git.m6w6.name Git - awesomized/libmemcached/blob - libmemcachedutil/memcached_pool.rst

   1 Working with memcached pools
   2 ============================
   3
   4 SYNOPSIS
   5 --------
   6
   7 #include <libmemcachedutil-|libmemcached_version|/pool.h>
   8   Compile and link with -lmemcachedutil -lmemcached
   9
  10 .. type:: struct memcached_pool_st memcached_pool_st
  11
  12 .. function:: memcached_pool_st* memcached_pool(const char *option_string, size_t option_string_length)
  13
  14     :param option_string: :doc:`configuration </libmemcached/configuration>` string
  15     :param option_string_length: length of `options_string` without any trailing zero byte
  16     :returns: allocated and initialized `memcached_pool_st` instance on success or nullptr on failure
  17
  18 .. function:: memcached_st* memcached_pool_destroy(memcached_pool_st* pool)
  19
  20     :param pool: initialized `memcached_pool_st` instance to free
  21     :returns: pointer to the 'master' `memcached_st` instance by legacy
  22
  23 .. function:: memcached_st* memcached_pool_fetch(memcached_pool_st* pool, struct timespec* relative_time, memcached_return_t* rc)
  24
  25     .. versionadded:: 0.53
  26        Synonym for memcached_pool_pop
  27
  28     :param pool: initialized `memcached_pool_st` instance
  29     :param relative_time: time to block thread and wait for a connection to become available when pool size is exceeded, unless nullptr
  30     :param rc: out pointer to `memcached_return_t`
  31     :returns: pointer to an available `memcached_st` instance
  32
  33 .. function:: memcached_return_t memcached_pool_release(memcached_pool_st* pool, memcached_st* mmc)
  34
  35     .. versionadded:: 0.53
  36        Synonym for memcached_pool_push.
  37
  38     :param pool: initialized `memcached_pool_st` instance
  39     :param mmc: the `memcached_st` instance to return to the pool
  40     :returns: `memcached_return_t` indicating success
  41
  42 .. function:: memcached_return_t memcached_pool_behavior_set(memcached_pool_st *pool, memcached_behavior_t flag, uint64_t data)
  43
  44     :param pool: initialized `memcached_pool_st` instance
  45     :param flag: the :doc:`behavior </libmemcached/memcached_behavior>` to change
  46     :param value: the value to set for `flag`
  47     :returns: `memcached_return_t` indicating success
  48
  49 .. function:: memcached_return_t memcached_pool_behavior_get(memcached_pool_st *pool, memcached_behavior_t flag, uint64_t *value)
  50
  51     :param pool: initialized `memcached_pool_st` instance
  52     :param flag: the :doc:`behavior </libmemcached/memcached_behavior>` to read
  53     :param value: out pointer to receive the set value of `flag`
  54     :returns: `memcached_return_t` indicating success
  55
  56 .. function:: memcached_pool_st* memcached_pool_create(memcached_st* mmc, int initial, int max)
  57
  58     .. deprecated:: 0.46
  59        Use `memcached_pool`
  60
  61 .. function:: memcached_st* memcached_pool_pop(memcached_pool_st* pool, bool block, memcached_return_t *rc)
  62
  63     .. deprecated:: 0.53
  64        Use `memcached_pool_fetch`
  65
  66 .. function:: memcached_return_t memcached_pool_push(memcached_pool_st* pool, memcached_st *mmc)
  67
  68     .. deprecated:: 0.53
  69        Use `memcached_pool_release`
  70
  71 DESCRIPTION
  72 -----------
  73
  74 `memcached_pool` is used to create a connection pool of objects you may use to
  75 remove the overhead of using memcached_clone for short lived `memcached_st`
  76 objects. Please see :doc:`../libmemcached/configuration` for details on the
  77 format of the configuration string.
  78
  79 `memcached_pool_destroy` is used to destroy the connection pool created with
  80 `memcached_pool_create` and release all allocated resources. It will return the
  81 pointer to the `memcached_st` structure passed as an argument to
  82 `memcached_pool_create`, and returns the ownership of the pointer to the caller
  83 when created with `memcached_pool_create`, otherwise NULL is returned..
  84
  85 `memcached_pool_fetch` is used to fetch a connection structure from the
  86 connection pool. The relative_time argument specifies if the function should
  87 block and wait for a connection structure to be available if we try to exceed
  88 the maximum size. You need to specify time in relative time.
  89
  90 `memcached_pool_release` is used to return a connection structure back to the
  91 pool.
  92
  93 `memcached_pool_behavior_get` and `memcached_pool_behavior_set` is used to
  94 get/set behavior flags on all connections in the pool.
  95
  96 Both `memcached_pool_release` and `memcached_pool_fetch` are thread safe.
  97
  98 RETURN VALUE
  99 ------------
 100
 101 `memcached_pool_destroy` returns the pointer (and ownership) to the
 102 `memcached_st` structure used to create the pool. If connections are in use it
 103 returns NULL.
 104
 105 `memcached_pool_pop` returns a pointer to a `memcached_st` structure from the
 106 pool (or NULL if an allocation cannot be satisfied).
 107
 108 `memcached_pool_release` returns `MEMCACHED_SUCCESS` upon success.
 109
 110 `memcached_pool_behavior_get` and `memcached_pool_behavior_get` return
 111 `MEMCACHED_SUCCESS` upon success.
 112
 113 `memcached_pool_fetch` may return `MEMCACHED_TIMEOUT` if a timeout occurs while
 114 waiting for a free `memcached_st` instance, `MEMCACHED_NOTFOUND` if no `memcached_st`
 115 instance was available, respectively.
 116
 117 .. note::
 118     If any method returns `MEMCACHED_IN_PROGRESS` then a lock on the pool could not
 119     be obtained.
 120
 121     If any of the parameters passed to any of these functions is
 122     invalid, `MEMCACHED_INVALID_ARGUMENTS` will be returned.
 123
 124
 125 SEE ALSO
 126 --------
 127
 128 .. only:: man
 129
 130     :manpage:`memcached(1)`
 131     :manpage:`libmemcached(3)`
 132     :manpage:`libmemcached_configuration(3)`
 133     :manpage:`memcached_strerror(3)`
 134
 135 .. only:: html
 136
 137     * :manpage:`memcached(1)`
 138     * :doc:`../libmemcached`
 139     * :doc:`../libmemcached/configuration`
 140     * :doc:`../libmemcached/memcached_strerror`