FastDb client-server模式

就个人理解而言，fastdb client-server模式，只是在client和server之间添加了一个socket通信，其实操作都是在server端完成的。

但是client-server也有很多好处，其中一个就是可以同一个进程可以同时运用fastdb的无盘模式，和磁盘模式。

当然其中一个模式只是client（比如这个进程开启时需要用无盘模式，将数据全部存入内存，以方便读取，但是记录日志时希望用fastdb记录到库中，这时候就可以另外开始一个server进程，用磁盘模式打开数据库，client连接到server进行insert操作。）

server端代码：

// Sev_log.cpp : 定义控制台应用程序的入口点。
//
 
#include "stdafx.h"
#include "fastdb.h"
 
class CLog
{
	public:
		char const* sdatetime;
		int4		ProcessNo;
		int4		level;
		char const* logtext;
		char const* ifwrited;
 
	TYPE_DESCRIPTOR((FIELD(sdatetime),
					 FIELD(logtext),
					 FIELD(ProcessNo),
					 FIELD(level),
					 FIELD(ifwrited)
					 ));
};
 
#pragma comment(lib, "fastdb.lib")
#pragma comment(lib, "wsock32.lib")
 
#if THREADS_SUPPORTED && !defined(NO_SOCKETS)
#define SERVER_SUPPORTED 1
#include "server.h"
#else
#define SERVER_SUPPORTED 0
#endif
 
USE_FASTDB_NAMESPACE
 
REGISTER(CLog);
 
int _tmain(int argc, _TCHAR* argv[])
{	
	//由于不关闭数据库的话，内存占用会越来越大，所以定时重启数据库
	while(1)
	{
		dbDatabase* m_pdb;
		m_pdb = NULL;
 
		size_t dbInitSize = 16 * 1024 * 1024;			// 16M	指定了数据库文件的初始大小	缺省值为4MB
		size_t dbExtensionQuantum = 1 * 1024 * 1024;		//  1M	内存分配位图的扩展量子		缺省值为4MB
		size_t dbInitIndexSize = 2 * 1024 * 1024;		//  2M	指定了初始的索引大小			64K个对象标识符
 
		m_pdb = new dbDatabase(dbDatabase::dbAllAccess, dbExtensionQuantum, dbInitIndexSize);
	
		if(m_pdb->open("test"))
		{
			m_pdb->scheduleBackup("backup.fdb",2); //定时备份 2s备份一次
			char serverURL[64];
			strcpy(serverURL, "localhost:2100");
			dbServer* server = dbServer::find(serverURL);
 
			if (server == NULL){
				/*
				dbServer::dbServer(dbDatabase* db,
					char const* serverURL, 
					int optimalNumberOfThreads, 
					int connectionQueueLen)
				*/
				server = new dbServer(m_pdb, serverURL, 8);
				if (server != NULL){
					server->start();
					printf("Server started for URL %s\n", serverURL);
				}
			}
 
			Sleep(60000);
 
			if (server != NULL) { 
				server->stop();
				delete server;
				server = NULL;
				printf("Server stopped for URL %s\n", serverURL);
			} 
 
			m_pdb->close();
			printf("fastdb close!\n");
		}
 
		delete m_pdb;
		m_pdb=NULL;
	}
	return 0;
}

client端代码：

// cli_writelog.cpp : 定义控制台应用程序的入口点。
//
 
#include "stdafx.h"
#include "cli.h"
#include <string.h>
#include <process.h> //windows
//#include "unistd.h"  //linux
 
#include "fastdb.h"
 
class CLog
{
	public:
		char const* sdatetime;
		int4		ProcessNo;
		int4		level;
		char const* logtext;
		char const* ifwrited;
 
	TYPE_DESCRIPTOR((FIELD(sdatetime),
					 FIELD(logtext),
					 FIELD(ProcessNo),
					 FIELD(level),
					 FIELD(ifwrited)
					 ));
};
 
#pragma comment(lib, "cli.lib")
#pragma comment(lib, "wsock32.lib")
 
USE_FASTDB_NAMESPACE;
 
#define SUCCESS			1
#define CREATE_STATEMENT_ERROR -1
#define BIND_COLUMN_ERROR      -2
#define INSERT_ERROR	       -3
#define PRECOMMIT_ERROR        -4
#define FREE_STATEMENT_ERROR   -5
 
 
int WriteLog(char *format,...)
{
	FILE * fp;
	va_list args;
	char sLogFile[100];
	
	memset(sLogFile,0,sizeof(sLogFile));
	
	strcpy(sLogFile,"log.txt");
	
	if((fp=fopen(sLogFile,"a+"))==NULL)
	{
		//printf("open file happened errors!\n");
		return -1;
	}
 
	va_start(args,format);
	vfprintf(fp,format,args);
	va_end(args);
	
	fclose(fp);
	return 0;
}
 
int WriteLog(const char* log , const int level , const int session)
{
	const int MAXSTRLEN = 256;
	int inst_level,inst_processno;
	char inst_sdatetime[MAXSTRLEN];
	char inst_logs[MAXSTRLEN];
 
	int StatementToInst = cli_statement(session, "insert into CLog");
 
	if (StatementToInst < 0) { 
		WriteLog("cli_statement failed with code %d\n", StatementToInst);
		return CREATE_STATEMENT_ERROR;
	}
 
	int rc;//用于返回错误代码
	if ((rc = cli_column(StatementToInst, "sdatetime",cli_asciiz, NULL, &inst_sdatetime)) != cli_ok ||
		(rc = cli_column(StatementToInst, "logtext", cli_asciiz, NULL, &inst_logs)) != cli_ok		||
		(rc = cli_column(StatementToInst, "ProcessNo", cli_int4, NULL, &inst_processno)) != cli_ok   ||
		(rc = cli_column(StatementToInst, "level", cli_int4, NULL, &inst_level)) != cli_ok )
	
	{
		WriteLog("cli_column failed with code %d\n", rc);
		return BIND_COLUMN_ERROR;
	}
 
	char buf[MAXSTRLEN];//用于临时存储时间
 
	strcpy(inst_sdatetime,dbDateTime::current().asString(buf,sizeof buf,"%Y-%m-%d %H:%M:%S"));
	strcpy(inst_logs,log);
	inst_processno = (int)getpid();
	inst_level = level;
 
	if((rc = cli_insert(StatementToInst,NULL))!= cli_ok)
	{
		WriteLog("cli_insert failed with code %d\n", rc);
		return INSERT_ERROR;
	}
 
	/*
	if((rc = cli_commit(session)) != cli_ok)       //直接commit非常慢！
	{
		printf("cli_commit failed with code %d\n", rc);
		return PRECOMMIT_ERROR;
	}
	*/
	
	
	
	if((rc = cli_precommit(session)) != cli_ok)
	{
		WriteLog("cli_precommit failed with code %d\n", rc);
		return PRECOMMIT_ERROR;
	}
	
	
	if((rc = cli_free(StatementToInst)) != cli_ok){
		WriteLog("cli_free failed with code %d\n", rc);
		return FREE_STATEMENT_ERROR;
	}
 
	return SUCCESS;
}
 
 
int _tmain(int argc, _TCHAR* argv[])
{
	char* const serverURL = "127.0.0.1:2100";
 
	int session = cli_open(serverURL,10,1);//重连次数10，重连间隔1s
	if (session < 0) { 
        printf("cli_open failed with code %d\n", session);
		return -1;
    }
	
	DWORD dstart = GetTickCount();
 
	for(int i=0;i < 10;i++)
		WriteLog("this is a log test",i%10,session);
 
	printf("time is %d\n",GetTickCount()-dstart);
 
	int rc;
	/*
	if((rc = cli_commit(session)) != cli_ok)  //批量提交速度最快  但是在提交之前，这部分日志无法取出
	{
		printf("cli_commit failed with code %d\n", rc);
		return PRECOMMIT_ERROR;
	}
	*/
 
	//precommit最好加上定时备份日志
	/*FastDB为数据库提供了precommit的接口，用于完成除sync到磁盘文件外的所有事物操作
	，如释放mutex资源等。同时提供了backup接口，用来完成内存数据到磁盘文件的备份，
	甚至支持打开数据库时同时指定定时备份到磁盘文件的间隔，但是cli这个功能还没完善*/
 
 
	if ((rc = cli_close(session)) != 0) { 
		printf("cli_close failed with code %d\n", rc);
		return -1;	
	}
	printf("fastdb insert successfully!\n");
 
	dstart = GetTickCount();
	for(int i=0;i < 100;i++)
		WriteLog("this is a log test\n",i%10);
 
	printf("time is %d\n",GetTickCount()-dstart);                                                                  
	printf("file insert successfully!\n");
 
 
	getchar();
 
	return 0;
}

原文：https://blog.youkuaiyun.com/fuyun10036/article/details/8620816