plucky (3) memcached_result_create.3.gz
NAME
memcached_result_create - Working with result sets
SYNOPSIS
#include <libmemcached/memcached.h>
Compile and link with -lmemcachedutil -lmemcached
typedef struct memcached_result_st memcached_result_st
memcached_result_st *memcached_result_create(memcached_st *ptr, memcached_result_st *result)
Parameters
• ptr -- pointer to initialized memcached_st struct
• result -- pointer to an memcached_result_st instance to initialize or nullptr to allocate
a new instance
Returns
pointer to initialized memcached_result_st instance
void memcached_result_free(memcached_result_st *result)
Parameters
result -- pointer to initialized memcached_result_st struct
const char *memcached_result_key_value(memcached_result_st *result)
Parameters
result -- pointer to initialized memcached_result_st struct
Returns
the key value associated with the current result object
size_t memcached_result_key_length(const memcached_result_st *result)
Parameters
result -- pointer to initialized memcached_result_st struct
Returns
the key length associated with the current result object
const char *memcached_result_value(memcached_result_st *result)
Parameters
result -- pointer to initialized memcached_result_st struct
Returns
the result value associated with the current result object
char *memcached_result_take_value(memcached_result_st *result)
Parameters
result -- pointer to initialized memcached_result_st struct
Returns
the result value associated with the current result object
size_t memcached_result_length(const memcached_result_st *result)
Parameters
result -- pointer to initialized memcached_result_st struct
Returns
the result length associated with the current result object
uint32_t memcached_result_flags(const memcached_result_st *result)
Parameters
result -- pointer to initialized memcached_result_st struct
Returns
the flags associated with the current result object
uint64_t memcached_result_cas(const memcached_result_st *result)
Parameters
result -- pointer to initialized memcached_result_st struct
Returns
the cas associated with the current result object
memcached_return_t memcached_result_set_value(memcached_result_st *result, const char *value, size_t
length)
Parameters
• result -- pointer to initialized memcached_result_st struct
• value -- byte array to set the value of the current result object to
• length -- the length of value wothout any terminating zero
Returns
memcached_return_t indicating success
void memcached_result_set_flags(memcached_result_st *result, uint32_t flags)
Parameters
• result -- pointer to initialized memcached_result_st struct
• flags -- a new value for the flags field
void memcached_result_set_expiration(memcached_result_st *result, time_t expiration)
Parameters
• result -- pointer to initialized memcached_result_st struct
• expiration -- a new value for the expiration field
DESCRIPTION
libmemcached can optionally return a memcached_result_st which acts as a result object. The result
objects have added benefits over the character pointer return values, in that they are forward compatible
with new return items that future memcached servers may implement (the best current example of this is
the CAS return item). The structures can also be reused, which will save on calls to malloc(3). It is
suggested that you use result objects over char * return functions.
The structure of memcached_result_st has been encapsulated, you should not write code directly accessing
members of the structure.
memcached_result_create() will either allocate memory for a memcached_result_st or will initialize a
structure passed to it.
memcached_result_free() will deallocate any memory attached to the structure. If the structure was also
allocated, it will deallocate it.
memcached_result_key_value() returns the key value associated with the current result object.
memcached_result_key_length() returns the key length associated with the current result object.
memcached_result_value() returns the result value associated with the current result object.
memcached_result_take_value() returns and hands over the result value associated with the current result
object. You must call free(3) to release this value, unless you have made use of a custom allocator. Use
of a custom allocator requires that you create your own custom free() to release it.
memcached_result_length() returns the result length associated with the current result object.
memcached_result_flags() returns the flags associated with the current result object.
memcached_result_cas() returns the cas associated with the current result object. This value will only be
available if the server tests it.
memcached_result_set_value() takes a byte array and a size and sets the result to this value. This
function is used for trigger responses.
memcached_result_set_flags() takes a result structure and stores a new value for the flags field.
memcached_result_set_expiration() takes a result structure and stores a new value for the expiration
field (this is only used by read through triggers).
RETURN VALUE
Varies, see particular functions. All structures must have memcached_result_free() called on them for
cleanup purposes. Failure to do this will result in leaked memory.
SEE ALSO
memcached(1) libmemcached(3) memcached_strerror(3) memcached_memory_allocators(3)