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rocksdb/utilities/transactions/write_unprepared_txn.h

166 lines
6.3 KiB

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#pragma once
#ifndef ROCKSDB_LITE
#include <set>
#include "utilities/transactions/write_prepared_txn.h"
#include "utilities/transactions/write_unprepared_txn_db.h"
namespace rocksdb {
class WriteUnpreparedTxnDB;
class WriteUnpreparedTxn;
class WriteUnpreparedTxnReadCallback : public ReadCallback {
public:
WriteUnpreparedTxnReadCallback(WritePreparedTxnDB* db,
SequenceNumber snapshot,
SequenceNumber min_uncommitted,
WriteUnpreparedTxn* txn)
// Pass our last uncommitted seq as the snapshot to the parent class to
// ensure that the parent will not prematurely filter out own writes. We
// will do the exact comparison agaisnt snapshots in IsVisibleFullCheck
// override.
: ReadCallback(CalcMaxVisibleSeq(txn, snapshot), min_uncommitted),
db_(db),
txn_(txn),
wup_snapshot_(snapshot) {}
virtual bool IsVisibleFullCheck(SequenceNumber seq) override;
bool CanReseekToSkip() override {
return wup_snapshot_ == max_visible_seq_;
// Otherwise our own writes uncommitted are in db, and the assumptions
// behind reseek optimizations are no longer valid.
}
// TODO(myabandeh): override Refresh when Iterator::Refresh is supported
private:
static SequenceNumber CalcMaxVisibleSeq(WriteUnpreparedTxn* txn,
SequenceNumber snapshot_seq) {
SequenceNumber max_unprepared = CalcMaxUnpreparedSequenceNumber(txn);
assert(snapshot_seq < max_unprepared || max_unprepared == 0 ||
snapshot_seq == kMaxSequenceNumber);
return std::max(max_unprepared, snapshot_seq);
}
static SequenceNumber CalcMaxUnpreparedSequenceNumber(
WriteUnpreparedTxn* txn);
WritePreparedTxnDB* db_;
WriteUnpreparedTxn* txn_;
SequenceNumber wup_snapshot_;
};
class WriteUnpreparedTxn : public WritePreparedTxn {
public:
WriteUnpreparedTxn(WriteUnpreparedTxnDB* db,
const WriteOptions& write_options,
const TransactionOptions& txn_options);
virtual ~WriteUnpreparedTxn();
using TransactionBaseImpl::Put;
virtual Status Put(ColumnFamilyHandle* column_family, const Slice& key,
const Slice& value,
const bool assume_tracked = false) override;
virtual Status Put(ColumnFamilyHandle* column_family, const SliceParts& key,
const SliceParts& value,
const bool assume_tracked = false) override;
using TransactionBaseImpl::Merge;
virtual Status Merge(ColumnFamilyHandle* column_family, const Slice& key,
const Slice& value,
const bool assume_tracked = false) override;
using TransactionBaseImpl::Delete;
virtual Status Delete(ColumnFamilyHandle* column_family, const Slice& key,
const bool assume_tracked = false) override;
virtual Status Delete(ColumnFamilyHandle* column_family,
const SliceParts& key,
const bool assume_tracked = false) override;
using TransactionBaseImpl::SingleDelete;
virtual Status SingleDelete(ColumnFamilyHandle* column_family,
const Slice& key,
const bool assume_tracked = false) override;
virtual Status SingleDelete(ColumnFamilyHandle* column_family,
const SliceParts& key,
const bool assume_tracked = false) override;
virtual Status RebuildFromWriteBatch(WriteBatch*) override {
// This function was only useful for recovering prepared transactions, but
// is unused for write prepared because a transaction may consist of
// multiple write batches.
//
// If there are use cases outside of recovery that can make use of this,
// then support could be added.
return Status::NotSupported("Not supported for WriteUnprepared");
}
const std::map<SequenceNumber, size_t>& GetUnpreparedSequenceNumbers();
void UpdateWriteKeySet(uint32_t cfid, const Slice& key);
protected:
void Initialize(const TransactionOptions& txn_options) override;
Status PrepareInternal() override;
Status CommitWithoutPrepareInternal() override;
Status CommitInternal() override;
Status RollbackInternal() override;
// Get and GetIterator needs to be overridden so that a ReadCallback to
// handle read-your-own-write is used.
using Transaction::Get;
virtual Status Get(const ReadOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
PinnableSlice* value) override;
using Transaction::GetIterator;
virtual Iterator* GetIterator(const ReadOptions& options) override;
virtual Iterator* GetIterator(const ReadOptions& options,
ColumnFamilyHandle* column_family) override;
private:
friend class WriteUnpreparedTransactionTest_ReadYourOwnWrite_Test;
friend class WriteUnpreparedTransactionTest_RecoveryTest_Test;
friend class WriteUnpreparedTransactionTest_UnpreparedBatch_Test;
friend class WriteUnpreparedTxnDB;
Status MaybeFlushWriteBatchToDB();
Status FlushWriteBatchToDB(bool prepared);
// For write unprepared, we check on every writebatch append to see if
// max_write_batch_size_ has been exceeded, and then call
// FlushWriteBatchToDB if so. This logic is encapsulated in
// MaybeFlushWriteBatchToDB.
size_t max_write_batch_size_;
WriteUnpreparedTxnDB* wupt_db_;
// Ordered list of unprep_seq sequence numbers that we have already written
// to DB.
//
// This maps unprep_seq => prepare_batch_cnt for each unprepared batch
// written by this transaction.
//
// Note that this contains both prepared and unprepared batches, since they
// are treated similarily in prepare heap/commit map, so it simplifies the
// commit callbacks.
std::map<SequenceNumber, size_t> unprep_seqs_;
// Set of keys that have written to that have already been written to DB
// (ie. not in write_batch_).
//
std::map<uint32_t, std::vector<std::string>> write_set_keys_;
};
} // namespace rocksdb
#endif // ROCKSDB_LITE