git.m6w6.name Git - m6w6/libmemcached/blob - libmemcached/purge.cc

   1 /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
   2  *
   3  *  LibMemcached
   4  *
   5  *  Copyright (C) 2011 Data Differential, http://datadifferential.com/
   6  *  Copyright (C) 2006-2009 Brian Aker
   7  *  All rights reserved.
   8  *
   9  *  Redistribution and use in source and binary forms, with or without
  10  *  modification, are permitted provided that the following conditions are
  11  *  met:
  12  *
  13  *      * Redistributions of source code must retain the above copyright
  14  *  notice, this list of conditions and the following disclaimer.
  15  *
  16  *      * Redistributions in binary form must reproduce the above
  17  *  copyright notice, this list of conditions and the following disclaimer
  18  *  in the documentation and/or other materials provided with the
  19  *  distribution.
  20  *
  21  *      * The names of its contributors may not be used to endorse or
  22  *  promote products derived from this software without specific prior
  23  *  written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  */
  38
  39
  40 #include <libmemcached/common.h>
  41
  42
  43 bool memcached_purge(memcached_server_write_instance_st ptr)
  44 {
  45   memcached_st *root= (memcached_st *)ptr->root;
  46
  47   if (memcached_is_purging(ptr->root) || /* already purging */
  48       (memcached_server_response_count(ptr) < ptr->root->io_msg_watermark &&
  49        ptr->io_bytes_sent < ptr->root->io_bytes_watermark) ||
  50       (ptr->io_bytes_sent >= ptr->root->io_bytes_watermark &&
  51        memcached_server_response_count(ptr) < 2))
  52   {
  53     return true;
  54   }
  55
  56   /*
  57     memcached_io_write and memcached_response may call memcached_purge
  58     so we need to be able stop any recursion..
  59   */
  60   memcached_set_purging(root, true);
  61
  62   WATCHPOINT_ASSERT(ptr->fd != INVALID_SOCKET);
  63   /*
  64     Force a flush of the buffer to ensure that we don't have the n-1 pending
  65     requests buffered up..
  66   */
  67   if (memcached_io_write(ptr) == false)
  68   {
  69     memcached_set_purging(root, true);
  70
  71     memcached_set_error(*ptr, MEMCACHED_WRITE_FAILURE, MEMCACHED_AT);
  72     return false;
  73   }
  74   WATCHPOINT_ASSERT(ptr->fd != INVALID_SOCKET);
  75
  76   bool is_successful= true;
  77   uint32_t no_msg= memcached_server_response_count(ptr) - 1;
  78   if (no_msg > 0)
  79   {
  80     memcached_result_st result;
  81     memcached_result_st *result_ptr;
  82
  83     /*
  84      * We need to increase the timeout, because we might be waiting for
  85      * data to be sent from the server (the commands was in the output buffer
  86      * and just flushed
  87    */
  88     const int32_t timeo= ptr->root->poll_timeout;
  89     root->poll_timeout= 2000;
  90
  91     result_ptr= memcached_result_create(root, &result);
  92     WATCHPOINT_ASSERT(result_ptr);
  93
  94     for (uint32_t x= 0; x < no_msg; x++)
  95     {
  96       memcached_result_reset(result_ptr);
  97       memcached_return_t rc= memcached_read_one_response(ptr, result_ptr);
  98       /*
  99        * Purge doesn't care for what kind of command results that is received.
 100        * The only kind of errors I care about if is I'm out of sync with the
 101        * protocol or have problems reading data from the network..
 102      */
 103       if (rc== MEMCACHED_PROTOCOL_ERROR or rc == MEMCACHED_UNKNOWN_READ_FAILURE or rc == MEMCACHED_READ_FAILURE)
 104       {
 105         WATCHPOINT_ERROR(rc);
 106         memcached_io_reset(ptr);
 107         is_successful= false;
 108       }
 109
 110       if (ptr->root->callbacks != NULL)
 111       {
 112         memcached_callback_st cb = *ptr->root->callbacks;
 113         if (memcached_success(rc))
 114         {
 115           for (uint32_t y= 0; y < cb.number_of_callback; y++)
 116           {
 117             if (memcached_fatal((*cb.callback[y])(ptr->root, result_ptr, cb.context)))
 118             {
 119               break;
 120             }
 121           }
 122         }
 123       }
 124     }
 125
 126     memcached_result_free(result_ptr);
 127     root->poll_timeout= timeo;
 128   }
 129   memcached_set_purging(root, false);
 130
 131   return is_successful;
 132 }