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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.
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  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,
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  30  *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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  32  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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  34  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  */
  37
  38 #include <libmemcached/common.h>
  39
  40 char *memcached_fetch(memcached_st *ptr, char *key, size_t *key_length,
  41                       size_t *value_length,
  42                       uint32_t *flags,
  43                       memcached_return_t *error)
  44 {
  45   memcached_result_st *result_buffer= &ptr->result;
  46   memcached_return_t unused;
  47   if (error == NULL)
  48   {
  49     error= &unused;
  50   }
  51
  52   if (memcached_is_udp(ptr))
  53   {
  54     if (value_length)
  55     {
  56       *value_length= 0;
  57     }
  58
  59     if (key_length)
  60     {
  61       *key_length= 0;
  62     }
  63
  64     if (flags)
  65     {
  66       *flags= 0;
  67     }
  68
  69     if (key)
  70     {
  71       *key= 0;
  72     }
  73
  74     *error= MEMCACHED_NOT_SUPPORTED;
  75     return NULL;
  76   }
  77
  78   result_buffer= memcached_fetch_result(ptr, result_buffer, error);
  79   if (result_buffer == NULL or memcached_failed(*error))
  80   {
  81     WATCHPOINT_ASSERT(result_buffer == NULL);
  82     if (value_length)
  83     {
  84       *value_length= 0;
  85     }
  86
  87     if (key_length)
  88     {
  89       *key_length= 0;
  90     }
  91
  92     if (flags)
  93     {
  94       *flags= 0;
  95     }
  96
  97     if (key)
  98     {
  99       *key= 0;
 100     }
 101
 102     return NULL;
 103   }
 104
 105   if (value_length)
 106   {
 107     *value_length= memcached_string_length(&result_buffer->value);
 108   }
 109
 110   if (key)
 111   {
 112     if (result_buffer->key_length > MEMCACHED_MAX_KEY)
 113     {
 114       *error= MEMCACHED_KEY_TOO_BIG;
 115       if (value_length)
 116       {
 117         *value_length= 0;
 118       }
 119
 120       if (key_length)
 121       {
 122         *key_length= 0;
 123       }
 124
 125       if (flags)
 126       {
 127         *flags= 0;
 128       }
 129
 130       if (key)
 131       {
 132         *key= 0;
 133       }
 134
 135       return NULL;
 136     }
 137
 138     strncpy(key, result_buffer->item_key, result_buffer->key_length); // For the binary protocol we will cut off the key :(
 139     if (key_length)
 140     {
 141       *key_length= result_buffer->key_length;
 142     }
 143   }
 144
 145   if (flags)
 146   {
 147     *flags= result_buffer->item_flags;
 148   }
 149
 150   return memcached_string_take_value(&result_buffer->value);
 151 }
 152
 153 memcached_result_st *memcached_fetch_result(memcached_st *ptr,
 154                                             memcached_result_st *result,
 155                                             memcached_return_t *error)
 156 {
 157   memcached_return_t unused;
 158   if (not error)
 159     error= &unused;
 160
 161   if (not ptr)
 162   {
 163     *error= MEMCACHED_INVALID_ARGUMENTS;
 164     return NULL;
 165   }
 166
 167   if (memcached_is_udp(ptr))
 168   {
 169     *error= MEMCACHED_NOT_SUPPORTED;
 170     return NULL;
 171   }
 172
 173   if (result == NULL)
 174   {
 175     // If we have already initialized (ie it is in use) our internal, we
 176     // create one.
 177     if (memcached_is_initialized(&ptr->result))
 178     {
 179       if (not (result= memcached_result_create(ptr, NULL)))
 180       {
 181         *error= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 182         return NULL;
 183       }
 184     }
 185     else
 186     {
 187       result= memcached_result_create(ptr, &ptr->result);
 188     }
 189   }
 190
 191   *error= MEMCACHED_MAXIMUM_RETURN; // We use this to see if we ever go into the loop
 192   memcached_server_st *server;
 193   while ((server= memcached_io_get_readable_server(ptr)))
 194   {
 195     char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
 196     *error= memcached_response(server, buffer, sizeof(buffer), result);
 197
 198     if (*error == MEMCACHED_IN_PROGRESS)
 199     {
 200       continue;
 201     }
 202     else if (*error == MEMCACHED_SUCCESS)
 203     {
 204       result->count++;
 205       return result;
 206     }
 207     else if (*error == MEMCACHED_END)
 208     {
 209       memcached_server_response_reset(server);
 210     }
 211     else if (*error != MEMCACHED_NOTFOUND)
 212     {
 213       break;
 214     }
 215   }
 216
 217   if (*error == MEMCACHED_NOTFOUND and result->count)
 218   {
 219     *error= MEMCACHED_END;
 220   }
 221   else if (*error == MEMCACHED_MAXIMUM_RETURN and result->count)
 222   {
 223     *error= MEMCACHED_END;
 224   }
 225   else if (*error == MEMCACHED_MAXIMUM_RETURN) // while() loop was never entered
 226   {
 227     *error= MEMCACHED_NOTFOUND;
 228   }
 229   else if (*error == MEMCACHED_SUCCESS)
 230   {
 231     *error= MEMCACHED_END;
 232   }
 233   else if (result->count == 0)
 234   {
 235     *error= MEMCACHED_NOTFOUND;
 236   }
 237
 238   /* We have completed reading data */
 239   if (memcached_is_allocated(result))
 240   {
 241     memcached_result_free(result);
 242   }
 243   else
 244   {
 245     result->count= 0;
 246     memcached_string_reset(&result->value);
 247   }
 248
 249   return NULL;
 250 }
 251
 252 memcached_return_t memcached_fetch_execute(memcached_st *ptr,
 253                                            memcached_execute_fn *callback,
 254                                            void *context,
 255                                            uint32_t number_of_callbacks)
 256 {
 257   memcached_result_st *result= &ptr->result;
 258   memcached_return_t rc;
 259   bool some_errors= false;
 260
 261   while ((result= memcached_fetch_result(ptr, result, &rc)))
 262   {
 263     if (memcached_failed(rc) and rc == MEMCACHED_NOTFOUND)
 264     {
 265       continue;
 266     }
 267     else if (memcached_failed(rc))
 268     {
 269       memcached_set_error(*ptr, rc, MEMCACHED_AT);
 270       some_errors= true;
 271       continue;
 272     }
 273
 274     for (uint32_t x= 0; x < number_of_callbacks; x++)
 275     {
 276       memcached_return_t ret= (*callback[x])(ptr, result, context);
 277       if (memcached_failed(ret))
 278       {
 279         some_errors= true;
 280         memcached_set_error(*ptr, ret, MEMCACHED_AT);
 281         break;
 282       }
 283     }
 284   }
 285
 286   if (some_errors)
 287   {
 288     return MEMCACHED_SOME_ERRORS;
 289   }
 290
 291   // If we were able to run all keys without issue we return
 292   // MEMCACHED_SUCCESS
 293   if (memcached_success(rc))
 294   {
 295     return MEMCACHED_SUCCESS;
 296   }
 297
 298   return rc;
 299 }