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[awesomized/libmemcached] / docs / libmemcached.rst
1 ==============================================
2 Introducing the C Client Library for memcached
3 ==============================================
4
5 --------
6 SYNOPSIS
7 --------
8
9 #include <libmemcached/memcached.h>
10
11 Compile and link with -lmemcached
12
13 =======
14
15 libMemcached is an open source C/C++ client library and tools for the memcached server (http://memcached.org/). It has been designed to be light on memory usage, thread safe, and provide full access to server side methods.
16
17 libMemcached was designed to provide the greatest number of options to use Memcached. Some of the features provided:
18
19 1. Asynchronous and Synchronous Transport Support.
20 2. Consistent Hashing and Distribution.
21 3. Tunable Hashing algorithm to match keys.
22 4. Access to large object support.
23 5. Local replication.
24 6. A complete reference guide and documentation to the API.
25 7. Tools to Manage your Memcached networks.
26
27 -----------
28 DESCRIPTION
29 -----------
30
31
32 "Memcached is a high-performance, distributed memory object caching
33 system, generic in nature, but intended for use in speeding up dynamic web
34 applications by alleviating database load." `http://memcached.org/ <http://memcached.org/>`_
35
36 :program:`libmemcached` is a small, thread-safe client library for the
37 memcached protocol. The code has all been written to allow
38 for both web and embedded usage. It handles the work behind routing
39 individual keys to specific servers specified by the developer (and values are
40 matched based on server order as supplied by the user). It implements
41 a modular and consistent method of object distribution.
42
43 There are multiple implemented routing and hashing methods. See the
44 :c:func:`memcached_behavior_set` manpage for more information.
45
46 All operations are performed against a :c:type:`memcached_st` structure.
47 These structures can either be dynamically allocated or statically
48 allocated and then initialized by :c:func:`memcached_create`. Functions have
49 been written in order to encapsulate the :c:type:`memcached_st`. It is not
50 recommended that you operate directly against the structure.
51
52 Nearly all functions return a :c:type:`memcached_return_t` value.
53 This value can be translated to a printable string with
54 :c:type:`memcached_strerror`.
55
56 Objects are stored on servers by hashing keys. The hash value maps the key to a particular server. All clients understand how this hashing works, so it is possibly to reliably both push data to a server and retrieve data from a server.
57
58 Group keys can be optionally used to group sets of objects with servers.
59
60 Namespaces are supported, and can be used to partition caches so that multiple applications can use the same memcached servers.
61
62 :c:type:`memcached_st` structures are thread-safe, but each thread must
63 contain its own structure (that is, if you want to share these among
64 threads you must provide your own locking). No global variables are
65 used in this library.
66
67 If you are working with GNU autotools you will want to add the following to
68 your COPYING to properly include libmemcached in your application.
69
70 PKG_CHECK_MODULES(DEPS, libmemcached >= 0.8.0)
71 AC_SUBST(DEPS_CFLAGS)
72 AC_SUBST(DEPS_LIBS)
73
74 Some features of the library must be enabled through :c:func:`memcached_behavior_set`.
75
76 Hope you enjoy it!
77
78
79 ---------
80 CONSTANTS
81 ---------
82
83
84 A number of constants have been provided for in the library.
85
86
87 .. c:macro:: MEMCACHED_DEFAULT_PORT
88
89 The default port used by memcached(3).
90
91
92 .. c:macro:: MEMCACHED_MAX_KEY
93
94 Default maximum size of a key (which includes the null pointer). Master keys
95 have no limit, this only applies to keys used for storage.
96
97
98 .. c:macro:: MEMCACHED_MAX_KEY
99
100 Default size of key (which includes the null pointer).
101
102
103 .. c:macro:: MEMCACHED_STRIDE
104
105 This is the "stride" used in the consistent hash used between replicas.
106
107
108 .. c:macro:: MEMCACHED_MAX_HOST_LENGTH
109
110 Maximum allowed size of the hostname.
111
112
113 .. c:macro:: LIBMEMCACHED_VERSION_STRING
114
115 String value of libmemcached version such as "1.23.4"
116
117
118 .. c:macro:: LIBMEMCACHED_VERSION_HEX
119
120 Hex value of the version number. "0x00048000" This can be used for comparing versions based on number.
121
122
123 .. c:macro:: MEMCACHED_PREFIX_KEY_MAX_SIZE
124
125 Maximum length allowed for namespacing of a key.
126
127
128
129 ---------------------
130 THREADS AND PROCESSES
131 ---------------------
132
133
134 When using threads or forked processes it is important to keep one instance
135 of :c:type:`memcached_st` per process or thread. Without creating your own
136 locking structures you can not share a single :c:type:`memcached_st`. However,
137 you can call :c:func:`memcached_quit` on a :c:type:`memcached_st` and then use the resulting cloned structure.
138
139
140 ----
141 HOME
142 ----
143
144
145 To find out more information please check:
146 `http://libmemcached.org/ <http://libmemcached.org/>`_
147
148
149 --------
150 SEE ALSO
151 --------
152
153
154 :manpage:`memcached(1)` :manpage:`libmemcached_examples(3)`
155 :manpage:`libmemcached(1)` :manpage:`memcat(1)` :manpage:`memcp(1)`
156 :manpage:`memflush(1)` :manpage:`memrm(1)` :manpage:`memslap(1)`
157 :manpage:`memstat(1)` :manpage:`memcached_fetch(3)`
158 :manpage:`memcached_replace(3)` :manpage:`memcached_server_list_free(3)`
159 :manpage:`libmemcached_examples(3)` :manpage:`memcached_clone(3)`
160 :manpage:`memcached_free(3)` :manpage:`memcached_server_add(3)`
161 :manpage:`memcached_server_push(3)` :manpage:`memcached_add(3)`
162 :manpage:`memcached_get(3)` :manpage:`memcached_server_count(3)`
163 :manpage:`memcached_create(3)` :manpage:`memcached_increment(3)`
164 :manpage:`memcached_server_list(3)` :manpage:`memcached_set(3)`
165 :manpage:`memcached_decrement(3)` :manpage:`memcached_mget(3)`
166 :manpage:`memcached_server_list_append(3)` :manpage:`memcached_strerror(3)`
167 :manpage:`memcached_delete(3)` :manpage:`memcached_quit(3)`
168 :manpage:`memcached_server_list_count(3)` :manpage:`memcached_verbosity(3)`
169 :manpage:`memcached_server_add_unix_socket(3)`
170 :manpage:`memcached_result_create(3)` :manpage:`memcached_result_free(3)`
171 :manpage:`memcached_result_key_value(3)`
172 :manpage:`memcached_result_key_length(3)`
173 :manpage:`memcached_result_value(3)` :manpage:`memcached_result_length(3)`
174 :manpage:`memcached_result_flags(3)` :manpage:`memcached_result_cas(3)`
175 :manpage:`memcached_result_st(3)` :manpage:`memcached_append(3)`
176 :manpage:`memcached_prepend(3)` :manpage:`memcached_fetch_result(3)`
177 :manpage:`memerror(1)` :manpage:`memcached_get_by_key(3)`
178 :manpage:`memcached_mget_by_key(3)` :manpage:`memcached_delete_by_key(3)`
179 :manpage:`memcached_fetch_execute(3)` :manpage:`memcached_callback_get(3)`
180 :manpage:`memcached_callback_set(3)` :manpage:`memcached_version(3)`
181 :manpage:`memcached_lib_version(3)` :manpage:`memcached_result_set_value(3)`
182 :manpage:`memcached_dump(3)` :manpage:`memdump(1)`
183 :manpage:`memcached_set_memory_allocators(3)`
184 :manpage:`memcached_get_memory_allocators(3)`
185 :manpage:`memcached_get_user_data(3)` :manpage:`memcached_set_user_data(3)`