git.m6w6.name Git - awesomized/libmemcached/blob - libmemcached/quit.cc

   1 /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
   2  *
   3  *  Libmemcached library
   4  *
   5  *  Copyright (C) 2011 Data Differential, http://datadifferential.com/
   6  *  Copyright (C) 2010 Brian Aker All rights reserved.
   7  *
   8  *  Redistribution and use in source and binary forms, with or without
   9  *  modification, are permitted provided that the following conditions are
  10  *  met:
  11  *
  12  *      * Redistributions of source code must retain the above copyright
  13  *  notice, this list of conditions and the following disclaimer.
  14  *
  15  *      * Redistributions in binary form must reproduce the above
  16  *  copyright notice, this list of conditions and the following disclaimer
  17  *  in the documentation and/or other materials provided with the
  18  *  distribution.
  19  *
  20  *      * The names of its contributors may not be used to endorse or
  21  *  promote products derived from this software without specific prior
  22  *  written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  25  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  26  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  27  *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  28  *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  29  *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  30  *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  34  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  */
  37
  38 #include <libmemcached/common.h>
  39
  40 namespace {
  41   memcached_return_t send_quit_message(memcached_instance_st* instance)
  42   {
  43     memcached_return_t rc;
  44     if (instance->root->flags.binary_protocol)
  45     {
  46       protocol_binary_request_quit request= {}; // = {.bytes= {0}};
  47
  48       initialize_binary_request(instance, request.message.header);
  49
  50       request.message.header.request.opcode = PROTOCOL_BINARY_CMD_QUIT;
  51       request.message.header.request.datatype = PROTOCOL_BINARY_RAW_BYTES;
  52
  53       libmemcached_io_vector_st vector[]=
  54       {
  55         { request.bytes, sizeof(request.bytes) }
  56       };
  57
  58       rc= memcached_vdo(instance, vector, 1, true);
  59     }
  60     else
  61     {
  62       libmemcached_io_vector_st vector[]=
  63       {
  64         { memcached_literal_param("quit\r\n") }
  65       };
  66
  67       rc= memcached_vdo(instance, vector, 1, true);
  68     }
  69
  70     return rc;
  71   }
  72
  73   void drain_instance(memcached_instance_st* instance)
  74   {
  75     /* read until socket is closed, or there is an error
  76      * closing the socket before all data is read
  77      * results in server throwing away all data which is
  78      * not read
  79      *
  80      * In .40 we began to only do this if we had been doing buffered
  81      * requests of had replication enabled.
  82      */
  83     if (instance->root->flags.buffer_requests or instance->root->number_of_replicas)
  84     {
  85       memcached_io_slurp(instance);
  86     }
  87
  88     /*
  89      * memcached_io_read may call memcached_quit_server with io_death if
  90      * it encounters problems, but we don't care about those occurences.
  91      * The intention of that loop is to drain the data sent from the
  92      * server to ensure that the server processed all of the data we
  93      * sent to the server.
  94      */
  95     instance->server_failure_counter= 0;
  96     instance->server_timeout_counter= 0;
  97   }
  98 }
  99
 100 /*
 101   This closes all connections (forces flush of input as well).
 102
 103   Maybe add a host specific, or key specific version?
 104
 105   The reason we send "quit" is that in case we have buffered IO, this
 106   will force data to be completed.
 107 */
 108
 109 void memcached_quit_server(memcached_instance_st* instance, bool io_death)
 110 {
 111   if (instance->valid())
 112   {
 113     if (io_death == false and memcached_is_udp(instance->root) == false and instance->is_shutting_down() == false)
 114     {
 115       send_quit_message(instance);
 116
 117       instance->start_close_socket();
 118       drain_instance(instance);
 119     }
 120   }
 121
 122   instance->close_socket();
 123
 124   if (io_death and memcached_is_udp(instance->root))
 125   {
 126     /*
 127        If using UDP, we should stop using the server briefly on every IO
 128        failure. If using TCP, it may be that the connection went down a
 129        short while ago (e.g. the server failed) and we've only just
 130        noticed, so we should only set the retry timeout on a connect
 131        failure (which doesn't call this method).
 132        */
 133     memcached_mark_server_for_timeout(instance);
 134   }
 135 }
 136
 137 void send_quit(Memcached *memc)
 138 {
 139   for (uint32_t x= 0; x < memcached_server_count(memc); x++)
 140   {
 141     memcached_instance_st* instance= memcached_instance_fetch(memc, x);
 142
 143     memcached_quit_server(instance, false);
 144   }
 145 }
 146
 147 void memcached_quit(memcached_st *shell)
 148 {
 149   Memcached* memc= memcached2Memcached(shell);
 150   memcached_return_t rc;
 151   if (memcached_failed(rc= initialize_query(memc, true)))
 152   {
 153     return;
 154   }
 155
 156   send_quit(memc);
 157 }