rocksdb/utilities/transactions/optimistic_transaction_db_i...

112 lines
3.7 KiB
C++

// 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
#include <algorithm>
#include <cstdint>
#include <memory>
#include <vector>
#include "rocksdb/db.h"
#include "rocksdb/options.h"
#include "rocksdb/utilities/optimistic_transaction_db.h"
#include "util/cast_util.h"
#include "util/mutexlock.h"
namespace ROCKSDB_NAMESPACE {
class OccLockBucketsImplBase : public OccLockBuckets {
public:
virtual port::Mutex& GetLockBucket(const Slice& key, uint64_t seed) = 0;
};
template <bool cache_aligned>
class OccLockBucketsImpl : public OccLockBucketsImplBase {
public:
explicit OccLockBucketsImpl(size_t bucket_count) : locks_(bucket_count) {}
port::Mutex& GetLockBucket(const Slice& key, uint64_t seed) override {
return locks_.Get(key, seed);
}
size_t ApproximateMemoryUsage() const override {
return locks_.ApproximateMemoryUsage();
}
private:
// TODO: investigate optionally using folly::MicroLock to majorly save space
using M = std::conditional_t<cache_aligned, CacheAlignedWrapper<port::Mutex>,
port::Mutex>;
Striped<M> locks_;
};
class OptimisticTransactionDBImpl : public OptimisticTransactionDB {
public:
explicit OptimisticTransactionDBImpl(
DB* db, const OptimisticTransactionDBOptions& occ_options,
bool take_ownership = true)
: OptimisticTransactionDB(db),
db_owner_(take_ownership),
validate_policy_(occ_options.validate_policy) {
if (validate_policy_ == OccValidationPolicy::kValidateParallel) {
auto bucketed_locks = occ_options.shared_lock_buckets;
if (!bucketed_locks) {
uint32_t bucket_count = std::max(16u, occ_options.occ_lock_buckets);
bucketed_locks = MakeSharedOccLockBuckets(bucket_count);
}
bucketed_locks_ = static_cast_with_check<OccLockBucketsImplBase>(
std::move(bucketed_locks));
}
}
~OptimisticTransactionDBImpl() {
// Prevent this stackable from destroying
// base db
if (!db_owner_) {
db_ = nullptr;
}
}
Transaction* BeginTransaction(const WriteOptions& write_options,
const OptimisticTransactionOptions& txn_options,
Transaction* old_txn) override;
// Transactional `DeleteRange()` is not yet supported.
using StackableDB::DeleteRange;
virtual Status DeleteRange(const WriteOptions&, ColumnFamilyHandle*,
const Slice&, const Slice&) override {
return Status::NotSupported();
}
// Range deletions also must not be snuck into `WriteBatch`es as they are
// incompatible with `OptimisticTransactionDB`.
virtual Status Write(const WriteOptions& write_opts,
WriteBatch* batch) override {
if (batch->HasDeleteRange()) {
return Status::NotSupported();
}
return OptimisticTransactionDB::Write(write_opts, batch);
}
OccValidationPolicy GetValidatePolicy() const { return validate_policy_; }
port::Mutex& GetLockBucket(const Slice& key, uint64_t seed) {
return bucketed_locks_->GetLockBucket(key, seed);
}
private:
std::shared_ptr<OccLockBucketsImplBase> bucketed_locks_;
bool db_owner_;
const OccValidationPolicy validate_policy_;
void ReinitializeTransaction(Transaction* txn,
const WriteOptions& write_options,
const OptimisticTransactionOptions& txn_options =
OptimisticTransactionOptions());
};
} // namespace ROCKSDB_NAMESPACE