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         memcached_io_write(instance);
 264       }
 265
 266       while(memcached_server_response_count(instance))
 267       {
 268         (void)memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, &ptr->result);
 269       }
 270     }
 271   }
 272
 273   if (ptr->flags.binary_protocol)
 274   {
 275     return binary_mget_by_key(ptr, master_server_key, is_group_key_set, keys,
 276                               key_length, number_of_keys, mget_mode);
 277   }
 278
 279   if (ptr->flags.support_cas)
 280   {
 281     get_command= "gets ";
 282     get_command_length= 5;
 283   }
 284
 285   /*
 286     If a server fails we warn about errors and start all over with sending keys
 287     to the server.
 288   */
 289   WATCHPOINT_ASSERT(rc == MEMCACHED_SUCCESS);
 290   size_t hosts_connected= 0;
 291   for (uint32_t x= 0; x < number_of_keys; x++)
 292   {
 293     memcached_server_write_instance_st instance;
 294     uint32_t server_key;
 295
 296     if (is_group_key_set)
 297     {
 298       server_key= master_server_key;
 299     }
 300     else
 301     {
 302       server_key= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 303     }
 304
 305     instance= memcached_server_instance_fetch(ptr, server_key);
 306
 307     struct libmemcached_io_vector_st vector[]=
 308     {
 309       { get_command, get_command_length },
 310       { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 311       { keys[x], key_length[x] },
 312       { memcached_literal_param(" ") }
 313     };
 314
 315
 316     if (memcached_server_response_count(instance) == 0)
 317     {
 318       rc= memcached_connect(instance);
 319
 320       if (memcached_failed(rc))
 321       {
 322         memcached_set_error(*instance, rc, MEMCACHED_AT);
 323         continue;
 324       }
 325       hosts_connected++;
 326
 327       if ((memcached_io_writev(instance, vector, 4, false)) == -1)
 328       {
 329         failures_occured_in_sending= true;
 330         continue;
 331       }
 332       WATCHPOINT_ASSERT(instance->cursor_active == 0);
 333       memcached_server_response_increment(instance);
 334       WATCHPOINT_ASSERT(instance->cursor_active == 1);
 335     }
 336     else
 337     {
 338       if ((memcached_io_writev(instance, (vector + 1), 3, false)) == -1)
 339       {
 340         memcached_server_response_reset(instance);
 341         failures_occured_in_sending= true;
 342         continue;
 343       }
 344     }
 345   }
 346
 347   if (hosts_connected == 0)
 348   {
 349     LIBMEMCACHED_MEMCACHED_MGET_END();
 350
 351     if (memcached_failed(rc))
 352       return rc;
 353
 354     return memcached_set_error(*ptr, MEMCACHED_NO_SERVERS, MEMCACHED_AT);
 355   }
 356
 357
 358   /*
 359     Should we muddle on if some servers are dead?
 360   */
 361   bool success_happened= false;
 362   for (uint32_t x= 0; x < memcached_server_count(ptr); x++)
 363   {
 364     memcached_server_write_instance_st instance=
 365       memcached_server_instance_fetch(ptr, x);
 366
 367     if (memcached_server_response_count(instance))
 368     {
 369       /* We need to do something about non-connnected hosts in the future */
 370       if ((memcached_io_write(instance, "\r\n", 2, true)) == -1)
 371       {
 372         failures_occured_in_sending= true;
 373       }
 374       else
 375       {
 376         success_happened= true;
 377       }
 378     }
 379   }
 380
 381   LIBMEMCACHED_MEMCACHED_MGET_END();
 382
 383   if (failures_occured_in_sending && success_happened)
 384   {
 385     return MEMCACHED_SOME_ERRORS;
 386   }
 387
 388   if (success_happened)
 389     return MEMCACHED_SUCCESS;
 390
 391   return MEMCACHED_FAILURE; // Complete failure occurred
 392 }
 393
 394 memcached_return_t memcached_mget_by_key(memcached_st *ptr,
 395                                          const char *group_key,
 396                                          size_t group_key_length,
 397                                          const char * const *keys,
 398                                          const size_t *key_length,
 399                                          size_t number_of_keys)
 400 {
 401   return memcached_mget_by_key_real(ptr, group_key, group_key_length, keys,
 402                                     key_length, number_of_keys, true);
 403 }
 404
 405 memcached_return_t memcached_mget_execute(memcached_st *ptr,
 406                                           const char * const *keys,
 407                                           const size_t *key_length,
 408                                           size_t number_of_keys,
 409                                           memcached_execute_fn *callback,
 410                                           void *context,
 411                                           unsigned int number_of_callbacks)
 412 {
 413   return memcached_mget_execute_by_key(ptr, NULL, 0, keys, key_length,
 414                                        number_of_keys, callback,
 415                                        context, number_of_callbacks);
 416 }
 417
 418 memcached_return_t memcached_mget_execute_by_key(memcached_st *ptr,
 419                                                  const char *group_key,
 420                                                  size_t group_key_length,
 421                                                  const char * const *keys,
 422                                                  const size_t *key_length,
 423                                                  size_t number_of_keys,
 424                                                  memcached_execute_fn *callback,
 425                                                  void *context,
 426                                                  unsigned int number_of_callbacks)
 427 {
 428   if ((ptr->flags.binary_protocol) == 0)
 429   {
 430     return MEMCACHED_NOT_SUPPORTED;
 431   }
 432
 433   memcached_return_t rc;
 434   memcached_callback_st *original_callbacks= ptr->callbacks;
 435   memcached_callback_st cb= {
 436     callback,
 437     context,
 438     number_of_callbacks
 439   };
 440
 441   ptr->callbacks= &cb;
 442   rc= memcached_mget_by_key(ptr, group_key, group_key_length, keys,
 443                             key_length, number_of_keys);
 444   ptr->callbacks= original_callbacks;
 445   return rc;
 446 }
 447
 448 static memcached_return_t simple_binary_mget(memcached_st *ptr,
 449                                              uint32_t master_server_key,
 450                                              bool is_group_key_set,
 451                                              const char * const *keys,
 452                                              const size_t *key_length,
 453                                              size_t number_of_keys, bool mget_mode)
 454 {
 455   memcached_return_t rc= MEMCACHED_NOTFOUND;
 456
 457   bool flush= (number_of_keys == 1);
 458
 459   /*
 460     If a server fails we warn about errors and start all over with sending keys
 461     to the server.
 462   */
 463   for (uint32_t x= 0; x < number_of_keys; ++x)
 464   {
 465     uint32_t server_key;
 466
 467     if (is_group_key_set)
 468     {
 469       server_key= master_server_key;
 470     }
 471     else
 472     {
 473       server_key= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 474     }
 475
 476     memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, server_key);
 477
 478     if (memcached_server_response_count(instance) == 0)
 479     {
 480       rc= memcached_connect(instance);
 481       if (memcached_failed(rc))
 482       {
 483         continue;
 484       }
 485     }
 486
 487     protocol_binary_request_getk request= { }; //= {.bytes= {0}};
 488     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 489     if (mget_mode)
 490       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETKQ;
 491     else
 492       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETK;
 493
 494     memcached_return_t vk;
 495     vk= memcached_validate_key_length(key_length[x],
 496                                       ptr->flags.binary_protocol);
 497     unlikely (vk != MEMCACHED_SUCCESS)
 498     {
 499       if (x > 0)
 500       {
 501         memcached_io_reset(instance);
 502       }
 503
 504       return vk;
 505     }
 506
 507     request.message.header.request.keylen= htons((uint16_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 508     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 509     request.message.header.request.bodylen= htonl((uint32_t)( key_length[x] + memcached_array_size(ptr->_namespace)));
 510
 511     struct libmemcached_io_vector_st vector[]=
 512     {
 513       { request.bytes, sizeof(request.bytes) },
 514       { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 515       { keys[x], key_length[x] }
 516     };
 517
 518     if (memcached_io_writev(instance, vector, 3, flush) == -1)
 519     {
 520       memcached_server_response_reset(instance);
 521       rc= MEMCACHED_SOME_ERRORS;
 522       continue;
 523     }
 524
 525     /* We just want one pending response per server */
 526     memcached_server_response_reset(instance);
 527     memcached_server_response_increment(instance);
 528     if ((x > 0 && x == ptr->io_key_prefetch) && memcached_flush_buffers(ptr) != MEMCACHED_SUCCESS)
 529     {
 530       rc= MEMCACHED_SOME_ERRORS;
 531     }
 532   }
 533
 534   if (mget_mode)
 535   {
 536     /*
 537       Send a noop command to flush the buffers
 538     */
 539     protocol_binary_request_noop request= {}; //= {.bytes= {0}};
 540     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 541     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_NOOP;
 542     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 543
 544     for (uint32_t x= 0; x < memcached_server_count(ptr); ++x)
 545     {
 546       memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, x);
 547
 548       if (memcached_server_response_count(instance))
 549       {
 550         if (memcached_io_write(instance) == false)
 551         {
 552           memcached_server_response_reset(instance);
 553           memcached_io_reset(instance);
 554           rc= MEMCACHED_SOME_ERRORS;
 555         }
 556
 557         if (memcached_io_write(instance, request.bytes,
 558                                sizeof(request.bytes), true) == -1)
 559         {
 560           memcached_server_response_reset(instance);
 561           memcached_io_reset(instance);
 562           rc= MEMCACHED_SOME_ERRORS;
 563         }
 564       }
 565     }
 566   }
 567
 568
 569   return rc;
 570 }
 571
 572 static memcached_return_t replication_binary_mget(memcached_st *ptr,
 573                                                   uint32_t* hash,
 574                                                   bool* dead_servers,
 575                                                   const char *const *keys,
 576                                                   const size_t *key_length,
 577                                                   size_t number_of_keys)
 578 {
 579   memcached_return_t rc= MEMCACHED_NOTFOUND;
 580   uint32_t start= 0;
 581   uint64_t randomize_read= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ);
 582
 583   if (randomize_read)
 584     start= (uint32_t)random() % (uint32_t)(ptr->number_of_replicas + 1);
 585
 586   /* Loop for each replica */
 587   for (uint32_t replica= 0; replica <= ptr->number_of_replicas; ++replica)
 588   {
 589     bool success= true;
 590
 591     for (uint32_t x= 0; x < number_of_keys; ++x)
 592     {
 593       if (hash[x] == memcached_server_count(ptr))
 594         continue; /* Already successfully sent */
 595
 596       uint32_t server= hash[x] + replica;
 597
 598       /* In case of randomized reads */
 599       if (randomize_read && ((server + start) <= (hash[x] + ptr->number_of_replicas)))
 600         server += start;
 601
 602       while (server >= memcached_server_count(ptr))
 603       {
 604         server -= memcached_server_count(ptr);
 605       }
 606
 607       if (dead_servers[server])
 608       {
 609         continue;
 610       }
 611
 612       memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, server);
 613
 614       if (memcached_server_response_count(instance) == 0)
 615       {
 616         rc= memcached_connect(instance);
 617
 618         if (memcached_failed(rc))
 619         {
 620           memcached_io_reset(instance);
 621           dead_servers[server]= true;
 622           success= false;
 623           continue;
 624         }
 625       }
 626
 627       protocol_binary_request_getk request= {};
 628       request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 629       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETK;
 630       request.message.header.request.keylen= htons((uint16_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 631       request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 632       request.message.header.request.bodylen= htonl((uint32_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 633
 634       /*
 635        * We need to disable buffering to actually know that the request was
 636        * successfully sent to the server (so that we should expect a result
 637        * back). It would be nice to do this in buffered mode, but then it
 638        * would be complex to handle all error situations if we got to send
 639        * some of the messages, and then we failed on writing out some others
 640        * and we used the callback interface from memcached_mget_execute so
 641        * that we might have processed some of the responses etc. For now,
 642        * just make sure we work _correctly_
 643      */
 644       struct libmemcached_io_vector_st vector[]=
 645       {
 646         { request.bytes, sizeof(request.bytes) },
 647         { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 648         { keys[x], key_length[x] }
 649       };
 650
 651       if (memcached_io_writev(instance, vector, 3, true) == -1)
 652       {
 653         memcached_io_reset(instance);
 654         dead_servers[server]= true;
 655         success= false;
 656         continue;
 657       }
 658
 659       memcached_server_response_increment(instance);
 660       hash[x]= memcached_server_count(ptr);
 661     }
 662
 663     if (success)
 664     {
 665       break;
 666     }
 667   }
 668
 669   return rc;
 670 }
 671
 672 static memcached_return_t binary_mget_by_key(memcached_st *ptr,
 673                                              uint32_t master_server_key,
 674                                              bool is_group_key_set,
 675                                              const char * const *keys,
 676                                              const size_t *key_length,
 677                                              size_t number_of_keys,
 678                                              bool mget_mode)
 679 {
 680   if (ptr->number_of_replicas == 0)
 681   {
 682     return simple_binary_mget(ptr, master_server_key, is_group_key_set,
 683                               keys, key_length, number_of_keys, mget_mode);
 684   }
 685
 686   uint32_t* hash= libmemcached_xvalloc(ptr, number_of_keys, uint32_t);
 687   bool* dead_servers= libmemcached_xcalloc(ptr, memcached_server_count(ptr), bool);
 688
 689   if (hash == NULL || dead_servers == NULL)
 690   {
 691     libmemcached_free(ptr, hash);
 692     libmemcached_free(ptr, dead_servers);
 693     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 694   }
 695
 696   if (is_group_key_set)
 697   {
 698     for (size_t x= 0; x < number_of_keys; x++)
 699     {
 700       hash[x]= master_server_key;
 701     }
 702   }
 703   else
 704   {
 705     for (size_t x= 0; x < number_of_keys; x++)
 706     {
 707       hash[x]= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 708     }
 709   }
 710
 711   memcached_return_t rc= replication_binary_mget(ptr, hash, dead_servers, keys,
 712                                                  key_length, number_of_keys);
 713
 714   WATCHPOINT_IFERROR(rc);
 715   libmemcached_free(ptr, hash);
 716   libmemcached_free(ptr, dead_servers);
 717
 718   return MEMCACHED_SUCCESS;
 719 }