git.m6w6.name Git - m6w6/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,
  45                                  key, key_length, expiration);
  46 }
  47
  48 static inline memcached_return_t ascii_delete(memcached_st *ptr,
  49                                               memcached_server_write_instance_st instance,
  50                                               uint32_t ,
  51                                               const char *key,
  52                                               size_t key_length,
  53                                               uint64_t expiration,
  54                                               bool& reply,
  55                                               bool& flush)
  56 {
  57   char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
  58   int send_length;
  59
  60   if (expiration)
  61   {
  62     if ((instance->major_version == 1 and
  63          instance->minor_version > 2) or
  64         instance->major_version > 1)
  65     {
  66       return memcached_set_error(*ptr, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT,
  67                                  memcached_literal_param("Memcached server version does not allow expiration of deleted items"));
  68     }
  69     else
  70     {
  71       /* ensure that we are connected, otherwise we might bump the
  72        * command counter before connection */
  73       memcached_return_t rc;
  74       if ((rc= memcached_connect(instance)) != MEMCACHED_SUCCESS)
  75       {
  76         WATCHPOINT_ERROR(rc);
  77         return rc;
  78       }
  79
  80       if (instance->minor_version == 0)
  81       {
  82         if (reply == false or flush == false)
  83         {
  84           /* We might get out of sync with the server if we send this command
  85            * to a server newer than 1.2.x..  enable reply and buffered mode.
  86          */
  87           flush= true;
  88           if (reply == false)
  89           {
  90             memcached_server_response_increment(instance);
  91           }
  92           reply= true;
  93         }
  94       }
  95
  96       send_length= snprintf(buffer, MEMCACHED_DEFAULT_COMMAND_SIZE,
  97                             "delete %.*s%.*s %u%s\r\n",
  98                             memcached_print_array(ptr->_namespace),
  99                             (int) key_length, key,
 100                             (uint32_t)expiration,
 101                             reply ? "" :  " noreply");
 102     }
 103   }
 104   else
 105   {
 106     send_length= snprintf(buffer, MEMCACHED_DEFAULT_COMMAND_SIZE,
 107                           "delete %.*s%.*s%s\r\n",
 108                           memcached_print_array(ptr->_namespace),
 109                           (int)key_length, key,
 110                           reply ? "" :  " noreply");
 111   }
 112
 113   if (send_length >= MEMCACHED_DEFAULT_COMMAND_SIZE || send_length < 0)
 114   {
 115     return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT,
 116                                memcached_literal_param("snprintf(MEMCACHED_DEFAULT_COMMAND_SIZE)"));
 117   }
 118
 119   if (ptr->flags.use_udp and flush == false)
 120   {
 121     if (send_length > MAX_UDP_DATAGRAM_LENGTH - UDP_DATAGRAM_HEADER_LENGTH)
 122     {
 123       return MEMCACHED_WRITE_FAILURE;
 124     }
 125
 126     if (send_length +instance->write_buffer_offset > MAX_UDP_DATAGRAM_LENGTH)
 127     {
 128       memcached_io_write(instance, NULL, 0, true);
 129     }
 130   }
 131
 132   return memcached_do(instance, buffer, (size_t)send_length, flush);
 133 }
 134
 135 static inline memcached_return_t binary_delete(memcached_st *ptr,
 136                                                memcached_server_write_instance_st instance,
 137                                                uint32_t server_key,
 138                                                const char *key,
 139                                                size_t key_length,
 140                                                time_t expiration,
 141                                                bool& reply,
 142                                                bool& flush)
 143 {
 144   protocol_binary_request_delete request= {};
 145
 146   // No expiration is supported in the binary protocol
 147   if (expiration)
 148   {
 149     return MEMCACHED_INVALID_ARGUMENTS;
 150   }
 151
 152   request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 153   if (reply)
 154   {
 155     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_DELETE;
 156   }
 157   else
 158   {
 159     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_DELETEQ;
 160   }
 161   request.message.header.request.keylen= htons((uint16_t)(key_length + memcached_array_size(ptr->_namespace)));
 162   request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 163   request.message.header.request.bodylen= htonl((uint32_t)(key_length + memcached_array_size(ptr->_namespace)));
 164
 165   if (ptr->flags.use_udp and flush == false)
 166   {
 167     size_t cmd_size= sizeof(request.bytes) + key_length;
 168     if (cmd_size > MAX_UDP_DATAGRAM_LENGTH - UDP_DATAGRAM_HEADER_LENGTH)
 169     {
 170       return MEMCACHED_WRITE_FAILURE;
 171     }
 172
 173     if (cmd_size +instance->write_buffer_offset > MAX_UDP_DATAGRAM_LENGTH)
 174     {
 175       memcached_io_write(instance, NULL, 0, true);
 176     }
 177   }
 178
 179   struct libmemcached_io_vector_st vector[]=
 180   {
 181     { sizeof(request.bytes), request.bytes},
 182     { memcached_array_size(ptr->_namespace), memcached_array_string(ptr->_namespace) },
 183     { key_length, key },
 184   };
 185
 186   memcached_return_t rc= MEMCACHED_SUCCESS;
 187
 188   if ((rc= memcached_vdo(instance, vector,  3, flush)) != MEMCACHED_SUCCESS)
 189   {
 190     memcached_io_reset(instance);
 191   }
 192
 193   if (ptr->number_of_replicas > 0)
 194   {
 195     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_DELETEQ;
 196
 197     for (uint32_t x= 0; x < ptr->number_of_replicas; ++x)
 198     {
 199       memcached_server_write_instance_st replica;
 200
 201       ++server_key;
 202       if (server_key == memcached_server_count(ptr))
 203         server_key= 0;
 204
 205       replica= memcached_server_instance_fetch(ptr, server_key);
 206
 207       if (memcached_vdo(replica, vector, 3, flush) != MEMCACHED_SUCCESS)
 208       {
 209         memcached_io_reset(replica);
 210       }
 211       else
 212       {
 213         memcached_server_response_decrement(replica);
 214       }
 215     }
 216   }
 217
 218   return rc;
 219 }
 220
 221 memcached_return_t memcached_delete_by_key(memcached_st *ptr,
 222                                            const char *group_key, size_t group_key_length,
 223                                            const char *key, size_t key_length,
 224                                            time_t expiration)
 225 {
 226   LIBMEMCACHED_MEMCACHED_DELETE_START();
 227
 228   memcached_return_t rc;
 229   if (memcached_failed(rc= initialize_query(ptr)))
 230   {
 231     return rc;
 232   }
 233
 234   rc= memcached_validate_key_length(key_length, ptr->flags.binary_protocol);
 235   if (memcached_failed(rc))
 236   {
 237     return rc;
 238   }
 239
 240   // If a delete trigger exists, we need a response, so no buffering/noreply
 241   if (ptr->delete_trigger)
 242   {
 243     if (ptr->flags.buffer_requests)
 244     {
 245       return memcached_set_error(*ptr, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT,
 246                                  memcached_literal_param("Delete triggers cannot be used if buffering is enabled"));
 247     }
 248
 249     if (ptr->flags.no_reply)
 250     {
 251       return memcached_set_error(*ptr, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT,
 252                                  memcached_literal_param("Delete triggers cannot be used if MEMCACHED_BEHAVIOR_NOREPLY is set"));
 253     }
 254   }
 255
 256
 257   uint32_t server_key= memcached_generate_hash_with_redistribution(ptr, group_key, group_key_length);
 258   memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, server_key);
 259
 260   bool to_write= (ptr->flags.buffer_requests) ? false : true;
 261
 262   // Invert the logic to make it simpler to read the code
 263   bool reply= (ptr->flags.no_reply) ? false : true;
 264
 265   if (ptr->flags.binary_protocol)
 266   {
 267     rc= binary_delete(ptr, instance, server_key, key, key_length, expiration, reply, to_write);
 268   }
 269   else
 270   {
 271     rc= ascii_delete(ptr, instance, server_key, key, key_length, expiration, reply, to_write);
 272   }
 273
 274   if (rc == MEMCACHED_SUCCESS)
 275   {
 276     if (to_write == false)
 277     {
 278       rc= MEMCACHED_BUFFERED;
 279     }
 280     else if (reply)
 281     {
 282       char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
 283       rc= memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, NULL);
 284       if (rc == MEMCACHED_DELETED)
 285       {
 286         rc= MEMCACHED_SUCCESS;
 287       }
 288     }
 289
 290     if (rc == MEMCACHED_SUCCESS and ptr->delete_trigger)
 291     {
 292       ptr->delete_trigger(ptr, key, key_length);
 293     }
 294   }
 295
 296   LIBMEMCACHED_MEMCACHED_DELETE_END();
 297   return rc;
 298 }