options_to_open);
DB* db;
if (read_only) {
st = DB::OpenForReadOnly(options_to_open, dbname, &db);
} else {
st = DB::Open(options_to_open, dbname, &db);
}
if (st.ok()) {
*dbptr = new DBWithTTL(db);
} else {
delete db;
}
return st;
}
// Gives back the current time
Status DBWithTTL::GetCurrentTime(int64_t& curtime) {
return Env::Default()->GetCurrentTime(&curtime);
}
// Appends the current timestamp to the string.
// Returns false if could not get the current_time, true if append succeeds
Status DBWithTTL::AppendTS(const Slice& val, std::string& val_with_ts) {
val_with_ts.reserve(kTSLength + val.size());
char ts_string[kTSLength];
int64_t curtime;
Status st = GetCurrentTime(curtime);
if (!st.ok()) {
return st;
}
EncodeFixed32(ts_string, (int32_t)curtime);
val_with_ts.append(val.data(), val.size());
val_with_ts.append(ts_string, kTSLength);
return st;
}
// Returns corruption if the length of the string is lesser than timestamp, or
// timestamp refers to a time lesser than ttl-feature release time
Status DBWithTTL::SanityCheckTimestamp(const Slice& str) {
if (str.size() < kTSLength) {
return Status::Corruption("Error: value's length less than timestamp's\n");
}
// Checks that TS is not lesser than kMinTimestamp
// Gaurds against corruption & normal database opened incorrectly in ttl mode
int32_t timestamp_value =
DecodeFixed32(str.data() + str.size() - kTSLength);
if (timestamp_value < kMinTimestamp){
return Status::Corruption("Error: Timestamp < ttl feature release time!\n");
}
return Status::OK();
}
// Checks if the string is stale or not according to TTl provided
bool DBWithTTL::IsStale(const Slice& value, int32_t ttl) {
if (ttl <= 0) { // Data is fresh if TTL is non-positive
return false;
}
int64_t curtime;
if (!GetCurrentTime(curtime).ok()) {
return false; // Treat the data as fresh if could not get current time
}
int32_t timestamp_value =
DecodeFixed32(value.data() + value.size() - kTSLength);
return (timestamp_value + ttl) < curtime;
}
// Strips the TS from the end of the string
Status DBWithTTL::StripTS(std::string* str) {
Status st;
if (str->length() < kTSLength) {
return Status::Corruption("Bad timestamp in key-value");
}
// Erasing characters which hold the TS
str->erase(str->length() - kTSLength, kTSLength);
return st;
}
Status DBWithTTL::Put(const WriteOptions& options,
const ColumnFamilyHandle& column_family, const Slice& key,
const Slice& val) {
WriteBatch batch;
batch.Put(key, val);
return Write(options, &batch);
}
Status DBWithTTL::Get(const ReadOptions& options,
const ColumnFamilyHandle& column_family, const Slice& key,
std::string* value) {
Status st = db_->Get(options, key, value);
if (!st.ok()) {
return st;
}
st = SanityCheckTimestamp(*value);
if (!st.ok()) {
return st;
}
return StripTS(value);
}
std::vector<Status> DBWithTTL::MultiGet(
const ReadOptions& options,
const std::vector<ColumnFamilyHandle>& column_family,
const std::vector<Slice>& keys, std::vector<std::string>* values) {
return std::vector<Status>(keys.size(),
Status::NotSupported("MultiGet not\
supported with TTL"));
}
bool DBWithTTL::KeyMayExist(const ReadOptions& options,
const ColumnFamilyHandle& column_family,
const Slice& key, std::string* value,
bool* value_found) {
bool ret = db_->KeyMayExist(options, key, value, value_found);
if (ret && value != nullptr && value_found != nullptr && *value_found) {
if (!SanityCheckTimestamp(*value).ok() || !StripTS(value).ok()) {
return false;
}
}
return ret;
}
Status DBWithTTL::Merge(const WriteOptions& options,
const ColumnFamilyHandle& column_family,
const Slice& key, const Slice& value) {
WriteBatch batch;
batch.Merge(key, value);
return Write(options, &batch);
}
Status DBWithTTL::Write(const WriteOptions& opts, WriteBatch* updates) {
class Handler : public WriteBatch::Handler {
public:
WriteBatch updates_ttl;
Status batch_rewrite_status;
virtual void Put(const Slice& key, const Slice& value) {
std::string value_with_ts;
Status st = AppendTS(value, value_with_ts);
if (!st.ok()) {
batch_rewrite_status = st;
} else {
updates_ttl.Put(key, value_with_ts);
}
}
virtual void Merge(const Slice& key, const Slice& value) {
std::string value_with_ts;
Status st = AppendTS(value, value_with_ts);
if (!st.ok()) {
batch_rewrite_status = st;
} else {
updates_ttl.Merge(key, value_with_ts);
}
}
virtual void Delete(const Slice& key) {
updates_ttl.Delete(key);
}
virtual void LogData(const Slice& blob) {
updates_ttl.PutLogData(blob);
}
};
Handler handler;
updates->Iterate(&handler);
if (!handler.batch_rewrite_status.ok()) {
return handler.batch_rewrite_status;
} else {
return db_->Write(opts, &(handler.updates_ttl));
}
}
Iterator* DBWithTTL::NewIterator(const ReadOptions& opts,
const ColumnFamilyHandle& column_family) {
return new TtlIterator(db_->NewIterator(opts, column_family));
}
void DBWithTTL::TEST_Destroy_DBWithTtl() {
((DBImpl*) db_)->TEST_Destroy_DBImpl();
}
} // namespace rocksdb