oracular (3) memcached_decrement_with_initial.3.gz

NAME

       memcached_decrement_with_initial - Incrementing and Decrementing Values

SYNOPSIS

       #include <libmemcached/memcached.h>
              Compile and link with -lmemcached

       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)

              Parameters

                     • ptr -- pointer to an initialized memcached_st struct

                     • group_key -- key namespace

                     • group_key_length -- length of the key namespace without any terminating zero

                     • key -- the key

                     • key_length -- length of the key without any terminating zero

                     • offset -- offset to increment/decrement

                     • initial   --   initial   value   if   key   does   not   exist   and  expiration  is  not
                       MEMCACHED_EXPIRATION_NOT_ADD

                     • expiration -- expiration as a unix timestamp or as relative expiration time in seconds

                     • value -- the resulting value after initialization/increment/decrement

              Returns
                     memcached_return_t indicating success

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 key_length 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 key_length 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  key_length 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  key_length 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 VALUE

       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.

SEE ALSO

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