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Updated: Wednesday, July 27, 2022
 
 

memcached_prepend_by_key (3libmemcached)

Name

memcached_prepend_by_key - Appending to or Prepending to data on the server Appending or Prepending to data on the server

Synopsis

#include <libmemcached/memcached.h>

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)

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

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 expi-
ration, uint32_t flags)

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 expi-
ration, uint32_t flags)

Compile and link with -lmemcached

Description

libmemcached                           MEMCACHED_PREPEND_BY_KEY(3libmemcached)



NAME
       memcached_prepend_by_key  -  Appending  to or Prepending to data on the
       server

       Appending or Prepending to data on the server

SYNOPSIS
       #include <libmemcached/memcached.h>

       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)

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

       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 expi-
       ration, uint32_t flags)

       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 expi-
       ration, uint32_t flags)

       Compile and link with -lmemcached

DESCRIPTION
       memcached_prepend() and memcached_append are used to modify information
       on  a  server.  All  methods  take  a  key, and its length to store the
       object. Keys are currently limited to 250 characters when using  either
       a  version  of  memcached 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 along-
       side  of  the main value. Many sub libraries make use of this field, so
       in most cases users should avoid making use of it.

       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_prepend_by_key()  and  memcached_append_by_key() methods both
       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.

       If you are looking for performance, memcached_set()  with  non-blocking
       IO is the fastest way to store data on the server.

       All  of  the  above  functions  are  testsed  with the MEMCACHED_BEHAV-
       IOR_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_BEHAV-
       IOR_BINARY_PROTOCOL, the size of the key,value, flags and  expiry  com-
       bined  may not exceed 1368 bytes. When running with the ASCII protocol,
       the exact limit fluctuates depending on which function  is  being  exe-
       cuted  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 MEMCACHED_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_add(3) memcached_cas(3) memcached_replace(3)

AUTHOR
       Brian Aker

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



NOTES
       Source  code  for open source software components in Oracle Solaris can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-
       code-downloads.html.

       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_PREPEND_BY_KEY(3libmemcached)