Incrementing and Decrementing Values

SYNOPSIS

#include <libmemcached/memcached.h>

memcached_return_t memcached_increment(memcached_st *ptr, const char *key, size_t key_length, uint32_t offset, uint64_t *value)
memcached_return_t memcached_decrement(memcached_st *ptr, const char *key, size_t key_length, uint32_t offset, uint64_t *value)
memcached_return_t memcached_increment_with_initial(memcached_st *ptr, const char *key, size_t key_length, uint64_t offset, uint64_t initial, time_t expiration, uint64_t *value)
memcached_return_t memcached_decrement_with_initial(memcached_st *ptr, const char *key, size_t key_length, uint64_t offset, uint64_t initial, time_t expiration, uint64_t *value)
memcached_return_t memcached_increment_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, uint32_t offset, uint64_t *value)
memcached_return_t memcached_decrement_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, uint32_t offset, uint64_t *value)
memcached_return_t memcached_increment_with_initial_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, uint64_t offset, uint64_t initial, time_t expiration, uint64_t *value)
memcached_return_t memcached_decrement_with_initial_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, uint64_t offset, uint64_t initial, time_t expiration, uint64_t *value)

Compile and link with -lmemcached

DESCRIPTION

memcached(1) servers have the ability to increment and decrement keys (overflow and underflow are not detected). This gives you the ability to use memcached to generate shared sequences of values.

memcached_increment takes a key and keylength and increments the value by the offset passed to it. The value is then returned via the uint32_t value pointer you pass to it.

memcached_decrement takes a key and keylength and decrements the value by the offset passed to it. The value is then returned via the uint32_t value pointer you pass to it.

memcached_increment_with_initial takes a key and keylength and increments the value by the offset passed to it. If the object specified by key does not exist, one of two things may happen: If the expiration value is MEMCACHED_EXPIRATION_NOT_ADD, the operation will fail. For all other expiration values, the operation will succeed by seeding the value for that key with a initial value to expire with the provided expiration time. The flags will be set to zero.The value is then returned via the uint32_t value pointer you pass to it. memcached_increment_with_initial is only available when using the binary protocol.

memcached_decrement_with_initial takes a key and keylength and decrements the value by the offset passed to it. If the object specified by key does not exist, one of two things may happen: If the expiration value is MEMCACHED_EXPIRATION_NOT_ADD, the operation will fail. For all other expiration values, the operation will succeed by seeding the value for that key with a initial value to expire with the provided expiration time. The flags will be set to zero.The value is then returned via the uint32_t value pointer you pass to it. memcached_decrement_with_initial is only available when using the binary protocol.

memcached_increment_by_key(), memcached_decrement_by_key(), memcached_increment_with_initial_by_key(), and memcached_decrement_with_initial_by_key() are master key equivalents of the above.

RETURN

A value of type memcached_return_t is returned. On success that 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/

SEE ALSO

memcached(1) libmemcached(3) memcached_strerror(3)

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