redis資料庫操作的C++簡單封裝

用c++簡單封裝了redis的基本操作（hiredis）介面包括：①鏈接和斷開連接、②設置鍵值對(set)、③查詢鍵值對(get)、④刪除鍵值對(del)、⑤將所有鍵顯示出來若任何一處發生錯誤，返回對應的錯誤狀態碼，同時可以調用getErrorMsg()查看錯誤信息所有碼包括： M_REDIS ...

用c++簡單封裝了redis的基本操作（hiredis）

介面包括：①鏈接和斷開連接、②設置鍵值對(set)、③查詢鍵值對(get)、④刪除鍵值對(del)、⑤將所有鍵顯示出來

若任何一處發生錯誤，返回對應的錯誤狀態碼，同時可以調用getErrorMsg()查看錯誤信息

所有碼包括：

M_REDIS_OK = 0, //執行成功
M_CONNECT_FAIL = -1, //連接redis失敗
M_CONTEXT_ERROR = -2, //RedisContext返回錯誤
M_REPLY_ERROR = -3, //redisReply錯誤
M_EXE_COMMAND_ERROR = -4 //redis命令執行錯誤

tips：在鏈接hiredis時需要添加鏈接選項： -levent -lhiredis

代碼如下：

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, //執行成功
    M_CONNECT_FAIL = -1, //連接redis失敗
    M_CONTEXT_ERROR = -2, //RedisContext返回錯誤
    M_REPLY_ERROR = -3, //redisReply錯誤
    M_EXE_COMMAND_ERROR = -4 //redis命令執行錯誤
};


class RedisHandler
{
public:
    RedisHandler();
    ~RedisHandler();
    int connect(const string &addr, int port, const string &pwd = ""); //連接redis資料庫：addr：IP地址，port：埠號，pwd：密碼(預設為空)
    int disConnect(); //斷開連接

    int setValue(const string &key, const string &value); //添加或修改鍵值對，成功返回0，失敗<0
    int getValue(const string &key, string &value); //獲取鍵對應的值，成功返回0，失敗<0
    int delKey(const string &key); //刪除鍵，成功返回影響的行數，失敗<0
    int printAll(); //列印所有的鍵值對

    string getErrorMsg(); //獲取錯誤信息
private:
    string m_addr; //IP地址
    int m_port; //埠號
    string m_pwd; //密碼
    redisContext* pm_rct; //redis結構體
    redisReply* pm_rr; //返回結構體
    string error_msg; //錯誤信息

    int connectAuth(const string &pwd); //使用密碼登錄
    int handleReply(void* value = NULL, redisReply ***array = NULL); //處理返回的結果
};


#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;
}

/*
連接redis資料庫
addr: 地址，port：埠號，pwd：密碼
成功返回M_REDIS_OK，失敗返回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;
}

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

/*
添加或插入鍵值對
key：鍵，value：值
成功返回M_REDIS_OK，失敗返回<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();
}

/*
獲取鍵對應的值
key：鍵，value：值引用
成功返回M_REDIS_OK，失敗返回<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);
}

/*
刪除鍵
key：鍵
成功返回影響的行數（可能為0），失敗返回<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;
}

/*
列印所有鍵值對到屏幕上
*/
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;
}

/*
返回錯誤信息
*/
string RedisHandler::getErrorMsg()
{
    return error_msg;
}

/*
使用密碼登錄
psw：登錄密碼
成功返回M_REDIS_OK，失敗返回<0
*/
int RedisHandler::connectAuth(const string &psw)
{
    string cmd = "auth " + psw;

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

    return handleReply();
}

/*
處理redis返回的信息
value：數據指針，用於保存redis返回的基本類型（value指針指向該數據）
array：數組指針，用於保存redis返回的數組
成功返回M_REDIS_OK，失敗返回<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;
    }
}

測試程式main.cpp

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

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

    //連接測試
    cout << "錯誤測試: " << "地址錯誤" << endl;
    ret = rh->connect("34.15.14.15", 6379, "linesum");
    if (ret != M_REDIS_OK)
        cout << "redis error: " << rh->getErrorMsg() << endl;

    cout << "錯誤測試: " << "埠錯誤" << endl;
    ret = rh->connect("127.0.0.1", 1234, "linesum");
    if (ret != M_REDIS_OK)
        cout << "redis error: " << rh->getErrorMsg() << endl;

    cout << "錯誤測試: " << "密碼錯誤" << 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測試
    cout << "錯誤測試: " << "set不帶value參數" << 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測試
    string str;
    cout << "錯誤測試: " << "get不帶key參數" << 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測試
    ret = rh->printAll();
    if (ret != M_REDIS_OK)
    {
        cout << "redis error: " << rh->getErrorMsg() << endl;
        return ret;
    }


    //del測試
    cout << "錯誤測試: " << "刪除不存在的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;
}