//Define the handle queue
typedef std::list<MYSQL *> CONNECTION_HANDLE_LIST;
typedef std::list<MYSQL *>::iterator CONNECTION_HANDLE_LIST_IT;
//The parameter structure of the connection database
class CDBParameter
{
public:
char *host;
char *user; �
char *password; �
char *database; �
unsigned int port;
const char *unix_socket; ///<Socket, generally NULL
unsigned int client_flag; ///<usually 0
};
//Create two queues
CONNECTION_HANDLE_LIST m_lsBusyList; �
CONNECTION_HANDLE_LIST m_lsIdleList;
//All connection handles are first connected to the database, added to the idle queue, and waiting for use.
bool CDBManager::Connect(char * host /* = "localhost" */, char * user /* = "chenmin" */, \
char * password /* = "chenmin" */, char * database /* = "HostCache" */)
{
CDBParameter * lpDBParam = new CDBParameter();
lpDBParam->host = host;
lpDBParam->user = user;
lpDBParam->password = password;
lpDBParam->database = database;
lpDBParam->port = 0;
lpDBParam->unix_socket = NULL;
lpDBParam->client_flag = 0;
try
{
//connect
for(int index = 0; index < CONNECTION_NUM; index++)
{
MYSQL* pConnectHandle = mysql_init((MYSQL*) 0); //Initialize the connection handle
if(!mysql_real_connect(pConnectHandle, lpDBParam->host, lpDBParam->user, lpDBParam->password,\
lpDBParam->database,lpDBParam->port,lpDBParam->unix_socket,lpDBParam->client_fla))
return false;
//Join to the idle queue
m_lsIdleList.push_back(pConnectHandle);
}
}
catch(...)
{
return false;
}
return true;
}
//Extract an idle handle for use
MYSQL * CDBManager::GetIdleConnectHandle()
{
MYSQL * pConnectHandle = NULL;
m_ListMutex.acquire();
if(m_lsIdleList.size())
{
pConnectHandle = m_lsIdleList.front();
m_lsIdleList.pop_front();
m_lsBusyList.push_back(pConnectHandle);
}
else //Special case, the idle queue is empty, return is empty
{
pConnectHandle = 0;
}
m_ListMutex.release();
return pConnectHandle;
}
//Release a used handle from the usage queue and insert it into the idle queue.
void CDBManager::SetIdleConnectHandle(MYSQL * connecthandle)
{
m_ListMutex.acquire();
m_lsBusyList.remove(connecthandle);
m_lsIdleList.push_back(connecthandle);
m_ListMutex.release();
}
//Usage example, first get the idle handle, use this handle to do the real operation, and then insert it back to the idle queue.
bool CDBManager::DeleteHostCacheBySessionID(char * sessionid)
{
MYSQL * pConnectHandle = GetIdleConnectHandle();
if(!pConnectHandle)
return 0;
bool bRet = DeleteHostCacheBySessionID(pConnectHandle, sessionid);
SetIdleConnectHandle(pConnectHandle);
return bRet;
}
//Pass an idle handle and perform real deletion operation.
bool CDBManager::DeleteHostCacheBySessionID(MYSQL * connecthandle, char * sessionid)
{
char deleteSQL[SQL_LENGTH];
memset(deleteSQL, 0, sizeof(deleteSQL));
sprintf(deleteSQL,"delete from HostCache where SessionID = '%s'", sessionid);
if(mysql_query(connectthandle,deleteSQL) != 0) //Delete
return false;
return true;
}