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arangodb/arangod/Transaction/Context.cpp

229 lines
7.5 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// @brief transaction context
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2004-2013 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 triAGENS GmbH, Cologne, Germany
///
/// @author Jan Steemann
/// @author Copyright 2011-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#include "Context.h"
#include "BasicsC/logging.h"
#include "Transaction/Collection.h"
#include "Transaction/Manager.h"
#include "Transaction/Transaction.h"
#include "Transaction/WorkUnit.h"
#include "VocBase/vocbase.h"
#include "Wal/LogfileManager.h"
#define CONTEXT_LOG(msg) LOG_INFO("%s", msg)
using namespace std;
using namespace triagens::transaction;
using namespace triagens::wal;
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief create the transaction context
////////////////////////////////////////////////////////////////////////////////
Context::Context (Manager* manager,
wal::LogfileManager* logfileManager,
TRI_vocbase_t* vocbase,
Context** globalContext)
: _manager(manager),
_logfileManager(logfileManager),
_resolver(vocbase),
_globalContext(globalContext),
_transaction(0),
_workUnits(),
_nextWorkUnitId(0),
_refCount(0) {
CONTEXT_LOG("creating context");
if (_globalContext != nullptr) {
*_globalContext = this;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief destroy the transaction context
////////////////////////////////////////////////////////////////////////////////
Context::~Context () {
assert(_workUnits.empty());
assert(_transaction == nullptr);
if (_globalContext != nullptr) {
*_globalContext = nullptr;
}
CONTEXT_LOG("destroyed context");
}
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief reuse or create a transaction context
////////////////////////////////////////////////////////////////////////////////
Context* Context::getContext (Manager* manager,
wal::LogfileManager* logfileManager,
TRI_vocbase_t* vocbase,
Context** globalContext) {
return createContext(manager, logfileManager, vocbase, globalContext);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief create a transaction context
////////////////////////////////////////////////////////////////////////////////
Context* Context::getContext (Manager* manager,
wal::LogfileManager* logfileManager,
TRI_vocbase_t* vocbase) {
return createContext(manager, logfileManager, vocbase, nullptr);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief increase the reference count
////////////////////////////////////////////////////////////////////////////////
void Context::increaseRefCount () {
++_refCount;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief decrease the reference count
/// the last user that calls this will destroy the context!
////////////////////////////////////////////////////////////////////////////////
void Context::decreaseRefCount () {
assert(_refCount > 0);
if (--_refCount == 0) {
// last user has detached
delete this;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief resolve a collection name
////////////////////////////////////////////////////////////////////////////////
TRI_vocbase_col_t* Context::resolveCollection (std::string const& name) const {
return const_cast<TRI_vocbase_col_t*>(_resolver.getCollectionStruct(name));
}
////////////////////////////////////////////////////////////////////////////////
/// @brief find a collection in the top-level work units
////////////////////////////////////////////////////////////////////////////////
Collection* Context::findCollection (TRI_voc_cid_t id) const {
for (auto it = _workUnits.rbegin(); it != _workUnits.rend(); ++it) {
WorkUnit* workUnit = (*it);
Collection* collection = workUnit->findCollection(id);
if (collection != nullptr) {
// found the collection
return collection;
}
}
// did not find the collection
return nullptr;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief start a new unit of work
////////////////////////////////////////////////////////////////////////////////
int Context::startWorkUnit (WorkUnit* workUnit) {
if (_workUnits.empty()) {
assert(_transaction == nullptr);
_transaction = _manager->createTransaction(workUnit->isSingleOperation());
assert(_transaction != nullptr);
}
assert(_transaction != nullptr);
_workUnits.push_back(workUnit);
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief end a unit of work
////////////////////////////////////////////////////////////////////////////////
int Context::endWorkUnit (WorkUnit* workUnit) {
assert(! _workUnits.empty());
assert(_workUnits.back() == workUnit);
// pop last work unit from stack
_workUnits.pop_back();
if (_workUnits.empty()) {
// final level
if (_transaction != nullptr) {
delete _transaction;
_transaction = nullptr;
}
}
return TRI_ERROR_NO_ERROR;
}
// -----------------------------------------------------------------------------
// --SECTION-- private methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief create a new transaction context
////////////////////////////////////////////////////////////////////////////////
Context* Context::createContext (Manager* manager,
wal::LogfileManager* logfileManager,
TRI_vocbase_t* vocbase,
Context** globalContext) {
if (globalContext == nullptr ||
*globalContext == nullptr) {
return new Context(manager, logfileManager, vocbase, globalContext);
}
return *globalContext;
}
// Local Variables:
// mode: outline-minor
// outline-regexp: "/// @brief\\|/// {@inheritDoc}\\|/// @addtogroup\\|/// @page\\|// --SECTION--\\|/// @\\}"
// End: