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   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 binary_delete(memcached_st *ptr,
  49                                                uint32_t server_key,
  50                                                const char *key,
  51                                                size_t key_length,
  52                                                bool flush);
  53
  54 memcached_return_t memcached_delete_by_key(memcached_st *ptr,
  55                                            const char *group_key, size_t group_key_length,
  56                                            const char *key, size_t key_length,
  57                                            time_t expiration)
  58 {
  59   char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
  60   memcached_server_write_instance_st instance;
  61
  62   LIBMEMCACHED_MEMCACHED_DELETE_START();
  63
  64   memcached_return_t rc;
  65   if (memcached_failed(rc= initialize_query(ptr)))
  66   {
  67     return rc;
  68   }
  69
  70   rc= memcached_validate_key_length(key_length,
  71                                     ptr->flags.binary_protocol);
  72
  73   if (memcached_failed(rc))
  74   {
  75     return rc;
  76   }
  77
  78   uint32_t server_key= memcached_generate_hash_with_redistribution(ptr, group_key, group_key_length);
  79   instance= memcached_server_instance_fetch(ptr, server_key);
  80
  81   bool to_write= (ptr->flags.buffer_requests) ? false : true;
  82
  83   bool no_reply= (ptr->flags.no_reply);
  84
  85   if (ptr->flags.binary_protocol)
  86   {
  87     if (expiration == 0)
  88     {
  89       rc= binary_delete(ptr, server_key, key, key_length, to_write);
  90     }
  91     else
  92     {
  93       rc= MEMCACHED_INVALID_ARGUMENTS;
  94     }
  95   }
  96   else
  97   {
  98     int send_length;
  99
 100     if (expiration)
 101     {
 102        if ((instance->major_version == 1 &&
 103             instance->minor_version > 2) ||
 104            instance->major_version > 1)
 105        {
 106          rc= MEMCACHED_INVALID_ARGUMENTS;
 107          goto error;
 108        }
 109        else
 110        {
 111           /* ensure that we are connected, otherwise we might bump the
 112            * command counter before connection */
 113           if ((rc= memcached_connect(instance)) != MEMCACHED_SUCCESS)
 114           {
 115             WATCHPOINT_ERROR(rc);
 116             return rc;
 117           }
 118
 119           if (instance->minor_version == 0)
 120           {
 121              if (no_reply or to_write == false)
 122              {
 123                 /* We might get out of sync with the server if we
 124                  * send this command to a server newer than 1.2.x..
 125                  * disable no_reply and buffered mode.
 126                  */
 127                 to_write= true;
 128                 if (no_reply)
 129                    memcached_server_response_increment(instance);
 130                 no_reply= false;
 131              }
 132           }
 133           send_length= snprintf(buffer, MEMCACHED_DEFAULT_COMMAND_SIZE,
 134                                 "delete %.*s%.*s %u%s\r\n",
 135                                 memcached_print_array(ptr->_namespace),
 136                                 (int) key_length, key,
 137                                 (uint32_t)expiration,
 138                                 no_reply ? " noreply" :"" );
 139        }
 140     }
 141     else
 142     {
 143       send_length= snprintf(buffer, MEMCACHED_DEFAULT_COMMAND_SIZE,
 144                             "delete %.*s%.*s%s\r\n",
 145                             memcached_print_array(ptr->_namespace),
 146                             (int)key_length, key, no_reply ? " noreply" :"");
 147     }
 148
 149     if (send_length >= MEMCACHED_DEFAULT_COMMAND_SIZE || send_length < 0)
 150     {
 151       rc=  memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT,
 152                                memcached_literal_param("snprintf(MEMCACHED_DEFAULT_COMMAND_SIZE)"));
 153       goto error;
 154     }
 155
 156     if (ptr->flags.use_udp and to_write == false)
 157     {
 158       if (send_length > MAX_UDP_DATAGRAM_LENGTH - UDP_DATAGRAM_HEADER_LENGTH)
 159         return MEMCACHED_WRITE_FAILURE;
 160
 161       if (send_length + instance->write_buffer_offset > MAX_UDP_DATAGRAM_LENGTH)
 162       {
 163         memcached_io_write(instance, NULL, 0, true);
 164       }
 165     }
 166
 167     rc= memcached_do(instance, buffer, (size_t)send_length, to_write);
 168   }
 169
 170   if (rc != MEMCACHED_SUCCESS)
 171   {
 172     goto error;
 173   }
 174
 175   if (to_write == false)
 176   {
 177     rc= MEMCACHED_BUFFERED;
 178   }
 179   else if (no_reply == false)
 180   {
 181     rc= memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, NULL);
 182     if (rc == MEMCACHED_DELETED)
 183     {
 184       rc= MEMCACHED_SUCCESS;
 185     }
 186   }
 187
 188   if (rc == MEMCACHED_SUCCESS and ptr->delete_trigger)
 189   {
 190     ptr->delete_trigger(ptr, key, key_length);
 191   }
 192
 193 error:
 194   LIBMEMCACHED_MEMCACHED_DELETE_END();
 195   return rc;
 196 }
 197
 198 static inline memcached_return_t binary_delete(memcached_st *ptr,
 199                                                uint32_t server_key,
 200                                                const char *key,
 201                                                size_t key_length,
 202                                                bool flush)
 203 {
 204   memcached_server_write_instance_st instance;
 205   protocol_binary_request_delete request= {};
 206
 207   instance= memcached_server_instance_fetch(ptr, server_key);
 208
 209   request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 210   if (ptr->flags.no_reply)
 211   {
 212     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_DELETEQ;
 213   }
 214   else
 215   {
 216     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_DELETE;
 217   }
 218   request.message.header.request.keylen= htons((uint16_t)(key_length + memcached_array_size(ptr->_namespace)));
 219   request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 220   request.message.header.request.bodylen= htonl((uint32_t)(key_length + memcached_array_size(ptr->_namespace)));
 221
 222   if (ptr->flags.use_udp && ! flush)
 223   {
 224     size_t cmd_size= sizeof(request.bytes) + key_length;
 225     if (cmd_size > MAX_UDP_DATAGRAM_LENGTH - UDP_DATAGRAM_HEADER_LENGTH)
 226       return MEMCACHED_WRITE_FAILURE;
 227
 228     if (cmd_size + instance->write_buffer_offset > MAX_UDP_DATAGRAM_LENGTH)
 229       memcached_io_write(instance, NULL, 0, true);
 230   }
 231
 232   struct libmemcached_io_vector_st vector[]=
 233   {
 234     { sizeof(request.bytes), request.bytes},
 235     { memcached_array_size(ptr->_namespace), memcached_array_string(ptr->_namespace) },
 236     { key_length, key },
 237   };
 238
 239   memcached_return_t rc= MEMCACHED_SUCCESS;
 240
 241   if ((rc= memcached_vdo(instance, vector,  3, flush)) != MEMCACHED_SUCCESS)
 242   {
 243     memcached_io_reset(instance);
 244   }
 245
 246   unlikely (ptr->number_of_replicas > 0)
 247   {
 248     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_DELETEQ;
 249
 250     for (uint32_t x= 0; x < ptr->number_of_replicas; ++x)
 251     {
 252       memcached_server_write_instance_st replica;
 253
 254       ++server_key;
 255       if (server_key == memcached_server_count(ptr))
 256         server_key= 0;
 257
 258       replica= memcached_server_instance_fetch(ptr, server_key);
 259
 260       if (memcached_vdo(replica, vector, 3, flush) != MEMCACHED_SUCCESS)
 261       {
 262         memcached_io_reset(replica);
 263       }
 264       else
 265       {
 266         memcached_server_response_decrement(replica);
 267       }
 268     }
 269   }
 270
 271   return rc;
 272 }