git.m6w6.name Git - m6w6/libmemcached/blob - libmemcached/memcached_hosts.c

   1 #include "common.h"
   2 #include <math.h>
   3
   4 /* Protoypes (static) */
   5 static memcached_return_t server_add(memcached_st *ptr, const char *hostname,
   6                                      in_port_t port,
   7                                      uint32_t weight,
   8                                      memcached_connection_t type);
   9 memcached_return_t update_continuum(memcached_st *ptr);
  10
  11 static int compare_servers(const void *p1, const void *p2)
  12 {
  13   int return_value;
  14   memcached_server_st *a= (memcached_server_st *)p1;
  15   memcached_server_st *b= (memcached_server_st *)p2;
  16
  17   return_value= strcmp(a->hostname, b->hostname);
  18
  19   if (return_value == 0)
  20   {
  21     return_value= (int) (a->port - b->port);
  22   }
  23
  24   return return_value;
  25 }
  26
  27 static void sort_hosts(memcached_st *ptr)
  28 {
  29   if (ptr->number_of_hosts)
  30   {
  31     qsort(ptr->hosts, ptr->number_of_hosts, sizeof(memcached_server_st), compare_servers);
  32     ptr->hosts[0].count= (uint16_t) ptr->number_of_hosts;
  33   }
  34 }
  35
  36
  37 memcached_return_t run_distribution(memcached_st *ptr)
  38 {
  39   switch (ptr->distribution)
  40   {
  41   case MEMCACHED_DISTRIBUTION_CONSISTENT:
  42   case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA:
  43   case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY:
  44     return update_continuum(ptr);
  45   case MEMCACHED_DISTRIBUTION_MODULA:
  46     if (ptr->flags.use_sort_hosts)
  47       sort_hosts(ptr);
  48     break;
  49   case MEMCACHED_DISTRIBUTION_RANDOM:
  50     break;
  51   default:
  52     WATCHPOINT_ASSERT(0); /* We have added a distribution without extending the logic */
  53   }
  54
  55   ptr->last_disconnected_server = NULL;
  56
  57   return MEMCACHED_SUCCESS;
  58 }
  59
  60 void server_list_free(memcached_st *ptr, memcached_server_st *servers)
  61 {
  62   unsigned int x;
  63
  64   if (servers == NULL)
  65     return;
  66
  67   for (x= 0; x < servers->count; x++)
  68     if (servers[x].address_info)
  69     {
  70       freeaddrinfo(servers[x].address_info);
  71       servers[x].address_info= NULL;
  72     }
  73
  74   if (ptr)
  75     ptr->call_free(ptr, servers);
  76   else
  77     free(servers);
  78 }
  79
  80 static uint32_t ketama_server_hash(const char *key, unsigned int key_length, int alignment)
  81 {
  82   unsigned char results[16];
  83
  84   md5_signature((unsigned char*)key, key_length, results);
  85   return ((uint32_t) (results[3 + alignment * 4] & 0xFF) << 24)
  86     | ((uint32_t) (results[2 + alignment * 4] & 0xFF) << 16)
  87     | ((uint32_t) (results[1 + alignment * 4] & 0xFF) << 8)
  88     | (results[0 + alignment * 4] & 0xFF);
  89 }
  90
  91 static int continuum_item_cmp(const void *t1, const void *t2)
  92 {
  93   memcached_continuum_item_st *ct1= (memcached_continuum_item_st *)t1;
  94   memcached_continuum_item_st *ct2= (memcached_continuum_item_st *)t2;
  95
  96   /* Why 153? Hmmm... */
  97   WATCHPOINT_ASSERT(ct1->value != 153);
  98   if (ct1->value == ct2->value)
  99     return 0;
 100   else if (ct1->value > ct2->value)
 101     return 1;
 102   else
 103     return -1;
 104 }
 105
 106 memcached_return_t update_continuum(memcached_st *ptr)
 107 {
 108   uint32_t host_index;
 109   uint32_t continuum_index= 0;
 110   uint32_t value;
 111   memcached_server_st *list;
 112   uint32_t pointer_index;
 113   uint32_t pointer_counter= 0;
 114   uint32_t pointer_per_server= MEMCACHED_POINTS_PER_SERVER;
 115   uint32_t pointer_per_hash= 1;
 116   uint64_t total_weight= 0;
 117   uint64_t is_ketama_weighted= 0;
 118   uint64_t is_auto_ejecting= 0;
 119   uint32_t points_per_server= 0;
 120   uint32_t live_servers= 0;
 121   struct timeval now;
 122
 123   if (gettimeofday(&now, NULL) != 0)
 124   {
 125     ptr->cached_errno = errno;
 126     return MEMCACHED_ERRNO;
 127   }
 128
 129   list = ptr->hosts;
 130
 131   /* count live servers (those without a retry delay set) */
 132   is_auto_ejecting= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_AUTO_EJECT_HOSTS);
 133   if (is_auto_ejecting)
 134   {
 135     live_servers= 0;
 136     ptr->next_distribution_rebuild= 0;
 137     for (host_index= 0; host_index < ptr->number_of_hosts; ++host_index)
 138     {
 139       if (list[host_index].next_retry <= now.tv_sec)
 140         live_servers++;
 141       else
 142       {
 143         if (ptr->next_distribution_rebuild == 0 || list[host_index].next_retry < ptr->next_distribution_rebuild)
 144           ptr->next_distribution_rebuild= list[host_index].next_retry;
 145       }
 146     }
 147   }
 148   else
 149     live_servers= ptr->number_of_hosts;
 150
 151   is_ketama_weighted= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED);
 152   points_per_server= (uint32_t) (is_ketama_weighted ? MEMCACHED_POINTS_PER_SERVER_KETAMA : MEMCACHED_POINTS_PER_SERVER);
 153
 154   if (live_servers == 0)
 155     return MEMCACHED_SUCCESS;
 156
 157   if (live_servers > ptr->continuum_count)
 158   {
 159     memcached_continuum_item_st *new_ptr;
 160
 161     new_ptr= ptr->call_realloc(ptr, ptr->continuum,
 162                                sizeof(memcached_continuum_item_st) * (live_servers + MEMCACHED_CONTINUUM_ADDITION) * points_per_server);
 163
 164     if (new_ptr == 0)
 165       return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 166
 167     ptr->continuum= new_ptr;
 168     ptr->continuum_count= live_servers + MEMCACHED_CONTINUUM_ADDITION;
 169   }
 170
 171   if (is_ketama_weighted)
 172   {
 173     for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
 174     {
 175       if (list[host_index].weight == 0)
 176       {
 177         list[host_index].weight = 1;
 178       }
 179       if (!is_auto_ejecting || list[host_index].next_retry <= now.tv_sec)
 180         total_weight += list[host_index].weight;
 181     }
 182   }
 183
 184   for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
 185   {
 186     if (is_auto_ejecting && list[host_index].next_retry > now.tv_sec)
 187       continue;
 188
 189     if (is_ketama_weighted)
 190     {
 191         float pct = (float)list[host_index].weight / (float)total_weight;
 192         pointer_per_server= (uint32_t) ((floorf((float) (pct * MEMCACHED_POINTS_PER_SERVER_KETAMA / 4 * (float)live_servers + 0.0000000001))) * 4);
 193         pointer_per_hash= 4;
 194 #ifdef DEBUG
 195         printf("ketama_weighted:%s|%d|%llu|%u\n",
 196                list[host_index].hostname,
 197                list[host_index].port,
 198                (unsigned long long)list[host_index].weight,
 199                pointer_per_server);
 200 #endif
 201     }
 202
 203
 204     if (ptr->distribution == MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY)
 205     {
 206       for (pointer_index= 0;
 207            pointer_index < pointer_per_server / pointer_per_hash;
 208            pointer_index++)
 209       {
 210         char sort_host[MEMCACHED_MAX_HOST_SORT_LENGTH]= "";
 211         size_t sort_host_length;
 212
 213         // Spymemcached ketema key format is: hostname/ip:port-index
 214         // If hostname is not available then: /ip:port-index
 215         sort_host_length= (size_t) snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH,
 216                                             "/%s:%d-%d",
 217                                             list[host_index].hostname,
 218                                             list[host_index].port,
 219                                             pointer_index);
 220 #ifdef DEBUG
 221         printf("update_continuum: key is %s\n", sort_host);
 222 #endif
 223
 224         WATCHPOINT_ASSERT(sort_host_length);
 225
 226         if (is_ketama_weighted)
 227         {
 228           unsigned int i;
 229           for (i = 0; i < pointer_per_hash; i++)
 230           {
 231              value= ketama_server_hash(sort_host, (uint32_t) sort_host_length, (int) i);
 232              ptr->continuum[continuum_index].index= host_index;
 233              ptr->continuum[continuum_index++].value= value;
 234           }
 235         }
 236         else
 237         {
 238           value= memcached_generate_hash_value(sort_host, sort_host_length, ptr->hash_continuum);
 239           ptr->continuum[continuum_index].index= host_index;
 240           ptr->continuum[continuum_index++].value= value;
 241         }
 242       }
 243     }
 244     else
 245     {
 246       for (pointer_index= 1;
 247            pointer_index <= pointer_per_server / pointer_per_hash;
 248            pointer_index++)
 249       {
 250         char sort_host[MEMCACHED_MAX_HOST_SORT_LENGTH]= "";
 251         size_t sort_host_length;
 252
 253         if (list[host_index].port == MEMCACHED_DEFAULT_PORT)
 254         {
 255           sort_host_length= (size_t) snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH,
 256                                               "%s-%d",
 257                                               list[host_index].hostname,
 258                                               pointer_index - 1);
 259         }
 260         else
 261         {
 262           sort_host_length= (size_t) snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH,
 263                                               "%s:%d-%d",
 264                                               list[host_index].hostname,
 265                                               list[host_index].port, pointer_index - 1);
 266         }
 267
 268         WATCHPOINT_ASSERT(sort_host_length);
 269
 270         if (is_ketama_weighted)
 271         {
 272           unsigned int i;
 273           for (i = 0; i < pointer_per_hash; i++)
 274           {
 275              value= ketama_server_hash(sort_host, (uint32_t) sort_host_length, (int) i);
 276              ptr->continuum[continuum_index].index= host_index;
 277              ptr->continuum[continuum_index++].value= value;
 278           }
 279         }
 280         else
 281         {
 282           value= memcached_generate_hash_value(sort_host, sort_host_length, ptr->hash_continuum);
 283           ptr->continuum[continuum_index].index= host_index;
 284           ptr->continuum[continuum_index++].value= value;
 285         }
 286       }
 287     }
 288
 289     pointer_counter+= pointer_per_server;
 290   }
 291
 292   WATCHPOINT_ASSERT(ptr);
 293   WATCHPOINT_ASSERT(ptr->continuum);
 294   WATCHPOINT_ASSERT(ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER <= MEMCACHED_CONTINUUM_SIZE);
 295   ptr->continuum_points_counter= pointer_counter;
 296   qsort(ptr->continuum, ptr->continuum_points_counter, sizeof(memcached_continuum_item_st), continuum_item_cmp);
 297
 298 #ifdef DEBUG
 299   for (pointer_index= 0; ptr->number_of_hosts && pointer_index < ((live_servers * MEMCACHED_POINTS_PER_SERVER) - 1); pointer_index++)
 300   {
 301     WATCHPOINT_ASSERT(ptr->continuum[pointer_index].value <= ptr->continuum[pointer_index + 1].value);
 302   }
 303 #endif
 304
 305   return MEMCACHED_SUCCESS;
 306 }
 307
 308
 309 memcached_return_t memcached_server_push(memcached_st *ptr, memcached_server_st *list)
 310 {
 311   unsigned int x;
 312   uint16_t count;
 313   memcached_server_st *new_host_list;
 314
 315   if (!list)
 316     return MEMCACHED_SUCCESS;
 317
 318   count= list[0].count;
 319   new_host_list= ptr->call_realloc(ptr, ptr->hosts,
 320                                    sizeof(memcached_server_st) * (count + ptr->number_of_hosts));
 321
 322   if (!new_host_list)
 323     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 324
 325   ptr->hosts= new_host_list;
 326
 327   for (x= 0; x < count; x++)
 328   {
 329     if ((ptr->flags.use_udp && list[x].type != MEMCACHED_CONNECTION_UDP)
 330             || ((list[x].type == MEMCACHED_CONNECTION_UDP)
 331             && ! (ptr->flags.use_udp)) )
 332       return MEMCACHED_INVALID_HOST_PROTOCOL;
 333
 334     WATCHPOINT_ASSERT(list[x].hostname[0] != 0);
 335     memcached_server_create(ptr, &ptr->hosts[ptr->number_of_hosts]);
 336     /* TODO check return type */
 337     (void)memcached_server_create_with(ptr, &ptr->hosts[ptr->number_of_hosts], list[x].hostname,
 338                                        list[x].port, list[x].weight, list[x].type);
 339     ptr->number_of_hosts++;
 340   }
 341   ptr->hosts[0].count= (uint16_t) ptr->number_of_hosts;
 342
 343   return run_distribution(ptr);
 344 }
 345
 346 memcached_return_t memcached_server_add_unix_socket(memcached_st *ptr,
 347                                                     const char *filename)
 348 {
 349   return memcached_server_add_unix_socket_with_weight(ptr, filename, 0);
 350 }
 351
 352 memcached_return_t memcached_server_add_unix_socket_with_weight(memcached_st *ptr,
 353                                                                 const char *filename,
 354                                                                 uint32_t weight)
 355 {
 356   if (!filename)
 357     return MEMCACHED_FAILURE;
 358
 359   return server_add(ptr, filename, 0, weight, MEMCACHED_CONNECTION_UNIX_SOCKET);
 360 }
 361
 362 memcached_return_t memcached_server_add_udp(memcached_st *ptr,
 363                                             const char *hostname,
 364                                             in_port_t port)
 365 {
 366   return memcached_server_add_udp_with_weight(ptr, hostname, port, 0);
 367 }
 368
 369 memcached_return_t memcached_server_add_udp_with_weight(memcached_st *ptr,
 370                                                         const char *hostname,
 371                                                         in_port_t port,
 372                                                         uint32_t weight)
 373 {
 374   if (!port)
 375     port= MEMCACHED_DEFAULT_PORT;
 376
 377   if (!hostname)
 378     hostname= "localhost";
 379
 380   return server_add(ptr, hostname, port, weight, MEMCACHED_CONNECTION_UDP);
 381 }
 382
 383 memcached_return_t memcached_server_add(memcached_st *ptr,
 384                                         const char *hostname,
 385                                         in_port_t port)
 386 {
 387   return memcached_server_add_with_weight(ptr, hostname, port, 0);
 388 }
 389
 390 memcached_return_t memcached_server_add_with_weight(memcached_st *ptr,
 391                                                     const char *hostname,
 392                                                     in_port_t port,
 393                                                     uint32_t weight)
 394 {
 395   if (!port)
 396     port= MEMCACHED_DEFAULT_PORT;
 397
 398   if (!hostname)
 399     hostname= "localhost";
 400
 401   return server_add(ptr, hostname, port, weight, MEMCACHED_CONNECTION_TCP);
 402 }
 403
 404 static memcached_return_t server_add(memcached_st *ptr, const char *hostname,
 405                                      in_port_t port,
 406                                      uint32_t weight,
 407                                      memcached_connection_t type)
 408 {
 409   memcached_server_st *new_host_list;
 410
 411   if ( (ptr->flags.use_udp && type != MEMCACHED_CONNECTION_UDP)
 412       || ( (type == MEMCACHED_CONNECTION_UDP) && (! ptr->flags.use_udp) ) )
 413     return MEMCACHED_INVALID_HOST_PROTOCOL;
 414
 415   new_host_list= ptr->call_realloc(ptr, ptr->hosts,
 416                                    sizeof(memcached_server_st) * (ptr->number_of_hosts+1));
 417
 418   if (new_host_list == NULL)
 419     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 420
 421   ptr->hosts= new_host_list;
 422
 423   /* TODO: Check return type */
 424   (void)memcached_server_create_with(ptr, &ptr->hosts[ptr->number_of_hosts], hostname, port, weight, type);
 425   ptr->number_of_hosts++;
 426   ptr->hosts[0].count= (uint16_t) ptr->number_of_hosts;
 427
 428   return run_distribution(ptr);
 429 }
 430
 431 memcached_return_t memcached_server_remove(memcached_server_st *st_ptr)
 432 {
 433   uint32_t x, host_index;
 434   memcached_st *ptr= st_ptr->root;
 435   memcached_server_st *list= ptr->hosts;
 436
 437   for (x= 0, host_index= 0; x < ptr->number_of_hosts; x++)
 438   {
 439     if (strncmp(list[x].hostname, st_ptr->hostname, MEMCACHED_MAX_HOST_LENGTH) != 0 || list[x].port != st_ptr->port)
 440     {
 441       if (host_index != x)
 442         memcpy(list+host_index, list+x, sizeof(memcached_server_st));
 443       host_index++;
 444     }
 445   }
 446   ptr->number_of_hosts= host_index;
 447
 448   if (st_ptr->address_info)
 449   {
 450     freeaddrinfo(st_ptr->address_info);
 451     st_ptr->address_info= NULL;
 452   }
 453   run_distribution(ptr);
 454
 455   return MEMCACHED_SUCCESS;
 456 }
 457
 458 memcached_server_st *memcached_server_list_append(memcached_server_st *ptr,
 459                                                   const char *hostname, in_port_t port,
 460                                                   memcached_return_t *error)
 461 {
 462   return memcached_server_list_append_with_weight(ptr, hostname, port, 0, error);
 463 }
 464
 465 memcached_server_st *memcached_server_list_append_with_weight(memcached_server_st *ptr,
 466                                                               const char *hostname, in_port_t port,
 467                                                               uint32_t weight,
 468                                                               memcached_return_t *error)
 469 {
 470   unsigned int count;
 471   memcached_server_st *new_host_list;
 472
 473   if (hostname == NULL || error == NULL)
 474     return NULL;
 475
 476   if (!port)
 477     port= MEMCACHED_DEFAULT_PORT;
 478
 479   /* Increment count for hosts */
 480   count= 1;
 481   if (ptr != NULL)
 482   {
 483     count+= ptr[0].count;
 484   }
 485
 486   new_host_list= (memcached_server_st *)realloc(ptr, sizeof(memcached_server_st) * count);
 487   if (!new_host_list)
 488   {
 489     *error= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 490     return NULL;
 491   }
 492
 493   /* TODO: Check return type */
 494   memcached_server_create_with(NULL, &new_host_list[count-1], hostname, port, weight, MEMCACHED_CONNECTION_TCP);
 495
 496   /* Backwards compatibility hack */
 497   new_host_list[0].count= (uint16_t) count;
 498
 499   *error= MEMCACHED_SUCCESS;
 500   return new_host_list;
 501 }
 502
 503 unsigned int memcached_server_list_count(memcached_server_st *ptr)
 504 {
 505   if (ptr == NULL)
 506     return 0;
 507
 508   return ptr[0].count;
 509 }
 510
 511 void memcached_server_list_free(memcached_server_st *ptr)
 512 {
 513   server_list_free(NULL, ptr);
 514 }