git.m6w6.name Git - awesomized/libmemcached/blob - libmemcached/delete.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) 2006-2009 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 #include <libmemcached/memcached/protocol_binary.h>
  40
  41 memcached_return_t memcached_delete(memcached_st *ptr, const char *key, size_t key_length,
  42                                     time_t expiration)
  43 {
  44   return memcached_delete_by_key(ptr, key, key_length, key, key_length, expiration);
  45 }
  46
  47 static inline memcached_return_t ascii_delete(memcached_st *ptr,
  48                                               memcached_server_write_instance_st instance,
  49                                               uint32_t ,
  50                                               const char *key,
  51                                               size_t key_length,
  52                                               bool& reply,
  53                                               bool& flush)
  54 {
  55   struct libmemcached_io_vector_st vector[]=
  56   {
  57     { memcached_literal_param("delete ") },
  58     { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
  59     { key, key_length },
  60     { " noreply", reply ? 0 : memcached_literal_param_size(" noreply") },
  61     { memcached_literal_param("\r\n") }
  62   };
  63
  64   if (memcached_is_udp(instance->root))
  65   {
  66     size_t send_length= io_vector_total_size(vector, 5);
  67
  68     if (send_length > MAX_UDP_DATAGRAM_LENGTH - UDP_DATAGRAM_HEADER_LENGTH)
  69     {
  70       return MEMCACHED_WRITE_FAILURE;
  71     }
  72
  73     if (send_length +instance->write_buffer_offset > MAX_UDP_DATAGRAM_LENGTH)
  74     {
  75       memcached_io_write(instance, NULL, 0, true);
  76     }
  77   }
  78
  79   /* Send command header */
  80   return memcached_vdo(instance, vector, 5, flush);
  81 }
  82
  83 static inline memcached_return_t binary_delete(memcached_st *ptr,
  84                                                memcached_server_write_instance_st instance,
  85                                                uint32_t server_key,
  86                                                const char *key,
  87                                                size_t key_length,
  88                                                bool& reply,
  89                                                bool& flush)
  90 {
  91   protocol_binary_request_delete request= {};
  92
  93   request.message.header.request.magic= PROTOCOL_BINARY_REQ;
  94   if (reply)
  95   {
  96     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_DELETE;
  97   }
  98   else
  99   {
 100     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_DELETEQ;
 101   }
 102   request.message.header.request.keylen= htons((uint16_t)(key_length + memcached_array_size(ptr->_namespace)));
 103   request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 104   request.message.header.request.bodylen= htonl((uint32_t)(key_length + memcached_array_size(ptr->_namespace)));
 105
 106   if (ptr->flags.use_udp and flush == false)
 107   {
 108     size_t cmd_size= sizeof(request.bytes) + key_length;
 109     if (cmd_size > MAX_UDP_DATAGRAM_LENGTH - UDP_DATAGRAM_HEADER_LENGTH)
 110     {
 111       return MEMCACHED_WRITE_FAILURE;
 112     }
 113
 114     if (cmd_size +instance->write_buffer_offset > MAX_UDP_DATAGRAM_LENGTH)
 115     {
 116       memcached_io_write(instance, NULL, 0, true);
 117     }
 118   }
 119
 120   struct libmemcached_io_vector_st vector[]=
 121   {
 122     { request.bytes, sizeof(request.bytes) },
 123     { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 124     { key, key_length }
 125   };
 126
 127   memcached_return_t rc= MEMCACHED_SUCCESS;
 128
 129   if ((rc= memcached_vdo(instance, vector,  3, flush)) != MEMCACHED_SUCCESS)
 130   {
 131     memcached_io_reset(instance);
 132   }
 133
 134   if (ptr->number_of_replicas > 0)
 135   {
 136     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_DELETEQ;
 137
 138     for (uint32_t x= 0; x < ptr->number_of_replicas; ++x)
 139     {
 140       memcached_server_write_instance_st replica;
 141
 142       ++server_key;
 143       if (server_key == memcached_server_count(ptr))
 144         server_key= 0;
 145
 146       replica= memcached_server_instance_fetch(ptr, server_key);
 147
 148       if (memcached_vdo(replica, vector, 3, flush) != MEMCACHED_SUCCESS)
 149       {
 150         memcached_io_reset(replica);
 151       }
 152       else
 153       {
 154         memcached_server_response_decrement(replica);
 155       }
 156     }
 157   }
 158
 159   return rc;
 160 }
 161
 162 memcached_return_t memcached_delete_by_key(memcached_st *ptr,
 163                                            const char *group_key, size_t group_key_length,
 164                                            const char *key, size_t key_length,
 165                                            time_t expiration)
 166 {
 167   LIBMEMCACHED_MEMCACHED_DELETE_START();
 168
 169   memcached_return_t rc;
 170   if (memcached_failed(rc= initialize_query(ptr)))
 171   {
 172     return rc;
 173   }
 174
 175   rc= memcached_validate_key_length(key_length, ptr->flags.binary_protocol);
 176   if (memcached_failed(rc))
 177   {
 178     return rc;
 179   }
 180
 181   if (expiration)
 182   {
 183     return memcached_set_error(*ptr, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT,
 184                                memcached_literal_param("Memcached server version does not allow expiration of deleted items"));
 185   }
 186
 187   // If a delete trigger exists, we need a response, so no buffering/noreply
 188   if (ptr->delete_trigger)
 189   {
 190     if (ptr->flags.buffer_requests)
 191     {
 192       return memcached_set_error(*ptr, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT,
 193                                  memcached_literal_param("Delete triggers cannot be used if buffering is enabled"));
 194     }
 195
 196     if (ptr->flags.no_reply)
 197     {
 198       return memcached_set_error(*ptr, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT,
 199                                  memcached_literal_param("Delete triggers cannot be used if MEMCACHED_BEHAVIOR_NOREPLY is set"));
 200     }
 201   }
 202
 203
 204   uint32_t server_key= memcached_generate_hash_with_redistribution(ptr, group_key, group_key_length);
 205   memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, server_key);
 206
 207   bool to_write= (ptr->flags.buffer_requests) ? false : true;
 208
 209   // Invert the logic to make it simpler to read the code
 210   bool reply= (ptr->flags.no_reply) ? false : true;
 211
 212   if (ptr->flags.binary_protocol)
 213   {
 214     rc= binary_delete(ptr, instance, server_key, key, key_length, reply, to_write);
 215   }
 216   else
 217   {
 218     rc= ascii_delete(ptr, instance, server_key, key, key_length, reply, to_write);
 219   }
 220
 221   if (rc == MEMCACHED_SUCCESS)
 222   {
 223     if (to_write == false)
 224     {
 225       rc= MEMCACHED_BUFFERED;
 226     }
 227     else if (reply)
 228     {
 229       char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
 230       rc= memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, NULL);
 231       if (rc == MEMCACHED_DELETED)
 232       {
 233         rc= MEMCACHED_SUCCESS;
 234       }
 235     }
 236
 237     if (rc == MEMCACHED_SUCCESS and ptr->delete_trigger)
 238     {
 239       ptr->delete_trigger(ptr, key, key_length);
 240     }
 241   }
 242
 243   LIBMEMCACHED_MEMCACHED_DELETE_END();
 244   return rc;
 245 }