Small style cleanup.
[m6w6/libmemcached] / libmemcached / 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 static 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_instance_st *a= (memcached_server_instance_st *)p1;
15 memcached_server_instance_st *b= (memcached_server_instance_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 (memcached_server_count(ptr))
30 {
31 memcached_server_instance_st *instance;
32
33 qsort(memcached_server_list(ptr), memcached_server_count(ptr), sizeof(memcached_server_instance_st), compare_servers);
34 instance= memcached_server_instance_fetch(ptr, 0);
35 instance->number_of_hosts= memcached_server_count(ptr);
36 }
37 }
38
39
40 memcached_return_t run_distribution(memcached_st *ptr)
41 {
42 if (ptr->flags.use_sort_hosts)
43 sort_hosts(ptr);
44
45 switch (ptr->distribution)
46 {
47 case MEMCACHED_DISTRIBUTION_CONSISTENT:
48 case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA:
49 case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY:
50 return update_continuum(ptr);
51 case MEMCACHED_DISTRIBUTION_MODULA:
52 break;
53 case MEMCACHED_DISTRIBUTION_RANDOM:
54 srandom((uint32_t) time(NULL));
55 break;
56 case MEMCACHED_DISTRIBUTION_CONSISTENT_MAX:
57 default:
58 WATCHPOINT_ASSERT(0); /* We have added a distribution without extending the logic */
59 }
60
61 ptr->last_disconnected_server = NULL;
62
63 return MEMCACHED_SUCCESS;
64 }
65
66 static uint32_t ketama_server_hash(const char *key, unsigned int key_length, int alignment)
67 {
68 unsigned char results[16];
69
70 md5_signature((unsigned char*)key, key_length, results);
71 return ((uint32_t) (results[3 + alignment * 4] & 0xFF) << 24)
72 | ((uint32_t) (results[2 + alignment * 4] & 0xFF) << 16)
73 | ((uint32_t) (results[1 + alignment * 4] & 0xFF) << 8)
74 | (results[0 + alignment * 4] & 0xFF);
75 }
76
77 static int continuum_item_cmp(const void *t1, const void *t2)
78 {
79 memcached_continuum_item_st *ct1= (memcached_continuum_item_st *)t1;
80 memcached_continuum_item_st *ct2= (memcached_continuum_item_st *)t2;
81
82 /* Why 153? Hmmm... */
83 WATCHPOINT_ASSERT(ct1->value != 153);
84 if (ct1->value == ct2->value)
85 return 0;
86 else if (ct1->value > ct2->value)
87 return 1;
88 else
89 return -1;
90 }
91
92 static memcached_return_t update_continuum(memcached_st *ptr)
93 {
94 uint32_t host_index;
95 uint32_t continuum_index= 0;
96 uint32_t value;
97 memcached_server_instance_st *list;
98 uint32_t pointer_index;
99 uint32_t pointer_counter= 0;
100 uint32_t pointer_per_server= MEMCACHED_POINTS_PER_SERVER;
101 uint32_t pointer_per_hash= 1;
102 uint64_t total_weight= 0;
103 uint64_t is_ketama_weighted= 0;
104 uint64_t is_auto_ejecting= 0;
105 uint32_t points_per_server= 0;
106 uint32_t live_servers= 0;
107 struct timeval now;
108
109 if (gettimeofday(&now, NULL) != 0)
110 {
111 ptr->cached_errno = errno;
112 return MEMCACHED_ERRNO;
113 }
114
115 list = memcached_server_list(ptr);
116
117 /* count live servers (those without a retry delay set) */
118 is_auto_ejecting= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_AUTO_EJECT_HOSTS);
119 if (is_auto_ejecting)
120 {
121 live_servers= 0;
122 ptr->next_distribution_rebuild= 0;
123 for (host_index= 0; host_index < memcached_server_count(ptr); ++host_index)
124 {
125 if (list[host_index].next_retry <= now.tv_sec)
126 live_servers++;
127 else
128 {
129 if (ptr->next_distribution_rebuild == 0 || list[host_index].next_retry < ptr->next_distribution_rebuild)
130 ptr->next_distribution_rebuild= list[host_index].next_retry;
131 }
132 }
133 }
134 else
135 {
136 live_servers= memcached_server_count(ptr);
137 }
138
139 is_ketama_weighted= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED);
140 points_per_server= (uint32_t) (is_ketama_weighted ? MEMCACHED_POINTS_PER_SERVER_KETAMA : MEMCACHED_POINTS_PER_SERVER);
141
142 if (live_servers == 0)
143 return MEMCACHED_SUCCESS;
144
145 if (live_servers > ptr->continuum_count)
146 {
147 memcached_continuum_item_st *new_ptr;
148
149 new_ptr= ptr->call_realloc(ptr, ptr->continuum,
150 sizeof(memcached_continuum_item_st) * (live_servers + MEMCACHED_CONTINUUM_ADDITION) * points_per_server);
151
152 if (new_ptr == 0)
153 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
154
155 ptr->continuum= new_ptr;
156 ptr->continuum_count= live_servers + MEMCACHED_CONTINUUM_ADDITION;
157 }
158
159 if (is_ketama_weighted)
160 {
161 for (host_index = 0; host_index < memcached_server_count(ptr); ++host_index)
162 {
163 if (list[host_index].weight == 0)
164 {
165 list[host_index].weight = 1;
166 }
167 if (!is_auto_ejecting || list[host_index].next_retry <= now.tv_sec)
168 total_weight += list[host_index].weight;
169 }
170 }
171
172 for (host_index = 0; host_index < memcached_server_count(ptr); ++host_index)
173 {
174 if (is_auto_ejecting && list[host_index].next_retry > now.tv_sec)
175 continue;
176
177 if (is_ketama_weighted)
178 {
179 float pct = (float)list[host_index].weight / (float)total_weight;
180 pointer_per_server= (uint32_t) ((floorf((float) (pct * MEMCACHED_POINTS_PER_SERVER_KETAMA / 4 * (float)live_servers + 0.0000000001))) * 4);
181 pointer_per_hash= 4;
182 #ifdef DEBUG
183 printf("ketama_weighted:%s|%d|%llu|%u\n",
184 list[host_index].hostname,
185 list[host_index].port,
186 (unsigned long long)list[host_index].weight,
187 pointer_per_server);
188 #endif
189 }
190
191
192 if (ptr->distribution == MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY)
193 {
194 for (pointer_index= 0;
195 pointer_index < pointer_per_server / pointer_per_hash;
196 pointer_index++)
197 {
198 char sort_host[MEMCACHED_MAX_HOST_SORT_LENGTH]= "";
199 size_t sort_host_length;
200
201 // Spymemcached ketema key format is: hostname/ip:port-index
202 // If hostname is not available then: /ip:port-index
203 sort_host_length= (size_t) snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH,
204 "/%s:%u-%u",
205 list[host_index].hostname,
206 (uint32_t)list[host_index].port,
207 pointer_index);
208 #ifdef DEBUG
209 printf("update_continuum: key is %s\n", sort_host);
210 #endif
211
212 WATCHPOINT_ASSERT(sort_host_length);
213
214 if (is_ketama_weighted)
215 {
216 unsigned int i;
217 for (i = 0; i < pointer_per_hash; i++)
218 {
219 value= ketama_server_hash(sort_host, (uint32_t) sort_host_length, (int) i);
220 ptr->continuum[continuum_index].index= host_index;
221 ptr->continuum[continuum_index++].value= value;
222 }
223 }
224 else
225 {
226 value= memcached_generate_hash_value(sort_host, sort_host_length, ptr->distribution_hash);
227 ptr->continuum[continuum_index].index= host_index;
228 ptr->continuum[continuum_index++].value= value;
229 }
230 }
231 }
232 else
233 {
234 for (pointer_index= 1;
235 pointer_index <= pointer_per_server / pointer_per_hash;
236 pointer_index++)
237 {
238 char sort_host[MEMCACHED_MAX_HOST_SORT_LENGTH]= "";
239 size_t sort_host_length;
240
241 if (list[host_index].port == MEMCACHED_DEFAULT_PORT)
242 {
243 sort_host_length= (size_t) snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH,
244 "%s-%u",
245 list[host_index].hostname,
246 pointer_index - 1);
247 }
248 else
249 {
250 sort_host_length= (size_t) snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH,
251 "%s:%u-%u",
252 list[host_index].hostname,
253 (uint32_t)list[host_index].port,
254 pointer_index - 1);
255 }
256
257 WATCHPOINT_ASSERT(sort_host_length);
258
259 if (is_ketama_weighted)
260 {
261 unsigned int i;
262 for (i = 0; i < pointer_per_hash; i++)
263 {
264 value= ketama_server_hash(sort_host, (uint32_t) sort_host_length, (int) i);
265 ptr->continuum[continuum_index].index= host_index;
266 ptr->continuum[continuum_index++].value= value;
267 }
268 }
269 else
270 {
271 value= memcached_generate_hash_value(sort_host, sort_host_length, ptr->distribution_hash);
272 ptr->continuum[continuum_index].index= host_index;
273 ptr->continuum[continuum_index++].value= value;
274 }
275 }
276 }
277
278 pointer_counter+= pointer_per_server;
279 }
280
281 WATCHPOINT_ASSERT(ptr);
282 WATCHPOINT_ASSERT(ptr->continuum);
283 WATCHPOINT_ASSERT(memcached_server_count(ptr) * MEMCACHED_POINTS_PER_SERVER <= MEMCACHED_CONTINUUM_SIZE);
284 ptr->continuum_points_counter= pointer_counter;
285 qsort(ptr->continuum, ptr->continuum_points_counter, sizeof(memcached_continuum_item_st), continuum_item_cmp);
286
287 #ifdef DEBUG
288 for (pointer_index= 0; memcached_server_count(ptr) && pointer_index < ((live_servers * MEMCACHED_POINTS_PER_SERVER) - 1); pointer_index++)
289 {
290 WATCHPOINT_ASSERT(ptr->continuum[pointer_index].value <= ptr->continuum[pointer_index + 1].value);
291 }
292 #endif
293
294 return MEMCACHED_SUCCESS;
295 }
296
297
298 memcached_return_t memcached_server_push(memcached_st *ptr, memcached_server_st *list)
299 {
300 uint32_t count;
301 memcached_server_st *new_host_list;
302
303 if (! list)
304 return MEMCACHED_SUCCESS;
305
306 count= memcached_servers_count(list);
307 new_host_list= ptr->call_realloc(ptr, memcached_server_list(ptr),
308 sizeof(memcached_server_instance_st) * (count + memcached_server_count(ptr)));
309
310 if (! new_host_list)
311 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
312
313 memcached_server_list_set(ptr, new_host_list);
314
315 for (uint32_t x= 0; x < count; x++)
316 {
317 memcached_server_instance_st *instance;
318
319 if ((ptr->flags.use_udp && list[x].type != MEMCACHED_CONNECTION_UDP)
320 || ((list[x].type == MEMCACHED_CONNECTION_UDP)
321 && ! (ptr->flags.use_udp)) )
322 return MEMCACHED_INVALID_HOST_PROTOCOL;
323
324 WATCHPOINT_ASSERT(list[x].hostname[0] != 0);
325
326 instance= memcached_server_instance_fetch(ptr, memcached_server_count(ptr));
327
328 /* TODO check return type */
329 (void)memcached_server_create_with(ptr, instance, list[x].hostname,
330 list[x].port, list[x].weight, list[x].type);
331 ptr->number_of_hosts++;
332 }
333
334 // Provides backwards compatibility with server list.
335 {
336 memcached_server_instance_st *instance;
337 instance= memcached_server_instance_fetch(ptr, 0);
338 instance->number_of_hosts= memcached_server_count(ptr);
339 }
340
341 return run_distribution(ptr);
342 }
343
344 memcached_return_t memcached_server_add_unix_socket(memcached_st *ptr,
345 const char *filename)
346 {
347 return memcached_server_add_unix_socket_with_weight(ptr, filename, 0);
348 }
349
350 memcached_return_t memcached_server_add_unix_socket_with_weight(memcached_st *ptr,
351 const char *filename,
352 uint32_t weight)
353 {
354 if (! filename)
355 return MEMCACHED_FAILURE;
356
357 return server_add(ptr, filename, 0, weight, MEMCACHED_CONNECTION_UNIX_SOCKET);
358 }
359
360 memcached_return_t memcached_server_add_udp(memcached_st *ptr,
361 const char *hostname,
362 in_port_t port)
363 {
364 return memcached_server_add_udp_with_weight(ptr, hostname, port, 0);
365 }
366
367 memcached_return_t memcached_server_add_udp_with_weight(memcached_st *ptr,
368 const char *hostname,
369 in_port_t port,
370 uint32_t weight)
371 {
372 if (! port)
373 port= MEMCACHED_DEFAULT_PORT;
374
375 if (! hostname)
376 hostname= "localhost";
377
378 return server_add(ptr, hostname, port, weight, MEMCACHED_CONNECTION_UDP);
379 }
380
381 memcached_return_t memcached_server_add(memcached_st *ptr,
382 const char *hostname,
383 in_port_t port)
384 {
385 return memcached_server_add_with_weight(ptr, hostname, port, 0);
386 }
387
388 memcached_return_t memcached_server_add_with_weight(memcached_st *ptr,
389 const char *hostname,
390 in_port_t port,
391 uint32_t weight)
392 {
393 if (! port)
394 port= MEMCACHED_DEFAULT_PORT;
395
396 if (! hostname)
397 hostname= "localhost";
398
399 return server_add(ptr, hostname, port, weight, MEMCACHED_CONNECTION_TCP);
400 }
401
402 static memcached_return_t server_add(memcached_st *ptr, const char *hostname,
403 in_port_t port,
404 uint32_t weight,
405 memcached_connection_t type)
406 {
407 memcached_server_instance_st *new_host_list;
408 memcached_server_instance_st *instance;
409
410 if ( (ptr->flags.use_udp && type != MEMCACHED_CONNECTION_UDP)
411 || ( (type == MEMCACHED_CONNECTION_UDP) && (! ptr->flags.use_udp) ) )
412 return MEMCACHED_INVALID_HOST_PROTOCOL;
413
414 new_host_list= ptr->call_realloc(ptr, memcached_server_list(ptr),
415 sizeof(memcached_server_instance_st) * (ptr->number_of_hosts + 1));
416
417 if (new_host_list == NULL)
418 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
419
420 memcached_server_list_set(ptr, new_host_list);
421
422 /* TODO: Check return type */
423 instance= memcached_server_instance_fetch(ptr, memcached_server_count(ptr));
424 (void)memcached_server_create_with(ptr, instance, hostname, port, weight, type);
425 ptr->number_of_hosts++;
426
427 instance= memcached_server_instance_fetch(ptr, 0);
428 memcached_servers_set_count(instance, memcached_server_count(ptr));
429
430 return run_distribution(ptr);
431 }
432
433 /**
434 @todo allow lists to query themselves even if they lack a root
435 */
436 memcached_return_t memcached_server_remove(memcached_server_st *st_ptr)
437 {
438 uint32_t x, host_index;
439 memcached_st *root= (memcached_st *)st_ptr->root;
440 memcached_server_st *list;
441
442 if (root == NULL)
443 return MEMCACHED_FAILURE;
444
445 list= memcached_server_list(root);
446
447 for (x= 0, host_index= 0; x < memcached_server_count(root); x++)
448 {
449 if (strncmp(list[x].hostname, st_ptr->hostname, MEMCACHED_MAX_HOST_LENGTH) != 0 || list[x].port != st_ptr->port)
450 {
451 if (host_index != x)
452 memcpy(list+host_index, list+x, sizeof(memcached_server_st));
453 host_index++;
454 }
455 }
456 root->number_of_hosts= host_index;
457
458 if (st_ptr->address_info)
459 {
460 freeaddrinfo(st_ptr->address_info);
461 st_ptr->address_info= NULL;
462 }
463 run_distribution(root);
464
465 return MEMCACHED_SUCCESS;
466 }
467
468 memcached_server_st *memcached_server_list_append(memcached_server_st *ptr,
469 const char *hostname, in_port_t port,
470 memcached_return_t *error)
471 {
472 return memcached_server_list_append_with_weight(ptr, hostname, port, 0, error);
473 }
474
475 memcached_server_st *memcached_server_list_append_with_weight(memcached_server_st *ptr,
476 const char *hostname, in_port_t port,
477 uint32_t weight,
478 memcached_return_t *error)
479 {
480 unsigned int count;
481 memcached_server_instance_st *new_host_list;
482
483 if (hostname == NULL || error == NULL)
484 return NULL;
485
486 if (! port)
487 port= MEMCACHED_DEFAULT_PORT;
488
489 /* Increment count for hosts */
490 count= 1;
491 if (ptr != NULL)
492 {
493 count+= memcached_servers_count(ptr);
494 }
495
496 new_host_list= (memcached_server_instance_st *)realloc(ptr, sizeof(memcached_server_instance_st) * count);
497 if (!new_host_list)
498 {
499 *error= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
500 return NULL;
501 }
502
503 /* TODO: Check return type */
504 memcached_server_create_with(NULL, &new_host_list[count-1], hostname, port, weight, MEMCACHED_CONNECTION_TCP);
505
506 /* Backwards compatibility hack */
507 memcached_servers_set_count(new_host_list, count);
508
509 *error= MEMCACHED_SUCCESS;
510 return new_host_list;
511 }