Redis的C客户端(hiredis库)使用

发布时间:2023年12月18日

Hiredis是一个Redis的C客户端库函数,基本实现了Redis的协议的最小集。这里对hiredis的api作基本的介绍以及应用,主要参考hiredis的README文件以及相关源码。

1、Ubuntu安装redis服务端

Redis全称为Remote Dictionary Server(远程数据服务),是一款开源的基于内存的键值对存储系统,其主要被用作高性能缓存服务器使用,当然也可以作为消息中间件和Session共享等。Redis独特的键值对模型使之支持丰富的数据结构类型,即它的值可以是字符串、哈希、列表、集合、有序集合,而不像Memcached要求的键和值都是字符串。同时由于Redis是基于内存的方式,免去了磁盘I/O速度的影响,因此其读写性能极高。

1、在Ubuntu中打开终端,输入下列命令,下载Redis安装包:

wget http://download.redis.io/releases/redis-4.0.9.tar.gz

2、对安装包进行解压,并将其移动放到usr/local?录下
命令如下:
解压:

tar xzf redis-4.0.9.tar.gz
移动到
sudo mv ./redis-4.0.9 /usr/local/redis/

3、进入redis?录,编译生成
命令:

cd /usr/local/redis/
sudo make

测试
sudo make test

4、安装,将redis的命令安装到/usr/local/bin/?录

sudo make install

5、安装完成后,我们进入目录/usr/local/bin中查看

cd /usr/local/bin
ls -all

6、配置?件,移动到/etc/?录下
配置?件?录为/usr/local/redis/redis.conf

sudo cp /usr/local/redis/redis.conf /etc/redis/

7、Redis的配置信息在/etc/redis/redis.conf下

sudo vi /etc/redis/redis.conf

绑定ip:如果需要远程访问,可将此?注释,或绑定?个真实ip
bind 127.0.0.1

端?,默认为6379
port 6379

是否以守护进程运?
如果以守护进程运?,则不会在命令?阻塞,类似于服务
如果以?守护进程运?,则当前终端被阻塞
设置为yes表示守护进程,设置为no表示?守护进程
推荐设置为yes
daemonize yes

数据?件
dbfilename dump.rdb

数据?件存储路径
dir /var/lib/redis

?志?件
logfile "/var/log/redis/redis-server.log"

数据库,默认有16个
database 16

主从复制,类似于双机备份。
slaveof

连接服务端

./redis-cli -h 127.0.0.1 -p 6379

2、hiredis库的安装

官网:https://redislabs.com/lp/hiredis/
发行版本:https://github.com/redis/hiredis/releases
目前最新的版本:https://codeload.github.com/redis/hiredis/tar.gz/v0.14.0

1、解压:tar -zxvf hiredis-0.14.0.tar.gz
2、编译:make
3、安装:make install

也可以直接将文件编译到自己的工程代码。

3、同步API接口的使用

我们的项目中使用的hireds接口都是同步的API,所谓同步意思就是使用阻塞的方式向redis server下发消息。
接口的主要部分为下面三个部分,下面分别介绍。

/**连接数据库*/
redisContext *redisConnect(const char *ip, int port);
/**发送命令请求*/
void *redisCommand(redisContext *c, const char *format, ...);
void *redisCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
void redisAppendCommand(redisContext *c, const char *format, ...);
void redisAppendCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
/*释放资源*/
void freeReplyObject(void *reply);
void redisFree(redisContext *c);

3.1、连接redis数据库redisConnect

redisContext *redisConnect(const char *ip, int port);

参数说明
● port:为redis数据监听的端口号,redis默认监听的端口号为6379
● ip:为redis数据库的IP地址,可以是远程的,也可以是本地的127.0.0.1
返回值
返回值是一个指向redisContext对象,可以不用了解这个对象的具体组成部分,只需要知道怎么使用就可以了。下面是其定义。

typedef struct redisContext {
    int err; /* Error flags, 0 when there is no error */
    char errstr[128]; /* String representation of error when applicable */
    int fd;
    int flags;
    char *obuf; /* Write buffer */
    redisReader *reader; /* Protocol reader */
    enum redisConnectionType connection_type;
    struct timeval *timeout;
    struct {
        char *host;
        char *source_addr;
        int port;
    } tcp;
    struct {
        char *path;
    } unix_sock;
} redisContext;

3.2、发送需要执行的命令redisCommand

void *redisCommand(redisContext *c, const char *format, ...);

参数说明
这个函数是一个带有不定参数的。可以按着format格式给出对应的参数,这就和printf函数类似。
c 是一个reidsConnect函数返回的一个对象。
返回值
返回值是一个void类型的指针,实际为指向一个redisReply类型的指针。

/* This is the reply object returned by redisCommand() */
typedef struct redisReply {
    /*命令执行结果的返回类型*/
    int type; /* REDIS_REPLY_* */
    /*存储执行结果返回为整数*/
    long long integer; /* The integer when type is REDIS_REPLY_INTEGER */
    /*字符串值的长度*/
    size_t len; /* Length of string */
    /*存储命令执行结果返回是字符串*/
    char *str; /* Used for both REDIS_REPLY_ERROR and REDIS_REPLY_STRING */
    /*返回结果是数组的大小*/
    size_t elements; /* number of elements, for REDIS_REPLY_ARRAY */
    /*存储执行结果返回是数组*/
    struct redisReply **element; /* elements vector for REDIS_REPLY_ARRAY */
} redisReply;

返回结果的类型reply->type,reply 为redisReply* 类型。
● REDIS_REPLY_STRING == 1:返回值是字符串,字符串储存在redis->str当中,字符串长度为redis->len。
● REDIS_REPLY_ARRAY == 2:返回值是数组,数组大小存在redis->elements里面,数组值存储在redis->element[i]里面。数组里面存储的是指向redisReply的指针,数组里面的返回值可以通过redis->element[i]->str来访问,数组的结果里全是type==REDIS_REPLY_STRING的redisReply对象指针。
● REDIS_REPLY_INTEGER == 3:返回值为整数 long long。
● REDIS_REPLY_NIL==4:返回值为空表示执行结果为空。
● REDIS_REPLY_STATUS ==5:返回命令执行的状态,比如set foo bar 返回的状态为OK,存储在str当中 reply->str == "OK"。
● REDIS_REPLY_ERROR ==6 :命令执行错误,错误信息存放在 reply->str当中。

3.3、redisCommandArgv函数

void *redisCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);

参数说明
argvlen这个数组存储了命令参数中,每一个参数的长度,包含命令本身,比如 set foo bar 则argvlen ={3,3,3},如果argvlen为空,那么这个函数内部会自动调用strlen函数对每个参数进行求长度。
argv 存放每个命令参数的指针,argv={“set”,“foo”,“bar”}
argc 存放命令参数的个数上面的例子中argc=3
c 为redisContext对象。
为每一个参数指定长度,可以是二进制安全的函数。函数会按着长度来决定字符串的终止,而不是’\0’.

char hkey[] = "123456";
char hset[] = "hset";
char key[] = "testkey";
char hvalue[] = "3210";
int argc = 4;
char *argv[] = {hset,key,hkey,hvalue};
size_t argvlen[] = {4,6,4,3};
redisCommandArgv(context,argc,argv,argvlen);

hgetall testkey
会得到321并不会得到和hvalue一样的值"3210",因为在hset命令中指定了长度,只会读取前面的三个字符。

3.4、redisAppendCommand*函数支持管道命令

void redisAppendCommand(redisContext *c, const char *format, ...);
void redisAppendCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
int redisGetReply(redisContext *context,redisReply** reply);

参数说明:
redisAppendCommand函数和redisCommand函数参数一致,format可以指定特定参数的类型。
c 为redisContext对象
redisAppendCommandArgv函数和redisCommandArgv函数类似,参数含义也相同。
redisGetReply函数用来获得执行的结果的一条返回,并存储在reply所指的对象当中。成功返回REDIS_OK,否则返回REIDS_ERR。多条命令的一次性返回结果都存放在redisContext里面。
所不同的是,这个两个命令的结果。这两个函数是把多个命令存放在缓冲区内,然后一起发送给redis服务器,一次执行。可以通过redisGetReply函数从
redisContext中取出返回的结果。
使用例子:

redisReply *reply;
/*添加命令set */
redisAppendCommand(context,"SET foo bar");
/*添加命令get */
redisAppendCommand(context,"GET foo");
/*获取set命令结果*/
redisGetReply(context,&reply); // reply for SET
freeReplyObject(reply);
/*获取get命令结果*/
redisGetReply(context,&reply); // reply for GET
freeReplyObject(reply);

3.5、释放资源

void freeReplyObject(void *reply);
void redisFree(redisContext *c);

参数说明
freeReplyObject函数中reply 实际为指向redisReply结构体的指针,可能是redisCommand的返回值,后续可以看到以也能是管道命令执行结果的返回值。
redisFree函数中c实际为指向redisContext对象,这个函数会清理连接资源并释放连接。

3.6、同步连接代码

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "hiredis/hiredis.h"

int main(int argc,char *argv[])
{
    unsigned int j,isunix = 0;
    redisContext *c;
    redisReply *reply;
    const char *hostname = "127.0.0.1";
    int port = 6379;

    struct timeval timeout = {1,500000};    // 1.5 seconds
    c = redisConnectWithTimeout(hostname,port,timeout);
    if(c == NULL || c->err){
        if(c){
            printf("Connection error:%s\n",c->errstr);
            redisFree(c);
        } else {
            printf("Connection error:can't allocate redis context\n");
        }
        exit(1);
    }

    int num = 1000;
    for(int i=0;i<num;i++){
    // INCR counter 是 Redis 的一个命令,它用于将名为 "counter" 的键的值递增1。如果该键不存在,它将被创建并初始化为0
        reply = redisCommand(c,"INCR counter");
        printf("INCR counter:%lld\n",reply->integer);
        freeReplyObject(reply);
    }
    redisFree(c);
    return 0;
}

如果执行的时候报这个错误
在这里插入图片描述
解决办法:
确保你的/etc/ld.so.conf里面有 /usr/local/lib 这一行
没有的话vim编辑在尾行加上
然后 sudo ldconfig

2、 ldconfig介绍
ldconfig是一个动态链接库管理命令,其目的为了让动态链接库为系统所共享。
当进程需要链接相应的库文件时候,会默认搜寻/lilb和/usr/lib,以及配置文件/etc/ld.so.conf内所列的目录下的库文件。若找不到的话,就会出现如上图的错误。
ldconfig通常在系统启动时运行,而当用户安装了一个新的动态链接库时,就需要手工运行这个命令。
ldconfig需要注意的地方:

/lib和/usr/lib里面加东西,是不用修改/etc/ld.so.conf文件的,但是添加完后需要调用下ldconfig,不然添加的library会找不到。

如果添加的library不在/lib和/usr/lib里面的话,就一定要修改/etc/ld.so.conf文件,往该文件追加library所在的路径,然后也需要重新调用下ldconfig命令。比如在安装MySQL的时候,其库文件/usr/local/mysql/lib,就需要追加到/etc/ld.so.conf文件中。命令如下:

echo "/usr/local/mysql/lib" >> /etc/ld.so.conf

ldconfig -v | grep mysql

最后注意:
如果添加的library不在/lib或/usr/lib下,但是却没有权限操作写/etc/ld.so.conf文件的话,这时就需要往export里写一个全局变量LD_LIBRARY_PATH,就可以了。

3.7、异步连接

#include "hiredis/hiredis.h"
#include "hiredis/async.h"
#include "reactor.h"
#include "adapter.h"
#include <time.h>

static reactor_t *R;
static int cnt, before, num;


int current_tick() {
    int t = 0;
    struct timespec ti;
	clock_gettime(CLOCK_MONOTONIC, &ti);
	t = (int)ti.tv_sec * 1000;
	t += ti.tv_nsec / 1000000;
    return t;
}

void getCallback(redisAsyncContext *c, void *r, void *privdata) {
    redisReply *reply = r;
    if (reply == NULL) return;
    printf("argv[%s]: %lld\n", (char*)privdata, reply->integer);

    /* Disconnect after receiving the reply to GET */
    cnt++;
    if (cnt == num) {
        int used = current_tick()-before;
        printf("after %d exec redis command, used %d ms\n", num, used);
        redisAsyncDisconnect(c);
    }
}


void connectCallback(const redisAsyncContext *c, int status) {
    if (status != REDIS_OK) {
        printf("Error: %s\n", c->errstr);
        stop_eventloop(R);
        return;
    }

    printf("Connected...\n");
}

void disconnectCallback(const redisAsyncContext *c, int status) {
    if (status != REDIS_OK) {
        printf("Error: %s\n", c->errstr);
        stop_eventloop(R);
        return;
    }

    printf("Disconnected...\n");
    stop_eventloop(R);
}

int main(int argc, char **argv) {
    redisAsyncContext *c = redisAsyncConnect("127.0.0.1", 6379);
    if (c->err) {
        /* Let *c leak for now... */
        printf("Error: %s\n", c->errstr);
        return 1;
    }
    R = create_reactor();

    redisAttach(R, c);
    
    redisAsyncSetConnectCallback(c, connectCallback);
    redisAsyncSetDisconnectCallback(c, disconnectCallback);

    before = current_tick();
    num = (argc > 1) ? atoi(argv[1]) : 1000;

    for (int i = 0; i < num; i++) {
        redisAsyncCommand(c, getCallback, "count", "INCR counter");
    }

    eventloop(R);

    release_reactor(R);
    return 0;
}

// gcc main.c -o main -L./hiredis -lhiredis

4、redis连接池实现

1、Thread.h头文件

#ifndef __THREAD_H__
#define __THREAD_H__
#include <stdint.h>
#include <pthread.h>

class CThreadNotify
{
public:
    CThreadNotify()
    {
        pthread_mutexattr_init(&m_mutexattr);
        pthread_mutexattr_settype(&m_mutexattr, PTHREAD_MUTEX_RECURSIVE);
        pthread_mutex_init(&m_mutex, &m_mutexattr);

        pthread_cond_init(&m_cond, NULL);
    }
    ~CThreadNotify()
    {
        pthread_mutexattr_destroy(&m_mutexattr);
        pthread_mutex_destroy(&m_mutex);
        pthread_cond_destroy(&m_cond);
    }
    void Lock()
    {
        pthread_mutex_lock(&m_mutex);
    }
    void Unlock()
    {
        pthread_mutex_unlock(&m_mutex);
    }
    void Wait()
    {
        pthread_cond_wait(&m_cond, &m_mutex);
    }
    // 返回0则正常,其他值为异常
    int WaitTime(int ms)
    {
        //获取时间
        struct timespec outtime;
        clock_gettime(CLOCK_MONOTONIC, &outtime);
        //ms为毫秒,换算成秒
        outtime.tv_sec += ms / 1000;

        //在outtime的基础上,增加ms毫秒
        //outtime.tv_nsec为纳秒,1微秒=1000纳秒
        //tv_nsec此值再加上剩余的毫秒数 ms%1000,有可能超过1秒。需要特殊处理
        uint64_t us = outtime.tv_nsec / 1000 + 1000 * (ms % 1000); //微秒
        //us的值有可能超过1秒,
        outtime.tv_sec += us / 1000000;

        us = us % 1000000;
        outtime.tv_nsec = us * 1000; //换算成纳秒
        return pthread_cond_timedwait(&m_cond, &m_mutex, &outtime);
    }
    void Signal()
    {
        pthread_cond_signal(&m_cond);
    }

private:
    pthread_mutex_t m_mutex;
    pthread_mutexattr_t m_mutexattr;

    pthread_cond_t m_cond;
};

#endif

2、头文件CachePool.h

/*
 * @Author: your name
 * @Date: 2019-12-07 10:54:57
 * @LastEditTime : 2020-01-10 16:35:13
 * @LastEditors  : Please set LastEditors
 * @Description: In User Settings Edit
 * @FilePath: \src\cache_pool\CachePool.h
 */
#ifndef CACHEPOOL_H_
#define CACHEPOOL_H_

#include <iostream>
#include <vector>
#include <map>
#include <list>

#include "Thread.h"

#include "hiredis.h"


using std::string;
using std::list;
using std::map; 
using std::vector; 

class CachePool;

class CacheConn {
public:
	CacheConn(const char* server_ip, int server_port, int db_index, const char* password, 
		const char *pool_name ="");
	CacheConn(CachePool* pCachePool);	
	virtual ~CacheConn();
	
	int Init();
	void DeInit();
	const char* GetPoolName();
    // 通用操作
    // 判断一个key是否存在
    bool isExists(string &key);
    // 删除某个key
    long del(string &key);

    // ------------------- 字符串相关 -------------------
	string get(string key);
    string set(string key, string& value);
	string setex(string key, int timeout, string value);
	
	// string mset(string key, map);
    //批量获取
    bool mget(const vector<string>& keys, map<string, string>& ret_value);
	//原子加减1
    long incr(string key);
    long decr(string key);


	// ---------------- 哈希相关 ------------------------
	long hdel(string key, string field);
	string hget(string key, string field);
	bool hgetAll(string key, map<string, string>& ret_value);
	long hset(string key, string field, string value);

	long hincrBy(string key, string field, long value);
    long incrBy(string key, long value);
	string hmset(string key, map<string, string>& hash);
	bool hmget(string key, list<string>& fields, list<string>& ret_value);
    
    

	// ------------ 链表相关 ------------
	long lpush(string key, string value);
	long rpush(string key, string value);
	long llen(string key);
	bool lrange(string key, long start, long end, list<string>& ret_value);

	
    bool flushdb();

private:
	CachePool* 		m_pCachePool;
	redisContext* 	m_pContext;
	uint64_t		m_last_connect_time;
	uint16_t 		m_server_port;
	string 			m_server_ip;
    string          m_password;
	uint16_t        m_db_index;
	string 			m_pool_name;
};


class CachePool {
public:
	// db_index和mysql不同的地方 
	CachePool(const char* pool_name, const char* server_ip, int server_port, int db_index, 
		const char *password, int max_conn_cnt);
	virtual ~CachePool();

	int Init();
    // 获取空闲的连接资源
	CacheConn* GetCacheConn();
    // Pool回收连接资源
	void RelCacheConn(CacheConn* pCacheConn);

	const char* GetPoolName() { return m_pool_name.c_str(); }
	const char* GetServerIP() { return m_server_ip.c_str(); }
	const char* GetPassword() { return m_password.c_str(); }
	int GetServerPort() { return m_server_port; }
	int GetDBIndex() { return m_db_index; }
private:
	string 		m_pool_name;
	string		m_server_ip;
	string 		m_password;
	int			m_server_port;
	int			m_db_index;	// mysql 数据库名字, redis db index

	int			m_cur_conn_cnt;
	int 		m_max_conn_cnt;
	list<CacheConn*>	m_free_list;
	CThreadNotify		m_free_notify;
};



#endif /* CACHEPOOL_H_ */

3、CachePool.cpp文件

#include "CachePool.h"

#include <stdlib.h>
#include <string.h>
#include "Thread.h"

#define log_error printf
#define log_info printf

#define MIN_CACHE_CONN_CNT 2
#define MAX_CACHE_CONN_FAIL_NUM 10

CacheConn::CacheConn(const char *server_ip, int server_port, int db_index, const char *password,
					 const char *pool_name)
{
	m_server_ip = server_ip;
	m_server_port = server_port;

	m_db_index = db_index;
	m_password = password;
	m_pool_name = pool_name;
	m_pContext = NULL;
	m_last_connect_time = 0;
}

CacheConn::CacheConn(CachePool *pCachePool)
{
	m_pCachePool = pCachePool;
	if (pCachePool)
	{
		m_server_ip = pCachePool->GetServerIP();
		m_server_port = pCachePool->GetServerPort();
		m_db_index = pCachePool->GetDBIndex();
		m_password = pCachePool->GetPassword();
		m_pool_name = pCachePool->GetPoolName();
	}
	else
	{
		log_error("pCachePool is NULL\n");
	}

	m_pContext = NULL;
	m_last_connect_time = 0;
}

CacheConn::~CacheConn()
{
	if (m_pContext)
	{
		redisFree(m_pContext);
		m_pContext = NULL;
	}
}

/*
 * redis初始化连接和重连操作,类似mysql_ping()
 */
int CacheConn::Init()
{
	if (m_pContext)	// 非空,连接是正常的
	{
		return 0;
	}

	// 1s 尝试重连一次
	uint64_t cur_time = (uint64_t)time(NULL);
	if (cur_time < m_last_connect_time + 1) 		// 重连尝试 间隔1秒 
	{
		printf("cur_time:%lu, m_last_connect_time:%lu\n", cur_time, m_last_connect_time);
		return 1;
	}
	// printf("m_last_connect_time = cur_time\n");
	m_last_connect_time = cur_time;

	// 1000ms超时
	struct timeval timeout = {0, 1000000};
	// 建立连接后使用 redisContext 来保存连接状态。
	// redisContext 在每次操作后会修改其中的 err 和  errstr 字段来表示发生的错误码(大于0)和对应的描述。
	m_pContext = redisConnectWithTimeout(m_server_ip.c_str(), m_server_port, timeout);

	if (!m_pContext || m_pContext->err)
	{
		if (m_pContext)
		{
			log_error("redisConnect failed: %s\n", m_pContext->errstr);
			redisFree(m_pContext);
			m_pContext = NULL;
		}
		else
		{
			log_error("redisConnect failed\n");
		}

		return 1;
	}

	redisReply *reply;
	// 验证
	if (!m_password.empty())
	{
		reply = (redisReply *)redisCommand(m_pContext, "AUTH %s", m_password.c_str());

		if (!reply || reply->type == REDIS_REPLY_ERROR)
		{
			log_error("Authentication failure:%p\n", reply);
			if (reply)
				freeReplyObject(reply);
			return -1;
		}
		else
		{
			// log_info("Authentication success\n");
		}

		freeReplyObject(reply);
	}

	reply = (redisReply *)redisCommand(m_pContext, "SELECT %d", 0);

	if (reply && (reply->type == REDIS_REPLY_STATUS) && (strncmp(reply->str, "OK", 2) == 0))
	{
		freeReplyObject(reply);
		return 0;
	}
	else
	{
		if (reply)
			log_error("select cache db failed:%s\n", reply->str);
		return 2;
	}
}

void CacheConn::DeInit()
{
	if (m_pContext)
	{
		redisFree(m_pContext);
		m_pContext = NULL;
	}
}

const char *CacheConn::GetPoolName()
{
	return m_pool_name.c_str();
}

string CacheConn::get(string key)
{
	string value;

	if (Init())
	{
		return value;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "GET %s", key.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return value;
	}

	if (reply->type == REDIS_REPLY_STRING)
	{
		value.append(reply->str, reply->len);
	}

	freeReplyObject(reply);
	return value;
}

string CacheConn::set(string key, string &value)
{
	string ret_value;

	if (Init())
	{
		return ret_value;
	}
	// 返回的结果存放在redisReply
	redisReply *reply = (redisReply *)redisCommand(m_pContext, "SET %s %s", key.c_str(), value.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return ret_value;
	}

	ret_value.append(reply->str, reply->len);
	freeReplyObject(reply); // 释放资源
	return ret_value;
}

string CacheConn::setex(string key, int timeout, string value)
{
	string ret_value;

	if (Init())
	{
		return ret_value;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "SETEX %s %d %s", key.c_str(), timeout, value.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return ret_value;
	}

	ret_value.append(reply->str, reply->len);
	freeReplyObject(reply);
	return ret_value;
}

bool CacheConn::mget(const vector<string> &keys, map<string, string> &ret_value)
{
	if (Init())
	{
		return false;
	}
	if (keys.empty())
	{
		return false;
	}

	string strKey;
	bool bFirst = true;
	for (vector<string>::const_iterator it = keys.begin(); it != keys.end(); ++it)
	{
		if (bFirst)
		{
			bFirst = false;
			strKey = *it;
		}
		else
		{
			strKey += " " + *it;
		}
	}

	if (strKey.empty())
	{
		return false;
	}
	strKey = "MGET " + strKey;
	redisReply *reply = (redisReply *)redisCommand(m_pContext, strKey.c_str());
	if (!reply)
	{
		log_info("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return false;
	}
	if (reply->type == REDIS_REPLY_ARRAY)
	{
		for (size_t i = 0; i < reply->elements; ++i)
		{
			redisReply *child_reply = reply->element[i];
			if (child_reply->type == REDIS_REPLY_STRING)
			{
				ret_value[keys[i]] = child_reply->str;
			}
		}
	}
	freeReplyObject(reply);
	return true;
}

bool CacheConn::isExists(string &key)
{
	if (Init())
	{
		return false;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "EXISTS %s", key.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return false;
	}
	long ret_value = reply->integer;
	freeReplyObject(reply);
	if (0 == ret_value)
	{
		return false;
	}
	else
	{
		return true;
	}
}

long CacheConn::del(string &key)
{
	if (Init())
	{
		return 0;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "DEL %s", key.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return 0;
	}

	long ret_value = reply->integer;
	freeReplyObject(reply);
	return ret_value;
}

long CacheConn::hdel(string key, string field)
{
	if (Init())
	{
		return 0;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "HDEL %s %s", key.c_str(), field.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return 0;
	}

	long ret_value = reply->integer;
	freeReplyObject(reply);
	return ret_value;
}

string CacheConn::hget(string key, string field)
{
	string ret_value;
	if (Init())
	{
		return ret_value;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "HGET %s %s", key.c_str(), field.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return ret_value;
	}

	if (reply->type == REDIS_REPLY_STRING)
	{
		ret_value.append(reply->str, reply->len);
	}

	freeReplyObject(reply);
	return ret_value;
}

bool CacheConn::hgetAll(string key, map<string, string> &ret_value)
{
	if (Init())
	{
		return false;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "HGETALL %s", key.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return false;
	}

	if ((reply->type == REDIS_REPLY_ARRAY) && (reply->elements % 2 == 0))
	{
		for (size_t i = 0; i < reply->elements; i += 2)
		{
			redisReply *field_reply = reply->element[i];
			redisReply *value_reply = reply->element[i + 1];

			string field(field_reply->str, field_reply->len);
			string value(value_reply->str, value_reply->len);
			ret_value.insert(make_pair(field, value));
		}
	}

	freeReplyObject(reply);
	return true;
}

long CacheConn::hset(string key, string field, string value)
{
	if (Init())
	{
		return -1;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "HSET %s %s %s", key.c_str(), field.c_str(), value.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return -1;
	}

	long ret_value = reply->integer;
	freeReplyObject(reply);
	return ret_value;
}

long CacheConn::hincrBy(string key, string field, long value)
{
	if (Init())
	{
		return -1;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "HINCRBY %s %s %ld", key.c_str(), field.c_str(), value);
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return -1;
	}

	long ret_value = reply->integer;
	freeReplyObject(reply);
	return ret_value;
}

long CacheConn::incrBy(string key, long value)
{
	if (Init())
	{
		return -1;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "INCRBY %s %ld", key.c_str(), value);
	if (!reply)
	{
		log_error("redis Command failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return -1;
	}
	long ret_value = reply->integer;
	freeReplyObject(reply);
	return ret_value;
}

string CacheConn::hmset(string key, map<string, string> &hash)
{
	string ret_value;

	if (Init())
	{
		return ret_value;
	}

	int argc = hash.size() * 2 + 2;
	const char **argv = new const char *[argc];
	if (!argv)
	{
		return ret_value;
	}

	argv[0] = "HMSET";
	argv[1] = key.c_str();
	int i = 2;
	for (map<string, string>::iterator it = hash.begin(); it != hash.end(); it++)
	{
		argv[i++] = it->first.c_str();
		argv[i++] = it->second.c_str();
	}

	redisReply *reply = (redisReply *)redisCommandArgv(m_pContext, argc, argv, NULL);
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		delete[] argv;

		redisFree(m_pContext);
		m_pContext = NULL;
		return ret_value;
	}

	ret_value.append(reply->str, reply->len);

	delete[] argv;
	freeReplyObject(reply);
	return ret_value;
}

bool CacheConn::hmget(string key, list<string> &fields, list<string> &ret_value)
{
	if (Init())
	{
		return false;
	}

	int argc = fields.size() + 2;
	const char **argv = new const char *[argc];
	if (!argv)
	{
		return false;
	}

	argv[0] = "HMGET";
	argv[1] = key.c_str();
	int i = 2;
	for (list<string>::iterator it = fields.begin(); it != fields.end(); it++)
	{
		argv[i++] = it->c_str();
	}

	redisReply *reply = (redisReply *)redisCommandArgv(m_pContext, argc, (const char **)argv, NULL);
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		delete[] argv;

		redisFree(m_pContext);
		m_pContext = NULL;

		return false;
	}

	if (reply->type == REDIS_REPLY_ARRAY)
	{
		for (size_t i = 0; i < reply->elements; i++)
		{
			redisReply *value_reply = reply->element[i];
			string value(value_reply->str, value_reply->len);
			ret_value.push_back(value);
		}
	}

	delete[] argv;
	freeReplyObject(reply);
	return true;
}

long CacheConn::incr(string key)
{
	if (Init())
	{
		return -1;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "INCR %s", key.c_str());
	if (!reply)
	{
		log_error("redis Command failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return -1;
	}
	long ret_value = reply->integer;
	freeReplyObject(reply);
	return ret_value;
}

long CacheConn::decr(string key)
{
	if (Init())
	{
		return -1;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "DECR %s", key.c_str());
	if (!reply)
	{
		log_error("redis Command failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return -1;
	}
	long ret_value = reply->integer;
	freeReplyObject(reply);
	return ret_value;
}

long CacheConn::lpush(string key, string value)
{
	if (Init())
	{
		return -1;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "LPUSH %s %s", key.c_str(), value.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return -1;
	}

	long ret_value = reply->integer;
	freeReplyObject(reply);
	return ret_value;
}

long CacheConn::rpush(string key, string value)
{
	if (Init())
	{
		return -1;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "RPUSH %s %s", key.c_str(), value.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return -1;
	}

	long ret_value = reply->integer;
	freeReplyObject(reply);
	return ret_value;
}

long CacheConn::llen(string key)
{
	if (Init())
	{
		return -1;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "LLEN %s", key.c_str());
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return -1;
	}

	long ret_value = reply->integer;
	freeReplyObject(reply);
	return ret_value;
}

bool CacheConn::lrange(string key, long start, long end, list<string> &ret_value)
{
	if (Init())
	{
		return false;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "LRANGE %s %d %d", key.c_str(), start, end);
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return false;
	}

	if (reply->type == REDIS_REPLY_ARRAY)
	{
		for (size_t i = 0; i < reply->elements; i++)
		{
			redisReply *value_reply = reply->element[i];
			string value(value_reply->str, value_reply->len);
			ret_value.push_back(value);
		}
	}

	freeReplyObject(reply);
	return true;
}

bool CacheConn::flushdb()
{
	bool ret = false;
	if (Init())
	{
		return false;
	}

	redisReply *reply = (redisReply *)redisCommand(m_pContext, "FLUSHDB");
	if (!reply)
	{
		log_error("redisCommand failed:%s\n", m_pContext->errstr);
		redisFree(m_pContext);
		m_pContext = NULL;
		return false;
	}

	if (reply->type == REDIS_REPLY_STRING && strncmp(reply->str, "OK", 2) == 0)
	{
		ret = true;
	}

	freeReplyObject(reply);

	return ret;
}
///
CachePool::CachePool(const char *pool_name, const char *server_ip, int server_port, int db_index,
					 const char *password, int max_conn_cnt)
{
	m_pool_name = pool_name;
	m_server_ip = server_ip;
	m_server_port = server_port;
	m_db_index = db_index;
	m_password = password;
	m_max_conn_cnt = max_conn_cnt;
	m_cur_conn_cnt = MIN_CACHE_CONN_CNT;
}

CachePool::~CachePool()
{
	m_free_notify.Lock();
	for (list<CacheConn *>::iterator it = m_free_list.begin(); it != m_free_list.end(); it++)
	{
		CacheConn *pConn = *it;
		delete pConn;
	}

	m_free_list.clear();
	m_cur_conn_cnt = 0;
	m_free_notify.Unlock();
}

int CachePool::Init()
{
	for (int i = 0; i < m_cur_conn_cnt; i++)
	{
		CacheConn *pConn = new CacheConn(m_server_ip.c_str(), m_server_port,
										 m_db_index, m_password.c_str(), m_pool_name.c_str());
		if (pConn->Init())
		{
			delete pConn;
			return 1;
		}

		m_free_list.push_back(pConn);
	}

	log_info("cache pool: %s, list size: %lu\n", m_pool_name.c_str(), m_free_list.size());
	return 0;
}

CacheConn *CachePool::GetCacheConn()
{
	m_free_notify.Lock();

	while (m_free_list.empty())
	{
		if (m_cur_conn_cnt >= m_max_conn_cnt)
		{
			m_free_notify.Wait();
		}
		else
		{
			CacheConn *p_cache_conn = new CacheConn(m_server_ip.c_str(), m_server_port,
													m_db_index, m_password.c_str(), m_pool_name.c_str());
			int ret = p_cache_conn->Init();
			if (ret)
			{
				log_error("Init CacheConn failed\n");
				delete p_cache_conn;
				m_free_notify.Unlock();
				return NULL;
			}
			else
			{
				m_free_list.push_back(p_cache_conn);
				m_cur_conn_cnt++;
				log_info("new cache connection: %s, conn_cnt: %d\n", m_pool_name.c_str(), m_cur_conn_cnt);
			}
		}
	}

	CacheConn *pConn = m_free_list.front();
	m_free_list.pop_front();

	m_free_notify.Unlock();

	return pConn;
}

void CachePool::RelCacheConn(CacheConn *p_cache_conn)
{
	m_free_notify.Lock();

	list<CacheConn *>::iterator it = m_free_list.begin();
	for (; it != m_free_list.end(); it++)
	{
		if (*it == p_cache_conn)
		{
			break;
		}
	}

	if (it == m_free_list.end())
	{
		m_free_list.push_back(p_cache_conn);
	}

	m_free_notify.Signal();
	m_free_notify.Unlock();
}

文章来源:https://blog.csdn.net/weixin_45715405/article/details/133705328
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