c0d0f0367c99c84295585db213792bc3151aebad
[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 == 0)
121 return MEMCACHED_SUCCESS;
122
123 if (ptr->number_of_hosts > ptr->continuum_count)
124 {
125 memcached_continuum_item_st *new_ptr;
126
127 if (ptr->call_realloc)
128 new_ptr= (memcached_continuum_item_st *)ptr->call_realloc(ptr, ptr->continuum,
129 sizeof(memcached_continuum_item_st) * (ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION) * points_per_server);
130 else
131 new_ptr= (memcached_continuum_item_st *)realloc(ptr->continuum,
132 sizeof(memcached_continuum_item_st) * (ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION) * points_per_server);
133
134 if (new_ptr == 0)
135 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
136
137 ptr->continuum= new_ptr;
138 ptr->continuum_count= ptr->number_of_hosts + MEMCACHED_CONTINUUM_ADDITION;
139 }
140
141 list = ptr->hosts;
142
143 if (is_ketama_weighted)
144 {
145 for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
146 {
147 if (list[host_index].weight == 0)
148 {
149 list[host_index].weight = 1;
150 }
151 total_weight += list[host_index].weight;
152 }
153 }
154
155 for (host_index = 0; host_index < ptr->number_of_hosts; ++host_index)
156 {
157 if (is_ketama_weighted)
158 {
159 float pct = (float)list[host_index].weight / (float)total_weight;
160 pointer_per_server= floorf(pct * MEMCACHED_POINTS_PER_SERVER_KETAMA / 4 * (float)(ptr->number_of_hosts) + 0.0000000001) * 4;
161 pointer_per_hash= 4;
162 #ifdef HAVE_DEBUG
163 printf("ketama_weighted:%s|%d|%llu|%u\n",
164 list[host_index].hostname,
165 list[host_index].port,
166 (unsigned long long)list[host_index].weight,
167 pointer_per_server);
168 #endif
169 }
170 for (index= 1; index <= pointer_per_server / pointer_per_hash; ++index)
171 {
172 char sort_host[MEMCACHED_MAX_HOST_SORT_LENGTH]= "";
173 size_t sort_host_length;
174
175 if (list[host_index].port == MEMCACHED_DEFAULT_PORT)
176 {
177 sort_host_length= snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH, "%s-%d",
178 list[host_index].hostname, index - 1);
179
180 }
181 else
182 {
183 sort_host_length= snprintf(sort_host, MEMCACHED_MAX_HOST_SORT_LENGTH, "%s:%d-%d",
184 list[host_index].hostname, list[host_index].port, index - 1);
185 }
186 WATCHPOINT_ASSERT(sort_host_length);
187
188 if (is_ketama_weighted)
189 {
190 int i;
191 for (i = 0; i < pointer_per_hash; i++)
192 {
193 value= ketama_server_hash(sort_host, sort_host_length, i);
194 ptr->continuum[continuum_index].index= host_index;
195 ptr->continuum[continuum_index++].value= value;
196 }
197 }
198 else
199 {
200 value= memcached_generate_hash_value(sort_host, sort_host_length, ptr->hash_continuum);
201 ptr->continuum[continuum_index].index= host_index;
202 ptr->continuum[continuum_index++].value= value;
203 }
204 }
205 pointer_counter+= pointer_per_server;
206 }
207
208 WATCHPOINT_ASSERT(ptr);
209 WATCHPOINT_ASSERT(ptr->continuum);
210 WATCHPOINT_ASSERT(ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER <= MEMCACHED_CONTINUUM_SIZE);
211 ptr->continuum_points_counter= pointer_counter;
212 qsort(ptr->continuum, ptr->continuum_points_counter, sizeof(memcached_continuum_item_st), continuum_item_cmp);
213
214 #ifdef HAVE_DEBUG
215 for (index= 0; ptr->number_of_hosts && index < ((ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER) - 1); index++)
216 {
217 WATCHPOINT_ASSERT(ptr->continuum[index].value <= ptr->continuum[index + 1].value);
218 }
219 #endif
220
221 return MEMCACHED_SUCCESS;
222 }
223
224
225 memcached_return memcached_server_push(memcached_st *ptr, memcached_server_st *list)
226 {
227 unsigned int x;
228 uint16_t count;
229 memcached_server_st *new_host_list;
230
231 if (!list)
232 return MEMCACHED_SUCCESS;
233
234 count= list[0].count;
235 if (ptr->call_realloc)
236 new_host_list=
237 (memcached_server_st *)ptr->call_realloc(ptr, ptr->hosts,
238 sizeof(memcached_server_st) * (count + ptr->number_of_hosts));
239 else
240 new_host_list=
241 (memcached_server_st *)realloc(ptr->hosts,
242 sizeof(memcached_server_st) * (count + ptr->number_of_hosts));
243
244 if (!new_host_list)
245 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
246
247 ptr->hosts= new_host_list;
248
249 for (x= 0; x < count; x++)
250 {
251 WATCHPOINT_ASSERT(list[x].hostname[0] != 0);
252 memcached_server_create(ptr, &ptr->hosts[ptr->number_of_hosts]);
253 /* TODO check return type */
254 (void)memcached_server_create_with(ptr, &ptr->hosts[ptr->number_of_hosts], list[x].hostname,
255 list[x].port, list[x].weight, list[x].type);
256 ptr->number_of_hosts++;
257 }
258 ptr->hosts[0].count= ptr->number_of_hosts;
259
260 return run_distribution(ptr);
261 }
262
263 memcached_return memcached_server_add_unix_socket(memcached_st *ptr,
264 const char *filename)
265 {
266 return memcached_server_add_unix_socket_with_weight(ptr, filename, 0);
267 }
268
269 memcached_return memcached_server_add_unix_socket_with_weight(memcached_st *ptr,
270 const char *filename,
271 uint32_t weight)
272 {
273 if (!filename)
274 return MEMCACHED_FAILURE;
275
276 return server_add(ptr, filename, 0, weight, MEMCACHED_CONNECTION_UNIX_SOCKET);
277 }
278
279 memcached_return memcached_server_add_udp(memcached_st *ptr,
280 const char *hostname,
281 unsigned int port)
282 {
283 return memcached_server_add_udp_with_weight(ptr, hostname, port, 0);
284 }
285
286 memcached_return memcached_server_add_udp_with_weight(memcached_st *ptr,
287 const char *hostname,
288 unsigned int port,
289 uint32_t weight)
290 {
291 if (!port)
292 port= MEMCACHED_DEFAULT_PORT;
293
294 if (!hostname)
295 hostname= "localhost";
296
297 return server_add(ptr, hostname, port, weight, MEMCACHED_CONNECTION_UDP);
298 }
299
300 memcached_return memcached_server_add(memcached_st *ptr,
301 const char *hostname,
302 unsigned int port)
303 {
304 return memcached_server_add_with_weight(ptr, hostname, port, 0);
305 }
306
307 memcached_return memcached_server_add_with_weight(memcached_st *ptr,
308 const char *hostname,
309 unsigned int port,
310 uint32_t weight)
311 {
312 if (!port)
313 port= MEMCACHED_DEFAULT_PORT;
314
315 if (!hostname)
316 hostname= "localhost";
317
318 return server_add(ptr, hostname, port, weight, MEMCACHED_CONNECTION_TCP);
319 }
320
321 static memcached_return server_add(memcached_st *ptr, const char *hostname,
322 unsigned int port,
323 uint32_t weight,
324 memcached_connection type)
325 {
326 memcached_server_st *new_host_list;
327
328 if (ptr->call_realloc)
329 new_host_list= (memcached_server_st *)ptr->call_realloc(ptr, ptr->hosts,
330 sizeof(memcached_server_st) * (ptr->number_of_hosts+1));
331 else
332 new_host_list= (memcached_server_st *)realloc(ptr->hosts,
333 sizeof(memcached_server_st) * (ptr->number_of_hosts+1));
334 if (new_host_list == NULL)
335 return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
336
337 ptr->hosts= new_host_list;
338
339 /* TODO: Check return type */
340 (void)memcached_server_create_with(ptr, &ptr->hosts[ptr->number_of_hosts], hostname, port, weight, type);
341 ptr->number_of_hosts++;
342 ptr->hosts[0].count= ptr->number_of_hosts;
343
344 return run_distribution(ptr);
345 }
346
347 memcached_return memcached_server_remove(memcached_server_st *st_ptr)
348 {
349 uint32_t x, index;
350 memcached_st *ptr= st_ptr->root;
351 memcached_server_st *list= ptr->hosts;
352
353 for (x= 0, index= 0; x < ptr->number_of_hosts; x++)
354 {
355 if (strncmp(list[x].hostname, st_ptr->hostname, MEMCACHED_MAX_HOST_LENGTH) != 0 || list[x].port != st_ptr->port)
356 {
357 if (index != x)
358 memcpy(list+index, list+x, sizeof(memcached_server_st));
359 index++;
360 }
361 }
362 ptr->number_of_hosts= index;
363
364 if (st_ptr->address_info)
365 {
366 freeaddrinfo(st_ptr->address_info);
367 st_ptr->address_info= NULL;
368 }
369 run_distribution(ptr);
370
371 return MEMCACHED_SUCCESS;
372 }
373
374 memcached_server_st *memcached_server_list_append(memcached_server_st *ptr,
375 const char *hostname, unsigned int port,
376 memcached_return *error)
377 {
378 return memcached_server_list_append_with_weight(ptr, hostname, port, 0, error);
379 }
380
381 memcached_server_st *memcached_server_list_append_with_weight(memcached_server_st *ptr,
382 const char *hostname, unsigned int port,
383 uint32_t weight,
384 memcached_return *error)
385 {
386 unsigned int count;
387 memcached_server_st *new_host_list;
388
389 if (hostname == NULL || error == NULL)
390 return NULL;
391
392 if (!port)
393 port= MEMCACHED_DEFAULT_PORT;
394
395 /* Increment count for hosts */
396 count= 1;
397 if (ptr != NULL)
398 {
399 count+= ptr[0].count;
400 }
401
402 new_host_list= (memcached_server_st *)realloc(ptr, sizeof(memcached_server_st) * count);
403 if (!new_host_list)
404 {
405 *error= MEMCACHED_MEMORY_ALLOCATION_FAILURE;
406 return NULL;
407 }
408
409 /* TODO: Check return type */
410 memcached_server_create_with(NULL, &new_host_list[count-1], hostname, port, weight, MEMCACHED_CONNECTION_TCP);
411
412 /* Backwards compatibility hack */
413 new_host_list[0].count= count;
414
415 *error= MEMCACHED_SUCCESS;
416 return new_host_list;
417 }
418
419 unsigned int memcached_server_list_count(memcached_server_st *ptr)
420 {
421 if (ptr == NULL)
422 return 0;
423
424 return ptr[0].count;
425 }
426
427 void memcached_server_list_free(memcached_server_st *ptr)
428 {
429 server_list_free(NULL, ptr);
430 }