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arangodb/arangod/StorageEngine/TransactionState.h

285 lines
9.4 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGOD_STORAGE_ENGINE_TRANSACTION_STATE_H
#define ARANGOD_STORAGE_ENGINE_TRANSACTION_STATE_H 1
#include "Basics/Common.h"
#include "Basics/Result.h"
#include "Basics/HashSet.h"
#include "Basics/SmallVector.h"
#include "Cluster/ServerState.h"
#include "Transaction/Hints.h"
#include "Transaction/Options.h"
#include "Transaction/Status.h"
#include "VocBase/AccessMode.h"
#include "VocBase/voc-types.h"
#include <map>
#ifdef ARANGODB_ENABLE_MAINTAINER_MODE
#define LOG_TRX(logid, llevel, trx, tlevel) \
LOG_TOPIC(logid, llevel, arangodb::Logger::TRANSACTIONS) \
<< "#" << trx->id() << "." << tlevel << " (" \
<< transaction::statusString(trx->status()) << "): "
#else
#define LOG_TRX(logid, llevel, ...) \
while (0) LOG_TOPIC(logid, llevel, arangodb::Logger::TRANSACTIONS)
#endif
struct TRI_vocbase_t;
namespace arangodb {
namespace transaction {
class Methods;
struct Options;
} // namespace transaction
class TransactionCollection;
/// @brief transaction type
class TransactionState {
public:
/// @brief an implementation-dependent structure for storing runtime data
struct Cookie {
typedef std::unique_ptr<Cookie> ptr;
virtual ~Cookie() {}
};
typedef std::function<void(TransactionState& state)> StatusChangeCallback;
TransactionState() = delete;
TransactionState(TransactionState const&) = delete;
TransactionState& operator=(TransactionState const&) = delete;
TransactionState(TRI_vocbase_t& vocbase, TRI_voc_tid_t tid,
transaction::Options const& options);
virtual ~TransactionState();
/// @return a cookie associated with the specified key, nullptr if none
Cookie* cookie(void const* key) noexcept;
/// @brief associate the specified cookie with the specified key
/// @return the previously associated cookie, if any
Cookie::ptr cookie(void const* key, Cookie::ptr&& cookie);
bool isRunningInCluster() const {
return ServerState::isRunningInCluster(_serverRole);
}
bool isDBServer() const { return ServerState::isDBServer(_serverRole); }
bool isCoordinator() const { return ServerState::isCoordinator(_serverRole); }
inline transaction::Options& options() { return _options; }
inline transaction::Options const& options() const { return _options; }
inline TRI_vocbase_t& vocbase() const { return _vocbase; }
inline TRI_voc_tid_t id() const { return _id; }
inline transaction::Status status() const { return _status; }
inline bool isRunning() const {
return _status == transaction::Status::RUNNING;
}
void setRegistered() noexcept { _registeredTransaction = true; }
bool wasRegistered() const noexcept { return _registeredTransaction; }
int increaseNesting() {
return _nestingLevel.fetch_add(1, std::memory_order_relaxed) + 1;
}
int decreaseNesting() {
TRI_ASSERT(nestingLevel() > 0);
return _nestingLevel.fetch_sub(1, std::memory_order_relaxed) - 1;
}
int nestingLevel() const {
return _nestingLevel.load(std::memory_order_relaxed);
}
bool isTopLevelTransaction() const { return nestingLevel() == 0; }
bool isEmbeddedTransaction() const { return !isTopLevelTransaction(); }
double timeout() const { return _options.lockTimeout; }
void timeout(double value) {
if (value > 0.0) {
_options.lockTimeout = value;
}
}
bool waitForSync() const { return _options.waitForSync; }
void waitForSync(bool value) { _options.waitForSync = value; }
bool allowImplicitCollections() const {
return _options.allowImplicitCollections;
}
void allowImplicitCollections(bool value) {
_options.allowImplicitCollections = value;
}
/// @brief return the collection from a transaction
TransactionCollection* collection(TRI_voc_cid_t cid,
AccessMode::Type accessType) const;
/// @brief return the collection from a transaction
TransactionCollection* collection(std::string const& name,
AccessMode::Type accessType) const;
/// @brief add a collection to a transaction
Result addCollection(TRI_voc_cid_t cid, std::string const& cname,
AccessMode::Type accessType, int nestingLevel, bool force);
/// @brief make sure all declared collections are used & locked
Result ensureCollections(int nestingLevel = 0);
/// @brief use all participating collections of a transaction
Result useCollections(int nestingLevel);
/// @brief run a callback on all collections of the transaction
void allCollections(std::function<bool(TransactionCollection&)> const& cb);
/// @brief return the number of collections in the transaction
size_t numCollections() const { return _collections.size(); }
/// @brief release collection locks for a transaction
int unuseCollections(int nestingLevel);
/// FIXME delete, server-based locking should take care of this
int lockCollections();
/// @brief whether or not a transaction consists of a single operation
bool isSingleOperation() const {
return hasHint(transaction::Hints::Hint::SINGLE_OPERATION);
}
/// @brief update the status of a transaction
void updateStatus(transaction::Status status);
/// @brief whether or not a specific hint is set for the transaction
bool hasHint(transaction::Hints::Hint hint) const { return _hints.has(hint); }
/// @brief begin a transaction
virtual arangodb::Result beginTransaction(transaction::Hints hints) = 0;
/// @brief commit a transaction
virtual arangodb::Result commitTransaction(transaction::Methods* trx) = 0;
/// @brief abort a transaction
virtual arangodb::Result abortTransaction(transaction::Methods* trx) = 0;
virtual bool hasFailedOperations() const = 0;
TransactionCollection* findCollection(TRI_voc_cid_t cid) const;
/// @brief make a exclusive transaction, only valid before begin
void setExclusiveAccessType();
/// @brief whether or not a transaction is read-only
bool isReadOnlyTransaction() const {
return (_type == AccessMode::Type::READ);
}
/// @brief whether or not a transaction only has exculsive or read accesses
bool isOnlyExclusiveTransaction() const;
/// @brief servers already contacted
arangodb::HashSet<std::string> const& knownServers() const {
return _knownServers;
}
bool knowsServer(std::string const& uuid) const {
return _knownServers.find(uuid) != _knownServers.end();
}
/// @brief add a server to the known set
void addKnownServer(std::string const& uuid) {
_knownServers.emplace(uuid);
}
/// @brief remove a server from the known set
void removeKnownServer(std::string const& uuid) {
_knownServers.erase(uuid);
}
void clearKnownServers() {
_knownServers.clear();
}
/// @returns tick of last operation in a transaction
/// @note the value is guaranteed to be valid only after
/// transaction is committed
TRI_voc_tick_t lastOperationTick() const noexcept {
return _lastWrittenOperationTick;
}
protected:
/// @brief find a collection in the transaction's list of collections
TransactionCollection* findCollection(TRI_voc_cid_t cid, size_t& position) const;
/// @brief release collection locks for a transaction
void releaseCollections();
/// @brief clear the query cache for all collections that were modified by
/// the transaction
void clearQueryCache();
private:
/// @brief check if current user can access this collection
Result checkCollectionPermission(std::string const& cname, AccessMode::Type) const;
protected:
TRI_vocbase_t& _vocbase; /// @brief vocbase for this transaction
TRI_voc_tid_t const _id; /// @brief local trx id
/// @brief tick of last added & written operation
TRI_voc_tick_t _lastWrittenOperationTick;
/// @brief access type (read|write)
AccessMode::Type _type;
/// @brief current status
transaction::Status _status;
SmallVector<TransactionCollection*>::allocator_type::arena_type _arena; // memory for collections
SmallVector<TransactionCollection*> _collections; // list of participating collections
ServerState::RoleEnum const _serverRole; /// role of the server
transaction::Hints _hints; // hints; set on _nestingLevel == 0
transaction::Options _options;
private:
/// a collection of stored cookies
std::map<void const*, Cookie::ptr> _cookies;
/// @brief servers we already talked to for this transactions
arangodb::HashSet<std::string> _knownServers;
/// @brief reference counter of # of 'Methods' instances using this object
std::atomic<int> _nestingLevel;
bool _registeredTransaction;
};
} // namespace arangodb
#endif