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, char *hostname,
   6                                    unsigned int port,
   7                                    memcached_connection type);
   8 memcached_return update_continuum(memcached_st *ptr);
   9
  10 static int compare_servers(const void *p1, const void *p2)
  11 {
  12   int return_value;
  13   memcached_server_st *a= (memcached_server_st *)p1;
  14   memcached_server_st *b= (memcached_server_st *)p2;
  15
  16   return_value= strcmp(a->hostname, b->hostname);
  17
  18   if (return_value == 0)
  19   {
  20     return_value= (int) (a->port - b->port);
  21   }
  22
  23   return return_value;
  24 }
  25
  26 static void sort_hosts(memcached_st *ptr)
  27 {
  28   if (ptr->number_of_hosts)
  29   {
  30     qsort(ptr->hosts, ptr->number_of_hosts, sizeof(memcached_server_st), compare_servers);
  31     ptr->hosts[0].count= ptr->number_of_hosts;
  32   }
  33 }
  34
  35
  36 memcached_return run_distribution(memcached_st *ptr)
  37 {
  38   switch (ptr->distribution)
  39   {
  40   case MEMCACHED_DISTRIBUTION_CONSISTENT:
  41   case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA:
  42     return update_continuum(ptr);
  43   case MEMCACHED_DISTRIBUTION_MODULA:
  44     if (ptr->flags & MEM_USE_SORT_HOSTS)
  45       sort_hosts(ptr);
  46     break;
  47   default:
  48     WATCHPOINT_ASSERT(0); /* We have added a distribution without extending the logic */
  49   }
  50
  51   return MEMCACHED_SUCCESS;
  52 }
  53
  54 static void host_reset(memcached_st *ptr, memcached_server_st *host,
  55                        char *hostname, unsigned int port,
  56                        memcached_connection type)
  57 {
  58   memset(host,  0, sizeof(memcached_server_st));
  59   strncpy(host->hostname, hostname, MEMCACHED_MAX_HOST_LENGTH - 1);
  60   host->root= ptr ? ptr : NULL;
  61   host->port= port;
  62   host->fd= -1;
  63   host->type= type;
  64   host->read_ptr= host->read_buffer;
  65   if (ptr)
  66     host->next_retry= ptr->retry_timeout;
  67   host->sockaddr_inited= MEMCACHED_NOT_ALLOCATED;
  68 }
  69
  70 void server_list_free(memcached_st *ptr, memcached_server_st *servers)
  71 {
  72   unsigned int x;
  73
  74   if (servers == NULL)
  75     return;
  76
  77   for (x= 0; x < servers->count; x++)
  78     if (servers[x].address_info)
  79     {
  80       freeaddrinfo(servers[x].address_info);
  81       servers[x].address_info= NULL;
  82     }
  83
  84   if (ptr && ptr->call_free)
  85     ptr->call_free(ptr, servers);
  86   else
  87     free(servers);
  88 }
  89
  90 static int continuum_item_cmp(const void *t1, const void *t2)
  91 {
  92   memcached_continuum_item_st *ct1= (memcached_continuum_item_st *)t1;
  93   memcached_continuum_item_st *ct2= (memcached_continuum_item_st *)t2;
  94
  95   /* Why 153? Hmmm... */
  96   WATCHPOINT_ASSERT(ct1->value != 153);
  97   if (ct1->value == ct2->value)
  98     return 0;
  99   else if (ct1->value > ct2->value)
 100     return 1;
 101   else
 102     return -1;
 103 }
 104
 105 memcached_return update_continuum(memcached_st *ptr)
 106 {
 107   uint32_t index;
 108   uint32_t host_index;
 109   uint32_t continuum_index= 0;
 110   uint32_t value;
 111   memcached_server_st *list;
 112   uint32_t pointer_counter= 0;
 113   uint32_t pointer_per_server= MEMCACHED_POINTS_PER_SERVER;
 114   memcached_return rc;
 115   uint64_t total_mem_bytes= 0;
 116   memcached_stat_st *stat_p= NULL;
 117   uint32_t is_ketama_weighted= 0;
 118
 119   if (ptr->number_of_hosts > ptr->continuum_count)
 120   {
 121     memcached_continuum_item_st *new_ptr;
 122
 123     if (ptr->call_realloc)
 124       new_ptr= (memcached_continuum_item_st *)ptr->call_realloc(ptr, ptr->continuum, sizeof(memcached_continuum_item_st) * (ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION) * MEMCACHED_POINTS_PER_SERVER);
 125     else
 126       new_ptr= (memcached_continuum_item_st *)realloc(ptr->continuum, sizeof(memcached_continuum_item_st) * (ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION) * MEMCACHED_POINTS_PER_SERVER);
 127
 128     if (new_ptr == 0)
 129       return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 130
 131     ptr->continuum= new_ptr;
 132     ptr->continuum_count= ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION;
 133   }
 134
 135   list = ptr->hosts;
 136
 137   is_ketama_weighted= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED);
 138   if(is_ketama_weighted)
 139   {
 140     stat_p = memcached_stat(ptr, NULL, &rc);
 141     for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
 142     {
 143       list[host_index].limit_maxbytes= (stat_p + host_index)->limit_maxbytes;
 144       total_mem_bytes += (stat_p + host_index)->limit_maxbytes;
 145     }
 146   }
 147
 148   for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
 149   {
 150     if(is_ketama_weighted)
 151     {
 152         float pct = (float)list[host_index].limit_maxbytes/ (float)total_mem_bytes;
 153         pointer_per_server= floorf( pct * MEMCACHED_POINTS_PER_SERVER * (float)(ptr->number_of_hosts));
 154 #ifdef HAVE_DEBUG
 155         printf("ketama_weighted:%s|%d|%llu|%u\n", list[host_index].hostname, list[host_index].port,  list[host_index].limit_maxbytes, pointer_per_server);
 156 #endif
 157     }
 158     for(index= 1; index <= pointer_per_server; ++index)
 159     {
 160       char sort_host[MEMCACHED_MAX_HOST_SORT_LENGTH]= "";
 161       size_t sort_host_length;
 162
 163       sort_host_length= snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH, "%s:%d-%d",
 164                                  list[host_index].hostname, list[host_index].port, index);
 165       WATCHPOINT_ASSERT(sort_host_length);
 166       value= generate_hash_value(sort_host, sort_host_length, ptr->hash_continuum);
 167       ptr->continuum[continuum_index].index= host_index;
 168       ptr->continuum[continuum_index++].value= value;
 169     }
 170     pointer_counter+= pointer_per_server;
 171   }
 172
 173   WATCHPOINT_ASSERT(ptr);
 174   WATCHPOINT_ASSERT(ptr->continuum);
 175   WATCHPOINT_ASSERT(ptr->number_of_hosts);
 176   WATCHPOINT_ASSERT(ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER <= MEMCACHED_CONTINUUM_SIZE);
 177   ptr->continuum_points_counter= pointer_counter;
 178   qsort(ptr->continuum, ptr->continuum_points_counter, sizeof(memcached_continuum_item_st), continuum_item_cmp);
 179
 180   if (stat_p)
 181     memcached_stat_free(NULL, stat_p);
 182
 183 #ifdef HAVE_DEBUG
 184   for (index= 0; index < ((ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER) - 1); index++)
 185   {
 186     WATCHPOINT_ASSERT(ptr->continuum[index].value <= ptr->continuum[index + 1].value);
 187   }
 188 #endif
 189
 190   return MEMCACHED_SUCCESS;
 191 }
 192
 193
 194 memcached_return memcached_server_push(memcached_st *ptr, memcached_server_st *list)
 195 {
 196   unsigned int x;
 197   uint16_t count;
 198   memcached_server_st *new_host_list;
 199
 200   if (!list)
 201     return MEMCACHED_SUCCESS;
 202
 203   count= list[0].count;
 204
 205   if (ptr->call_realloc)
 206     new_host_list=
 207       (memcached_server_st *)ptr->call_realloc(ptr, ptr->hosts,
 208                                                sizeof(memcached_server_st) * (count + ptr->number_of_hosts));
 209   else
 210     new_host_list=
 211       (memcached_server_st *)realloc(ptr->hosts,
 212                                      sizeof(memcached_server_st) * (count + ptr->number_of_hosts));
 213
 214   if (!new_host_list)
 215     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 216
 217   ptr->hosts= new_host_list;
 218
 219   for (x= 0; x < count; x++)
 220   {
 221     WATCHPOINT_ASSERT(list[x].hostname[0] != 0);
 222     host_reset(ptr, &ptr->hosts[ptr->number_of_hosts], list[x].hostname,
 223                list[x].port, list[x].type);
 224     ptr->number_of_hosts++;
 225   }
 226   ptr->hosts[0].count= ptr->number_of_hosts;
 227
 228   return run_distribution(ptr);
 229 }
 230
 231 memcached_return memcached_server_add_unix_socket(memcached_st *ptr, char *filename)
 232 {
 233   if (!filename)
 234     return MEMCACHED_FAILURE;
 235
 236   return server_add(ptr, filename, 0, MEMCACHED_CONNECTION_UNIX_SOCKET);
 237 }
 238
 239 memcached_return memcached_server_add_udp(memcached_st *ptr,
 240                                           char *hostname,
 241                                           unsigned int port)
 242 {
 243   if (!port)
 244     port= MEMCACHED_DEFAULT_PORT;
 245
 246   if (!hostname)
 247     hostname= "localhost";
 248
 249   return server_add(ptr, hostname, port, MEMCACHED_CONNECTION_UDP);
 250 }
 251
 252 memcached_return memcached_server_add(memcached_st *ptr,
 253                                       char *hostname,
 254                                       unsigned int port)
 255 {
 256   if (!port)
 257     port= MEMCACHED_DEFAULT_PORT;
 258
 259   if (!hostname)
 260     hostname= "localhost";
 261
 262   return server_add(ptr, hostname, port, MEMCACHED_CONNECTION_TCP);
 263 }
 264
 265 static memcached_return server_add(memcached_st *ptr, char *hostname,
 266                                    unsigned int port,
 267                                    memcached_connection type)
 268 {
 269   memcached_server_st *new_host_list;
 270
 271   if (ptr->call_realloc)
 272     new_host_list= (memcached_server_st *)ptr->call_realloc(ptr, ptr->hosts,
 273                                                             sizeof(memcached_server_st) * (ptr->number_of_hosts+1));
 274   else
 275     new_host_list= (memcached_server_st *)realloc(ptr->hosts,
 276                                                   sizeof(memcached_server_st) * (ptr->number_of_hosts+1));
 277   if (new_host_list == NULL)
 278     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 279
 280   ptr->hosts= new_host_list;
 281
 282   host_reset(ptr, &ptr->hosts[ptr->number_of_hosts], hostname, port, type);
 283   ptr->number_of_hosts++;
 284   ptr->hosts[0].count= ptr->number_of_hosts;
 285
 286   return run_distribution(ptr);
 287 }
 288
 289 memcached_return memcached_server_remove(memcached_server_st *st_ptr)
 290 {
 291   uint32_t x, index;
 292   memcached_st *ptr= st_ptr->root;
 293   memcached_server_st *list= ptr->hosts;
 294
 295   for (x= 0, index= 0; x < ptr->number_of_hosts; x++)
 296   {
 297     if (strncmp(list[x].hostname, st_ptr->hostname, MEMCACHED_MAX_HOST_LENGTH)!=0 || list[x].port != st_ptr->port)
 298     {
 299       memcpy(list+index, list+x, sizeof(memcached_server_st));
 300       index++;
 301     }
 302   }
 303   ptr->number_of_hosts= index;
 304
 305   if (st_ptr->address_info)
 306   {
 307     freeaddrinfo(st_ptr->address_info);
 308     st_ptr->address_info= NULL;
 309   }
 310   run_distribution(ptr);
 311
 312   return MEMCACHED_SUCCESS;
 313 }
 314
 315 memcached_server_st *memcached_server_list_append(memcached_server_st *ptr,
 316                                                   char *hostname, unsigned int port,
 317                                                   memcached_return *error)
 318 {
 319   unsigned int count;
 320   memcached_server_st *new_host_list;
 321
 322   if (hostname == NULL || error == NULL)
 323     return NULL;
 324
 325   if (!port)
 326     port= MEMCACHED_DEFAULT_PORT;
 327
 328   /* Increment count for hosts */
 329   count= 1;
 330   if (ptr != NULL)
 331   {
 332     count+= ptr[0].count;
 333   }
 334
 335   new_host_list= (memcached_server_st *)realloc(ptr, sizeof(memcached_server_st) * count);
 336   if (!new_host_list)
 337   {
 338     *error= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 339     return NULL;
 340   }
 341
 342   host_reset(NULL, &new_host_list[count-1], hostname, port, MEMCACHED_CONNECTION_TCP);
 343
 344   /* Backwards compatibility hack */
 345   new_host_list[0].count= count;
 346
 347   *error= MEMCACHED_SUCCESS;
 348   return new_host_list;
 349 }
 350
 351 unsigned int memcached_server_list_count(memcached_server_st *ptr)
 352 {
 353   if (ptr == NULL)
 354     return 0;
 355
 356   return ptr[0].count;
 357 }
 358
 359 void memcached_server_list_free(memcached_server_st *ptr)
 360 {
 361   server_list_free(NULL, ptr);
 362 }