git.m6w6.name Git - m6w6/libmemcached/blob - docs/memcached_behavior.pod

   1 =head1 NAME
   2
   3 memcached_behavior_get memcached_behavior_set
   4
   5 =head1 LIBRARY
   6
   7 C Client Library for memcached (libmemcached, -lmemcached)
   8
   9 =head1 SYNOPSIS
  10
  11   #include <memcached.h>
  12
  13   unsigned long long
  14     memcached_behavior_get (memcached_st *ptr,
  15                             memcached_behavior flag);
  16
  17   memcached_return
  18     memcached_behavior_set (memcached_st *ptr,
  19                             memcached_behavior flag,
  20                             void *data);
  21
  22 =head1 DESCRIPTION
  23
  24 libmemcached(3) behavior can be modified by use memcached_behavior_set().
  25 Default behavior is the library strives to be quick and accurate. Some
  26 behavior, while being faster, can also result in not entirely accurate
  27 behavior (for instance, memcached_set() will always respond with
  28 C<MEMCACHED_SUCCESS>).
  29
  30 memcached_behavior_get() takes a behavior flag and returns whether or not
  31 that behavior is currently enabled in the client.
  32
  33 memcached_behavior_set() changes the value of a particular option of the
  34 client. It takes both a flag (listed below) and a value. For simple on or
  35 off options you just need to pass in a value of 1. Calls to
  36 memcached_behavior_set() will flush and reset all connections.
  37
  38 =over 4
  39
  40 =item MEMCACHED_BEHAVIOR_NO_BLOCK
  41
  42 Causes libmemcached(3) to use asychronous IO. This is the fastest transport
  43 available for storage functions. For read operations it is currently
  44 similar in performance to the non-blocking method (this is being
  45 looked into).
  46
  47 =item MEMCACHED_BEHAVIOR_TCP_NODELAY
  48
  49 Turns on the no-delay feature for connecting sockets (may be faster in some
  50 environments).
  51
  52 =item MEMCACHED_BEHAVIOR_HASH
  53
  54 Makes the default hashing algorithm for keys use MD5. The value can be set to either MEMCACHED_HASH_DEFAULT, MEMCACHED_HASH_MD5, MEMCACHED_HASH_CRC, MEMCACHED_HASH_FNV1_64, MEMCACHED_HASH_FNV1A_64, MEMCACHED_HASH_FNV1_32, MEMCACHED_HASH_FNV1A_32, MEMCACHED_HASH_KETAMA. The behavior for all hashes but MEMCACHED_HASH_DEFAULT is identitical to the Java driver written by Dustin Sallings.
  55
  56 =item MEMCACHED_BEHAVIOR_DISTRIBUTION
  57
  58 Using this you can enable different means of distributing values to servers.
  59 The default method is MEMCACHED_DISTRIBUTION_MODULA. You can enable
  60 consistent hashing by setting MEMCACHED_DISTRIBUTION_CONSISTENT.
  61 Consistent hashing delivers better distribution and allows servers to be
  62 added to the cluster with minimal cache losses.
  63
  64 =item MEMCACHED_BEHAVIOR_CACHE_LOOKUPS
  65
  66 Memcached can cache named lookups so that DNS lookups are made only once.
  67
  68 =item MEMCACHED_BEHAVIOR_SUPPORT_CAS
  69
  70 Support CAS operations (this is not enabled by default at this point in the server since it imposes a slight performance penalty).
  71
  72 =item MEMCACHED_BEHAVIOR_POLL_TIMEOUT
  73
  74 Modify the timeout value that is used by poll(). The default value is -1. An signed int pointer must be passed to memcached_behavior_set() to change this value. For memcached_behavior_get() a signed int value will be cast and returned as the unsigned long long.
  75
  76 =item MEMCACHED_BEHAVIOR_USER_DATA
  77
  78 This allows you to store a pointer to a specifc piece of data. This can be
  79 retrieved from inside of memcached_fetch_execute(). Cloning a memcached_st
  80
  81 will copy the pointer to the clone. This was deprecated in 0.14 in favor
  82 of memcached_callback_set(3). This will be removed in 0.15.
  83
  84 =item MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
  85
  86 Enabling buffered IO causes commands to "buffer" instead of being sent. Any
  87 action that gets data causes this buffer to be be sent to the remote
  88 connection. Quiting the connection or closing down the connection will also
  89 cause the buffered data to be pushed to the remote connection.
  90
  91 =item MEMCACHED_BEHAVIOR_VERIFY_KEY
  92
  93 Enabling this will cause libmemcached(3) to test all keys to verify that they
  94 are valid keys.
  95
  96 =item MEMCACHED_BEHAVIOR_SORT_HOSTS
  97
  98 Enabling this will cause hosts that are added to be placed in the host list in
  99 sorted order. This will defeat consisten hashing.
 100
 101 =item MEMCACHED_BEHAVIOR_CONNECT_TIMEOUT
 102
 103 In non-blocking mode this changes the value of the timeout during socket
 104 connection.
 105
 106 =back
 107
 108 =head1 RETURN
 109
 110 memcached_behavior_get() returns either the current value of the get, or 0
 111 or 1 on simple flag behaviors (1 being enabled). memcached_behavior_set()
 112 returns whether or not the behavior was enabled.
 113
 114 =head1 HOME
 115
 116 To find out more information please check:
 117 L<http://tangent.org/552/libmemcached.html>
 118
 119 =head1 AUTHOR
 120
 121 Brian Aker, E<lt>brian@tangent.orgE<gt>
 122
 123 =head1 SEE ALSO
 124
 125 memcached(1) libmemcached(3) memcached_strerror(3)
 126
 127 =cut
 128