memcached的客户端

memcached有很多版本的Client,具体可参照：http://code.google.com/p/memcached/wiki/Clients

本次只讨论libmemcached这个client的安装及使用

官网：http://libmemcached.org/libMemcached.html

libMemcached was designed to provide the greatest number of options to use Memcached. Some of the features provided:

Asynchronous and Synchronous Transport Support.
Consistent Hashing and Distribution.
Tunable Hashing algorithm to match keys.
Access to large object support.
Local replication.
A complete reference guide and documentation to the API.
Tools to Manage your Memcached networks.

0.52版本：

http://launchpad.net/libmemcached/1.0/0.52/+download/libmemcached-0.52.tar.gz

1、安装

tar zxvf libmemcached-0.52.tar.gz

cd libmemcached-0.52

./configure

make

make install

2、测试

 1 #include<iostream>
 2 #include<string>
 3 #include<libmemcached/memcached.h>
 4 
 5 using namespace std;
 6 
 7 int main(int argc, char* argv[])
 8 {
 9     // connect server
10     memcached_st *memc;
11     memcached_return rc;
12     memcached_server_st* server;
13     time_t expiration = 0;
14     uint32_t flags;
15     
16     memc = memcached_create(NULL);
17     server = memcached_server_list_append(NULL, "localhost", 11211, &rc);
18     rc = memcached_server_push(memc, server);
19     memcached_server_list_free(server);
20 
21     server = memcached_server_list_append(NULL, "localhost", 11212, &rc);
22     rc = memcached_server_push(memc, server);
23     memcached_server_list_free(server);
24 
25     memcached_behavior_set(memc, MEMCACHED_BEHAVIOR_BINARY_PROTOCOL, 0);
26 
27     string key = "keyvalue";
28     string value = "value";
29     size_t value_length = value.length();
30     size_t key_length = key.length();
31     
32     // save data
33     rc = memcached_set(memc, key.c_str(), key.length(), value.c_str(), value.length(), expiration, flags);
34     if(rc == MEMCACHED_SUCCESS)
35     {
36         cout<<"Save data "<<value<<" successful!!"<<endl;
37     }
38 
39     char* result = memcached_get(memc, key.c_str(), key_length, &value_length, &flags, &rc);
40     if(rc == MEMCACHED_SUCCESS)
41     {
42         cout<<"Get Value "<<result<<" successful!!"<<endl;
43         free(result);
44     }
45     
46     // delete data
47     rc = memcached_delete(memc, key.c_str(), key_length, expiration);
48     if ( rc == MEMCACHED_SUCCESS)
49     {
50         cout<<" Delete key:"<<key<<" successful!!"<<endl;
51     }
52     
53     // free
54     memcached_free(memc);
55     return 0;
56 }

g++ -o testmemcached testmemcached.cpp -lmemcached

[ybt@mj247 memcached]$ ./testmemcached

Save data value successful!!

Get Value value successful!!

Delete key:keyvalue successful!!

此时在server端上有输出：

[root@mj247 memcached]# <28 new auto-negotiating client connection

28: Client using the ascii protocol

<28 set keyvalue 0 0 5

>28 STORED

<28 get keyvalue

>28 sending key keyvalue

>28 END

<28 delete keyvalue

>28 DELETED

<28 quit

<28 connection closed.

　　由于memcached支持分布式，所以在libmemcached上会根据key值做hash来得到需要存储在哪个server上。代码上memcached server分别11211及11212这两个端口来测试。

2013-07-01更新

1.0.17版本安装

会报错：

error: tr1/cinttypes: No such file or directory

要求gcc版本比较高

# yum install gcc44 gcc44-c++ libstdc++44-devel

# export CC=/usr/bin/gcc44
# export CXX=/usr/bin/g++44

# ./configure --enable-tcmalloc