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// **********************************************************************
//
// Copyright (c) 2003
// ZeroC, Inc.
// Billerica, MA, USA
//
// All Rights Reserved.
//
// Ice is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License version 2 as published by
// the Free Software Foundation.
//
// **********************************************************************
#include <Freeze/SharedDb.h>
#include <IceUtil/StaticMutex.h>
#include <Freeze/DBException.h>
#include <sys/stat.h>
using namespace std;
using namespace IceUtil;
using namespace Ice;
#ifdef _WIN32
# define FREEZE_DB_MODE 0
#else
# define FREEZE_DB_MODE (S_IRUSR | S_IWUSR)
#endif
namespace
{
StaticMutex _mapMutex = ICE_STATIC_MUTEX_INITIALIZER;
StaticMutex _refCountMutex = ICE_STATIC_MUTEX_INITIALIZER;
}
Freeze::SharedDb::Map* Freeze::SharedDb::sharedDbMap = 0;
Freeze::SharedDbPtr
Freeze::SharedDb::get(const ConnectionIPtr& connection,
const string& dbName, bool createDb)
{
StaticMutex::Lock lock(_mapMutex);
if(sharedDbMap == 0)
{
sharedDbMap = new Map;
}
MapKey key;
key.envName = connection->envName();
key.communicator = connection->communicator();
key.dbName = dbName;
{
Map::iterator p = sharedDbMap->find(key);
if(p != sharedDbMap->end())
{
return p->second;
}
}
//
// MapKey not found, let's create and open a new Db
//
auto_ptr<SharedDb> result(new SharedDb(key, connection, createDb));
//
// Insert it into the map
//
pair<Map::iterator, bool> insertResult = sharedDbMap->insert(Map::value_type(key, result.get()));
assert(insertResult.second);
return result.release();
}
Freeze::SharedDb::~SharedDb()
{
if(_trace >= 1)
{
Trace out(_key.communicator->getLogger(), "DB");
out << "closing database \"" << _key.dbName << "\"";
}
try
{
close(0);
}
catch(const ::DbException& dx)
{
DBException ex(__FILE__, __LINE__);
ex.message = dx.what();
throw ex;
}
}
void Freeze::SharedDb::__incRef()
{
IceUtil::StaticMutex::Lock lock(_refCountMutex);
_refCount++;
}
void Freeze::SharedDb::__decRef()
{
IceUtil::StaticMutex::Lock lock(_refCountMutex);
if(--_refCount == 0)
{
IceUtil::StaticMutex::TryLock mapLock(_mapMutex);
if(!mapLock.acquired())
{
//
// Reacquire mutex in proper order and check again
//
lock.release();
mapLock.acquire();
lock.acquire();
if(_refCount > 0)
{
return;
}
}
//
// Remove from map
//
size_t one = sharedDbMap->erase(_key);
assert(one == 1);
if(sharedDbMap->size() == 0)
{
delete sharedDbMap;
sharedDbMap = 0;
}
//
// Keep lock to prevent somebody else to re-open this Db
// before it's closed.
//
delete this;
}
}
Freeze::SharedDb::SharedDb(const MapKey& key,
const ConnectionIPtr& connection,
bool createDb) :
Db(connection->dbEnv(), 0),
_key(key),
_refCount(0),
_trace(connection->trace())
{
try
{
u_int32_t flags = DB_AUTO_COMMIT | DB_THREAD;
if(createDb)
{
flags |= DB_CREATE;
}
open(0, key.dbName.c_str(), 0, DB_BTREE, flags, FREEZE_DB_MODE);
}
catch(const ::DbException& dx)
{
DBException ex(__FILE__, __LINE__);
ex.message = dx.what();
throw ex;
}
}
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