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rocksdb/utilities/transactions/optimistic_transaction_impl.cc

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// Copyright (c) 2015, 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.
#ifndef ROCKSDB_LITE
#include "utilities/transactions/optimistic_transaction_impl.h"
#include <algorithm>
#include <string>
#include <vector>
#include "db/column_family.h"
#include "db/db_impl.h"
#include "rocksdb/comparator.h"
#include "rocksdb/db.h"
#include "rocksdb/status.h"
#include "rocksdb/utilities/optimistic_transaction_db.h"
#include "util/string_util.h"
#include "utilities/transactions/transaction_util.h"
namespace rocksdb {
struct WriteOptions;
OptimisticTransactionImpl::OptimisticTransactionImpl(
OptimisticTransactionDB* txn_db, const WriteOptions& write_options,
const OptimisticTransactionOptions& txn_options)
: txn_db_(txn_db),
db_(txn_db->GetBaseDB()),
write_options_(write_options),
cmp_(txn_options.cmp),
write_batch_(new WriteBatchWithIndex(txn_options.cmp, 0, true)) {
if (txn_options.set_snapshot) {
SetSnapshot();
}
}
OptimisticTransactionImpl::~OptimisticTransactionImpl() {
}
void OptimisticTransactionImpl::Cleanup() {
tracked_keys_.clear();
save_points_.reset(nullptr);
write_batch_->Clear();
}
void OptimisticTransactionImpl::SetSnapshot() {
snapshot_.reset(new ManagedSnapshot(db_));
}
Status OptimisticTransactionImpl::Commit() {
// Set up callback which will call CheckTransactionForConflicts() to
// check whether this transaction is safe to be committed.
OptimisticTransactionCallback callback(this);
DBImpl* db_impl = dynamic_cast<DBImpl*>(db_->GetRootDB());
if (db_impl == nullptr) {
// This should only happen if we support creating transactions from
// a StackableDB and someone overrides GetRootDB().
return Status::InvalidArgument(
"DB::GetRootDB() returned an unexpected DB class");
}
Status s = db_impl->WriteWithCallback(
write_options_, write_batch_->GetWriteBatch(), &callback);
if (s.ok()) {
Cleanup();
}
return s;
}
void OptimisticTransactionImpl::Rollback() {
Cleanup();
}
void OptimisticTransactionImpl::SetSavePoint() {
if (save_points_ == nullptr) {
save_points_.reset(new std::stack<std::shared_ptr<ManagedSnapshot>>());
}
save_points_->push(snapshot_);
write_batch_->SetSavePoint();
}
Status OptimisticTransactionImpl::RollbackToSavePoint() {
if (save_points_ != nullptr && save_points_->size() > 0) {
// Restore saved snapshot
snapshot_ = save_points_->top();
save_points_->pop();
// Rollback batch
Status s = write_batch_->RollbackToSavePoint();
assert(s.ok());
return s;
} else {
assert(write_batch_->RollbackToSavePoint().IsNotFound());
return Status::NotFound();
}
}
// Record this key so that we can check it for conflicts at commit time.
void OptimisticTransactionImpl::RecordOperation(
ColumnFamilyHandle* column_family, const Slice& key) {
uint32_t cfh_id = GetColumnFamilyID(column_family);
SequenceNumber seq;
if (snapshot_) {
seq = snapshot_->snapshot()->GetSequenceNumber();
} else {
seq = db_->GetLatestSequenceNumber();
}
std::string key_str = key.ToString();
auto iter = tracked_keys_[cfh_id].find(key_str);
if (iter == tracked_keys_[cfh_id].end()) {
// key not yet seen, store it.
tracked_keys_[cfh_id].insert({std::move(key_str), seq});
} else {
SequenceNumber old_seq = iter->second;
if (seq < old_seq) {
// Snapshot has changed since we last saw this key, need to
// store the earliest seen sequence number.
tracked_keys_[cfh_id][key_str] = seq;
}
}
}
void OptimisticTransactionImpl::RecordOperation(
ColumnFamilyHandle* column_family, const SliceParts& key) {
size_t key_size = 0;
for (int i = 0; i < key.num_parts; ++i) {
key_size += key.parts[i].size();
}
std::string str;
str.reserve(key_size);
for (int i = 0; i < key.num_parts; ++i) {
str.append(key.parts[i].data(), key.parts[i].size());
}
RecordOperation(column_family, str);
}
Status OptimisticTransactionImpl::Get(const ReadOptions& read_options,
ColumnFamilyHandle* column_family,
const Slice& key, std::string* value) {
return write_batch_->GetFromBatchAndDB(db_, read_options, column_family, key,
value);
}
Status OptimisticTransactionImpl::GetForUpdate(
const ReadOptions& read_options, ColumnFamilyHandle* column_family,
const Slice& key, std::string* value) {
// Regardless of whether the Get succeeded, track this key.
RecordOperation(column_family, key);
if (value == nullptr) {
return Status::OK();
} else {
return Get(read_options, column_family, key, value);
}
}
std::vector<Status> OptimisticTransactionImpl::MultiGet(
const ReadOptions& read_options,
const std::vector<ColumnFamilyHandle*>& column_family,
const std::vector<Slice>& keys, std::vector<std::string>* values) {
// Regardless of whether the MultiGet succeeded, track these keys.
size_t num_keys = keys.size();
values->resize(num_keys);
// TODO(agiardullo): optimize multiget?
std::vector<Status> stat_list(num_keys);
for (size_t i = 0; i < num_keys; ++i) {
std::string* value = values ? &(*values)[i] : nullptr;
stat_list[i] = Get(read_options, column_family[i], keys[i], value);
}
return stat_list;
}
std::vector<Status> OptimisticTransactionImpl::MultiGetForUpdate(
const ReadOptions& read_options,
const std::vector<ColumnFamilyHandle*>& column_family,
const std::vector<Slice>& keys, std::vector<std::string>* values) {
// Regardless of whether the MultiGet succeeded, track these keys.
size_t num_keys = keys.size();
values->resize(num_keys);
// TODO(agiardullo): optimize multiget?
std::vector<Status> stat_list(num_keys);
for (size_t i = 0; i < num_keys; ++i) {
// Regardless of whether the Get succeeded, track this key.
RecordOperation(column_family[i], keys[i]);
std::string* value = values ? &(*values)[i] : nullptr;
stat_list[i] = Get(read_options, column_family[i], keys[i], value);
}
return stat_list;
}
Iterator* OptimisticTransactionImpl::GetIterator(
const ReadOptions& read_options) {
Iterator* db_iter = db_->NewIterator(read_options);
assert(db_iter);
return write_batch_->NewIteratorWithBase(db_iter);
}
Iterator* OptimisticTransactionImpl::GetIterator(
const ReadOptions& read_options, ColumnFamilyHandle* column_family) {
Iterator* db_iter = db_->NewIterator(read_options, column_family);
assert(db_iter);
return write_batch_->NewIteratorWithBase(column_family, db_iter);
}
Status OptimisticTransactionImpl::Put(ColumnFamilyHandle* column_family,
const Slice& key, const Slice& value) {
RecordOperation(column_family, key);
write_batch_->Put(column_family, key, value);
return Status::OK();
}
Status OptimisticTransactionImpl::Put(ColumnFamilyHandle* column_family,
const SliceParts& key,
const SliceParts& value) {
RecordOperation(column_family, key);
write_batch_->Put(column_family, key, value);
return Status::OK();
}
Status OptimisticTransactionImpl::Merge(ColumnFamilyHandle* column_family,
const Slice& key, const Slice& value) {
RecordOperation(column_family, key);
write_batch_->Merge(column_family, key, value);
return Status::OK();
}
Status OptimisticTransactionImpl::Delete(ColumnFamilyHandle* column_family,
const Slice& key) {
RecordOperation(column_family, key);
write_batch_->Delete(column_family, key);
return Status::OK();
}
Status OptimisticTransactionImpl::Delete(ColumnFamilyHandle* column_family,
const SliceParts& key) {
RecordOperation(column_family, key);
write_batch_->Delete(column_family, key);
return Status::OK();
}
Status OptimisticTransactionImpl::PutUntracked(
ColumnFamilyHandle* column_family, const Slice& key, const Slice& value) {
write_batch_->Put(column_family, key, value);
return Status::OK();
}
Status OptimisticTransactionImpl::PutUntracked(
ColumnFamilyHandle* column_family, const SliceParts& key,
const SliceParts& value) {
write_batch_->Put(column_family, key, value);
return Status::OK();
}
Status OptimisticTransactionImpl::MergeUntracked(
ColumnFamilyHandle* column_family, const Slice& key, const Slice& value) {
write_batch_->Merge(column_family, key, value);
return Status::OK();
}
Status OptimisticTransactionImpl::DeleteUntracked(
ColumnFamilyHandle* column_family, const Slice& key) {
write_batch_->Delete(column_family, key);
return Status::OK();
}
Status OptimisticTransactionImpl::DeleteUntracked(
ColumnFamilyHandle* column_family, const SliceParts& key) {
write_batch_->Delete(column_family, key);
return Status::OK();
}
void OptimisticTransactionImpl::PutLogData(const Slice& blob) {
write_batch_->PutLogData(blob);
}
WriteBatchWithIndex* OptimisticTransactionImpl::GetWriteBatch() {
return write_batch_.get();
}
// Returns OK if it is safe to commit this transaction. Returns Status::Busy
// if there are read or write conflicts that would prevent us from committing OR
// if we can not determine whether there would be any such conflicts.
//
// Should only be called on writer thread in order to avoid any race conditions
// in detecting
// write conflicts.
Status OptimisticTransactionImpl::CheckTransactionForConflicts(DB* db) {
Status result;
assert(dynamic_cast<DBImpl*>(db) != nullptr);
auto db_impl = reinterpret_cast<DBImpl*>(db);
return TransactionUtil::CheckKeysForConflicts(db_impl, &tracked_keys_);
}
} // namespace rocksdb
#endif // ROCKSDB_LITE