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   1 /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
   2  *
   3  *  Libmemcached library
   4  *
   5  *  Copyright (C) 2011-2012 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 and *error == MEMCACHED_NOTFOUND)
 121     {
 122       memcached_result_st key_failure_result;
 123       memcached_result_st* result_ptr= memcached_result_create(ptr, &key_failure_result);
 124       memcached_return_t rc= ptr->get_key_failure(ptr, key, key_length, result_ptr);
 125
 126       /* On all failure drop to returning NULL */
 127       if (rc == MEMCACHED_SUCCESS or rc == MEMCACHED_BUFFERED)
 128       {
 129         if (rc == MEMCACHED_BUFFERED)
 130         {
 131           uint64_t latch; /* We use latch to track the state of the original socket */
 132           latch= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS);
 133           if (latch == 0)
 134           {
 135             memcached_behavior_set(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS, 1);
 136           }
 137
 138           rc= memcached_set(ptr, key, key_length,
 139                             (memcached_result_value(result_ptr)),
 140                             (memcached_result_length(result_ptr)),
 141                             0,
 142                             (memcached_result_flags(result_ptr)));
 143
 144           if (rc == MEMCACHED_BUFFERED and latch == 0)
 145           {
 146             memcached_behavior_set(ptr, MEMCACHED_BEHAVIOR_BUFFER_REQUESTS, 0);
 147           }
 148         }
 149         else
 150         {
 151           rc= memcached_set(ptr, key, key_length,
 152                             (memcached_result_value(result_ptr)),
 153                             (memcached_result_length(result_ptr)),
 154                             0,
 155                             (memcached_result_flags(result_ptr)));
 156         }
 157
 158         if (rc == MEMCACHED_SUCCESS or rc == MEMCACHED_BUFFERED)
 159         {
 160           *error= rc;
 161           *value_length= memcached_result_length(result_ptr);
 162           *flags= memcached_result_flags(result_ptr);
 163           char *result_value=  memcached_string_take_value(&result_ptr->value);
 164           memcached_result_free(result_ptr);
 165
 166           return result_value;
 167         }
 168       }
 169
 170       memcached_result_free(result_ptr);
 171     }
 172     assert_msg(ptr->query_id == query_id +1, "Programmer error, the query_id was not incremented.");
 173
 174     return NULL;
 175   }
 176
 177   return value;
 178 }
 179
 180 memcached_return_t memcached_mget(memcached_st *ptr,
 181                                   const char * const *keys,
 182                                   const size_t *key_length,
 183                                   size_t number_of_keys)
 184 {
 185   return memcached_mget_by_key(ptr, NULL, 0, keys, key_length, number_of_keys);
 186 }
 187
 188 static memcached_return_t binary_mget_by_key(memcached_st *ptr,
 189                                              uint32_t master_server_key,
 190                                              bool is_group_key_set,
 191                                              const char * const *keys,
 192                                              const size_t *key_length,
 193                                              size_t number_of_keys,
 194                                              bool mget_mode);
 195
 196 static memcached_return_t memcached_mget_by_key_real(memcached_st *ptr,
 197                                                      const char *group_key,
 198                                                      size_t group_key_length,
 199                                                      const char * const *keys,
 200                                                      const size_t *key_length,
 201                                                      size_t number_of_keys,
 202                                                      bool mget_mode)
 203 {
 204   bool failures_occured_in_sending= false;
 205   const char *get_command= "get ";
 206   uint8_t get_command_length= 4;
 207   unsigned int master_server_key= (unsigned int)-1; /* 0 is a valid server id! */
 208
 209   memcached_return_t rc;
 210   if (memcached_failed(rc= initialize_query(ptr, true)))
 211   {
 212     return rc;
 213   }
 214
 215   if (memcached_is_udp(ptr))
 216   {
 217     return memcached_set_error(*ptr, MEMCACHED_NOT_SUPPORTED, MEMCACHED_AT);
 218   }
 219
 220   LIBMEMCACHED_MEMCACHED_MGET_START();
 221
 222   if (number_of_keys == 0)
 223   {
 224     return memcached_set_error(*ptr, MEMCACHED_NOTFOUND, MEMCACHED_AT, memcached_literal_param("number_of_keys was zero"));
 225   }
 226
 227   if (memcached_failed(memcached_key_test(*ptr, keys, key_length, number_of_keys)))
 228   {
 229     return memcached_last_error(ptr);
 230   }
 231
 232   bool is_group_key_set= false;
 233   if (group_key and group_key_length)
 234   {
 235     master_server_key= memcached_generate_hash_with_redistribution(ptr, group_key, group_key_length);
 236     is_group_key_set= true;
 237   }
 238
 239   /*
 240     Here is where we pay for the non-block API. We need to remove any data sitting
 241     in the queue before we start our get.
 242
 243     It might be optimum to bounce the connection if count > some number.
 244   */
 245   for (uint32_t x= 0; x < memcached_server_count(ptr); x++)
 246   {
 247     memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, x);
 248
 249     if (memcached_server_response_count(instance))
 250     {
 251       char buffer[MEMCACHED_DEFAULT_COMMAND_SIZE];
 252
 253       if (ptr->flags.no_block)
 254       {
 255         memcached_io_write(instance);
 256       }
 257
 258       while(memcached_server_response_count(instance))
 259       {
 260         (void)memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, &ptr->result);
 261       }
 262     }
 263   }
 264
 265   if (memcached_is_binary(ptr))
 266   {
 267     return binary_mget_by_key(ptr, master_server_key, is_group_key_set, keys,
 268                               key_length, number_of_keys, mget_mode);
 269   }
 270
 271   if (ptr->flags.support_cas)
 272   {
 273     get_command= "gets ";
 274     get_command_length= 5;
 275   }
 276
 277   /*
 278     If a server fails we warn about errors and start all over with sending keys
 279     to the server.
 280   */
 281   WATCHPOINT_ASSERT(rc == MEMCACHED_SUCCESS);
 282   size_t hosts_connected= 0;
 283   for (uint32_t x= 0; x < number_of_keys; x++)
 284   {
 285     memcached_server_write_instance_st instance;
 286     uint32_t server_key;
 287
 288     if (is_group_key_set)
 289     {
 290       server_key= master_server_key;
 291     }
 292     else
 293     {
 294       server_key= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 295     }
 296
 297     instance= memcached_server_instance_fetch(ptr, server_key);
 298
 299     libmemcached_io_vector_st vector[]=
 300     {
 301       { get_command, get_command_length },
 302       { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 303       { keys[x], key_length[x] },
 304       { memcached_literal_param(" ") }
 305     };
 306
 307
 308     if (memcached_server_response_count(instance) == 0)
 309     {
 310       rc= memcached_connect(instance);
 311
 312       if (memcached_failed(rc))
 313       {
 314         memcached_set_error(*instance, rc, MEMCACHED_AT);
 315         continue;
 316       }
 317       hosts_connected++;
 318
 319       if ((memcached_io_writev(instance, vector, 4, false)) == false)
 320       {
 321         failures_occured_in_sending= true;
 322         continue;
 323       }
 324       WATCHPOINT_ASSERT(instance->cursor_active == 0);
 325       memcached_server_response_increment(instance);
 326       WATCHPOINT_ASSERT(instance->cursor_active == 1);
 327     }
 328     else
 329     {
 330       if ((memcached_io_writev(instance, (vector + 1), 3, false)) == false)
 331       {
 332         memcached_server_response_reset(instance);
 333         failures_occured_in_sending= true;
 334         continue;
 335       }
 336     }
 337   }
 338
 339   if (hosts_connected == 0)
 340   {
 341     LIBMEMCACHED_MEMCACHED_MGET_END();
 342
 343     if (memcached_failed(rc))
 344     {
 345       return rc;
 346     }
 347
 348     return memcached_set_error(*ptr, MEMCACHED_NO_SERVERS, MEMCACHED_AT);
 349   }
 350
 351
 352   /*
 353     Should we muddle on if some servers are dead?
 354   */
 355   bool success_happened= false;
 356   for (uint32_t x= 0; x < memcached_server_count(ptr); x++)
 357   {
 358     memcached_server_write_instance_st instance=
 359       memcached_server_instance_fetch(ptr, x);
 360
 361     if (memcached_server_response_count(instance))
 362     {
 363       /* We need to do something about non-connnected hosts in the future */
 364       if ((memcached_io_write(instance, "\r\n", 2, true)) == -1)
 365       {
 366         failures_occured_in_sending= true;
 367       }
 368       else
 369       {
 370         success_happened= true;
 371       }
 372     }
 373   }
 374
 375   LIBMEMCACHED_MEMCACHED_MGET_END();
 376
 377   if (failures_occured_in_sending and success_happened)
 378   {
 379     return MEMCACHED_SOME_ERRORS;
 380   }
 381
 382   if (success_happened)
 383   {
 384     return MEMCACHED_SUCCESS;
 385   }
 386
 387   return MEMCACHED_FAILURE; // Complete failure occurred
 388 }
 389
 390 memcached_return_t memcached_mget_by_key(memcached_st *ptr,
 391                                          const char *group_key,
 392                                          size_t group_key_length,
 393                                          const char * const *keys,
 394                                          const size_t *key_length,
 395                                          size_t number_of_keys)
 396 {
 397   return memcached_mget_by_key_real(ptr, group_key, group_key_length, keys,
 398                                     key_length, number_of_keys, true);
 399 }
 400
 401 memcached_return_t memcached_mget_execute(memcached_st *ptr,
 402                                           const char * const *keys,
 403                                           const size_t *key_length,
 404                                           size_t number_of_keys,
 405                                           memcached_execute_fn *callback,
 406                                           void *context,
 407                                           unsigned int number_of_callbacks)
 408 {
 409   return memcached_mget_execute_by_key(ptr, NULL, 0, keys, key_length,
 410                                        number_of_keys, callback,
 411                                        context, number_of_callbacks);
 412 }
 413
 414 memcached_return_t memcached_mget_execute_by_key(memcached_st *ptr,
 415                                                  const char *group_key,
 416                                                  size_t group_key_length,
 417                                                  const char * const *keys,
 418                                                  const size_t *key_length,
 419                                                  size_t number_of_keys,
 420                                                  memcached_execute_fn *callback,
 421                                                  void *context,
 422                                                  unsigned int number_of_callbacks)
 423 {
 424   memcached_return_t rc;
 425   if (memcached_failed(rc= initialize_query(ptr, false)))
 426   {
 427     return rc;
 428   }
 429
 430   if (memcached_is_udp(ptr))
 431   {
 432     return memcached_set_error(*ptr, MEMCACHED_NOT_SUPPORTED, MEMCACHED_AT);
 433   }
 434
 435   if (memcached_is_binary(ptr) == false)
 436   {
 437     return memcached_set_error(*ptr, MEMCACHED_NOT_SUPPORTED, MEMCACHED_AT,
 438                                memcached_literal_param("ASCII protocol is not supported for memcached_mget_execute_by_key()"));
 439   }
 440
 441   memcached_callback_st *original_callbacks= ptr->callbacks;
 442   memcached_callback_st cb= {
 443     callback,
 444     context,
 445     number_of_callbacks
 446   };
 447
 448   ptr->callbacks= &cb;
 449   rc= memcached_mget_by_key(ptr, group_key, group_key_length, keys,
 450                             key_length, number_of_keys);
 451   ptr->callbacks= original_callbacks;
 452   return rc;
 453 }
 454
 455 static memcached_return_t simple_binary_mget(memcached_st *ptr,
 456                                              uint32_t master_server_key,
 457                                              bool is_group_key_set,
 458                                              const char * const *keys,
 459                                              const size_t *key_length,
 460                                              size_t number_of_keys, bool mget_mode)
 461 {
 462   memcached_return_t rc= MEMCACHED_NOTFOUND;
 463
 464   bool flush= (number_of_keys == 1);
 465
 466   /*
 467     If a server fails we warn about errors and start all over with sending keys
 468     to the server.
 469   */
 470   for (uint32_t x= 0; x < number_of_keys; ++x)
 471   {
 472     uint32_t server_key;
 473
 474     if (is_group_key_set)
 475     {
 476       server_key= master_server_key;
 477     }
 478     else
 479     {
 480       server_key= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 481     }
 482
 483     memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, server_key);
 484
 485     if (memcached_server_response_count(instance) == 0)
 486     {
 487       rc= memcached_connect(instance);
 488       if (memcached_failed(rc))
 489       {
 490         continue;
 491       }
 492     }
 493
 494     protocol_binary_request_getk request= { }; //= {.bytes= {0}};
 495     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 496     if (mget_mode)
 497     {
 498       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETKQ;
 499     }
 500     else
 501     {
 502       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETK;
 503     }
 504
 505     memcached_return_t vk;
 506     vk= memcached_validate_key_length(key_length[x],
 507                                       ptr->flags.binary_protocol);
 508     if (vk != MEMCACHED_SUCCESS)
 509     {
 510       if (x > 0)
 511       {
 512         memcached_io_reset(instance);
 513       }
 514
 515       return vk;
 516     }
 517
 518     request.message.header.request.keylen= htons((uint16_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 519     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 520     request.message.header.request.bodylen= htonl((uint32_t)( key_length[x] + memcached_array_size(ptr->_namespace)));
 521
 522     libmemcached_io_vector_st vector[]=
 523     {
 524       { request.bytes, sizeof(request.bytes) },
 525       { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 526       { keys[x], key_length[x] }
 527     };
 528
 529     if (memcached_io_writev(instance, vector, 3, flush) == false)
 530     {
 531       memcached_server_response_reset(instance);
 532       rc= MEMCACHED_SOME_ERRORS;
 533       continue;
 534     }
 535
 536     /* We just want one pending response per server */
 537     memcached_server_response_reset(instance);
 538     memcached_server_response_increment(instance);
 539     if ((x > 0 and x == ptr->io_key_prefetch) and memcached_flush_buffers(ptr) != MEMCACHED_SUCCESS)
 540     {
 541       rc= MEMCACHED_SOME_ERRORS;
 542     }
 543   }
 544
 545   if (mget_mode)
 546   {
 547     /*
 548       Send a noop command to flush the buffers
 549     */
 550     protocol_binary_request_noop request= {}; //= {.bytes= {0}};
 551     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 552     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_NOOP;
 553     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 554
 555     for (uint32_t x= 0; x < memcached_server_count(ptr); ++x)
 556     {
 557       memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, x);
 558
 559       if (memcached_server_response_count(instance))
 560       {
 561         if (memcached_io_write(instance) == false)
 562         {
 563           memcached_server_response_reset(instance);
 564           memcached_io_reset(instance);
 565           rc= MEMCACHED_SOME_ERRORS;
 566         }
 567
 568         if (memcached_io_write(instance, request.bytes,
 569                                sizeof(request.bytes), true) == -1)
 570         {
 571           memcached_server_response_reset(instance);
 572           memcached_io_reset(instance);
 573           rc= MEMCACHED_SOME_ERRORS;
 574         }
 575       }
 576     }
 577   }
 578
 579
 580   return rc;
 581 }
 582
 583 static memcached_return_t replication_binary_mget(memcached_st *ptr,
 584                                                   uint32_t* hash,
 585                                                   bool* dead_servers,
 586                                                   const char *const *keys,
 587                                                   const size_t *key_length,
 588                                                   size_t number_of_keys)
 589 {
 590   memcached_return_t rc= MEMCACHED_NOTFOUND;
 591   uint32_t start= 0;
 592   uint64_t randomize_read= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ);
 593
 594   if (randomize_read)
 595   {
 596     start= (uint32_t)random() % (uint32_t)(ptr->number_of_replicas + 1);
 597   }
 598
 599   /* Loop for each replica */
 600   for (uint32_t replica= 0; replica <= ptr->number_of_replicas; ++replica)
 601   {
 602     bool success= true;
 603
 604     for (uint32_t x= 0; x < number_of_keys; ++x)
 605     {
 606       if (hash[x] == memcached_server_count(ptr))
 607         continue; /* Already successfully sent */
 608
 609       uint32_t server= hash[x] + replica;
 610
 611       /* In case of randomized reads */
 612       if (randomize_read and ((server + start) <= (hash[x] + ptr->number_of_replicas)))
 613       {
 614         server+= start;
 615       }
 616
 617       while (server >= memcached_server_count(ptr))
 618       {
 619         server -= memcached_server_count(ptr);
 620       }
 621
 622       if (dead_servers[server])
 623       {
 624         continue;
 625       }
 626
 627       memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, server);
 628
 629       if (memcached_server_response_count(instance) == 0)
 630       {
 631         rc= memcached_connect(instance);
 632
 633         if (memcached_failed(rc))
 634         {
 635           memcached_io_reset(instance);
 636           dead_servers[server]= true;
 637           success= false;
 638           continue;
 639         }
 640       }
 641
 642       protocol_binary_request_getk request= {};
 643       request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 644       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETK;
 645       request.message.header.request.keylen= htons((uint16_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 646       request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 647       request.message.header.request.bodylen= htonl((uint32_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 648
 649       /*
 650        * We need to disable buffering to actually know that the request was
 651        * successfully sent to the server (so that we should expect a result
 652        * back). It would be nice to do this in buffered mode, but then it
 653        * would be complex to handle all error situations if we got to send
 654        * some of the messages, and then we failed on writing out some others
 655        * and we used the callback interface from memcached_mget_execute so
 656        * that we might have processed some of the responses etc. For now,
 657        * just make sure we work _correctly_
 658      */
 659       libmemcached_io_vector_st vector[]=
 660       {
 661         { request.bytes, sizeof(request.bytes) },
 662         { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 663         { keys[x], key_length[x] }
 664       };
 665
 666       if (memcached_io_writev(instance, vector, 3, true) == false)
 667       {
 668         memcached_io_reset(instance);
 669         dead_servers[server]= true;
 670         success= false;
 671         continue;
 672       }
 673
 674       memcached_server_response_increment(instance);
 675       hash[x]= memcached_server_count(ptr);
 676     }
 677
 678     if (success)
 679     {
 680       break;
 681     }
 682   }
 683
 684   return rc;
 685 }
 686
 687 static memcached_return_t binary_mget_by_key(memcached_st *ptr,
 688                                              uint32_t master_server_key,
 689                                              bool is_group_key_set,
 690                                              const char * const *keys,
 691                                              const size_t *key_length,
 692                                              size_t number_of_keys,
 693                                              bool mget_mode)
 694 {
 695   if (ptr->number_of_replicas == 0)
 696   {
 697     return simple_binary_mget(ptr, master_server_key, is_group_key_set,
 698                               keys, key_length, number_of_keys, mget_mode);
 699   }
 700
 701   uint32_t* hash= libmemcached_xvalloc(ptr, number_of_keys, uint32_t);
 702   bool* dead_servers= libmemcached_xcalloc(ptr, memcached_server_count(ptr), bool);
 703
 704   if (hash == NULL or dead_servers == NULL)
 705   {
 706     libmemcached_free(ptr, hash);
 707     libmemcached_free(ptr, dead_servers);
 708     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 709   }
 710
 711   if (is_group_key_set)
 712   {
 713     for (size_t x= 0; x < number_of_keys; x++)
 714     {
 715       hash[x]= master_server_key;
 716     }
 717   }
 718   else
 719   {
 720     for (size_t x= 0; x < number_of_keys; x++)
 721     {
 722       hash[x]= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 723     }
 724   }
 725
 726   memcached_return_t rc= replication_binary_mget(ptr, hash, dead_servers, keys,
 727                                                  key_length, number_of_keys);
 728
 729   WATCHPOINT_IFERROR(rc);
 730   libmemcached_free(ptr, hash);
 731   libmemcached_free(ptr, dead_servers);
 732
 733   return MEMCACHED_SUCCESS;
 734 }