git.m6w6.name Git - m6w6/libmemcached/blob - src/libmemcached/do.cc

   1 /*
   2     +--------------------------------------------------------------------+
   3     | libmemcached - C/C++ Client Library for memcached                  |
   4     +--------------------------------------------------------------------+
   5     | Redistribution and use in source and binary forms, with or without |
   6     | modification, are permitted under the terms of the BSD license.    |
   7     | You should have received a copy of the license in a bundled file   |
   8     | named LICENSE; in case you did not receive a copy you can review   |
   9     | the terms online at: https://opensource.org/licenses/BSD-3-Clause  |
  10     +--------------------------------------------------------------------+
  11     | Copyright (c) 2006-2014 Brian Aker   https://datadifferential.com/ |
  12     | Copyright (c) 2020 Michael Wallner   <mike@php.net>                |
  13     +--------------------------------------------------------------------+
  14 */
  15
  16 #include "libmemcached/common.h"
  17
  18 static memcached_return_t _vdo_udp(memcached_instance_st *instance,
  19                                    libmemcached_io_vector_st vector[], const size_t count) {
  20 #if HAVE_SENDMSG && HAVE_STRUCT_MSGHDR
  21   if (vector[0].buffer or vector[0].length) {
  22     return memcached_set_error(
  23         *instance->root, MEMCACHED_NOT_SUPPORTED, MEMCACHED_AT,
  24         memcached_literal_param("UDP messages was attempted, but vector was not setup for it"));
  25   }
  26
  27   struct msghdr msg;
  28   memset(&msg, 0, sizeof(msg));
  29
  30   increment_udp_message_id(instance);
  31   vector[0].buffer = instance->write_buffer;
  32   vector[0].length = UDP_DATAGRAM_HEADER_LENGTH;
  33
  34   msg.msg_iov = (struct iovec *) vector;
  35 #  ifdef __APPLE__
  36   msg.msg_iovlen = int(count);
  37 #  else
  38   msg.msg_iovlen = count;
  39 #  endif
  40
  41   uint32_t retry = 5;
  42   while (--retry) {
  43     ssize_t sendmsg_length = ::sendmsg(instance->fd, &msg, 0);
  44     if (sendmsg_length > 0) {
  45       break;
  46     } else if (sendmsg_length < 0) {
  47       if (errno == EMSGSIZE) {
  48         return memcached_set_error(*instance, MEMCACHED_WRITE_FAILURE, MEMCACHED_AT);
  49       }
  50
  51       return memcached_set_errno(*instance, errno, MEMCACHED_AT);
  52     }
  53   }
  54
  55   return MEMCACHED_SUCCESS;
  56 #else
  57   (void) instance;
  58   (void) vector;
  59   (void) count;
  60   return MEMCACHED_FAILURE;
  61 #endif
  62 }
  63
  64 memcached_return_t memcached_vdo(memcached_instance_st *instance,
  65                                  libmemcached_io_vector_st vector[], const size_t count,
  66                                  const bool with_flush) {
  67   memcached_return_t rc;
  68
  69   assert_msg(vector, "Invalid vector passed");
  70
  71   if (memcached_failed(rc = memcached_connect(instance))) {
  72     WATCHPOINT_ERROR(rc);
  73     assert_msg(instance->error_messages,
  74                "memcached_connect() returned an error but the Instance showed none.");
  75     return rc;
  76   }
  77
  78   /*
  79   ** Since non buffering ops in UDP mode dont check to make sure they will fit
  80   ** before they start writing, if there is any data in buffer, clear it out,
  81   ** otherwise we might get a partial write.
  82   **/
  83   bool sent_success;
  84   if (memcached_is_udp(instance->root)) {
  85     sent_success = memcached_success(rc = _vdo_udp(instance, vector, count));
  86   } else {
  87     sent_success = memcached_io_writev(instance, vector, count, with_flush);
  88   }
  89   if (sent_success == false) {
  90     rc = memcached_last_error(instance->root);
  91     if (rc == MEMCACHED_SUCCESS) {
  92       memcached_set_error(*instance, MEMCACHED_WRITE_FAILURE, MEMCACHED_AT);
  93     }
  94     memcached_io_reset(instance);
  95   } else if (memcached_is_replying(instance->root) && !memcached_is_udp(instance->root)) {
  96     memcached_server_response_increment(instance);
  97   }
  98
  99   return rc;
 100 }