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 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 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   WATCHPOINT_ASSERT(ct1->value != 153);
  96   if (ct1->value == ct2->value)
  97     return 0;
  98   else if (ct1->value > ct2->value)
  99     return 1;
 100   else
 101     return -1;
 102 }
 103
 104 memcached_return update_continuum(memcached_st *ptr)
 105 {
 106   uint32_t index;
 107   uint32_t host_index;
 108   uint32_t continuum_index= 0;
 109   uint32_t value;
 110   memcached_server_st *list;
 111   uint32_t pointer_counter= 0;
 112   uint32_t pointer_per_server= MEMCACHED_POINTS_PER_SERVER;
 113   memcached_return rc;
 114   uint64_t total_mem_bytes= 0;
 115   memcached_stat_st *stat_p= NULL;
 116   uint32_t is_ketama_weighted= 0;
 117
 118   if (ptr->number_of_hosts > ptr->continuum_count)
 119   {
 120     memcached_continuum_item_st *new_ptr;
 121
 122     if (ptr->call_realloc)
 123       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);
 124     else
 125       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);
 126
 127     if (new_ptr == 0)
 128       return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 129
 130     ptr->continuum= new_ptr;
 131     ptr->continuum_count= ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION;
 132   }
 133
 134   list = ptr->hosts;
 135
 136   is_ketama_weighted= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED);
 137   if(is_ketama_weighted)
 138   {
 139     stat_p = memcached_stat(ptr, NULL, &rc);
 140     for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
 141     {
 142       list[host_index].limit_maxbytes= (stat_p + host_index)->limit_maxbytes;
 143       total_mem_bytes += (stat_p + host_index)->limit_maxbytes;
 144     }
 145   }
 146
 147   for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
 148   {
 149     if(is_ketama_weighted)
 150     {
 151         float pct = (float)list[host_index].limit_maxbytes/ (float)total_mem_bytes;
 152         pointer_per_server= floorf( pct * MEMCACHED_POINTS_PER_SERVER * (float)(ptr->number_of_hosts));
 153 #ifdef HAVE_DEBUG
 154         printf("ketama_weighted:%s|%d|%llu|%u\n", list[host_index].hostname, list[host_index].port,  list[host_index].limit_maxbytes, pointer_per_server);
 155 #endif
 156     }
 157     for(index= 1; index <= pointer_per_server; ++index)
 158     {
 159       char sort_host[MEMCACHED_MAX_HOST_SORT_LENGTH]= "";
 160       size_t sort_host_length;
 161
 162       sort_host_length= snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH, "%s:%d-%d",
 163                                  list[host_index].hostname, list[host_index].port, index);
 164       WATCHPOINT_ASSERT(sort_host_length);
 165       value= generate_hash_value(sort_host, sort_host_length, ptr->hash_continuum);
 166       ptr->continuum[continuum_index].index= host_index;
 167       ptr->continuum[continuum_index++].value= value;
 168     }
 169     pointer_counter+= pointer_per_server;
 170   }
 171
 172   WATCHPOINT_ASSERT(ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER <= MEMCACHED_CONTINUUM_SIZE);
 173   qsort(ptr->continuum, ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER, sizeof(memcached_continuum_item_st), continuum_item_cmp);
 174
 175   ptr->continuum_points_counter= pointer_counter;
 176   if (stat_p)
 177     memcached_stat_free(NULL, stat_p);
 178
 179 #ifdef HAVE_DEBUG
 180   for (index= 0; index < ((ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER) - 1); index++)
 181   {
 182     WATCHPOINT_ASSERT(ptr->continuum[index].value <= ptr->continuum[index + 1].value);
 183   }
 184 #endif
 185
 186   return MEMCACHED_SUCCESS;
 187 }
 188
 189
 190 memcached_return memcached_server_push(memcached_st *ptr, memcached_server_st *list)
 191 {
 192   unsigned int x;
 193   uint16_t count;
 194   memcached_server_st *new_host_list;
 195
 196   if (!list)
 197     return MEMCACHED_SUCCESS;
 198
 199   count= list[0].count;
 200
 201   if (ptr->call_realloc)
 202     new_host_list=
 203       (memcached_server_st *)ptr->call_realloc(ptr, ptr->hosts,
 204                                                sizeof(memcached_server_st) * (count + ptr->number_of_hosts));
 205   else
 206     new_host_list=
 207       (memcached_server_st *)realloc(ptr->hosts,
 208                                      sizeof(memcached_server_st) * (count + ptr->number_of_hosts));
 209
 210   if (!new_host_list)
 211     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 212
 213   ptr->hosts= new_host_list;
 214
 215   for (x= 0; x < count; x++)
 216   {
 217     WATCHPOINT_ASSERT(list[x].hostname[0] != 0);
 218     host_reset(ptr, &ptr->hosts[ptr->number_of_hosts], list[x].hostname,
 219                list[x].port, list[x].type);
 220     ptr->number_of_hosts++;
 221   }
 222   ptr->hosts[0].count= ptr->number_of_hosts;
 223
 224   return run_distribution(ptr);
 225 }
 226
 227 memcached_return memcached_server_add_unix_socket(memcached_st *ptr, char *filename)
 228 {
 229   if (!filename)
 230     return MEMCACHED_FAILURE;
 231
 232   return server_add(ptr, filename, 0, MEMCACHED_CONNECTION_UNIX_SOCKET);
 233 }
 234
 235 memcached_return memcached_server_add_udp(memcached_st *ptr,
 236                                           char *hostname,
 237                                           unsigned int port)
 238 {
 239   if (!port)
 240     port= MEMCACHED_DEFAULT_PORT;
 241
 242   if (!hostname)
 243     hostname= "localhost";
 244
 245   return server_add(ptr, hostname, port, MEMCACHED_CONNECTION_UDP);
 246 }
 247
 248 memcached_return memcached_server_add(memcached_st *ptr,
 249                                       char *hostname,
 250                                       unsigned int port)
 251 {
 252   if (!port)
 253     port= MEMCACHED_DEFAULT_PORT;
 254
 255   if (!hostname)
 256     hostname= "localhost";
 257
 258   return server_add(ptr, hostname, port, MEMCACHED_CONNECTION_TCP);
 259 }
 260
 261 static memcached_return server_add(memcached_st *ptr, char *hostname,
 262                                    unsigned int port,
 263                                    memcached_connection type)
 264 {
 265   memcached_server_st *new_host_list;
 266
 267   if (ptr->call_realloc)
 268     new_host_list= (memcached_server_st *)ptr->call_realloc(ptr, ptr->hosts,
 269                                                             sizeof(memcached_server_st) * (ptr->number_of_hosts+1));
 270   else
 271     new_host_list= (memcached_server_st *)realloc(ptr->hosts,
 272                                                   sizeof(memcached_server_st) * (ptr->number_of_hosts+1));
 273   if (new_host_list == NULL)
 274     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 275
 276   ptr->hosts= new_host_list;
 277
 278   host_reset(ptr, &ptr->hosts[ptr->number_of_hosts], hostname, port, type);
 279   ptr->number_of_hosts++;
 280   ptr->hosts[0].count= ptr->number_of_hosts;
 281
 282   return run_distribution(ptr);
 283 }
 284
 285 memcached_return memcached_server_remove(memcached_server_st *st_ptr)
 286 {
 287   uint32_t x, index;
 288   memcached_st *ptr= st_ptr->root;
 289   memcached_server_st *list= ptr->hosts;
 290
 291   for (x= 0, index= 0; x < ptr->number_of_hosts; x++)
 292   {
 293     if (strncmp(list[x].hostname, st_ptr->hostname, MEMCACHED_MAX_HOST_LENGTH)!=0 || list[x].port != st_ptr->port)
 294     {
 295       memcpy(list+index, list+x, sizeof(memcached_server_st));
 296       index++;
 297     }
 298     else
 299     {
 300       ptr->number_of_hosts--;
 301     }
 302   }
 303
 304
 305   if (st_ptr->address_info)
 306     freeaddrinfo(st_ptr->address_info);
 307   run_distribution(ptr);
 308
 309   return MEMCACHED_SUCCESS;
 310 }
 311
 312 memcached_server_st *memcached_server_list_append(memcached_server_st *ptr,
 313                                                   char *hostname, unsigned int port,
 314                                                   memcached_return *error)
 315 {
 316   unsigned int count;
 317   memcached_server_st *new_host_list;
 318
 319   if (hostname == NULL || error == NULL)
 320     return NULL;
 321
 322   if (!port)
 323     port= MEMCACHED_DEFAULT_PORT;
 324
 325   /* Increment count for hosts */
 326   count= 1;
 327   if (ptr != NULL)
 328   {
 329     count+= ptr[0].count;
 330   }
 331
 332   new_host_list= (memcached_server_st *)realloc(ptr, sizeof(memcached_server_st) * count);
 333   if (!new_host_list)
 334   {
 335     *error= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 336     return NULL;
 337   }
 338
 339   host_reset(NULL, &new_host_list[count-1], hostname, port, MEMCACHED_CONNECTION_TCP);
 340
 341   /* Backwards compatibility hack */
 342   new_host_list[0].count= count;
 343
 344   *error= MEMCACHED_SUCCESS;
 345   return new_host_list;
 346 }
 347
 348 unsigned int memcached_server_list_count(memcached_server_st *ptr)
 349 {
 350   if (ptr == NULL)
 351     return 0;
 352
 353   return ptr[0].count;
 354 }
 355
 356 void memcached_server_list_free(memcached_server_st *ptr)
 357 {
 358   server_list_free(NULL, ptr);
 359 }