memcached的客户端

yywx001

　　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：
　　[iyunv@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