memcached_append_by_key(3)

1MEMCACHED_APPEND_BY_KEY(3)       libmemcached       MEMCACHED_APPEND_BY_KEY(3)
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NAME

6       memcached_append_by_key  -  Appending  to  or Prepending to data on the
7       server
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9       Appending or Prepending to data on the server
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SYNOPSIS

12       #include <libmemcached/memcached.h>
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14       memcached_return_t      memcached_prepend(memcached_st *ptr,      const
15       char *key,  size_t key_length,  const char *value, size_t value_length,
16       time_t expiration, uint32_t flags)
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18       memcached_return_t memcached_append(memcached_st *ptr, const char *key,
19       size_t key_length, const char *value, size_t value_length, time_t expi‐
20       ration, uint32_t flags)
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22       memcached_return_t  memcached_prepend_by_key(memcached_st *ptr,   const
23       char *group_key,      size_t group_key_length,     const     char *key,
24       size_t key_length, const char *value, size_t value_length, time_t expi‐
25       ration, uint32_t flags)
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27       memcached_return_t   memcached_append_by_key(memcached_st *ptr,   const
28       char *group_key,     size_t group_key_length,     const      char *key,
29       size_t key_length, const char *value, size_t value_length, time_t expi‐
30       ration, uint32_t flags)
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32       Compile and link with -lmemcached
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DESCRIPTION

35       memcached_prepend() and memcached_append are used to modify information
36       on  a  server.  All  methods  take  a  key, and its length to store the
37       object. Keys are currently limited to 250 characters when using  either
38       a  version  of  memcached which is 1.4 or below, or when using the text
39       protocol. You must supply both a value and a length. Optionally you may
40       test an expiration time for the object and a 16 byte value (it is meant
41       to be used as a bitmap). "flags" is a 4byte space that is stored along‐
42       side  of  the main value. Many sub libraries make use of this field, so
43       in most cases users should avoid making use of it.
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45       memcached_prepend() places a segment of data before the last  piece  of
46       data stored. Currently expiration and key are not used in the server.
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48       memcached_append()  places  a  segment  of  data at the end of the last
49       piece of data stored. Currently expiration and key are not used in  the
50       server.
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52       memcached_prepend_by_key()  and  memcached_append_by_key() methods both
53       behave in a similar method as the non key methods.  The  difference  is
54       that  they  use  their group_key parameter to map objects to particular
55       servers.
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57       If you are looking for performance, memcached_set()  with  non-blocking
58       IO is the fastest way to store data on the server.
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60       All  of  the  above  functions  are  testsed  with the MEMCACHED_BEHAV‐
61       IOR_USE_UDP behavior enabled. However, when using these operations with
62       this  behavior  on,  there  are limits to the size of the payload being
63       sent to the server.  The reason for these limits is that the  Memcached
64       Server  does  not  allow multi-datagram requests and the current server
65       implementation sets a datagram size to  1400  bytes.  Due  to  protocol
66       overhead,  the actual limit of the user supplied data is less than 1400
67       bytes and depends on the protocol in use  as,  well  as  the  operation
68       being executed. When running with the binary protocol, MEMCACHED_BEHAV‐
69       IOR_BINARY_PROTOCOL, the size of the key,value, flags and  expiry  com‐
70       bined  may not exceed 1368 bytes. When running with the ASCII protocol,
71       the exact limit fluctuates depending on which function  is  being  exe‐
72       cuted  and  whether the function is a cas operation or not. For non-cas
73       ASCII set operations, there are at least 1335 bytes available to  split
74       among  the  key,  key_prefix, and value; for cas ASCII operations there
75       are at least 1318 bytes available to split among  the  key,  key_prefix
76       and  value.  If  the  total  size  of  the command, including overhead,
77       exceeds 1400 bytes, a MEMCACHED_WRITE_FAILURE will be returned.
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RETURN

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

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

92       Brian Aker
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COPYRIGHT

95       2011-2013, Brian Aker DataDifferential, http://datadifferential.com/
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1001.0.16                         January 31, 2013     MEMCACHED_APPEND_BY_KEY(3)