git.m6w6.name Git - awesomized/libmemcached/blob - libmemcached/get.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,
  29  *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  30  *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  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 /*
  41   What happens if no servers exist?
  42 */
  43 char *memcached_get(memcached_st *ptr, const char *key,
  44                     size_t key_length,
  45                     size_t *value_length,
  46                     uint32_t *flags,
  47                     memcached_return_t *error)
  48 {
  49   return memcached_get_by_key(ptr, NULL, 0, key, key_length, value_length,
  50                               flags, error);
  51 }
  52
  53 static memcached_return_t memcached_mget_by_key_real(memcached_st *ptr,
  54                                                      const char *group_key,
  55                                                      size_t group_key_length,
  56                                                      const char * const *keys,
  57                                                      const size_t *key_length,
  58                                                      size_t number_of_keys,
  59                                                      bool mget_mode);
  60
  61 char *memcached_get_by_key(memcached_st *ptr,
  62                            const char *group_key,
  63                            size_t group_key_length,
  64                            const char *key, size_t key_length,
  65                            size_t *value_length,
  66                            uint32_t *flags,
  67                            memcached_return_t *error)
  68 {
  69   memcached_return_t unused;
  70   if (error == NULL)
  71   {
  72     error= &unused;
  73   }
  74
  75   uint64_t query_id= 0;
  76   if (ptr)
  77   {
  78     query_id= ptr->query_id;
  79   }
  80
  81   /* Request the key */
  82   *error= memcached_mget_by_key_real(ptr, group_key, group_key_length,
  83                                      (const char * const *)&key, &key_length,
  84                                      1, false);
  85   if (ptr)
  86   {
  87     assert_msg(ptr->query_id == query_id +1, "Programmer error, the query_id was not incremented.");
  88   }
  89
  90   if (memcached_failed(*error))
  91   {
  92     if (ptr)
  93     {
  94       if (memcached_has_current_error(*ptr)) // Find the most accurate error
  95       {
  96         *error= memcached_last_error(ptr);
  97       }
  98     }
  99
 100     if (value_length)
 101     {
 102       *value_length= 0;
 103     }
 104
 105     return NULL;
 106   }
 107
 108   char *value= memcached_fetch(ptr, NULL, NULL,
 109                                value_length, flags, error);
 110   assert_msg(ptr->query_id == query_id +1, "Programmer error, the query_id was not incremented.");
 111
 112   /* This is for historical reasons */
 113   if (*error == MEMCACHED_END)
 114   {
 115     *error= MEMCACHED_NOTFOUND;
 116   }
 117
 118   if (value == NULL)
 119   {
 120     if (ptr->get_key_failure && *error == MEMCACHED_NOTFOUND)
 121     {
 122       memcached_result_reset(&ptr->result);
 123       memcached_return_t rc= ptr->get_key_failure(ptr, key, key_length, &ptr->result);
 124
 125       /* On all failure drop to returning NULL */
 126       if (rc == MEMCACHED_SUCCESS or rc == MEMCACHED_BUFFERED)
 127       {
 128         if (rc == MEMCACHED_BUFFERED)
 129         {
 130           uint64_t latch; /* We use latch to track the state of the original socket */
 131           latch= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS);
 132           if (latch == 0)
 133           {
 134             memcached_behavior_set(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS, 1);
 135           }
 136
 137           rc= memcached_set(ptr, key, key_length,
 138                             (memcached_result_value(&ptr->result)),
 139                             (memcached_result_length(&ptr->result)),
 140                             0,
 141                             (memcached_result_flags(&ptr->result)));
 142
 143           if (rc == MEMCACHED_BUFFERED && latch == 0)
 144           {
 145             memcached_behavior_set(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS, 0);
 146           }
 147         }
 148         else
 149         {
 150           rc= memcached_set(ptr, key, key_length,
 151                             (memcached_result_value(&ptr->result)),
 152                             (memcached_result_length(&ptr->result)),
 153                             0,
 154                             (memcached_result_flags(&ptr->result)));
 155         }
 156
 157         if (rc == MEMCACHED_SUCCESS || rc == MEMCACHED_BUFFERED)
 158         {
 159           *error= rc;
 160           *value_length= memcached_result_length(&ptr->result);
 161           *flags= memcached_result_flags(&ptr->result);
 162           return memcached_string_take_value(&ptr->result.value);
 163         }
 164       }
 165     }
 166     assert_msg(ptr->query_id == query_id +1, "Programmer error, the query_id was not incremented.");
 167
 168     return NULL;
 169   }
 170
 171   return value;
 172 }
 173
 174 memcached_return_t memcached_mget(memcached_st *ptr,
 175                                   const char * const *keys,
 176                                   const size_t *key_length,
 177                                   size_t number_of_keys)
 178 {
 179   return memcached_mget_by_key(ptr, NULL, 0, keys, key_length, number_of_keys);
 180 }
 181
 182 static memcached_return_t binary_mget_by_key(memcached_st *ptr,
 183                                              uint32_t master_server_key,
 184                                              bool is_group_key_set,
 185                                              const char * const *keys,
 186                                              const size_t *key_length,
 187                                              size_t number_of_keys,
 188                                              bool mget_mode);
 189
 190 static memcached_return_t memcached_mget_by_key_real(memcached_st *ptr,
 191                                                      const char *group_key,
 192                                                      size_t group_key_length,
 193                                                      const char * const *keys,
 194                                                      const size_t *key_length,
 195                                                      size_t number_of_keys,
 196                                                      bool mget_mode)
 197 {
 198   bool failures_occured_in_sending= false;
 199   const char *get_command= "get ";
 200   uint8_t get_command_length= 4;
 201   unsigned int master_server_key= (unsigned int)-1; /* 0 is a valid server id! */
 202
 203   memcached_return_t rc;
 204   if (memcached_failed(rc= initialize_query(ptr, true)))
 205   {
 206     return rc;
 207   }
 208
 209   if (memcached_is_udp(ptr))
 210   {
 211     return memcached_set_error(*ptr, MEMCACHED_NOT_SUPPORTED, MEMCACHED_AT);
 212   }
 213
 214   LIBMEMCACHED_MEMCACHED_MGET_START();
 215
 216   if (number_of_keys == 0)
 217   {
 218     return memcached_set_error(*ptr, MEMCACHED_NOTFOUND, MEMCACHED_AT, memcached_literal_param("number_of_keys was zero"));
 219   }
 220
 221   if (memcached_failed(memcached_key_test(*ptr, keys, key_length, number_of_keys)))
 222   {
 223     return memcached_last_error(ptr);
 224   }
 225
 226   bool is_group_key_set= false;
 227   if (group_key and group_key_length)
 228   {
 229     master_server_key= memcached_generate_hash_with_redistribution(ptr, group_key, group_key_length);
 230     is_group_key_set= true;
 231   }
 232
 233   /*
 234     Here is where we pay for the non-block API. We need to remove any data sitting
 235     in the queue before we start our get.
 236
 237     It might be optimum to bounce the connection if count > some number.
 238   */
 239   for (uint32_t x= 0; x < memcached_server_count(ptr); x++)
 240   {
 241     memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, x);
 242
 243     if (memcached_server_response_count(instance))
 244     {
 245       char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
 246
 247       if (ptr->flags.no_block)
 248       {
 249         memcached_io_write(instance);
 250       }
 251
 252       while(memcached_server_response_count(instance))
 253       {
 254         (void)memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, &ptr->result);
 255       }
 256     }
 257   }
 258
 259   if (memcached_is_binary(ptr))
 260   {
 261     return binary_mget_by_key(ptr, master_server_key, is_group_key_set, keys,
 262                               key_length, number_of_keys, mget_mode);
 263   }
 264
 265   if (ptr->flags.support_cas)
 266   {
 267     get_command= "gets ";
 268     get_command_length= 5;
 269   }
 270
 271   /*
 272     If a server fails we warn about errors and start all over with sending keys
 273     to the server.
 274   */
 275   WATCHPOINT_ASSERT(rc == MEMCACHED_SUCCESS);
 276   size_t hosts_connected= 0;
 277   for (uint32_t x= 0; x < number_of_keys; x++)
 278   {
 279     memcached_server_write_instance_st instance;
 280     uint32_t server_key;
 281
 282     if (is_group_key_set)
 283     {
 284       server_key= master_server_key;
 285     }
 286     else
 287     {
 288       server_key= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 289     }
 290
 291     instance= memcached_server_instance_fetch(ptr, server_key);
 292
 293     libmemcached_io_vector_st vector[]=
 294     {
 295       { get_command, get_command_length },
 296       { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 297       { keys[x], key_length[x] },
 298       { memcached_literal_param(" ") }
 299     };
 300
 301
 302     if (memcached_server_response_count(instance) == 0)
 303     {
 304       rc= memcached_connect(instance);
 305
 306       if (memcached_failed(rc))
 307       {
 308         memcached_set_error(*instance, rc, MEMCACHED_AT);
 309         continue;
 310       }
 311       hosts_connected++;
 312
 313       if ((memcached_io_writev(instance, vector, 4, false)) == -1)
 314       {
 315         failures_occured_in_sending= true;
 316         continue;
 317       }
 318       WATCHPOINT_ASSERT(instance->cursor_active == 0);
 319       memcached_server_response_increment(instance);
 320       WATCHPOINT_ASSERT(instance->cursor_active == 1);
 321     }
 322     else
 323     {
 324       if ((memcached_io_writev(instance, (vector + 1), 3, false)) == -1)
 325       {
 326         memcached_server_response_reset(instance);
 327         failures_occured_in_sending= true;
 328         continue;
 329       }
 330     }
 331   }
 332
 333   if (hosts_connected == 0)
 334   {
 335     LIBMEMCACHED_MEMCACHED_MGET_END();
 336
 337     if (memcached_failed(rc))
 338     {
 339       return rc;
 340     }
 341
 342     return memcached_set_error(*ptr, MEMCACHED_NO_SERVERS, MEMCACHED_AT);
 343   }
 344
 345
 346   /*
 347     Should we muddle on if some servers are dead?
 348   */
 349   bool success_happened= false;
 350   for (uint32_t x= 0; x < memcached_server_count(ptr); x++)
 351   {
 352     memcached_server_write_instance_st instance=
 353       memcached_server_instance_fetch(ptr, x);
 354
 355     if (memcached_server_response_count(instance))
 356     {
 357       /* We need to do something about non-connnected hosts in the future */
 358       if ((memcached_io_write(instance, "\r\n", 2, true)) == -1)
 359       {
 360         failures_occured_in_sending= true;
 361       }
 362       else
 363       {
 364         success_happened= true;
 365       }
 366     }
 367   }
 368
 369   LIBMEMCACHED_MEMCACHED_MGET_END();
 370
 371   if (failures_occured_in_sending && success_happened)
 372   {
 373     return MEMCACHED_SOME_ERRORS;
 374   }
 375
 376   if (success_happened)
 377     return MEMCACHED_SUCCESS;
 378
 379   return MEMCACHED_FAILURE; // Complete failure occurred
 380 }
 381
 382 memcached_return_t memcached_mget_by_key(memcached_st *ptr,
 383                                          const char *group_key,
 384                                          size_t group_key_length,
 385                                          const char * const *keys,
 386                                          const size_t *key_length,
 387                                          size_t number_of_keys)
 388 {
 389   return memcached_mget_by_key_real(ptr, group_key, group_key_length, keys,
 390                                     key_length, number_of_keys, true);
 391 }
 392
 393 memcached_return_t memcached_mget_execute(memcached_st *ptr,
 394                                           const char * const *keys,
 395                                           const size_t *key_length,
 396                                           size_t number_of_keys,
 397                                           memcached_execute_fn *callback,
 398                                           void *context,
 399                                           unsigned int number_of_callbacks)
 400 {
 401   return memcached_mget_execute_by_key(ptr, NULL, 0, keys, key_length,
 402                                        number_of_keys, callback,
 403                                        context, number_of_callbacks);
 404 }
 405
 406 memcached_return_t memcached_mget_execute_by_key(memcached_st *ptr,
 407                                                  const char *group_key,
 408                                                  size_t group_key_length,
 409                                                  const char * const *keys,
 410                                                  const size_t *key_length,
 411                                                  size_t number_of_keys,
 412                                                  memcached_execute_fn *callback,
 413                                                  void *context,
 414                                                  unsigned int number_of_callbacks)
 415 {
 416   memcached_return_t rc;
 417   if (memcached_failed(rc= initialize_query(ptr, false)))
 418   {
 419     return rc;
 420   }
 421
 422   if (memcached_is_udp(ptr))
 423   {
 424     return memcached_set_error(*ptr, MEMCACHED_NOT_SUPPORTED, MEMCACHED_AT);
 425   }
 426
 427   if (memcached_is_binary(ptr) == false)
 428   {
 429     return memcached_set_error(*ptr, MEMCACHED_NOT_SUPPORTED, MEMCACHED_AT,
 430                                memcached_literal_param("ASCII protocol is not supported for memcached_mget_execute_by_key()"));
 431   }
 432
 433   memcached_callback_st *original_callbacks= ptr->callbacks;
 434   memcached_callback_st cb= {
 435     callback,
 436     context,
 437     number_of_callbacks
 438   };
 439
 440   ptr->callbacks= &cb;
 441   rc= memcached_mget_by_key(ptr, group_key, group_key_length, keys,
 442                             key_length, number_of_keys);
 443   ptr->callbacks= original_callbacks;
 444   return rc;
 445 }
 446
 447 static memcached_return_t simple_binary_mget(memcached_st *ptr,
 448                                              uint32_t master_server_key,
 449                                              bool is_group_key_set,
 450                                              const char * const *keys,
 451                                              const size_t *key_length,
 452                                              size_t number_of_keys, bool mget_mode)
 453 {
 454   memcached_return_t rc= MEMCACHED_NOTFOUND;
 455
 456   bool flush= (number_of_keys == 1);
 457
 458   /*
 459     If a server fails we warn about errors and start all over with sending keys
 460     to the server.
 461   */
 462   for (uint32_t x= 0; x < number_of_keys; ++x)
 463   {
 464     uint32_t server_key;
 465
 466     if (is_group_key_set)
 467     {
 468       server_key= master_server_key;
 469     }
 470     else
 471     {
 472       server_key= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 473     }
 474
 475     memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, server_key);
 476
 477     if (memcached_server_response_count(instance) == 0)
 478     {
 479       rc= memcached_connect(instance);
 480       if (memcached_failed(rc))
 481       {
 482         continue;
 483       }
 484     }
 485
 486     protocol_binary_request_getk request= { }; //= {.bytes= {0}};
 487     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 488     if (mget_mode)
 489     {
 490       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETKQ;
 491     }
 492     else
 493     {
 494       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETK;
 495     }
 496
 497     memcached_return_t vk;
 498     vk= memcached_validate_key_length(key_length[x],
 499                                       ptr->flags.binary_protocol);
 500     if (vk != MEMCACHED_SUCCESS)
 501     {
 502       if (x > 0)
 503       {
 504         memcached_io_reset(instance);
 505       }
 506
 507       return vk;
 508     }
 509
 510     request.message.header.request.keylen= htons((uint16_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 511     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 512     request.message.header.request.bodylen= htonl((uint32_t)( key_length[x] + memcached_array_size(ptr->_namespace)));
 513
 514     libmemcached_io_vector_st vector[]=
 515     {
 516       { request.bytes, sizeof(request.bytes) },
 517       { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 518       { keys[x], key_length[x] }
 519     };
 520
 521     if (memcached_io_writev(instance, vector, 3, flush) == -1)
 522     {
 523       memcached_server_response_reset(instance);
 524       rc= MEMCACHED_SOME_ERRORS;
 525       continue;
 526     }
 527
 528     /* We just want one pending response per server */
 529     memcached_server_response_reset(instance);
 530     memcached_server_response_increment(instance);
 531     if ((x > 0 && x == ptr->io_key_prefetch) && memcached_flush_buffers(ptr) != MEMCACHED_SUCCESS)
 532     {
 533       rc= MEMCACHED_SOME_ERRORS;
 534     }
 535   }
 536
 537   if (mget_mode)
 538   {
 539     /*
 540       Send a noop command to flush the buffers
 541     */
 542     protocol_binary_request_noop request= {}; //= {.bytes= {0}};
 543     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 544     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_NOOP;
 545     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 546
 547     for (uint32_t x= 0; x < memcached_server_count(ptr); ++x)
 548     {
 549       memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, x);
 550
 551       if (memcached_server_response_count(instance))
 552       {
 553         if (memcached_io_write(instance) == false)
 554         {
 555           memcached_server_response_reset(instance);
 556           memcached_io_reset(instance);
 557           rc= MEMCACHED_SOME_ERRORS;
 558         }
 559
 560         if (memcached_io_write(instance, request.bytes,
 561                                sizeof(request.bytes), true) == -1)
 562         {
 563           memcached_server_response_reset(instance);
 564           memcached_io_reset(instance);
 565           rc= MEMCACHED_SOME_ERRORS;
 566         }
 567       }
 568     }
 569   }
 570
 571
 572   return rc;
 573 }
 574
 575 static memcached_return_t replication_binary_mget(memcached_st *ptr,
 576                                                   uint32_t* hash,
 577                                                   bool* dead_servers,
 578                                                   const char *const *keys,
 579                                                   const size_t *key_length,
 580                                                   size_t number_of_keys)
 581 {
 582   memcached_return_t rc= MEMCACHED_NOTFOUND;
 583   uint32_t start= 0;
 584   uint64_t randomize_read= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ);
 585
 586   if (randomize_read)
 587     start= (uint32_t)random() % (uint32_t)(ptr->number_of_replicas + 1);
 588
 589   /* Loop for each replica */
 590   for (uint32_t replica= 0; replica <= ptr->number_of_replicas; ++replica)
 591   {
 592     bool success= true;
 593
 594     for (uint32_t x= 0; x < number_of_keys; ++x)
 595     {
 596       if (hash[x] == memcached_server_count(ptr))
 597         continue; /* Already successfully sent */
 598
 599       uint32_t server= hash[x] + replica;
 600
 601       /* In case of randomized reads */
 602       if (randomize_read && ((server + start) <= (hash[x] + ptr->number_of_replicas)))
 603         server += start;
 604
 605       while (server >= memcached_server_count(ptr))
 606       {
 607         server -= memcached_server_count(ptr);
 608       }
 609
 610       if (dead_servers[server])
 611       {
 612         continue;
 613       }
 614
 615       memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, server);
 616
 617       if (memcached_server_response_count(instance) == 0)
 618       {
 619         rc= memcached_connect(instance);
 620
 621         if (memcached_failed(rc))
 622         {
 623           memcached_io_reset(instance);
 624           dead_servers[server]= true;
 625           success= false;
 626           continue;
 627         }
 628       }
 629
 630       protocol_binary_request_getk request= {};
 631       request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 632       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETK;
 633       request.message.header.request.keylen= htons((uint16_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 634       request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 635       request.message.header.request.bodylen= htonl((uint32_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 636
 637       /*
 638        * We need to disable buffering to actually know that the request was
 639        * successfully sent to the server (so that we should expect a result
 640        * back). It would be nice to do this in buffered mode, but then it
 641        * would be complex to handle all error situations if we got to send
 642        * some of the messages, and then we failed on writing out some others
 643        * and we used the callback interface from memcached_mget_execute so
 644        * that we might have processed some of the responses etc. For now,
 645        * just make sure we work _correctly_
 646      */
 647       libmemcached_io_vector_st vector[]=
 648       {
 649         { request.bytes, sizeof(request.bytes) },
 650         { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 651         { keys[x], key_length[x] }
 652       };
 653
 654       if (memcached_io_writev(instance, vector, 3, true) == -1)
 655       {
 656         memcached_io_reset(instance);
 657         dead_servers[server]= true;
 658         success= false;
 659         continue;
 660       }
 661
 662       memcached_server_response_increment(instance);
 663       hash[x]= memcached_server_count(ptr);
 664     }
 665
 666     if (success)
 667     {
 668       break;
 669     }
 670   }
 671
 672   return rc;
 673 }
 674
 675 static memcached_return_t binary_mget_by_key(memcached_st *ptr,
 676                                              uint32_t master_server_key,
 677                                              bool is_group_key_set,
 678                                              const char * const *keys,
 679                                              const size_t *key_length,
 680                                              size_t number_of_keys,
 681                                              bool mget_mode)
 682 {
 683   if (ptr->number_of_replicas == 0)
 684   {
 685     return simple_binary_mget(ptr, master_server_key, is_group_key_set,
 686                               keys, key_length, number_of_keys, mget_mode);
 687   }
 688
 689   uint32_t* hash= libmemcached_xvalloc(ptr, number_of_keys, uint32_t);
 690   bool* dead_servers= libmemcached_xcalloc(ptr, memcached_server_count(ptr), bool);
 691
 692   if (hash == NULL || dead_servers == NULL)
 693   {
 694     libmemcached_free(ptr, hash);
 695     libmemcached_free(ptr, dead_servers);
 696     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 697   }
 698
 699   if (is_group_key_set)
 700   {
 701     for (size_t x= 0; x < number_of_keys; x++)
 702     {
 703       hash[x]= master_server_key;
 704     }
 705   }
 706   else
 707   {
 708     for (size_t x= 0; x < number_of_keys; x++)
 709     {
 710       hash[x]= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 711     }
 712   }
 713
 714   memcached_return_t rc= replication_binary_mget(ptr, hash, dead_servers, keys,
 715                                                  key_length, number_of_keys);
 716
 717   WATCHPOINT_IFERROR(rc);
 718   libmemcached_free(ptr, hash);
 719   libmemcached_free(ptr, dead_servers);
 720
 721   return MEMCACHED_SUCCESS;
 722 }