git.m6w6.name Git - m6w6/libmemcached/blob - docs/memcached_result_st.rst

   1 ========================
   2 Working with result sets
   3 ========================
   4
   5 --------
   6 SYNOPSIS
   7 --------
   8
   9 #include <libmemcached/memcached_pool.h>
  10
  11 .. c:type:: memcached_result_st
  12
  13 .. c:function:: memcached_result_st * memcached_result_create (memcached_st *ptr, memcached_result_st *result)
  14
  15 .. c:function:: void memcached_result_free (memcached_result_st *result)
  16
  17 .. c:function:: const char * memcached_result_key_value (memcached_result_st *result)
  18
  19 .. c:function:: size_t memcached_result_key_length (const memcached_result_st *result)
  20
  21 .. c:function:: const char *memcached_result_value (memcached_result_st *ptr)
  22
  23 .. c:function:: size_t memcached_result_length (const memcached_result_st *ptr)
  24
  25 .. c:function:: uint32_t memcached_result_flags (const memcached_result_st *result)
  26
  27 .. c:function:: uint64_t memcached_result_cas (const memcached_result_st *result)
  28
  29 .. c:function:: memcached_return_t memcached_result_set_value (memcached_result_st *ptr, const char *value, size_t length)
  30
  31 .. c:function:: void memcached_result_set_flags (memcached_result_st *ptr, uint32_t flags)
  32
  33 .. c:function:: void memcached_result_set_expiration (memcached_result_st *ptr, time_t)
  34
  35 Compile and link with -lmemcachedutil -lmemcached
  36
  37
  38
  39 -----------
  40 DESCRIPTION
  41 -----------
  42
  43
  44 libmemcached(3) can optionally return a :c:type:`memcached_result_st` which
  45 acts as a result object. The result objects have added benefits over the
  46 character pointer returns, in that they are forward compatible with new
  47 return items that future memcached servers may implement (the best current
  48 example of this is the CAS return item). The structures can also be reused,
  49 which will save on calls to malloc(3). It is suggested that you use result
  50 objects over char \* return functions.
  51
  52 The structure of :c:type:`memcached_result_st` has been encapsulated, you should
  53 not write code to directly access members of the structure.
  54
  55 :c:func:`memcached_result_create` will either allocate memory for a
  56 :c:type:`memcached_result_st` or will initialize a structure passed to it.
  57
  58 :c:func:`memcached_result_free` will deallocate any memory attached to the
  59 structure. If the structure was also allocated, it will deallocate it.
  60
  61 :c:func:`memcached_result_key_value` returns the key value associated with the
  62 current result object.
  63
  64 :c:func:`memcached_result_key_length` returns the key length associated with
  65 the current result object.
  66
  67 :c:func:`memcached_result_value` returns the result value associated with the
  68 current result object.
  69
  70 :c:func:`memcached_result_length` returns the result length associated with
  71 the current result object.
  72
  73 :c:func:`memcached_result_flags` returns the flags associated with the
  74 current result object.
  75
  76 :c:func:`memcached_result_cas` returns the cas associated with the
  77 current result object. This value will only be available if the server
  78 tests it.
  79
  80 :c:func:`memcached_result_set_value` takes a byte array and a size and sets
  81 the result to this value. This function is used for trigger responses.
  82
  83 :c:func:`memcached_result_set_flags` takes a result structure and stores a new
  84 value for the flags field.
  85
  86 :c:func:`memcached_result_set_expiration` takes a result structure and stores
  87 a new value for the expiration field (this is only used by read through
  88 triggers).
  89
  90 You may wish to avoid using memcached_result_create(3) with a
  91 stack based allocation. The most common issues related to ABI safety involve
  92 heap allocated structures.
  93
  94
  95 ------
  96 RETURN
  97 ------
  98
  99
 100 Varies, see particular functions. All structures must have
 101 :c:func:`memcached_result_free` called on them for cleanup purposes. Failure
 102 to do this will result in leaked memory.
 103
 104
 105 ----
 106 HOME
 107 ----
 108
 109
 110 To find out more information please check:
 111 `http://libmemcached.org/ <http://libmemcached.org/>`_
 112
 113
 114 --------
 115 SEE ALSO
 116 --------
 117
 118 :manpage:`memcached(1)` :manpage:`libmemcached(3)` :manpage:`memcached_strerror(3)`