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

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