3 memcached_get, memcached_mget, memcached_fetch
7 C Client Library for memcached (libmemcached, -lmemcached)
11 #include <memcached.h>
14 memcached_fetch_result(memcached_st *ptr,
15 memcached_result_st *result,
16 memcached_return *error);
18 char *memcached_get (memcached_st *ptr,
19 char *key, size_t key_length,
22 memcached_return *error);
25 memcached_mget (memcached_st *ptr,
26 char **keys, size_t *key_length,
27 unsigned int number_of_keys);
29 memcached_get_by_key(memcached_st *ptr,
30 char *master_key, size_t master_key_length,
31 char *key, size_t key_length,
34 memcached_return *error);
37 memcached_mget_by_key(memcached_st *ptr,
38 char *master_key, size_t master_key_length,
39 char **keys, size_t *key_length,
40 unsigned int number_of_keys);
42 char *memcached_fetch (memcached_st *ptr,
43 char *key, size_t *key_length,
46 memcached_return *error);
50 memcached_get() is used to fetch an individual value from the server. You
51 must pass in a key and its length to fetch the object. You must supply
52 three pointer variables which will give you the state of the returned
53 object. A uint16_t pointer to contain whatever flags you stored with the value,
54 a size_t pointer which will be filled with size of of the object, and a
55 memcached_return pointer to hold any error. The object will be returned
56 upon success and NULL will be returned on failure.
58 memcached_mget() is used to select multiple keys at once. For multiple key
59 operations it is always faster to use this function. This function always
60 works asynchronously. memcached_fetch() is then used to retrieve any keys
61 found. No error is given on keys that are not found. You must call either
62 memcached_fetch() or memcached_fetch_result() after a successful call to
63 memcached_mget(). You should continue to call these functions until they
64 return NULL (aka no more values). If you need to quit in the middle of a
65 memcached_get() call, execute a memcached_quit(). After you do this, you can
66 issue new queries against the server.
68 memcached_fetch() is used to fetch an individual value from the server.
69 memcached_mget() must always be called before using this method. You
70 must pass in a key and its length to fetch the object. You must supply
71 three pointer variables which will give you the state of the returned
72 object. A uint16_t pointer to contain whatever flags you stored with the value,
73 a size_t pointer which will be filled with size of of the object, and a
74 memcached_return pointer to hold any error. The object will be returned
75 upon success and NULL will be returned on failure.
77 memcached_fetch_result() is used to return a memcached_result_st(3) structure
78 from a memcached server. The result object is forward compatible with changes
79 to the server. For more information please refer to the memcached_result_st(3)
80 help. This function will dynamically allocate a result structure for you
81 if you do not pass one to the function.
83 memcached_get_by_key() and memcached_mget_by_key() behave in a similar nature
84 as memcached_get() and memcached_mget(). The difference is that they take
85 a master key that is used for determining which server an object was stored
86 if key partitioning was used for storage.
90 All objects returned must be freed by the calling application.
91 memcached_get() and memcached_fetch() will return NULL on error. You must
92 look at the value of error to determine what the actual error was.
96 To find out more information please check:
97 L<http://tangent.org/552/libmemcached.html>
101 Brian Aker, E<lt>brian@tangent.orgE<gt>
105 memcached(1) libmemcached(3) memcached_strerror(3)