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