30c8f954c697de6e8502558edb65a880f941d28c
[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 points_per_server= 0;
116
117 is_ketama_weighted= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED);
118 points_per_server= is_ketama_weighted ? MEMCACHED_POINTS_PER_SERVER_KETAMA : MEMCACHED_POINTS_PER_SERVER;
119
120 if (ptr->number_of_hosts > ptr->continuum_count)
121 {
122 memcached_continuum_item_st *new_ptr;
123
124 if (ptr->call_realloc)
125 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);
126 else
127 new_ptr= (memcached_continuum_item_st *)realloc(ptr->continuum, sizeof(memcached_continuum_item_st) * (ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION) * points_per_server);
128
129 if (new_ptr == 0)
130 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
131
132 ptr->continuum= new_ptr;
133 ptr->continuum_count= ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION;
134 }
135
136 list = ptr->hosts;
137
138 if (is_ketama_weighted)
139 {
140 for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
141 {
142 if (list[host_index].weight == 0)
143 {
144 list[host_index].weight = 1;
145 }
146 total_weight += list[host_index].weight;
147 }
148 }
149
150 for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
151 {
152 if (is_ketama_weighted)
153 {
154 float pct = (float)list[host_index].weight / (float)total_weight;
155 pointer_per_server= floorf(pct * MEMCACHED_POINTS_PER_SERVER_KETAMA / 4 * (float)(ptr->number_of_hosts) + 0.0000000001) * 4;
156 pointer_per_hash= 4;
157 #ifdef HAVE_DEBUG
158 printf("ketama_weighted:%s|%d|%llu|%u\n",
159 list[host_index].hostname,
160 list[host_index].port,
161 (unsigned long long)list[host_index].weight,
162 pointer_per_server);
163 #endif
164 }
165 for (index= 1; index <= pointer_per_server / pointer_per_hash; ++index)
166 {
167 char sort_host[MEMCACHED_MAX_HOST_SORT_LENGTH]= "";
168 size_t sort_host_length;
169
170 if (list[host_index].port == MEMCACHED_DEFAULT_PORT)
171 {
172 sort_host_length= snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH, "%s-%d",
173 list[host_index].hostname, index - 1);
174
175 }
176 else
177 {
178 sort_host_length= snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH, "%s:%d-%d",
179 list[host_index].hostname, list[host_index].port, index - 1);
180 }
181 WATCHPOINT_ASSERT(sort_host_length);
182
183 if (is_ketama_weighted)
184 {
185 int i;
186 for (i = 0; i < pointer_per_hash; i++)
187 {
188 value= ketama_server_hash(sort_host, sort_host_length, i);
189 ptr->continuum[continuum_index].index= host_index;
190 ptr->continuum[continuum_index++].value= value;
191 }
192 }
193 else
194 {
195 value= generate_hash_value(sort_host, sort_host_length, ptr->hash_continuum);
196 ptr->continuum[continuum_index].index= host_index;
197 ptr->continuum[continuum_index++].value= value;
198 }
199 }
200 pointer_counter+= pointer_per_server;
201 }
202
203 WATCHPOINT_ASSERT(ptr);
204 WATCHPOINT_ASSERT(ptr->continuum);
205 WATCHPOINT_ASSERT(ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER <= MEMCACHED_CONTINUUM_SIZE);
206 ptr->continuum_points_counter= pointer_counter;
207 qsort(ptr->continuum, ptr->continuum_points_counter, sizeof(memcached_continuum_item_st), continuum_item_cmp);
208
209 #ifdef HAVE_DEBUG
210 for (index= 0; ptr->number_of_hosts && index < ((ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER) - 1); index++)
211 {
212 WATCHPOINT_ASSERT(ptr->continuum[index].value <= ptr->continuum[index + 1].value);
213 }
214 #endif
215
216 return MEMCACHED_SUCCESS;
217 }
218
219
220 memcached_return memcached_server_push(memcached_st *ptr, memcached_server_st *list)
221 {
222 unsigned int x;
223 uint16_t count;
224 memcached_server_st *new_host_list;
225
226 if (!list)
227 return MEMCACHED_SUCCESS;
228
229 count= list[0].count;
230 if (ptr->call_realloc)
231 new_host_list=
232 (memcached_server_st *)ptr->call_realloc(ptr, ptr->hosts,
233 sizeof(memcached_server_st) * (count + ptr->number_of_hosts));
234 else
235 new_host_list=
236 (memcached_server_st *)realloc(ptr->hosts,
237 sizeof(memcached_server_st) * (count + ptr->number_of_hosts));
238
239 if (!new_host_list)
240 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
241
242 ptr->hosts= new_host_list;
243
244 for (x= 0; x < count; x++)
245 {
246 WATCHPOINT_ASSERT(list[x].hostname[0] != 0);
247 memcached_server_create(ptr, &ptr->hosts[ptr->number_of_hosts]);
248 /* TODO check return type */
249 (void)memcached_server_create_with(ptr, &ptr->hosts[ptr->number_of_hosts], list[x].hostname,
250 list[x].port, list[x].weight, list[x].type);
251 ptr->number_of_hosts++;
252 }
253 ptr->hosts[0].count= ptr->number_of_hosts;
254
255 return run_distribution(ptr);
256 }
257
258 memcached_return memcached_server_add_unix_socket(memcached_st *ptr,
259 const char *filename)
260 {
261 return memcached_server_add_unix_socket_with_weight(ptr, filename, 0);
262 }
263
264 memcached_return memcached_server_add_unix_socket_with_weight(memcached_st *ptr,
265 const char *filename,
266 uint32_t weight)
267 {
268 if (!filename)
269 return MEMCACHED_FAILURE;
270
271 return server_add(ptr, filename, 0, weight, MEMCACHED_CONNECTION_UNIX_SOCKET);
272 }
273
274 memcached_return memcached_server_add_udp(memcached_st *ptr,
275 const char *hostname,
276 unsigned int port)
277 {
278 return memcached_server_add_udp_with_weight(ptr, hostname, port, 0);
279 }
280
281 memcached_return memcached_server_add_udp_with_weight(memcached_st *ptr,
282 const char *hostname,
283 unsigned int port,
284 uint32_t weight)
285 {
286 if (!port)
287 port= MEMCACHED_DEFAULT_PORT;
288
289 if (!hostname)
290 hostname= "localhost";
291
292 return server_add(ptr, hostname, port, weight, MEMCACHED_CONNECTION_UDP);
293 }
294
295 memcached_return memcached_server_add(memcached_st *ptr,
296 const char *hostname,
297 unsigned int port)
298 {
299 return memcached_server_add_with_weight(ptr, hostname, port, 0);
300 }
301
302 memcached_return memcached_server_add_with_weight(memcached_st *ptr,
303 const char *hostname,
304 unsigned int port,
305 uint32_t weight)
306 {
307 if (!port)
308 port= MEMCACHED_DEFAULT_PORT;
309
310 if (!hostname)
311 hostname= "localhost";
312
313 return server_add(ptr, hostname, port, weight, MEMCACHED_CONNECTION_TCP);
314 }
315
316 static memcached_return server_add(memcached_st *ptr, const char *hostname,
317 unsigned int port,
318 uint32_t weight,
319 memcached_connection type)
320 {
321 memcached_server_st *new_host_list;
322
323 if (ptr->call_realloc)
324 new_host_list= (memcached_server_st *)ptr->call_realloc(ptr, ptr->hosts,
325 sizeof(memcached_server_st) * (ptr->number_of_hosts+1));
326 else
327 new_host_list= (memcached_server_st *)realloc(ptr->hosts,
328 sizeof(memcached_server_st) * (ptr->number_of_hosts+1));
329 if (new_host_list == NULL)
330 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
331
332 ptr->hosts= new_host_list;
333
334 /* TODO: Check return type */
335 (void)memcached_server_create_with(ptr, &ptr->hosts[ptr->number_of_hosts], hostname, port, weight, type);
336 ptr->number_of_hosts++;
337 ptr->hosts[0].count= ptr->number_of_hosts;
338
339 return run_distribution(ptr);
340 }
341
342 memcached_return memcached_server_remove(memcached_server_st *st_ptr)
343 {
344 uint32_t x, index;
345 memcached_st *ptr= st_ptr->root;
346 memcached_server_st *list= ptr->hosts;
347
348 for (x= 0, index= 0; x < ptr->number_of_hosts; x++)
349 {
350 if (strncmp(list[x].hostname, st_ptr->hostname, MEMCACHED_MAX_HOST_LENGTH) != 0 || list[x].port != st_ptr->port)
351 {
352 if (index != x)
353 memcpy(list+index, list+x, sizeof(memcached_server_st));
354 index++;
355 }
356 }
357 ptr->number_of_hosts= index;
358
359 if (st_ptr->address_info)
360 {
361 freeaddrinfo(st_ptr->address_info);
362 st_ptr->address_info= NULL;
363 }
364 run_distribution(ptr);
365
366 return MEMCACHED_SUCCESS;
367 }
368
369 memcached_server_st *memcached_server_list_append(memcached_server_st *ptr,
370 const char *hostname, unsigned int port,
371 memcached_return *error)
372 {
373 return memcached_server_list_append_with_weight(ptr, hostname, port, 0, error);
374 }
375
376 memcached_server_st *memcached_server_list_append_with_weight(memcached_server_st *ptr,
377 const char *hostname, unsigned int port,
378 uint32_t weight,
379 memcached_return *error)
380 {
381 unsigned int count;
382 memcached_server_st *new_host_list;
383
384 if (hostname == NULL || error == NULL)
385 return NULL;
386
387 if (!port)
388 port= MEMCACHED_DEFAULT_PORT;
389
390 /* Increment count for hosts */
391 count= 1;
392 if (ptr != NULL)
393 {
394 count+= ptr[0].count;
395 }
396
397 new_host_list= (memcached_server_st *)realloc(ptr, sizeof(memcached_server_st) * count);
398 if (!new_host_list)
399 {
400 *error= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
401 return NULL;
402 }
403
404 /* TODO: Check return type */
405 memcached_server_create_with(NULL, &new_host_list[count-1], hostname, port, weight, MEMCACHED_CONNECTION_TCP);
406
407 /* Backwards compatibility hack */
408 new_host_list[0].count= count;
409
410 *error= MEMCACHED_SUCCESS;
411 return new_host_list;
412 }
413
414 unsigned int memcached_server_list_count(memcached_server_st *ptr)
415 {
416 if (ptr == NULL)
417 return 0;
418
419 return ptr[0].count;
420 }
421
422 void memcached_server_list_free(memcached_server_st *ptr)
423 {
424 server_list_free(NULL, ptr);
425 }