databaseserver.cpp

MPICH是MPI的重要研究,提供了一系列的接口函数,为并行计算的实现提供了编程环境.

#include "Database.h"
#include <stdio.h>

HANDLE g_hStopDBSLoopEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

// Function name	: DatabaseServer::DatabaseServer
// Description	    : 
// Return type		: 
DatabaseServer::DatabaseServer()
{
	// Start the Winsock dll
	WSADATA wsaData;
	int err = WSAStartup( MAKEWORD( 2, 0 ), &wsaData );
	if (err != 0)
		printf("Winsock2 dll not initialized\n");

	m_hServerThread = NULL;
	m_nPort = 0;
	strcpy(m_pszHost, "127.0.0.1");
	gethostname(m_pszHost, 100);
	m_pList = NULL;
	m_hMutex = CreateMutex(NULL, FALSE, NULL);
}

// Function name	: DeleteValueList
// Description	    : 
// Return type		: void 
// Argument         : DatabaseServer::ValueNode *pList
void DeleteValueList(DatabaseServer::ValueNode *pList)
{
	if (pList == NULL)
		return;
	DeleteValueList(pList->pNext);
	if (pList->pData != NULL)
		delete pList->pData;
	delete pList;
}

// Function name	: DeleteKeyList
// Description	    : 
// Return type		: void 
// Argument         : DatabaseServer::KeyNode *pList
void DeleteKeyList(DatabaseServer::KeyNode *pList)
{
	if (pList == NULL)
		return;
	DeleteKeyList(pList->pNext);
	DeleteValueList(pList->pValueList);
	if (pList->pszKey != NULL)
		delete pList->pszKey;
	delete pList;
}

// Function name	: DeleteIDList
// Description	    : 
// Return type		: void 
// Argument         : DatabaseServer::IDNode *pList
void DeleteIDList(DatabaseServer::IDNode *pList)
{
	if (pList == NULL)
		return;
	DeleteIDList(pList->pNext);
	DeleteKeyList(pList->pKeyList);
	delete pList;
}

// Function name	: DatabaseServer::~DatabaseServer
// Description	    : 
// Return type		: 
DatabaseServer::~DatabaseServer()
{
	if (m_hServerThread != NULL)
	{
		//TerminateThread(m_hServerThread, 0);
		//m_hServerThread = NULL;
		SetEvent(g_hStopDBSLoopEvent);
		while (m_hServerThread)
			Sleep(200);
	}
	CloseHandle(g_hStopDBSLoopEvent);
	g_hStopDBSLoopEvent = NULL;
	WaitForSingleObject(m_hMutex, 5000);
	DeleteIDList(m_pList);
	m_pList = NULL;
	ReleaseMutex(m_hMutex);
	CloseHandle(m_hMutex);
	m_hMutex = NULL;
}

// Function name	: DatabaseServer::Start
// Description	    : 
// Return type		: bool 
bool DatabaseServer::Start()
{
	if (m_hServerThread == NULL)
	{
		DWORD dwThreadID;
		m_hServerThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)DatabaseServerThread, this, 0, &dwThreadID);
		if (m_hServerThread == NULL)
		{
			return false;
		}
	}
	return true;
}

// Function name	: DatabaseServer::GetHost
// Description	    : 
// Return type		: bool 
// Argument         : char *pszHost
// Argument         : int length
bool DatabaseServer::GetHost(char *pszHost, int length)
{
	if (strlen(m_pszHost) >= (unsigned int)length)
		return false;
	strcpy(pszHost, m_pszHost);
	return true;
}

// Function name	: DatabaseServer::SetPort
// Description	    : 
// Return type		: bool 
// Argument         : int nPort
bool DatabaseServer::SetPort(int nPort)
{
	if (m_hServerThread != NULL)
		return false;
	m_nPort = nPort;
	return true;
}

// Function name	: DatabaseServer::GetPort
// Description	    : 
// Return type		: int 
int DatabaseServer::GetPort()
{
	if (m_hServerThread != NULL)
	{
		while (m_nPort == 0)
			Sleep(200);
		return m_nPort;
	}
	return -1;
}

// Function name	: DatabaseServer::Stop
// Description	    : 
// Return type		: bool 
bool DatabaseServer::Stop()
{
	if (m_hServerThread != NULL)
	{
		//TerminateThread(m_hServerThread, 0);
		//m_hServerThread = NULL;
		SetEvent(g_hStopDBSLoopEvent);
		while (m_hServerThread)
			Sleep(200);
	}
	return true;
}

// Function name	: DatabaseServer::Delete
// Description	    : 
// Return type		: int 
// Argument         : char *pszID
int DatabaseServer::Delete(char *pszID)
{
	IDNode *pNode, *pTrailer;

	if (WaitForSingleObject(m_hMutex, DATABASE_TIMEOUT) != WAIT_OBJECT_0)
		return MPI_DBS_FAIL;

	pNode = pTrailer = m_pList;

	while (pNode != NULL)
	{
		if (strcmp(pNode->pszID, pszID) == 0)
		{
			if (m_pList == pNode)
				m_pList = pNode->pNext;
			else
				pTrailer->pNext = pNode->pNext;
			pNode->pNext = NULL;
			DeleteIDList(pNode);
			ReleaseMutex(m_hMutex);
			return MPI_DBS_SUCCESS;
		}
		if (pTrailer != pNode)
			pTrailer = pTrailer->pNext;
		pNode = pNode->pNext;
	}

	ReleaseMutex(m_hMutex);

	return MPI_DBS_SUCCESS;
}

// Function name	: DatabaseServer::Delete
// Description	    : 
// Return type		: int 
// Argument         : char *pszID
// Argument         : char *pszKey
int DatabaseServer::Delete(char *pszID, char *pszKey)
{
	IDNode *pNode;

	if (WaitForSingleObject(m_hMutex, DATABASE_TIMEOUT) != WAIT_OBJECT_0)
		return MPI_DBS_FAIL;

	pNode = m_pList;

	while (pNode != NULL)
	{
		if (strcmp(pNode->pszID, pszID) == 0)
		{
			KeyNode *pKey, *pTrailer;
			pKey = pTrailer = pNode->pKeyList;
			while (pKey != NULL)
			{
				if (strcmp(pKey->pszKey, pszKey) == 0)
				{
					if (pNode->pKeyList == pKey)
						pNode->pKeyList = pNode->pKeyList->pNext;
					else
						pTrailer->pNext = pKey->pNext;
					DeleteValueList(pKey->pValueList);
					delete pKey;
					ReleaseMutex(m_hMutex);
					return MPI_DBS_SUCCESS;
				}
				if (pTrailer != pKey)
					pTrailer = pTrailer->pNext;
				pKey = pKey->pNext;
			}
		}
		pNode = pNode->pNext;
	}

	ReleaseMutex(m_hMutex);

	return MPI_DBS_SUCCESS;
}

// Function name	: DatabaseServer::Get
// Description	    : 
// Return type		: int 
// Argument         : char *pszID
// Argument         : char *pszKey
// Argument         : void *&pValueData
// Argument         : int *length
int DatabaseServer::Get(char *pszID, char *pszKey, void *&pValueData, int *length)
{
	IDNode *pNode;
	KeyNode *pKey;
	ValueNode *pValue;

	while (true)
	{
		if (WaitForSingleObject(m_hMutex, DATABASE_TIMEOUT) != WAIT_OBJECT_0)
			return MPI_DBS_FAIL;
		
		pNode = m_pList;
		while (pNode != NULL)
		{
			if (strcmp(pNode->pszID, pszID) == 0)
			{
				pKey = pNode->pKeyList;
				while (pKey != NULL)
				{
					if (strcmp(pKey->pszKey, pszKey) == 0)
					{
						if (pKey->pValueList != NULL)
						{
							pValue = pKey->pValueList;
							if (pValue->length > *length)
							{
								*length = pValue->length;
								ReleaseMutex(m_hMutex);
								return MPI_DBS_FAIL;
							}
							if (pKey->bPersistent)
							{
								// make a copy of the data
								pValueData = new char[pValue->length];
								memcpy(pValueData, pValue->pData, pValue->length);
								*length = pValue->length;
							}
							else
							{
								// consume the data
								pValueData = pValue->pData;
								*length = pValue->length;
								// put the next entry as the new head of the list
								pKey->pValueList = pValue->pNext;
								delete pValue;
							}
							ReleaseMutex(m_hMutex);
							return MPI_DBS_SUCCESS;
						}
					}
					pKey = pKey->pNext;
				}
			}
			pNode = pNode->pNext;
		}

		ReleaseMutex(m_hMutex);
		Sleep(100);
	}
		
	return MPI_DBS_SUCCESS;
}

// Function name	: DatabaseServer::Put
// Description	    : 
// Return type		: int 
// Argument         : char *pszID
// Argument         : char *pszKey
// Argument         : void *pValueData
// Argument         : int length
// Argument         : bool bPersistent
int DatabaseServer::Put(char *pszID, char *pszKey, void *pValueData, int length, bool bPersistent)
{
	IDNode *pIter, *pLast;

	if (WaitForSingleObject(m_hMutex, DATABASE_TIMEOUT) != WAIT_OBJECT_0)
		return MPI_DBS_FAIL;

	if (m_pList == NULL)
	{
		// The list is empty
		KeyNode *pKey = new KeyNode;
		ValueNode *pValue = new ValueNode;
		IDNode *pNode = new IDNode;

		pNode->pKeyList = NULL;
		pNode->pNext = NULL;
		pNode->pKeyList = pKey;
		strcpy(pNode->pszID, pszID);

		pKey->bPersistent = bPersistent;
		pKey->pNext = NULL;
		pKey->pValueList = pValue;
		pKey->pszKey = pszKey;