MEMCACHED_CALLBACK_SET(3) libmemcached-awesome MEMCACHED_CALLBACK_SET(3)
NAME
memcached_callback_set - libmemcached Documentation
SYNOPSIS
#include <libmemcached/memcached.h>
Compile and link with -lmemcached
memcached_return_t memcached_callback_set(memcached_st *ptr,
memcached_callback_t flag, const void *data)
Parameters
o ptr -- pointer to initialized memcached_st struct
o flag -- memcached_callback_t flag to set
o data -- data corresponding to flag
Returns
memcached_return_t indicating success
void *memcached_callback_get(memcached_st *ptr, memcached_callback_t
flag, memcached_return_t *error)
Parameters
o ptr -- pointer to initialized memcached_st struct
o flag -- memcached_callback_t flag to query
o error -- pointer to memcached_return_t indicating suc-
cess
Returns
the data previously set
typedef enum memcached_callback_t memcached_callback_t
enum memcached_callback_t
enumerator MEMCACHED_CALLBACK_CLEANUP_FUNCTION
When memcached_free() or memcached_reset is called this
function will be executed. At the point of its execution
all connections are closed.
Its signature is:
typedef memcached_return_t (*memcached_cleanup_fn)(const
memcached_st *ptr)
enumerator MEMCACHED_CALLBACK_CLONE_FUNCTION
When memcached_clone() is called this function will be
executed.
Its signature is:
typedef memcached_return_t (*memcached_clone_fn)(-
memcached_st *destination, const memcached_st *source)
enumerator MEMCACHED_CALLBACK_PREFIX_KEY
See MEMCACHED_CALLBACK_NAMESPACE.
enumerator MEMCACHED_CALLBACK_NAMESPACE
You can set a value which will be used to create a domain
for your keys. The value specified here will be prefixed
to each of your keys. The value can not be greater then
MEMCACHED_MAX_NAMESPACE - 1 and will reduce
MEMCACHED_MAX_KEY by the value of your key.
The prefix key is only applied to the primary key, not
the master key. MEMCACHED_FAILURE will be returned if no
key is set. In the case of a key which is too long,
MEMCACHED_BAD_KEY_PROVIDED will be returned.
If you set a value with the value being NULL then the
prefix key is disabled.
enumerator MEMCACHED_CALLBACK_USER_DATA
This allows you to store a pointer to a specific piece of
data. This can be retrieved from inside of
memcached_fetch_execute(). Cloning a memcached_st will
copy the pointer to the clone.
enumerator MEMCACHED_CALLBACK_MALLOC_FUNCTION
Deprecated since version <0.32: Use
memcached_set_memory_allocators() instead.
enumerator MEMCACHED_CALLBACK_REALLOC_FUNCTION
Deprecated since version <0.32: Use
memcached_set_memory_allocators() instead.
enumerator MEMCACHED_CALLBACK_FREE_FUNCTION
Deprecated since version <0.32: Use
memcached_set_memory_allocators() instead.
enumerator MEMCACHED_CALLBACK_GET_FAILURE
This function implements the read through cache behavior.
On failure of retrieval this callback will be called.
You are responsible for populating the result object pro-
vided. This result object will then be stored in the
server and returned to the calling process.
You must clone the memcached_st in order to make use of
it. The value will be stored only if you return
MEMCACHED_SUCCESS or MEMCACHED_BUFFERED. Returning
MEMCACHED_BUFFERED will cause the object to be buffered
and not sent immediately (if this is the default behavior
based on your connection setup this will happen automati-
cally).
The prototype for this is:
typedef memcached_return_t (*memcached_trigger_key)(-
memcached_st *ptr, char *key, size_t key_length,
memcached_result_st *result)
enumerator MEMCACHED_CALLBACK_DELETE_TRIGGER
This function implements a trigger upon successful dele-
tion of a key. The memcached_st structure will need to
be cloned in order to make use of it.
The prototype for this is:
typedef memcached_return_t
(*memcached_trigger_delete_key)(memcached_st *ptr, char
*key, size_t key_length)
DESCRIPTION
libmemcached can have callbacks set key execution points. These either
provide function calls at points in the code, or return pointers to
structures for particular usages.
memcached_callback_get() takes a callback flag and returns the struc-
ture or function set by memcached_callback_set().
memcached_callback_set() changes the function/structure assigned by a
callback flag. No connections are reset.
You can use MEMCACHED_CALLBACK_USER_DATA to provide custom context if
required for any of the callbacks.
RETURN VALUE
memcached_callback_get() returns the function or structure that was
provided. Upon error, nothing is set, NULL is returned, and the
memcached_return_t argument is set to MEMCACHED_FAILURE.
memcached_callback_set() returns MEMCACHED_SUCCESS upon successful set-
ting, otherwise MEMCACHED_FAILURE on error.
SEE ALSO
memcached(1) libmemcached(3) memcached_strerror(3)
1.1 Mar 06, 2023 MEMCACHED_CALLBACK_SET(3)
Czas wygenerowania: 0.00019 sek.
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