git.m6w6.name Git - awesomized/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   uint64_t
  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                             uint64_t 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
  55 to either MEMCACHED_HASH_DEFAULT, MEMCACHED_HASH_MD5, MEMCACHED_HASH_CRC, MEMCACHED_HASH_FNV1_64, MEMCACHED_HASH_FNV1A_64, MEMCACHED_HASH_FNV1_32, and MEMCACHED_HASH_FNV1A_32. The behavior for all hashes but MEMCACHED_HASH_DEFAULT is identitical to the Java driver written by Dustin Sallings.
  56
  57 =item MEMCACHED_BEHAVIOR_DISTRIBUTION
  58
  59 Using this you can enable different means of distributing values to servers.
  60 The default method is MEMCACHED_DISTRIBUTION_MODULA. You can enable
  61 consistent hashing by setting MEMCACHED_DISTRIBUTION_CONSISTENT.
  62 Consistent hashing delivers better distribution and allows servers to be
  63 added to the cluster with minimal cache losses. Currently
  64 MEMCACHED_DISTRIBUTION_CONSISTENT is an alias for the value
  65 MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA.
  66
  67 =item MEMCACHED_BEHAVIOR_CACHE_LOOKUPS
  68
  69 Memcached can cache named lookups so that DNS lookups are made only once.
  70
  71 =item MEMCACHED_BEHAVIOR_SUPPORT_CAS
  72
  73 Support CAS operations (this is not enabled by default at this point in the server since it imposes a slight performance penalty).
  74
  75 =item MEMCACHED_BEHAVIOR_KETAMA
  76
  77 Sets the default distribution to MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA
  78 and the hash to MEMCACHED_HASH_MD5.
  79
  80 =item MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED
  81
  82 Sets the default distribution to MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA with the weighted support.
  83 and the hash to MEMCACHED_HASH_MD5.
  84
  85 =item MEMCACHED_BEHAVIOR_KETAMA_HASH
  86
  87 Sets the hashing algorithm for host mapping on continuum. The value can be set
  88 to either MEMCACHED_HASH_DEFAULT, MEMCACHED_HASH_MD5, MEMCACHED_HASH_CRC, MEMCACHED_HASH_FNV1_64, MEMCACHED_HASH_FNV1A_64, MEMCACHED_HASH_FNV1_32, and MEMCACHED_HASH_FNV1A_32.
  89
  90 =item MEMCACHED_BEHAVIOR_POLL_TIMEOUT
  91
  92 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.
  93
  94 =item MEMCACHED_BEHAVIOR_USER_DATA
  95
  96 This allows you to store a pointer to a specifc piece of data. This can be
  97 retrieved from inside of memcached_fetch_execute(). Cloning a memcached_st
  98
  99 will copy the pointer to the clone. This was deprecated in 0.14 in favor
 100 of memcached_callback_set(3). This will be removed in 0.15.
 101
 102 =item MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
 103
 104 Enabling buffered IO causes commands to "buffer" instead of being sent. Any
 105 action that gets data causes this buffer to be be sent to the remote
 106 connection. Quiting the connection or closing down the connection will also
 107 cause the buffered data to be pushed to the remote connection.
 108
 109 =item MEMCACHED_BEHAVIOR_VERIFY_KEY
 110
 111 Enabling this will cause libmemcached(3) to test all keys to verify that they
 112 are valid keys.
 113
 114 =item MEMCACHED_BEHAVIOR_SORT_HOSTS
 115
 116 Enabling this will cause hosts that are added to be placed in the host list in
 117 sorted order. This will defeat consisten hashing.
 118
 119 =item MEMCACHED_BEHAVIOR_CONNECT_TIMEOUT
 120
 121 In non-blocking mode this changes the value of the timeout during socket
 122 connection.
 123
 124 =back
 125
 126 =head1 RETURN
 127
 128 memcached_behavior_get() returns either the current value of the get, or 0
 129 or 1 on simple flag behaviors (1 being enabled). memcached_behavior_set()
 130 returns failure or success.
 131
 132 =head1 NOTES
 133
 134 memcached_behavior_set() in version .17 was changed from taking a pointer
 135 to data value, to taking a uin64_t.
 136
 137 =head1 HOME
 138
 139 To find out more information please check:
 140 L<http://tangent.org/552/libmemcached.html>
 141
 142 =head1 AUTHOR
 143
 144 Brian Aker, E<lt>brian@tangent.orgE<gt>
 145
 146 =head1 SEE ALSO
 147
 148 memcached(1) libmemcached(3) memcached_strerror(3)
 149
 150 =cut
 151