c8e15c4c0351e798f9f632791285471d1c32cca1
[awesomized/libmemcached] / 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 }