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   1 /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
   2  *
   3  *  Libmemcached library
   4  *
   5  *  Copyright (C) 2011-2012 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.
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  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
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  34  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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  36  */
  37
  38 #include <libmemcached/common.h>
  39
  40 char *memcached_fetch(memcached_st *shell, char *key, size_t *key_length,
  41                       size_t *value_length,
  42                       uint32_t *flags,
  43                       memcached_return_t *error)
  44 {
  45   Memcached* ptr= memcached2Memcached(shell);
  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   memcached_result_st *result_buffer= &ptr->result;
  79   result_buffer= memcached_fetch_result(ptr, result_buffer, error);
  80   if (result_buffer == NULL or memcached_failed(*error))
  81   {
  82     WATCHPOINT_ASSERT(result_buffer == NULL);
  83     if (value_length)
  84     {
  85       *value_length= 0;
  86     }
  87
  88     if (key_length)
  89     {
  90       *key_length= 0;
  91     }
  92
  93     if (flags)
  94     {
  95       *flags= 0;
  96     }
  97
  98     if (key)
  99     {
 100       *key= 0;
 101     }
 102
 103     return NULL;
 104   }
 105
 106   if (value_length)
 107   {
 108     *value_length= memcached_string_length(&result_buffer->value);
 109   }
 110
 111   if (key)
 112   {
 113     if (result_buffer->key_length > MEMCACHED_MAX_KEY)
 114     {
 115       *error= MEMCACHED_KEY_TOO_BIG;
 116       if (value_length)
 117       {
 118         *value_length= 0;
 119       }
 120
 121       if (key_length)
 122       {
 123         *key_length= 0;
 124       }
 125
 126       if (flags)
 127       {
 128         *flags= 0;
 129       }
 130
 131       if (key)
 132       {
 133         *key= 0;
 134       }
 135
 136       return NULL;
 137     }
 138
 139     strncpy(key, result_buffer->item_key, result_buffer->key_length); // For the binary protocol we will cut off the key :(
 140     if (key_length)
 141     {
 142       *key_length= result_buffer->key_length;
 143     }
 144   }
 145
 146   if (flags)
 147   {
 148     *flags= result_buffer->item_flags;
 149   }
 150
 151   return memcached_string_take_value(&result_buffer->value);
 152 }
 153
 154 memcached_result_st *memcached_fetch_result(memcached_st *ptr,
 155                                             memcached_result_st *result,
 156                                             memcached_return_t *error)
 157 {
 158   memcached_return_t unused;
 159   if (error == NULL)
 160   {
 161     error= &unused;
 162   }
 163
 164   if (ptr == NULL)
 165   {
 166     *error= MEMCACHED_INVALID_ARGUMENTS;
 167     return NULL;
 168   }
 169
 170   if (memcached_is_udp(ptr))
 171   {
 172     *error= MEMCACHED_NOT_SUPPORTED;
 173     return NULL;
 174   }
 175
 176   if (result == NULL)
 177   {
 178     // If we have already initialized (ie it is in use) our internal, we
 179     // create one.
 180     if (memcached_is_initialized(&ptr->result))
 181     {
 182       if ((result= memcached_result_create(ptr, NULL)) == NULL)
 183       {
 184         *error= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 185         return NULL;
 186       }
 187     }
 188     else
 189     {
 190       result= memcached_result_create(ptr, &ptr->result);
 191     }
 192   }
 193
 194   *error= MEMCACHED_MAXIMUM_RETURN; // We use this to see if we ever go into the loop
 195   memcached_instance_st *server;
 196   memcached_return_t read_ret= MEMCACHED_SUCCESS;
 197   bool connection_failures= false;
 198   while ((server= memcached_io_get_readable_server(ptr, read_ret)))
 199   {
 200     char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
 201     *error= memcached_response(server, buffer, sizeof(buffer), result);
 202
 203     if (*error == MEMCACHED_IN_PROGRESS)
 204     {
 205       continue;
 206     }
 207     else if (*error == MEMCACHED_CONNECTION_FAILURE)
 208     {
 209       connection_failures= true;
 210       continue;
 211     }
 212     else if (*error == MEMCACHED_SUCCESS)
 213     {
 214       result->count++;
 215       return result;
 216     }
 217     else if (*error == MEMCACHED_END)
 218     {
 219       memcached_server_response_reset(server);
 220     }
 221     else if (*error != MEMCACHED_NOTFOUND)
 222     {
 223       break;
 224     }
 225   }
 226
 227   if (*error == MEMCACHED_NOTFOUND and result->count)
 228   {
 229     *error= MEMCACHED_END;
 230   }
 231   else if (*error == MEMCACHED_MAXIMUM_RETURN and result->count)
 232   {
 233     *error= MEMCACHED_END;
 234   }
 235   else if (*error == MEMCACHED_MAXIMUM_RETURN) // while() loop was never entered
 236   {
 237     *error= MEMCACHED_NOTFOUND;
 238   }
 239   else if (connection_failures)
 240   {
 241     /*
 242         If we have a connection failure to some servers, the caller may
 243         wish to treat that differently to getting a definitive NOT_FOUND
 244         from all servers, so return MEMCACHED_CONNECTION_FAILURE to allow
 245         that.
 246         */
 247     *error= MEMCACHED_CONNECTION_FAILURE;
 248   }
 249   else if (*error == MEMCACHED_SUCCESS)
 250   {
 251     *error= MEMCACHED_END;
 252   }
 253   else if (result->count == 0)
 254   {
 255     *error= MEMCACHED_NOTFOUND;
 256   }
 257
 258   /* We have completed reading data */
 259   if (memcached_is_allocated(result))
 260   {
 261     memcached_result_free(result);
 262   }
 263   else
 264   {
 265     result->count= 0;
 266     memcached_string_reset(&result->value);
 267   }
 268
 269   return NULL;
 270 }
 271
 272 memcached_return_t memcached_fetch_execute(memcached_st *shell,
 273                                            memcached_execute_fn *callback,
 274                                            void *context,
 275                                            uint32_t number_of_callbacks)
 276 {
 277   Memcached* ptr= memcached2Memcached(shell);
 278   memcached_result_st *result= &ptr->result;
 279   memcached_return_t rc;
 280   bool some_errors= false;
 281
 282   while ((result= memcached_fetch_result(ptr, result, &rc)))
 283   {
 284     if (memcached_failed(rc) and rc == MEMCACHED_NOTFOUND)
 285     {
 286       continue;
 287     }
 288     else if (memcached_failed(rc))
 289     {
 290       memcached_set_error(*ptr, rc, MEMCACHED_AT);
 291       some_errors= true;
 292       continue;
 293     }
 294
 295     for (uint32_t x= 0; x < number_of_callbacks; x++)
 296     {
 297       memcached_return_t ret= (*callback[x])(ptr, result, context);
 298       if (memcached_failed(ret))
 299       {
 300         some_errors= true;
 301         memcached_set_error(*ptr, ret, MEMCACHED_AT);
 302         break;
 303       }
 304     }
 305   }
 306
 307   if (some_errors)
 308   {
 309     return MEMCACHED_SOME_ERRORS;
 310   }
 311
 312   // If we were able to run all keys without issue we return
 313   // MEMCACHED_SUCCESS
 314   if (memcached_success(rc))
 315   {
 316     return MEMCACHED_SUCCESS;
 317   }
 318
 319   return rc;
 320 }