首页 > > 网络编程 > 其它 >

redis数据库操作的C++简单封装

2018-06-17 19:57:16来源：未知阅读 ()

用c++简单封装了redis的基本操作（hiredis）

接口包括：①链接和断开连接、②设置键值对(set)、③查询键值对(get)、④删除键值对(del)、⑤将所有键显示出来

若任何一处发生错误，返回对应的错误状态码，同时可以调用getErrorMsg()查看错误信息

所有码包括：

M_REDIS_OK = 0, //执行成功
M_CONNECT_FAIL = -1, //连接redis失败
M_CONTEXT_ERROR = -2, //RedisContext返回错误
M_REPLY_ERROR = -3, //redisReply错误
M_EXE_COMMAND_ERROR = -4 //redis命令执行错误

tips：在链接hiredis时需要添加链接选项： -levent -lhiredis

代码如下：

redis_handler.h

#ifndef __REDIS_HANDLER_H__
#define __REDIS_HANDLER_H__

//#include "hiredis\hiredis.h" 
#include <hiredis/hiredis.h>
#include <string>

using namespace std;

enum
{
    M_REDIS_OK = 0, //执行成功
    M_CONNECT_FAIL = -1, //连接redis失败
    M_CONTEXT_ERROR = -2, //RedisContext返回错误
    M_REPLY_ERROR = -3, //redisReply错误
    M_EXE_COMMAND_ERROR = -4 //redis命令执行错误
};


class RedisHandler
{
public:
    RedisHandler();
    ~RedisHandler();
    int connect(const string &addr, int port, const string &pwd = ""); //连接redis数据库：addr：IP地址，port：端口号，pwd：密码(默认为空)
    int disConnect(); //断开连接

    int setValue(const string &key, const string &value); //添加或修改键值对，成功返回0，失败<0
    int getValue(const string &key, string &value); //获取键对应的值，成功返回0，失败<0
    int delKey(const string &key); //删除键，成功返回影响的行数，失败<0
    int printAll(); //打印所有的键值对

    string getErrorMsg(); //获取错误信息
private:
    string m_addr; //IP地址
    int m_port; //端口号
    string m_pwd; //密码
    redisContext* pm_rct; //redis结构体
    redisReply* pm_rr; //返回结构体
    string error_msg; //错误信息

    int connectAuth(const string &pwd); //使用密码登录
    int handleReply(void* value = NULL, redisReply ***array = NULL); //处理返回的结果
};


#endif

redis_handler.cpp

#include "redis_handler.h"
#include <string>
#include <cstring>
#include <iostream>
using namespace std;

RedisHandler::RedisHandler()
{
    m_addr = "";
    m_port = 0;
    m_pwd = "";
    pm_rct = NULL;
    pm_rr = NULL;
    error_msg = "";
}

RedisHandler::~RedisHandler()
{
    disConnect();
    pm_rct = NULL;
    pm_rr = NULL;
}

/*
连接redis数据库
addr: 地址，port：端口号，pwd：密码
成功返回M_REDIS_OK，失败返回M_CONNECT_FAIL
*/
int RedisHandler::connect(const string &addr = "127.0.0.1", int port = 6379, const string &pwd) {
    m_addr = addr;
    m_port = port;
    m_pwd = pwd;

    pm_rct = redisConnect(m_addr.c_str(), m_port);

    if (pm_rct->err)
    {
        error_msg = pm_rct->errstr;
        return M_CONNECT_FAIL;
    }

    if (!m_pwd.empty())
    {
        return connectAuth(m_pwd);
    }

    return M_REDIS_OK;
}

/*
断开redis连接
*/
int RedisHandler::disConnect()
{
    redisFree(pm_rct);
    freeReplyObject(pm_rr);
}

/*
添加或插入键值对
key：键，value：值
成功返回M_REDIS_OK，失败返回<0
*/
int RedisHandler::setValue(const string &key, const string &value)
{
    string cmd = "set " + key + " " + value;

    pm_rr = (redisReply*)redisCommand(pm_rct, cmd.c_str());

    return handleReply();
}

/*
获取键对应的值
key：键，value：值引用
成功返回M_REDIS_OK，失败返回<0
*/
int RedisHandler::getValue(const string &key, string &value)
{
    string cmd = "get " + key;

    pm_rr = (redisReply*)redisCommand(pm_rct, cmd.c_str());

    int ret = handleReply(&value);
}

/*
删除键
key：键
成功返回影响的行数（可能为0），失败返回<0
*/
int RedisHandler::delKey(const string &key)
{
    string cmd = "del " + key;

    pm_rr = (redisReply*)redisCommand(pm_rct, cmd.c_str());

    int rows = 0;
    int ret = handleReply(&rows);
    if (ret == M_REDIS_OK)
        return rows;
    else
        return ret;
}

/*
打印所有键值对到屏幕上
*/
int RedisHandler::printAll()
{
    string cmd = "keys *";

    pm_rr = (redisReply*)redisCommand(pm_rct, cmd.c_str());

    int len ;
    redisReply **array;
    int ret = handleReply(&len, &array);
    if (ret == M_REDIS_OK)
    {
        for (int i = 0; i < len; i++)
            cout << string(array[i]->str) << endl;
    }
    else
        return 0;
}

/*
返回错误信息
*/
string RedisHandler::getErrorMsg()
{
    return error_msg;
}

/*
使用密码登录
psw：登录密码
成功返回M_REDIS_OK，失败返回<0
*/
int RedisHandler::connectAuth(const string &psw)
{
    string cmd = "auth " + psw;

    pm_rr = (redisReply*)redisCommand(pm_rct, cmd.c_str());

    return handleReply();
}

/*
处理redis返回的信息
value：数据指针，用于保存redis返回的基本类型（value指针指向该数据）
array：数组指针，用于保存redis返回的数组
成功返回M_REDIS_OK，失败返回<0
*/
int RedisHandler::handleReply(void* value, redisReply*** array)
{
    if (pm_rct->err)
    {
        error_msg = pm_rct->errstr;
        return M_CONTEXT_ERROR;
    }

    if (pm_rr == NULL)
    {
        error_msg = "auth redisReply is NULL";
        return M_REPLY_ERROR;
    }

    switch (pm_rr->type)
    {
    case REDIS_REPLY_ERROR:
        error_msg = pm_rr->str;
        return M_EXE_COMMAND_ERROR;
    case REDIS_REPLY_STATUS:
        if (!strcmp(pm_rr->str, "OK"))
            return M_REDIS_OK;
        else
        {
            error_msg = pm_rr->str;
            return M_EXE_COMMAND_ERROR;
        }
    case REDIS_REPLY_INTEGER:
        *(int*)value = pm_rr->integer;
        return M_REDIS_OK;
    case REDIS_REPLY_STRING:
        *(string*)value = pm_rr->str;
        return M_REDIS_OK;
    case REDIS_REPLY_NIL:
        *(string*)value = "";
        return M_REDIS_OK;
    case REDIS_REPLY_ARRAY:
        *(int*)value = pm_rr->elements;
        *array = pm_rr->element;
        return M_REDIS_OK;
    default:
        error_msg = "unknow reply type";
        return M_EXE_COMMAND_ERROR;
    }
}

测试程序main.cpp

#include <iostream>
#include <string>
#include "redis_handler.h"
using namespace std;

int main()
{
    RedisHandler* rh = new RedisHandler();
    int ret;

    //连接测试
    cout << "错误测试: " << "地址错误" << endl;
    ret = rh->connect("34.15.14.15", 6379, "linesum");
    if (ret != M_REDIS_OK)
        cout << "redis error: " << rh->getErrorMsg() << endl;

    cout << "错误测试: " << "端口错误" << endl;
    ret = rh->connect("127.0.0.1", 1234, "linesum");
    if (ret != M_REDIS_OK)
        cout << "redis error: " << rh->getErrorMsg() << endl;

    cout << "错误测试: " << "密码错误" << endl;
    ret = rh->connect("127.0.0.1", 6479, "linsum");
    if (ret != M_REDIS_OK)
        cout << "redis error: " << rh->getErrorMsg() << endl;


    ret = rh->connect("127.0.0.1", 6479, "linesum");
    if (ret != M_REDIS_OK)
    {
        cout << "redis error: " << rh->getErrorMsg() << endl;
        return ret;
    }


    //set测试
    cout << "错误测试: " << "set不带value参数" << endl;
    ret = rh->setValue("key11", "");
    if (ret != M_REDIS_OK)
        cout << "redis error: " << rh->getErrorMsg() << endl;


    ret = rh->setValue("key11", "value11");
    if (ret != M_REDIS_OK)
    {
        cout << "redis error: " << rh->getErrorMsg() << endl;
        return ret;
    }

    ret = rh->setValue("key22", "value22");
    if (ret != M_REDIS_OK)
    {
        cout << "redis error: " << rh->getErrorMsg() << endl;
        return ret;
    }


    //get测试
    string str;
    cout << "错误测试: " << "get不带key参数" << endl;
    ret = rh->getValue("key1111", str);
    if (ret != M_REDIS_OK)
        cout << "redis error: " << rh->getErrorMsg() << endl;

    ret = rh->getValue("key11", str);
    if (ret != M_REDIS_OK)
    {
        cout << "redis error: " << rh->getErrorMsg() << endl;
        return ret;
    }
    else
        cout << "value : " << str << endl;



    //print测试
    ret = rh->printAll();
    if (ret != M_REDIS_OK)
    {
        cout << "redis error: " << rh->getErrorMsg() << endl;
        return ret;
    }


    //del测试
    cout << "错误测试: " << "删除不存在的key" << endl;
    ret = rh->delKey("key1111");
    if (ret != M_REDIS_OK)
        cout << "redis error: " << rh->getErrorMsg() << endl;


    ret = rh->delKey("key11");
    if (ret != M_REDIS_OK)
    {
        cout << "redis error: " << rh->getErrorMsg() << endl;
        return ret;
    }

    delete rh;

    return 0;
}