git.m6w6.name Git - m6w6/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                                            bool is_master_key_set,
 114                                            char **keys, size_t *key_length,
 115                                            unsigned int number_of_keys);
 116
 117 memcached_return memcached_mget_by_key(memcached_st *ptr,
 118                                        const char *master_key,
 119                                        size_t master_key_length,
 120                                        char **keys,
 121                                        size_t *key_length,
 122                                        unsigned int number_of_keys)
 123 {
 124   unsigned int x;
 125   memcached_return rc= MEMCACHED_NOTFOUND;
 126   char *get_command= "get ";
 127   uint8_t get_command_length= 4;
 128   unsigned int master_server_key= (unsigned int)-1; /* 0 is a valid server id! */
 129   bool is_master_key_set= false;
 130
 131    if (ptr->flags & MEM_USE_UDP)
 132     return MEMCACHED_NOT_SUPPORTED;
 133
 134   LIBMEMCACHED_MEMCACHED_MGET_START();
 135   ptr->cursor_server= 0;
 136
 137   if (number_of_keys == 0)
 138     return MEMCACHED_NOTFOUND;
 139
 140   if (ptr->number_of_hosts == 0)
 141     return MEMCACHED_NO_SERVERS;
 142
 143   if ((ptr->flags & MEM_VERIFY_KEY) && (memcached_key_test(keys, key_length, number_of_keys) == MEMCACHED_BAD_KEY_PROVIDED))
 144     return MEMCACHED_BAD_KEY_PROVIDED;
 145
 146   if (ptr->flags & MEM_SUPPORT_CAS)
 147   {
 148     get_command= "gets ";
 149     get_command_length= 5;
 150   }
 151
 152   if (master_key && master_key_length)
 153   {
 154     if ((ptr->flags & MEM_VERIFY_KEY) && (memcached_key_test((char **)&master_key, &master_key_length, 1) == MEMCACHED_BAD_KEY_PROVIDED))
 155       return MEMCACHED_BAD_KEY_PROVIDED;
 156     master_server_key= memcached_generate_hash(ptr, master_key, master_key_length);
 157     is_master_key_set= true;
 158   }
 159
 160   /*
 161     Here is where we pay for the non-block API. We need to remove any data sitting
 162     in the queue before we start our get.
 163
 164     It might be optimum to bounce the connection if count > some number.
 165   */
 166   for (x= 0; x < ptr->number_of_hosts; x++)
 167   {
 168     if (memcached_server_response_count(&ptr->hosts[x]))
 169     {
 170       char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
 171
 172       if (ptr->flags & MEM_NO_BLOCK)
 173         (void)memcached_io_write(&ptr->hosts[x], NULL, 0, 1);
 174
 175       while(memcached_server_response_count(&ptr->hosts[x]))
 176         (void)memcached_response(&ptr->hosts[x], buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, &ptr->result);
 177     }
 178   }
 179
 180   if (ptr->flags & MEM_BINARY_PROTOCOL)
 181     return binary_mget_by_key(ptr, master_server_key, is_master_key_set, keys,
 182                               key_length, number_of_keys);
 183
 184   /*
 185     If a server fails we warn about errors and start all over with sending keys
 186     to the server.
 187   */
 188   for (x= 0; x < number_of_keys; x++)
 189   {
 190     unsigned int server_key;
 191
 192     if (is_master_key_set)
 193       server_key= master_server_key;
 194     else
 195       server_key= memcached_generate_hash(ptr, keys[x], key_length[x]);
 196
 197     if (memcached_server_response_count(&ptr->hosts[server_key]) == 0)
 198     {
 199       rc= memcached_connect(&ptr->hosts[server_key]);
 200
 201       if (rc != MEMCACHED_SUCCESS)
 202         continue;
 203
 204       if ((memcached_io_write(&ptr->hosts[server_key], get_command, get_command_length, 0)) == -1)
 205       {
 206         rc= MEMCACHED_SOME_ERRORS;
 207         continue;
 208       }
 209       WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 0);
 210       memcached_server_response_increment(&ptr->hosts[server_key]);
 211       WATCHPOINT_ASSERT(ptr->hosts[server_key].cursor_active == 1);
 212     }
 213
 214     /* Only called when we have a prefix key */
 215     if (ptr->prefix_key[0] != 0)
 216     {
 217       if ((memcached_io_write(&ptr->hosts[server_key], ptr->prefix_key, ptr->prefix_key_length, 0)) == -1)
 218       {
 219         memcached_server_response_reset(&ptr->hosts[server_key]);
 220         rc= MEMCACHED_SOME_ERRORS;
 221         continue;
 222       }
 223     }
 224
 225     if ((memcached_io_write(&ptr->hosts[server_key], keys[x], key_length[x], 0)) == -1)
 226     {
 227       memcached_server_response_reset(&ptr->hosts[server_key]);
 228       rc= MEMCACHED_SOME_ERRORS;
 229       continue;
 230     }
 231
 232     if ((memcached_io_write(&ptr->hosts[server_key], " ", 1, 0)) == -1)
 233     {
 234       memcached_server_response_reset(&ptr->hosts[server_key]);
 235       rc= MEMCACHED_SOME_ERRORS;
 236       continue;
 237     }
 238   }
 239
 240   /*
 241     Should we muddle on if some servers are dead?
 242   */
 243   for (x= 0; x < ptr->number_of_hosts; x++)
 244   {
 245     if (memcached_server_response_count(&ptr->hosts[x]))
 246     {
 247       /* We need to do something about non-connnected hosts in the future */
 248       if ((memcached_io_write(&ptr->hosts[x], "\r\n", 2, 1)) == -1)
 249       {
 250         rc= MEMCACHED_SOME_ERRORS;
 251       }
 252     }
 253   }
 254
 255   LIBMEMCACHED_MEMCACHED_MGET_END();
 256   return rc;
 257 }
 258
 259 static memcached_return binary_mget_by_key(memcached_st *ptr,
 260                                            unsigned int master_server_key,
 261                                            bool is_master_key_set,
 262                                            char **keys, size_t *key_length,
 263                                            unsigned int number_of_keys)
 264 {
 265   memcached_return rc= MEMCACHED_NOTFOUND;
 266   uint32_t x;
 267
 268   int flush= number_of_keys == 1;
 269
 270   /*
 271     If a server fails we warn about errors and start all over with sending keys
 272     to the server.
 273   */
 274   for (x= 0; x < number_of_keys; x++)
 275   {
 276     unsigned int server_key;
 277
 278     if (is_master_key_set)
 279       server_key= master_server_key;
 280     else
 281       server_key= memcached_generate_hash(ptr, keys[x], key_length[x]);
 282
 283     if (memcached_server_response_count(&ptr->hosts[server_key]) == 0)
 284     {
 285       rc= memcached_connect(&ptr->hosts[server_key]);
 286       if (rc != MEMCACHED_SUCCESS)
 287         continue;
 288     }
 289
 290     protocol_binary_request_getk request= {.bytes= {0}};
 291     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 292     if (number_of_keys == 1)
 293       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETK;
 294     else
 295       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETKQ;
 296
 297     memcached_return vk;
 298     vk= memcached_validate_key_length(key_length[x],
 299                                       ptr->flags & MEM_BINARY_PROTOCOL);
 300     unlikely (vk != MEMCACHED_SUCCESS)
 301     {
 302       if (x > 0)
 303         memcached_io_reset(&ptr->hosts[server_key]);
 304       return vk;
 305     }
 306
 307     request.message.header.request.keylen= htons((uint16_t)key_length[x]);
 308     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 309     request.message.header.request.bodylen= htonl(key_length[x]);
 310
 311     if ((memcached_io_write(&ptr->hosts[server_key], request.bytes,
 312                             sizeof(request.bytes), 0) == -1) ||
 313         (memcached_io_write(&ptr->hosts[server_key], keys[x],
 314                             key_length[x], flush) == -1))
 315     {
 316       memcached_server_response_reset(&ptr->hosts[server_key]);
 317       rc= MEMCACHED_SOME_ERRORS;
 318       continue;
 319     }
 320     memcached_server_response_increment(&ptr->hosts[server_key]);
 321     if ((x > 0 && x == ptr->io_key_prefetch) &&
 322         memcached_flush_buffers(ptr) != MEMCACHED_SUCCESS)
 323       rc= MEMCACHED_SOME_ERRORS;
 324   }
 325
 326   if (number_of_keys > 1)
 327   {
 328     /*
 329      * Send a noop command to flush the buffers
 330      */
 331     protocol_binary_request_noop request= {.bytes= {0}};
 332     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 333     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_NOOP;
 334     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 335
 336     for (x= 0; x < ptr->number_of_hosts; x++)
 337       if (memcached_server_response_count(&ptr->hosts[x]))
 338       {
 339         if (memcached_io_write(&ptr->hosts[x], NULL, 0, 1) == -1)
 340         {
 341           memcached_server_response_reset(&ptr->hosts[x]);
 342           memcached_io_reset(&ptr->hosts[x]);
 343           rc= MEMCACHED_SOME_ERRORS;
 344         }
 345
 346         if (memcached_io_write(&ptr->hosts[x], request.bytes,
 347                                sizeof(request.bytes), 1) == -1)
 348         {
 349           memcached_server_response_reset(&ptr->hosts[x]);
 350           memcached_io_reset(&ptr->hosts[x]);
 351           rc= MEMCACHED_SOME_ERRORS;
 352         }
 353         memcached_server_response_increment(&ptr->hosts[x]);
 354       }
 355     }
 356
 357
 358   return rc;
 359 }