-==========================
-Storing and Replacing Data
-==========================
+=========================================================
+Store, replace, add, or atomically add data to the server
+=========================================================
-
-Store value on server
+.. index:: object: memcached_st
--------
--------
-
#include <libmemcached/memcached.h>
.. c:function:: memcached_return_t memcached_set (memcached_st *ptr, const char *key, size_t key_length, const char *value, size_t value_length, time_t expiration, uint32_t flags);
.. c:function:: memcached_return_t memcached_replace (memcached_st *ptr, const char *key, size_t key_length, const char *value, size_t value_length, time_t expiration, uint32_t flags);
-.. c:function:: memcached_return_t memcached_prepend(memcached_st *ptr, const char *key, size_t key_length, const char *value, size_t value_length, time_t expiration, uint32_t flags)
-
-.. c:function:: memcached_return_t memcached_append(memcached_st *ptr, const char *key, size_t key_length, const char *value, size_t value_length, time_t expiration, uint32_t flags)
-
-.. c:function:: memcached_return_t memcached_cas(memcached_st *ptr, const char *key, size_t key_length, const char *value, size_t value_length, time_t expiration, uint32_t flags, uint64_t cas);
-
.. c:function:: memcached_return_t memcached_set_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, const char *value, size_t value_length, time_t expiration, uint32_t flags);
.. c:function:: memcached_return_t memcached_add_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, const char *value, size_t value_length, time_t expiration, uint32_t flags);
.. c:function:: memcached_return_t memcached_replace_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, const char *value, size_t value_length, time_t expiration, uint32_t flags);
-.. c:function:: memcached_return_t memcached_prepend_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, const char *value, size_t value_length, time_t expiration, uint32_t flags);
-
-.. c:function:: memcached_return_t memcached_append_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, const char *value, size_t value_length, time_t expiration, uint32_t flags);
-
-.. c:function:: memcached_return_t memcached_cas_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, const char *value, size_t value_length, time_t expiration, uint32_t flags, uint64_t cas);
-
Compile and link with -lmemcached
memcached_set(), memcached_add(), and memcached_replace() are all used to
store information on the server. All methods take a key, and its length to
-store the object. Keys are currently limited to 250 characters by the
-memcached(1) server. You must also supply a value and a length. Optionally you
-may tests an expiration time for the object and a 16 byte value (it is
-meant to be used as a bitmap).
+store the object. Keys are currently limited to 250 characters when using either a version of memcached(1) which is 1.4 or below, or when using the text protocol.
+You must supply both a value and a length. Optionally you
+may test an expiration time for the object and a 16 byte value (it is
+meant to be used as a bitmap). "flags" is a 4byte space that is stored alongside of the main value. Many sub libraries make use of this field, so in most cases users should avoid making use of it.
memcached_set() will write an object to the server. If an object already
exists it will overwrite what is in the server. If the object does not exist
memcached_add() adds an object to the server. If the object is found on the
server an error occurs, otherwise the value is stored.
-memcached_prepend() places a segment of data before the last piece of data
-stored. Currently expiration and key are not used in the server.
-
-memcached_append() places a segment of data at the end of the last piece of
-data stored. Currently expiration and key are not used in the server.
-
memcached_cas() overwrites data in the server as long as the "cas" value is
still the same in the server. You can get the cas value of a result by
calling memcached_result_cas() on a memcached_result_st(3) structure. At the point
for it in libmemcached(3) is optional. Please see memcached_set() for
information on how to do this.
-memcached_set_by_key(), memcached_add_by_key(), memcached_replace_by_key(),
-memcached_prepend_by_key(), memcached_append_by_key_by_key(),
-memcached_cas_by_key() methods all behave in a similar method as the non key
+memcached_set_by_key(), memcached_add_by_key(), and memcached_replace_by_key()
+methods all behave in a similar method as the non key
methods. The difference is that they use their group_key parameter to map
objects to particular servers.
the fastest way to store data on the server.
All of the above functions are testsed with the \ ``MEMCACHED_BEHAVIOR_USE_UDP``\
-behavior enabled. But when using these operations with this behavior on, there
+behavior enabled. However, when using these operations with this behavior on, there
are limits to the size of the payload being sent to the server. The reason for
-these limits is that the Memcahed Server does not allow multi-datagram requests
+these limits is that the Memcached Server does not allow multi-datagram requests
and the current server implementation sets a datagram size to 1400 bytes. Due
to protocol overhead, the actual limit of the user supplied data is less than
-1400 bytes and depends on the protocol in use as well as the operation being
+1400 bytes and depends on the protocol in use as, well as the operation being
executed. When running with the binary protocol, \ `` MEMCACHED_BEHAVIOR_BINARY_PROTOCOL``\ ,
the size of the key,value, flags and expiry combined may not exceed 1368 bytes.
When running with the ASCII protocol, the exact limit fluctuates depending on
--------
-memcached(1) libmemached(3) memcached_strerror(3)
+memcached(1) libmemached(3) memcached_strerror(3) memcached_prepend(3) memcached_cas(3) memcached_append(3)