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