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Updated: Thursday, June 13, 2019
 
 

memcached_cas_by_key (3libmemcached)

Name

memcached_cas_by_key - Storing and Replacing Data

Synopsis

#include <libmemcached/memcached.h>

memcached_return_t  memcached_cas(memcached_st *ptr,  const  char *key,
size_t key_length, const char *value, size_t value_length, time_t expi-
ration, uint32_t flags, uint64_t cas)

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 expi-
ration, uint32_t flags, uint64_t cas)

Compile and link with -lmemcached

Description

libmemcached                               MEMCACHED_CAS_BY_KEY(3libmemcached)



NAME
       memcached_cas_by_key - Storing and Replacing Data

SYNOPSIS
       #include <libmemcached/memcached.h>

       memcached_return_t  memcached_cas(memcached_st *ptr,  const  char *key,
       size_t key_length, const char *value, size_t value_length, time_t expi-
       ration, uint32_t flags, uint64_t cas)

       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 expi-
       ration, uint32_t flags, uint64_t cas)

       Compile and link with -lmemcached

DESCRIPTION
       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 that this note was written cas is still buggy
       in memached. Turning on tests for it in  libmemcached(3)  is  optional.
       Please see memcached_set() for information on how to do this.

       memcached_cas_by_key()  method  behaves  in a similar method as the non
       key methods. The difference is that it uses the group_key parameter  to
       map objects to particular servers.

       memcached_cas() is testsed with the MEMCACHED_BEHAVIOR_USE_UDP 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 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 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 which function is being executed and whether the  function
       is  a cas operation or not. For non-cas ASCII set operations, there are
       at least 1335 bytes available to split among the key,  key_prefix,  and
       value; for cas ASCII operations there are at least 1318 bytes available
       to split among the key, key_prefix and value. If the total size of  the
       command,    including    overhead,   exceeds   1400   bytes,   a   MEM-
       CACHED_WRITE_FAILURE will be returned.

RETURN
       All methods return a value of type memcached_return_t.  On success  the
       value will be MEMCACHED_SUCCESS.  Use memcached_strerror() to translate
       this value to a printable string.

HOME
       To find out more information please check: http://libmemcached.org/


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+----------------------+
       |ATTRIBUTE TYPE |   ATTRIBUTE VALUE    |
       +---------------+----------------------+
       |Availability   | library/libmemcached |
       +---------------+----------------------+
       |Stability      | Uncommitted          |
       +---------------+----------------------+
SEE ALSO
       memcached(1) libmemached(3) memcached_strerror(3) memcached_set(3) mem-
       cached_append(3)     memcached_add(3)     memcached_prepend(3)     mem-
       cached_replace(3)

AUTHOR
       Brian Aker

COPYRIGHT
       2011-2013, Brian Aker DataDifferential, http://datadifferential.com/



NOTES
       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source    was    downloaded     from      https://launchpad.net/libmem-
       cached/1.0/1.0.18/+download/libmemcached-1.0.18.tar.gz

       Further information about this software can be found on the open source
       community website at http://libmemcached.org/libMemcached.html.



1.0.18                         February 09, 2014
                                           MEMCACHED_CAS_BY_KEY(3libmemcached)