ssize_t memcached_io_read(memcached_st *ptr, unsigned int server_key,
char *buffer, size_t length);
memcached_return memcached_io_close(memcached_st *ptr, unsigned int server_key);
ssize_t memcached_io_read(memcached_st *ptr, unsigned int server_key,
char *buffer, size_t length);
memcached_return memcached_io_close(memcached_st *ptr, unsigned int server_key);