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   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         (void)memcached_io_write(instance, NULL, 0, true);
 263
 264       while(memcached_server_response_count(instance))
 265         (void)memcached_response(instance, buffer, MEMCACHED_DEFAULT_COMMAND_SIZE, &ptr->result);
 266     }
 267   }
 268
 269   if (ptr->flags.binary_protocol)
 270   {
 271     return binary_mget_by_key(ptr, master_server_key, is_group_key_set, keys,
 272                               key_length, number_of_keys, mget_mode);
 273   }
 274
 275   if (ptr->flags.support_cas)
 276   {
 277     get_command= "gets ";
 278     get_command_length= 5;
 279   }
 280
 281   /*
 282     If a server fails we warn about errors and start all over with sending keys
 283     to the server.
 284   */
 285   WATCHPOINT_ASSERT(rc == MEMCACHED_SUCCESS);
 286   size_t hosts_connected= 0;
 287   for (uint32_t x= 0; x < number_of_keys; x++)
 288   {
 289     memcached_server_write_instance_st instance;
 290     uint32_t server_key;
 291
 292     if (is_group_key_set)
 293     {
 294       server_key= master_server_key;
 295     }
 296     else
 297     {
 298       server_key= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 299     }
 300
 301     instance= memcached_server_instance_fetch(ptr, server_key);
 302
 303     struct libmemcached_io_vector_st vector[]=
 304     {
 305       { get_command, get_command_length },
 306       { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 307       { keys[x], key_length[x] },
 308       { memcached_literal_param(" ") }
 309     };
 310
 311
 312     if (memcached_server_response_count(instance) == 0)
 313     {
 314       rc= memcached_connect(instance);
 315
 316       if (memcached_failed(rc))
 317       {
 318         memcached_set_error(*instance, rc, MEMCACHED_AT);
 319         continue;
 320       }
 321       hosts_connected++;
 322
 323       if ((memcached_io_writev(instance, vector, 4, false)) == -1)
 324       {
 325         failures_occured_in_sending= true;
 326         continue;
 327       }
 328       WATCHPOINT_ASSERT(instance->cursor_active == 0);
 329       memcached_server_response_increment(instance);
 330       WATCHPOINT_ASSERT(instance->cursor_active == 1);
 331     }
 332     else
 333     {
 334       if ((memcached_io_writev(instance, (vector + 1), 3, false)) == -1)
 335       {
 336         memcached_server_response_reset(instance);
 337         failures_occured_in_sending= true;
 338         continue;
 339       }
 340     }
 341   }
 342
 343   if (hosts_connected == 0)
 344   {
 345     LIBMEMCACHED_MEMCACHED_MGET_END();
 346
 347     if (memcached_failed(rc))
 348       return rc;
 349
 350     return memcached_set_error(*ptr, MEMCACHED_NO_SERVERS, MEMCACHED_AT);
 351   }
 352
 353
 354   /*
 355     Should we muddle on if some servers are dead?
 356   */
 357   bool success_happened= false;
 358   for (uint32_t x= 0; x < memcached_server_count(ptr); x++)
 359   {
 360     memcached_server_write_instance_st instance=
 361       memcached_server_instance_fetch(ptr, x);
 362
 363     if (memcached_server_response_count(instance))
 364     {
 365       /* We need to do something about non-connnected hosts in the future */
 366       if ((memcached_io_write(instance, "\r\n", 2, true)) == -1)
 367       {
 368         failures_occured_in_sending= true;
 369       }
 370       else
 371       {
 372         success_happened= true;
 373       }
 374     }
 375   }
 376
 377   LIBMEMCACHED_MEMCACHED_MGET_END();
 378
 379   if (failures_occured_in_sending && success_happened)
 380   {
 381     return MEMCACHED_SOME_ERRORS;
 382   }
 383
 384   if (success_happened)
 385     return MEMCACHED_SUCCESS;
 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   if ((ptr->flags.binary_protocol) == 0)
 425   {
 426     return MEMCACHED_NOT_SUPPORTED;
 427   }
 428
 429   memcached_return_t rc;
 430   memcached_callback_st *original_callbacks= ptr->callbacks;
 431   memcached_callback_st cb= {
 432     callback,
 433     context,
 434     number_of_callbacks
 435   };
 436
 437   ptr->callbacks= &cb;
 438   rc= memcached_mget_by_key(ptr, group_key, group_key_length, keys,
 439                             key_length, number_of_keys);
 440   ptr->callbacks= original_callbacks;
 441   return rc;
 442 }
 443
 444 static memcached_return_t simple_binary_mget(memcached_st *ptr,
 445                                              uint32_t master_server_key,
 446                                              bool is_group_key_set,
 447                                              const char * const *keys,
 448                                              const size_t *key_length,
 449                                              size_t number_of_keys, bool mget_mode)
 450 {
 451   memcached_return_t rc= MEMCACHED_NOTFOUND;
 452
 453   bool flush= (number_of_keys == 1);
 454
 455   /*
 456     If a server fails we warn about errors and start all over with sending keys
 457     to the server.
 458   */
 459   for (uint32_t x= 0; x < number_of_keys; ++x)
 460   {
 461     uint32_t server_key;
 462
 463     if (is_group_key_set)
 464     {
 465       server_key= master_server_key;
 466     }
 467     else
 468     {
 469       server_key= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 470     }
 471
 472     memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, server_key);
 473
 474     if (memcached_server_response_count(instance) == 0)
 475     {
 476       rc= memcached_connect(instance);
 477       if (memcached_failed(rc))
 478       {
 479         continue;
 480       }
 481     }
 482
 483     protocol_binary_request_getk request= { }; //= {.bytes= {0}};
 484     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 485     if (mget_mode)
 486       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETKQ;
 487     else
 488       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETK;
 489
 490     memcached_return_t vk;
 491     vk= memcached_validate_key_length(key_length[x],
 492                                       ptr->flags.binary_protocol);
 493     unlikely (vk != MEMCACHED_SUCCESS)
 494     {
 495       if (x > 0)
 496       {
 497         memcached_io_reset(instance);
 498       }
 499
 500       return vk;
 501     }
 502
 503     request.message.header.request.keylen= htons((uint16_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 504     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 505     request.message.header.request.bodylen= htonl((uint32_t)( key_length[x] + memcached_array_size(ptr->_namespace)));
 506
 507     struct libmemcached_io_vector_st vector[]=
 508     {
 509       { request.bytes, sizeof(request.bytes) },
 510       { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 511       { keys[x], key_length[x] }
 512     };
 513
 514     if (memcached_io_writev(instance, vector, 3, flush) == -1)
 515     {
 516       memcached_server_response_reset(instance);
 517       rc= MEMCACHED_SOME_ERRORS;
 518       continue;
 519     }
 520
 521     /* We just want one pending response per server */
 522     memcached_server_response_reset(instance);
 523     memcached_server_response_increment(instance);
 524     if ((x > 0 && x == ptr->io_key_prefetch) && memcached_flush_buffers(ptr) != MEMCACHED_SUCCESS)
 525     {
 526       rc= MEMCACHED_SOME_ERRORS;
 527     }
 528   }
 529
 530   if (mget_mode)
 531   {
 532     /*
 533       Send a noop command to flush the buffers
 534     */
 535     protocol_binary_request_noop request= {}; //= {.bytes= {0}};
 536     request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 537     request.message.header.request.opcode= PROTOCOL_BINARY_CMD_NOOP;
 538     request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 539
 540     for (uint32_t x= 0; x < memcached_server_count(ptr); ++x)
 541     {
 542       memcached_server_write_instance_st instance=
 543         memcached_server_instance_fetch(ptr, x);
 544
 545       if (memcached_server_response_count(instance))
 546       {
 547         if (memcached_io_write(instance, NULL, 0, true) == -1)
 548         {
 549           memcached_server_response_reset(instance);
 550           memcached_io_reset(instance);
 551           rc= MEMCACHED_SOME_ERRORS;
 552         }
 553
 554         if (memcached_io_write(instance, request.bytes,
 555                                sizeof(request.bytes), true) == -1)
 556         {
 557           memcached_server_response_reset(instance);
 558           memcached_io_reset(instance);
 559           rc= MEMCACHED_SOME_ERRORS;
 560         }
 561       }
 562     }
 563   }
 564
 565
 566   return rc;
 567 }
 568
 569 static memcached_return_t replication_binary_mget(memcached_st *ptr,
 570                                                   uint32_t* hash,
 571                                                   bool* dead_servers,
 572                                                   const char *const *keys,
 573                                                   const size_t *key_length,
 574                                                   size_t number_of_keys)
 575 {
 576   memcached_return_t rc= MEMCACHED_NOTFOUND;
 577   uint32_t start= 0;
 578   uint64_t randomize_read= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ);
 579
 580   if (randomize_read)
 581     start= (uint32_t)random() % (uint32_t)(ptr->number_of_replicas + 1);
 582
 583   /* Loop for each replica */
 584   for (uint32_t replica= 0; replica <= ptr->number_of_replicas; ++replica)
 585   {
 586     bool success= true;
 587
 588     for (uint32_t x= 0; x < number_of_keys; ++x)
 589     {
 590       if (hash[x] == memcached_server_count(ptr))
 591         continue; /* Already successfully sent */
 592
 593       uint32_t server= hash[x] + replica;
 594
 595       /* In case of randomized reads */
 596       if (randomize_read && ((server + start) <= (hash[x] + ptr->number_of_replicas)))
 597         server += start;
 598
 599       while (server >= memcached_server_count(ptr))
 600       {
 601         server -= memcached_server_count(ptr);
 602       }
 603
 604       if (dead_servers[server])
 605       {
 606         continue;
 607       }
 608
 609       memcached_server_write_instance_st instance= memcached_server_instance_fetch(ptr, server);
 610
 611       if (memcached_server_response_count(instance) == 0)
 612       {
 613         rc= memcached_connect(instance);
 614
 615         if (memcached_failed(rc))
 616         {
 617           memcached_io_reset(instance);
 618           dead_servers[server]= true;
 619           success= false;
 620           continue;
 621         }
 622       }
 623
 624       protocol_binary_request_getk request= {};
 625       request.message.header.request.magic= PROTOCOL_BINARY_REQ;
 626       request.message.header.request.opcode= PROTOCOL_BINARY_CMD_GETK;
 627       request.message.header.request.keylen= htons((uint16_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 628       request.message.header.request.datatype= PROTOCOL_BINARY_RAW_BYTES;
 629       request.message.header.request.bodylen= htonl((uint32_t)(key_length[x] + memcached_array_size(ptr->_namespace)));
 630
 631       /*
 632        * We need to disable buffering to actually know that the request was
 633        * successfully sent to the server (so that we should expect a result
 634        * back). It would be nice to do this in buffered mode, but then it
 635        * would be complex to handle all error situations if we got to send
 636        * some of the messages, and then we failed on writing out some others
 637        * and we used the callback interface from memcached_mget_execute so
 638        * that we might have processed some of the responses etc. For now,
 639        * just make sure we work _correctly_
 640      */
 641       struct libmemcached_io_vector_st vector[]=
 642       {
 643         { request.bytes, sizeof(request.bytes) },
 644         { memcached_array_string(ptr->_namespace), memcached_array_size(ptr->_namespace) },
 645         { keys[x], key_length[x] }
 646       };
 647
 648       if (memcached_io_writev(instance, vector, 3, true) == -1)
 649       {
 650         memcached_io_reset(instance);
 651         dead_servers[server]= true;
 652         success= false;
 653         continue;
 654       }
 655
 656       memcached_server_response_increment(instance);
 657       hash[x]= memcached_server_count(ptr);
 658     }
 659
 660     if (success)
 661     {
 662       break;
 663     }
 664   }
 665
 666   return rc;
 667 }
 668
 669 static memcached_return_t binary_mget_by_key(memcached_st *ptr,
 670                                              uint32_t master_server_key,
 671                                              bool is_group_key_set,
 672                                              const char * const *keys,
 673                                              const size_t *key_length,
 674                                              size_t number_of_keys,
 675                                              bool mget_mode)
 676 {
 677   if (ptr->number_of_replicas == 0)
 678   {
 679     return simple_binary_mget(ptr, master_server_key, is_group_key_set,
 680                               keys, key_length, number_of_keys, mget_mode);
 681   }
 682
 683   uint32_t* hash= libmemcached_xvalloc(ptr, number_of_keys, uint32_t);
 684   bool* dead_servers= libmemcached_xcalloc(ptr, memcached_server_count(ptr), bool);
 685
 686   if (hash == NULL || dead_servers == NULL)
 687   {
 688     libmemcached_free(ptr, hash);
 689     libmemcached_free(ptr, dead_servers);
 690     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 691   }
 692
 693   if (is_group_key_set)
 694   {
 695     for (size_t x= 0; x < number_of_keys; x++)
 696     {
 697       hash[x]= master_server_key;
 698     }
 699   }
 700   else
 701   {
 702     for (size_t x= 0; x < number_of_keys; x++)
 703     {
 704       hash[x]= memcached_generate_hash_with_redistribution(ptr, keys[x], key_length[x]);
 705     }
 706   }
 707
 708   memcached_return_t rc= replication_binary_mget(ptr, hash, dead_servers, keys,
 709                                                  key_length, number_of_keys);
 710
 711   WATCHPOINT_IFERROR(rc);
 712   libmemcached_free(ptr, hash);
 713   libmemcached_free(ptr, dead_servers);
 714
 715   return MEMCACHED_SUCCESS;
 716 }