MEMCACHED_APPEND_BY_KEY(3) libmemcached-awesome MEMCACHED_APPEND_BY_KEY(3)
NAME
memcached_append_by_key - Appending to or Prepending Data
SYNOPSIS
#include <libmemcached-1.0/memcached.h>
Compile and link with -lmemcached
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 expiration,
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 expiration,
uint32_t flags)
Parameters
o ptr -- pointer to an initialized memcached_st struct
o group_key -- key namespace
o group_key_length -- length of the key namespace without
any terminating zero
o key -- the key
o key_length -- length of the key without any terminating
zero
o value -- the value to append/prepend
o value_length -- the length of the value without any
terminating zero
o expiration -- expiration as a unix timestamp or as rel-
ative expiration time in seconds
o flags -- 16 bit flags
Returns
memcached_return_t indicating success
DESCRIPTION
memcached_prepend() and memcached_append are used to modify information
on a server. All methods take a key, and key_length to store the ob-
ject. 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 pro-
tocol. You must supply both a value and a length. Optionally you may
set an expiration time for the object and a 16 bit value (it is meant
to be used as a bitmap). flags is a 4 byte space that is stored along
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 manner 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 tested 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 avail-
able to split among the key, key_prefix, and value; for cas ASCII oper-
ations there are at least 1318 bytes available to split among the key,
key_prefix and value. If the total size of the command, including over-
head, exceeds 1400 bytes, a MEMCACHED_WRITE_FAILURE will be returned.
RETURN VALUE
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.
SEE ALSO
memcached(1) libmemcached(3) memcached_strerror(3) memcached_set(3)
memcached_add(3) memcached_cas(3) memcached_replace(3)
1.1 Mar 06, 2023 MEMCACHED_APPEND_BY_KEY(3)
Czas wygenerowania: 0.00105 sek.
Created with the man page lookup class by Andrew Collington.
Based on a C man page viewer by Vadim Pavlov
Unicode soft-hyphen fix (as used by RedHat) by Dan Edwards
Some optimisations by Eli Argon
Caching idea and code contribution by James Richardson
Copyright © 2003-2025 Linux.pl
Hosted by Hosting Linux.pl