git.m6w6.name Git - awesomized/libmemcached/blob - libmemcached/fetch.cc

   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
  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
  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   {
  90     *value_length= memcached_string_length(&result_buffer->value);
  91   }
  92
  93   if (key)
  94   {
  95     if (result_buffer->key_length > MEMCACHED_MAX_KEY)
  96     {
  97       *error= MEMCACHED_KEY_TOO_BIG;
  98       if (value_length)
  99         *value_length= 0;
 100
 101     if (key_length)
 102       *key_length= 0;
 103
 104     if (flags)
 105       *flags= 0;
 106
 107     if (key)
 108       *key= 0;
 109
 110       return NULL;
 111     }
 112     strncpy(key, result_buffer->item_key, result_buffer->key_length); // For the binary protocol we will cut off the key :(
 113     if (key_length)
 114       *key_length= result_buffer->key_length;
 115   }
 116
 117   if (flags)
 118     *flags= result_buffer->item_flags;
 119
 120   return memcached_string_take_value(&result_buffer->value);
 121 }
 122
 123 memcached_result_st *memcached_fetch_result(memcached_st *ptr,
 124                                             memcached_result_st *result,
 125                                             memcached_return_t *error)
 126 {
 127   memcached_return_t unused;
 128   if (not error)
 129     error= &unused;
 130
 131   if (not ptr)
 132   {
 133     *error= MEMCACHED_INVALID_ARGUMENTS;
 134     return NULL;
 135   }
 136
 137   if (ptr->flags.use_udp)
 138   {
 139     *error= MEMCACHED_NOT_SUPPORTED;
 140     return NULL;
 141   }
 142
 143   if (not result)
 144   {
 145     // If we have already initialized (ie it is in use) our internal, we
 146     // create one.
 147     if (memcached_is_initialized(&ptr->result))
 148     {
 149       if (not (result= memcached_result_create(ptr, NULL)))
 150       {
 151         *error= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 152         return NULL;
 153       }
 154     }
 155     else
 156     {
 157       result= memcached_result_create(ptr, &ptr->result);
 158     }
 159   }
 160
 161   *error= MEMCACHED_MAXIMUM_RETURN; // We use this to see if we ever go into the loop
 162   memcached_server_st *server;
 163   while ((server= memcached_io_get_readable_server(ptr)))
 164   {
 165     char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
 166     *error= memcached_response(server, buffer, sizeof(buffer), result);
 167
 168     if (*error == MEMCACHED_IN_PROGRESS)
 169     {
 170       continue;
 171     }
 172     else if (*error == MEMCACHED_SUCCESS)
 173     {
 174       result->count++;
 175       return result;
 176     }
 177     else if (*error == MEMCACHED_END)
 178     {
 179       memcached_server_response_reset(server);
 180     }
 181     else if (*error != MEMCACHED_NOTFOUND)
 182     {
 183       break;
 184     }
 185   }
 186
 187   if (*error == MEMCACHED_NOTFOUND and result->count)
 188   {
 189     *error= MEMCACHED_END;
 190   }
 191   else if (*error == MEMCACHED_MAXIMUM_RETURN and result->count)
 192   {
 193     *error= MEMCACHED_END;
 194   }
 195   else if (*error == MEMCACHED_MAXIMUM_RETURN) // while() loop was never entered
 196   {
 197     *error= MEMCACHED_NOTFOUND;
 198   }
 199   else if (*error == MEMCACHED_SUCCESS)
 200   {
 201     *error= MEMCACHED_END;
 202   }
 203   else if (result->count == 0)
 204   {
 205     *error= MEMCACHED_NOTFOUND;
 206   }
 207
 208   /* We have completed reading data */
 209   if (memcached_is_allocated(result))
 210   {
 211     memcached_result_free(result);
 212   }
 213   else
 214   {
 215     result->count= 0;
 216     memcached_string_reset(&result->value);
 217   }
 218
 219   return NULL;
 220 }
 221
 222 memcached_return_t memcached_fetch_execute(memcached_st *ptr,
 223                                            memcached_execute_fn *callback,
 224                                            void *context,
 225                                            uint32_t number_of_callbacks)
 226 {
 227   memcached_result_st *result= &ptr->result;
 228   memcached_return_t rc;
 229   bool some_errors= false;
 230
 231   while ((result= memcached_fetch_result(ptr, result, &rc)))
 232   {
 233     if (memcached_failed(rc) and rc == MEMCACHED_NOTFOUND)
 234     {
 235       continue;
 236     }
 237     else if (memcached_failed(rc))
 238     {
 239       memcached_set_error(*ptr, rc, MEMCACHED_AT);
 240       some_errors= true;
 241       continue;
 242     }
 243
 244     for (uint32_t x= 0; x < number_of_callbacks; x++)
 245     {
 246       memcached_return_t ret= (*callback[x])(ptr, result, context);
 247       if (memcached_failed(ret))
 248       {
 249         some_errors= true;
 250         memcached_set_error(*ptr, ret, MEMCACHED_AT);
 251         break;
 252       }
 253     }
 254   }
 255
 256   if (some_errors)
 257   {
 258     return MEMCACHED_SOME_ERRORS;
 259   }
 260
 261   // If we were able to run all keys without issue we return
 262   // MEMCACHED_SUCCESS
 263   if (memcached_success(rc))
 264   {
 265     return MEMCACHED_SUCCESS;
 266   }
 267
 268   return rc;
 269 }