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