git.m6w6.name Git - awesomized/libmemcached/blob - docs/source/libmemcached/memcached_auto.rst

   1 Incrementing and Decrementing Values
   2 ====================================
   3
   4 SYNOPSIS
   5 --------
   6
   7 #include <libmemcached/memcached.h>
   8   Compile and link with -lmemcached
   9
  10 .. function:: memcached_return_t memcached_increment (memcached_st *ptr, const char *key, size_t key_length, uint32_t offset, uint64_t *value)
  11
  12 .. function:: memcached_return_t memcached_decrement (memcached_st *ptr, const char *key, size_t key_length, uint32_t offset, uint64_t *value)
  13
  14 .. function:: 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)
  15
  16 .. function:: 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)
  17
  18 .. function::  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)
  19
  20 .. function:: 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)
  21
  22 .. function:: 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)
  23
  24 .. function:: 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)
  25
  26
  27 DESCRIPTION
  28 -----------
  29
  30 :manpage:`memcached(1)` servers have the ability to increment and decrement keys
  31 (overflow and underflow are not detected). This gives you the ability to use
  32 memcached to generate shared sequences of values.
  33
  34 `memcached_increment` takes a ``key`` and ``key_length`` and increments the
  35 value by the ``offset`` passed to it. The value is then returned via the
  36 uint32_t ``value`` pointer you pass to it.
  37
  38 `memcached_decrement` takes a ``key`` and ``key_length`` and decrements the
  39 value by the ``offset`` passed to it. The value is then returned via the
  40 uint32_t ``value`` pointer you pass to it.
  41
  42 `memcached_increment_with_initial` takes a ``key`` and ``key_length`` and
  43 increments the value by the ``offset`` passed to it. If the object specified by
  44 ``key`` does not exist, one of two things may happen: If the ``expiration``
  45 value is :c:macro:`MEMCACHED_EXPIRATION_NOT_ADD`, the operation will fail. For
  46 all other ``expiration`` values, the operation will succeed by seeding the value
  47 for that key with a initial value to expire with the provided expiration time.
  48 The ``flags`` will be set to zero. The value is then returned via the uint32_t
  49 ``value`` pointer you pass to it. ``memcached_increment_with_initial`` is only
  50 available when using the binary protocol.
  51
  52 `memcached_decrement_with_initial` takes a ``key`` and ``key_length`` and
  53 decrements the value by the ``offset`` passed to it. If the object specified by
  54 ``key`` does not exist, one of two things may happen: If the ``expiration``
  55 value is :c:macro:`MEMCACHED_EXPIRATION_NOT_ADD`, the operation will fail. For
  56 all other ``expiration`` values, the operation will succeed by seeding the value
  57 for that key with a initial value to expire with the provided expiration time.
  58 The ``flags`` will be set to zero. The value is then returned via the uint32_t
  59 ``value`` pointer you pass to it. `memcached_decrement_with_initial` is only
  60 available when using the binary protocol.
  61
  62 `memcached_increment_by_key`, `memcached_decrement_by_key`,
  63 `memcached_increment_with_initial_by_key`, and
  64 `memcached_decrement_with_initial_by_key` are master key equivalents of the
  65 above.
  66
  67 RETURN VALUE
  68 ------------
  69
  70 A value of type `memcached_return_t`  is returned.
  71 On success that value will be `MEMCACHED_SUCCESS`.
  72 Use `memcached_strerror` to translate this value to a printable string.
  73
  74 SEE ALSO
  75 --------
  76
  77 .. only:: man
  78
  79     :manpage:`memcached(1)`
  80     :manpage:`libmemcached(3)`
  81     :manpage:`memcached_strerror(3)`
  82
  83 .. only:: html
  84
  85     * :manpage:`memcached(1)`
  86     * :doc:`../libmemcached`
  87     * :doc:`memcached_strerror`