git.m6w6.name Git - awesomized/libmemcached/blob - libmemcached/memcached_get.c

   1 #include "common.h"
   2 #include "memcached_io.h"
   3
   4 /*
   5   What happens if no servers exist?
   6 */
   7 char *memcached_get(memcached_st *ptr, const char *key,
   8                     size_t key_length,
   9                     size_t *value_length,
  10                     uint32_t *flags,
  11                     memcached_return *error)
  12 {
  13   return memcached_get_by_key(ptr, NULL, 0, key, key_length, value_length,
  14                               flags, error);
  15 }
  16
  17 char *memcached_get_by_key(memcached_st *ptr,
  18                            const char *master_key,
  19                            size_t master_key_length,
  20                            const char *key, size_t key_length,
  21                            size_t *value_length,
  22                            uint32_t *flags,
  23                            memcached_return *error)
  24 {
  25   char *value;
  26   size_t dummy_length;
  27   uint32_t dummy_flags;
  28   memcached_return dummy_error;
  29
  30   if (ptr->flags & MEM_USE_UDP)
  31   {
  32     *error= MEMCACHED_NOT_SUPPORTED;
  33     return NULL;
  34   }
  35
  36   /* Request the key */
  37   *error= memcached_mget_by_key(ptr,
  38                                 master_key,
  39                                 master_key_length,
  40                                 (char **)&key, &key_length, 1);
  41
  42   value= memcached_fetch(ptr, NULL, NULL,
  43                          value_length, flags, error);
  44   /* This is for historical reasons */
  45   if (*error == MEMCACHED_END)
  46     *error= MEMCACHED_NOTFOUND;
  47
  48   if (value == NULL)
  49   {
  50     if (ptr->get_key_failure && *error == MEMCACHED_NOTFOUND)
  51     {
  52       memcached_return rc;
  53
  54       memcached_result_reset(&ptr->result);
  55       rc= ptr->get_key_failure(ptr, key, key_length, &ptr->result);
  56
  57       /* On all failure drop to returning NULL */
  58       if (rc == MEMCACHED_SUCCESS || rc == MEMCACHED_BUFFERED)
  59       {
  60         if (rc == MEMCACHED_BUFFERED)
  61         {
  62           uint8_t latch; /* We use latch to track the state of the original socket */
  63           latch= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS);
  64           if (latch == 0)
  65             memcached_behavior_set(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS, 1);
  66
  67           rc= memcached_set(ptr, key, key_length,
  68                             memcached_result_value(&ptr->result),
  69                             memcached_result_length(&ptr->result),
  70                             0, memcached_result_flags(&ptr->result));
  71
  72           if (rc == MEMCACHED_BUFFERED && latch == 0)
  73             memcached_behavior_set(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS, 0);
  74         }
  75         else
  76         {
  77           rc= memcached_set(ptr, key, key_length,
  78                             memcached_result_value(&ptr->result),
  79                             memcached_result_length(&ptr->result),
  80                             0, memcached_result_flags(&ptr->result));
  81         }
  82
  83         if (rc == MEMCACHED_SUCCESS || rc == MEMCACHED_BUFFERED)
  84         {
  85           *error= rc;
  86           *value_length= memcached_result_length(&ptr->result);
  87           *flags= memcached_result_flags(&ptr->result);
  88           return memcached_string_c_copy(&ptr->result.value);
  89         }
  90       }
  91     }
  92
  93     return NULL;
  94   }
  95
  96   (void)memcached_fetch(ptr, NULL, NULL,
  97                         &dummy_length, &dummy_flags,
  98                         &dummy_error);
  99   WATCHPOINT_ASSERT(dummy_length == 0);
 100
 101   return value;
 102 }
 103
 104 memcached_return memcached_mget(memcached_st *ptr,
 105                                 char **keys, size_t *key_length,
 106                                 unsigned int number_of_keys)
 107 {
 108   return memcached_mget_by_key(ptr, NULL, 0, keys, key_length, number_of_keys);
 109 }
 110
 111 static memcached_return binary_mget_by_key(memcached_st *ptr,
 112                                            unsigned int master_server_key,
 113                                            char **keys, size_t *key_length,
 114                                            unsigned int number_of_keys);
 115
 116 memcached_return memcached_mget_by_key(memcached_st *ptr,
 117                                        const char *master_key,
 118                                        size_t master_key_length,
 119                                        char **keys,
 120                                        size_t *key_length,
 121                                        unsigned int number_of_keys)
 122 {
 123   unsigned int x;
 124   memcached_return rc= MEMCACHED_NOTFOUND;
 125   char *get_command= "get ";
 126   uint8_t get_command_length= 4;
 127   unsigned int master_server_key= -1; /* 0 is a valid server id! */
 128
 129    if (ptr->flags & MEM_USE_UDP)
 130     return MEMCACHED_NOT_SUPPORTED;
 131
 132   LIBMEMCACHED_MEMCACHED_MGET_START();
 133   ptr->cursor_server= 0;
 134
 135   if (number_of_keys == 0)
 136     return MEMCACHED_NOTFOUND;
 137
 138   if (ptr->number_of_hosts == 0)
 139     return MEMCACHED_NO_SERVERS;
 140
 141   if ((ptr->flags & MEM_VERIFY_KEY) && (memcached_key_test(keys, key_length, number_of_keys) == MEMCACHED_BAD_KEY_PROVIDED))
 142     return MEMCACHED_BAD_KEY_PROVIDED;
 143
 144   if (ptr->flags & MEM_SUPPORT_CAS)
 145   {
 146     get_command= "gets ";
 147     get_command_length= 5;
 148   }
 149
 150   if (master_key && master_key_length)
 151   {
 152     if ((ptr->flags & MEM_VERIFY_KEY) && (memcached_key_test((char **)&master_key, &master_key_length, 1) == MEMCACHED_BAD_KEY_PROVIDED))
 153       return MEMCACHED_BAD_KEY_PROVIDED;
 154     master_server_key= memcached_generate_hash(ptr, master_key, master_key_length);
 155   }
 156
 157   /*
 158     Here is where we pay for the non-block API. We need to remove any data sitting
 159     in the queue before we start our get.
 160
 161     It might be optimum to bounce the connection if count > some number.
 162   */
 163   for (x= 0; x < ptr->number_of_hosts; x++)
 164   {
 165     if (memcached_server_response_count(&ptr->hosts[x]))
 166     {
 167       char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
 168
 169       if (ptr->flags & MEM_NO_BLOCK)
 170         (void)memcached_io_write(&ptr->hosts[x], NULL, 0, 1);
 171
 172       while(memcached_server_response_count(&ptr->hosts[x]))
 173         (void)memcached_response(&ptr->hosts[x], buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, &ptr->result);
 174     }
 175   }
 176
 177   if (ptr->flags & MEM_BINARY_PROTOCOL)
 178     return binary_mget_by_key(ptr, master_server_key, keys,
 179                               key_length, number_of_keys);
 180
 181   /*
 182     If a server fails we warn about errors and start all over with sending keys
 183     to the server.
 184   */
 185   for (x= 0; x < number_of_keys; x++)
 186   {
 187     unsigned int server_key;
 188
 189     if (master_server_key != -1)
 190       server_key= master_server_key;
 191     else
 192       server_key= memcached_generate_hash(ptr, keys[x], key_length[x]);
 193
 194     if (memcached_server_response_count(&ptr->hosts[server_key]) == 0)
 195     {
 196       rc= memcached_connect(&ptr->hosts[server_key]);
 197
 198       if (rc != MEMCACHED_SUCCESS)
 199         continue;
 200
 201       if ((memcached_io_write(&ptr->hosts[server_key], get_command, get_command_length, 0)) == -1)
 202       {
 203         rc= MEMCACHED_SOME_ERRORS;
 204         continue;
 205       }
 206       WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 0);
 207       memcached_server_response_increment(&ptr->hosts[server_key]);
 208       WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 1);
 209     }
 210
 211     /* Only called when we have a prefix key */
 212     if (ptr->prefix_key[0] != 0)
 213     {
 214       if ((memcached_io_write(&ptr->hosts[server_key], ptr->prefix_key, ptr->prefix_key_length, 0)) == -1)
 215       {
 216         memcached_server_response_reset(&ptr->hosts[server_key]);
 217         rc= MEMCACHED_SOME_ERRORS;
 218         continue;
 219       }
 220     }
 221
 222     if ((memcached_io_write(&ptr->hosts[server_key], keys[x], key_length[x], 0)) == -1)
 223     {
 224       memcached_server_response_reset(&ptr->hosts[server_key]);
 225       rc= MEMCACHED_SOME_ERRORS;
 226       continue;
 227     }
 228
 229     if ((memcached_io_write(&ptr->hosts[server_key], " ", 1, 0)) == -1)
 230     {
 231       memcached_server_response_reset(&ptr->hosts[server_key]);
 232       rc= MEMCACHED_SOME_ERRORS;
 233       continue;
 234     }
 235   }
 236
 237   /*
 238     Should we muddle on if some servers are dead?
 239   */
 240   for (x= 0; x < ptr->number_of_hosts; x++)
 241   {
 242     if (memcached_server_response_count(&ptr->hosts[x]))
 243     {
 244       /* We need to do something about non-connnected hosts in the future */
 245       if ((memcached_io_write(&ptr->hosts[x], "\r\n", 2, 1)) == -1)
 246       {
 247         rc= MEMCACHED_SOME_ERRORS;
 248       }
 249     }
 250   }
 251
 252   LIBMEMCACHED_MEMCACHED_MGET_END();
 253   return rc;
 254 }
 255
 256 static memcached_return binary_mget_by_key(memcached_st *ptr,
 257                                            unsigned int master_server_key,
 258                                            char **keys, size_t *key_length,
 259                                            unsigned int number_of_keys)
 260 {
 261   memcached_return rc= MEMCACHED_NOTFOUND;
 262   uint32_t x;
 263
 264   int flush= number_of_keys == 1;
 265
 266   /*
 267     If a server fails we warn about errors and start all over with sending keys
 268     to the server.
 269   */
 270   for (x= 0; x < number_of_keys; x++)
 271   {
 272     unsigned int server_key;
 273
 274     if (master_server_key)
 275       server_key= master_server_key;
 276     else
 277       server_key= memcached_generate_hash(ptr, keys[x], key_length[x]);
 278
 279     if (memcached_server_response_count(&ptr->hosts[server_key]) == 0)
 280     {
 281       rc= memcached_connect(&ptr->hosts[server_key]);
 282       if (rc != MEMCACHED_SUCCESS)
 283         continue;
 284     }
 285
 286     protocol_binary_request_getk request= {.bytes= {0}};
 287     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 288     if (number_of_keys == 1)
 289       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETK;
 290     else
 291       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETKQ;
 292
 293     memcached_return vk;
 294     vk= memcached_validate_key_length(key_length[x],
 295                                       ptr->flags & MEM_BINARY_PROTOCOL);
 296     unlikely (vk != MEMCACHED_SUCCESS)
 297     {
 298       if (x > 0)
 299         memcached_io_reset(&ptr->hosts[server_key]);
 300       return vk;
 301     }
 302
 303     request.message.header.request.keylen= htons((uint16_t)key_length[x]);
 304     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 305     request.message.header.request.bodylen= htonl(key_length[x]);
 306
 307     if ((memcached_io_write(&ptr->hosts[server_key], request.bytes,
 308                             sizeof(request.bytes), 0) == -1) ||
 309         (memcached_io_write(&ptr->hosts[server_key], keys[x],
 310                             key_length[x], flush) == -1))
 311     {
 312       memcached_server_response_reset(&ptr->hosts[server_key]);
 313       rc= MEMCACHED_SOME_ERRORS;
 314       continue;
 315     }
 316     memcached_server_response_increment(&ptr->hosts[server_key]);
 317   }
 318
 319   if (number_of_keys > 1)
 320   {
 321     /*
 322      * Send a noop command to flush the buffers
 323      */
 324     protocol_binary_request_noop request= {.bytes= {0}};
 325     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 326     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_NOOP;
 327     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 328
 329     for (x= 0; x < ptr->number_of_hosts; x++)
 330       if (memcached_server_response_count(&ptr->hosts[x]))
 331       {
 332         if (memcached_io_write(&ptr->hosts[x], NULL, 0, 1) == -1)
 333         {
 334           memcached_server_response_reset(&ptr->hosts[x]);
 335           memcached_io_reset(&ptr->hosts[x]);
 336           rc= MEMCACHED_SOME_ERRORS;
 337         }
 338
 339         if (memcached_io_write(&ptr->hosts[x], request.bytes,
 340                                sizeof(request.bytes), 1) == -1)
 341         {
 342           memcached_server_response_reset(&ptr->hosts[x]);
 343           memcached_io_reset(&ptr->hosts[x]);
 344           rc= MEMCACHED_SOME_ERRORS;
 345         }
 346         memcached_server_response_increment(&ptr->hosts[x]);
 347       }
 348     }
 349
 350
 351   return rc;
 352 }