df384a9c56911958a8fad6afe709892a08b9a8b6
[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 host_reset(memcached_st *ptr, memcached_server_st *host,
58 const char *hostname, unsigned int port, uint32_t weight,
59 memcached_connection type)
60 {
61 strncpy(host->hostname, hostname, MEMCACHED_MAX_HOST_LENGTH - 1);
62 host->root= ptr ? ptr : NULL;
63 host->port= port;
64 host->weight= weight;
65 host->fd= -1;
66 host->type= type;
67 host->read_ptr= host->read_buffer;
68 if (ptr)
69 host->next_retry= ptr->retry_timeout;
70 host->sockaddr_inited= MEMCACHED_NOT_ALLOCATED;
71 }
72
73 void server_list_free(memcached_st *ptr, memcached_server_st *servers)
74 {
75 unsigned int x;
76
77 if (servers == NULL)
78 return;
79
80 for (x= 0; x < servers->count; x++)
81 if (servers[x].address_info)
82 {
83 freeaddrinfo(servers[x].address_info);
84 servers[x].address_info= NULL;
85 }
86
87 if (ptr && ptr->call_free)
88 ptr->call_free(ptr, servers);
89 else
90 free(servers);
91 }
92
93 static uint32_t ketama_server_hash(const char *key, unsigned int key_length, int alignment)
94 {
95 unsigned char results[16];
96
97 md5_signature((unsigned char*)key, key_length, results);
98 return ((uint32_t) (results[3 + alignment * 4] & 0xFF) << 24)
99 | ((uint32_t) (results[2 + alignment * 4] & 0xFF) << 16)
100 | ((uint32_t) (results[1 + alignment * 4] & 0xFF) << 8)
101 | (results[0 + alignment * 4] & 0xFF);
102 }
103
104 static int continuum_item_cmp(const void *t1, const void *t2)
105 {
106 memcached_continuum_item_st *ct1= (memcached_continuum_item_st *)t1;
107 memcached_continuum_item_st *ct2= (memcached_continuum_item_st *)t2;
108
109 /* Why 153? Hmmm... */
110 WATCHPOINT_ASSERT(ct1->value != 153);
111 if (ct1->value == ct2->value)
112 return 0;
113 else if (ct1->value > ct2->value)
114 return 1;
115 else
116 return -1;
117 }
118
119 memcached_return update_continuum(memcached_st *ptr)
120 {
121 uint32_t index;
122 uint32_t host_index;
123 uint32_t continuum_index= 0;
124 uint32_t value;
125 memcached_server_st *list;
126 uint32_t pointer_counter= 0;
127 uint32_t pointer_per_server= MEMCACHED_POINTS_PER_SERVER;
128 uint32_t pointer_per_hash= 1;
129 uint64_t total_weight= 0;
130 uint32_t is_ketama_weighted= 0;
131 uint32_t points_per_server= 0;
132
133 is_ketama_weighted= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED);
134 points_per_server= is_ketama_weighted ? MEMCACHED_POINTS_PER_SERVER_KETAMA : MEMCACHED_POINTS_PER_SERVER;
135
136 if (ptr->number_of_hosts > ptr->continuum_count)
137 {
138 memcached_continuum_item_st *new_ptr;
139
140 if (ptr->call_realloc)
141 new_ptr= (memcached_continuum_item_st *)ptr->call_realloc(ptr, ptr->continuum, sizeof(memcached_continuum_item_st) * (ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION) * points_per_server);
142 else
143 new_ptr= (memcached_continuum_item_st *)realloc(ptr->continuum, sizeof(memcached_continuum_item_st) * (ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION) * points_per_server);
144
145 if (new_ptr == 0)
146 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
147
148 ptr->continuum= new_ptr;
149 ptr->continuum_count= ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION;
150 }
151
152 list = ptr->hosts;
153
154 if (is_ketama_weighted)
155 {
156 for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
157 {
158 if (list[host_index].weight == 0)
159 {
160 list[host_index].weight = 1;
161 }
162 total_weight += list[host_index].weight;
163 }
164 }
165
166 for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
167 {
168 if (is_ketama_weighted)
169 {
170 float pct = (float)list[host_index].weight / (float)total_weight;
171 pointer_per_server= floorf(pct * MEMCACHED_POINTS_PER_SERVER_KETAMA / 4 * (float)(ptr->number_of_hosts) + 0.0000000001) * 4;
172 pointer_per_hash= 4;
173 #ifdef HAVE_DEBUG
174 printf("ketama_weighted:%s|%d|%llu|%u\n",
175 list[host_index].hostname,
176 list[host_index].port,
177 (unsigned long long)list[host_index].weight,
178 pointer_per_server);
179 #endif
180 }
181 for (index= 1; index <= pointer_per_server / pointer_per_hash; ++index)
182 {
183 char sort_host[MEMCACHED_MAX_HOST_SORT_LENGTH]= "";
184 size_t sort_host_length;
185
186 if (list[host_index].port == MEMCACHED_DEFAULT_PORT)
187 {
188 sort_host_length= snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH, "%s-%d",
189 list[host_index].hostname, index - 1);
190
191 }
192 else
193 {
194 sort_host_length= snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH, "%s:%d-%d",
195 list[host_index].hostname, list[host_index].port, index - 1);
196 }
197 WATCHPOINT_ASSERT(sort_host_length);
198
199 if (is_ketama_weighted)
200 {
201 int i;
202 for (i = 0; i < pointer_per_hash; i++)
203 {
204 value= ketama_server_hash(sort_host, sort_host_length, i);
205 ptr->continuum[continuum_index].index= host_index;
206 ptr->continuum[continuum_index++].value= value;
207 }
208 }
209 else
210 {
211 value= generate_hash_value(sort_host, sort_host_length, ptr->hash_continuum);
212 ptr->continuum[continuum_index].index= host_index;
213 ptr->continuum[continuum_index++].value= value;
214 }
215 }
216 pointer_counter+= pointer_per_server;
217 }
218
219 WATCHPOINT_ASSERT(ptr);
220 WATCHPOINT_ASSERT(ptr->continuum);
221 WATCHPOINT_ASSERT(ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER <= MEMCACHED_CONTINUUM_SIZE);
222 ptr->continuum_points_counter= pointer_counter;
223 qsort(ptr->continuum, ptr->continuum_points_counter, sizeof(memcached_continuum_item_st), continuum_item_cmp);
224
225 #ifdef HAVE_DEBUG
226 for (index= 0; ptr->number_of_hosts && index < ((ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER) - 1); index++)
227 {
228 WATCHPOINT_ASSERT(ptr->continuum[index].value <= ptr->continuum[index + 1].value);
229 }
230 #endif
231
232 return MEMCACHED_SUCCESS;
233 }
234
235
236 memcached_return memcached_server_push(memcached_st *ptr, memcached_server_st *list)
237 {
238 unsigned int x;
239 uint16_t count;
240 memcached_server_st *new_host_list;
241
242 if (!list)
243 return MEMCACHED_SUCCESS;
244
245 count= list[0].count;
246 if (ptr->call_realloc)
247 new_host_list=
248 (memcached_server_st *)ptr->call_realloc(ptr, ptr->hosts,
249 sizeof(memcached_server_st) * (count + ptr->number_of_hosts));
250 else
251 new_host_list=
252 (memcached_server_st *)realloc(ptr->hosts,
253 sizeof(memcached_server_st) * (count + ptr->number_of_hosts));
254
255 if (!new_host_list)
256 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
257
258 ptr->hosts= new_host_list;
259
260 for (x= 0; x < count; x++)
261 {
262 WATCHPOINT_ASSERT(list[x].hostname[0] != 0);
263 host_reset(ptr, &ptr->hosts[ptr->number_of_hosts], list[x].hostname,
264 list[x].port, list[x].weight, list[x].type);
265 ptr->number_of_hosts++;
266 }
267 ptr->hosts[0].count= ptr->number_of_hosts;
268
269 return run_distribution(ptr);
270 }
271
272 memcached_return memcached_server_add_unix_socket(memcached_st *ptr,
273 const char *filename)
274 {
275 return memcached_server_add_unix_socket_with_weight(ptr, filename, 0);
276 }
277
278 memcached_return memcached_server_add_unix_socket_with_weight(memcached_st *ptr,
279 const char *filename,
280 uint32_t weight)
281 {
282 if (!filename)
283 return MEMCACHED_FAILURE;
284
285 return server_add(ptr, filename, 0, weight, MEMCACHED_CONNECTION_UNIX_SOCKET);
286 }
287
288 memcached_return memcached_server_add_udp(memcached_st *ptr,
289 const char *hostname,
290 unsigned int port)
291 {
292 return memcached_server_add_udp_with_weight(ptr, hostname, port, 0);
293 }
294
295 memcached_return memcached_server_add_udp_with_weight(memcached_st *ptr,
296 const char *hostname,
297 unsigned int port,
298 uint32_t weight)
299 {
300 if (!port)
301 port= MEMCACHED_DEFAULT_PORT;
302
303 if (!hostname)
304 hostname= "localhost";
305
306 return server_add(ptr, hostname, port, weight, MEMCACHED_CONNECTION_UDP);
307 }
308
309 memcached_return memcached_server_add(memcached_st *ptr,
310 const char *hostname,
311 unsigned int port)
312 {
313 return memcached_server_add_with_weight(ptr, hostname, port, 0);
314 }
315
316 memcached_return memcached_server_add_with_weight(memcached_st *ptr,
317 const char *hostname,
318 unsigned int port,
319 uint32_t weight)
320 {
321 if (!port)
322 port= MEMCACHED_DEFAULT_PORT;
323
324 if (!hostname)
325 hostname= "localhost";
326
327 return server_add(ptr, hostname, port, weight, MEMCACHED_CONNECTION_TCP);
328 }
329
330 static memcached_return server_add(memcached_st *ptr, const char *hostname,
331 unsigned int port,
332 uint32_t weight,
333 memcached_connection type)
334 {
335 memcached_server_st *new_host_list;
336
337 if (ptr->call_realloc)
338 new_host_list= (memcached_server_st *)ptr->call_realloc(ptr, ptr->hosts,
339 sizeof(memcached_server_st) * (ptr->number_of_hosts+1));
340 else
341 new_host_list= (memcached_server_st *)realloc(ptr->hosts,
342 sizeof(memcached_server_st) * (ptr->number_of_hosts+1));
343 if (new_host_list == NULL)
344 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
345
346 ptr->hosts= new_host_list;
347
348 host_reset(ptr, &ptr->hosts[ptr->number_of_hosts], hostname, port, weight, type);
349 ptr->number_of_hosts++;
350 ptr->hosts[0].count= ptr->number_of_hosts;
351
352 return run_distribution(ptr);
353 }
354
355 memcached_return memcached_server_remove(memcached_server_st *st_ptr)
356 {
357 uint32_t x, index;
358 memcached_st *ptr= st_ptr->root;
359 memcached_server_st *list= ptr->hosts;
360
361 for (x= 0, index= 0; x < ptr->number_of_hosts; x++)
362 {
363 if (strncmp(list[x].hostname, st_ptr->hostname, MEMCACHED_MAX_HOST_LENGTH) != 0 || list[x].port != st_ptr->port)
364 {
365 if (index != x)
366 memcpy(list+index, list+x, sizeof(memcached_server_st));
367 index++;
368 }
369 }
370 ptr->number_of_hosts= index;
371
372 if (st_ptr->address_info)
373 {
374 freeaddrinfo(st_ptr->address_info);
375 st_ptr->address_info= NULL;
376 }
377 run_distribution(ptr);
378
379 return MEMCACHED_SUCCESS;
380 }
381
382 memcached_server_st *memcached_server_list_append(memcached_server_st *ptr,
383 const char *hostname, unsigned int port,
384 memcached_return *error)
385 {
386 return memcached_server_list_append_with_weight(ptr, hostname, port, 0, error);
387 }
388
389 memcached_server_st *memcached_server_list_append_with_weight(memcached_server_st *ptr,
390 const char *hostname, unsigned int port,
391 uint32_t weight,
392 memcached_return *error)
393 {
394 unsigned int count;
395 memcached_server_st *new_host_list;
396
397 if (hostname == NULL || error == NULL)
398 return NULL;
399
400 if (!port)
401 port= MEMCACHED_DEFAULT_PORT;
402
403 /* Increment count for hosts */
404 count= 1;
405 if (ptr != NULL)
406 {
407 count+= ptr[0].count;
408 }
409
410 new_host_list= (memcached_server_st *)realloc(ptr, sizeof(memcached_server_st) * count);
411 if (!new_host_list)
412 {
413 *error= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
414 return NULL;
415 }
416
417 host_reset(NULL, &new_host_list[count-1], hostname, port, weight, MEMCACHED_CONNECTION_TCP);
418
419 /* Backwards compatibility hack */
420 new_host_list[0].count= count;
421
422 *error= MEMCACHED_SUCCESS;
423 return new_host_list;
424 }
425
426 unsigned int memcached_server_list_count(memcached_server_st *ptr)
427 {
428 if (ptr == NULL)
429 return 0;
430
431 return ptr[0].count;
432 }
433
434 void memcached_server_list_free(memcached_server_st *ptr)
435 {
436 server_list_free(NULL, ptr);
437 }