NAME¶

libmemcached - Client library for memcached

LIBRARY¶

C Client Library for memcached (libmemcached, -lmemcached)

SYNOPSIS¶

  #include <memcached.h>

DESCRIPTION¶

"Memcached is a high-performance, distributed memory object caching system, generic in nature, but intended for use in speeding up dynamic web applications by alleviating database load." <http://danga.com/memcached/>

libmemcached is a small, thread-safe client library for the memcached protocol. The code has all been written with an eye to allow for both web and embedded usage. It handles the work behind routing particular keys to specific servers that you specify (and values are matched based on server order as supplied by you). It implements both a modula and consistent method of object distribution.

There are multiple implemented routing and hashing methods. See the memcached_behavior_set() manpage.

All operations are performed against a "memcached_st" structure. These structures can either be dynamically allocated or statically allocated and then initialized by memcached_create(). Functions have been written in order to encapsulate the "memcached_st". It is not recommended that you operate directly against the structure.

Nearly all functions return a "memcached_return" value. This value can be translated to a printable string with memcached_strerror(3).

Partitioning based on keys is supported in the library. Using the key partioning functions it is possible to group sets of object onto servers.

"memcached_st" structures are thread-safe, but each thread must contain its own structure (that is, if you want to share these among threads you must provide your own locking). No global variables are used in this library.

If you are working with GNU autotools you will want to add the following to your configure.ac to properly include libmemcached in your application.

PKG_CHECK_MODULES(DEPS, libmemcached >= 0.8.0) AC_SUBST(DEPS_CFLAGS) AC_SUBST(DEPS_LIBS)

Some features of the library must be enabled through memcached_behavior_set().

Hope you enjoy it!

CONSTANTS¶

A number of constants have been provided for in the library.

MEMCACHED_DEFAULT_PORT

The default port used by memcached(3).

MEMCACHED_MAX_KEY

Default maximum size of a key (which includes the null pointer). Master keys have no limit, this only applies to keys used for storage.

MEMCACHED_MAX_KEY

Default size of key (which includes the null pointer).

MEMCACHED_STRIDE

This is the "stride" used in the consistent hash used between replicas.

MEMCACHED_MAX_HOST_LENGTH

Maximum allowed size of the hostname.

MEMCACHED_VERSION_STRING

String value of libmemcached version such as "1.23.4"

MEMCACHED_MAJOR_VERSION

Major version value. Such as 1.23.4, would be 1

MEMCACHED_MINOR_VERSION

Major version value. Such as 1.23.4, would be 23

MEMCACHED_MICRO_VERSION

Major version value. Such as 1.23.4, would be 4

THREADS AND PROCESSES¶

When using threads or forked processes it is important to keep an instance of "memcached_st" per process or thread. Without creating your own locking structures you can not share a single "memcached_st". You can though call memcached_quit(3) on a "memcached_st" and then use the resulting cloned structure.

HOME¶

To find out more information please check: <http://tangent.org/552/libmemcached.html>

AUTHOR¶

Brian Aker, <brian@tangent.org>

SEE ALSO¶

memcached(1) libmemcached_examples(3) libmemcached(1) memcat(1) memcp(1) memflush(1) memrm(1) memslap(1) memstat(1) memcached_fetch(3) memcached_replace(3) memcached_server_list_free(3) libmemcached_examples(3) memcached_clone(3) memcached_free(3) memcached_server_add(3) memcached_server_push(3) memcached_add(3) memcached_get(3) memcached_server_count(3) memcached_servers_parse(3) memcached_create(3) memcached_increment(3) memcached_server_list(3) memcached_set(3) memcached_decrement(3) memcached_mget(3) memcached_server_list_append(3) memcached_strerror(3) memcached_delete(3) memcached_quit(3) memcached_server_list_count(3) memcached_verbosity(3) memcached_server_add_unix_socket(3) memcached_result_create(3) memcached_result_free(3) memcached_result_key_value(3) memcached_result_key_length(3) memcached_result_value(3) memcached_result_length(3) memcached_result_flags(3) memcached_result_cas(3) memcached_result_st(3) memcached_append(3) memcached_prepend(3) memcached_fetch_result(3) memerror(1) memcached_get_by_key(3) memcached_mget_by_key(3) memcached_delete_by_key(3) memcached_fetch_execute(3) memcached_callback_get(3) memcached_callback_set(3) memcached_version(3) memcached_lib_version(3) memcached_result_set_value(3) memcached_dump(3) memdump(1) memcached_set_memory_allocators(3) memcached_get_memory_allocators(3) memcached_get_user_data(3) memcached_set_user_data(3)