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6a566b9c | 1 | /* |
ef57eb7b | 2 | * Copyright (C) 1996-2016 The Squid Software Foundation and contributors |
6a566b9c | 3 | * |
bbc27441 AJ |
4 | * Squid software is distributed under GPLv2+ license and includes |
5 | * contributions from numerous individuals and organizations. | |
6 | * Please see the COPYING and CONTRIBUTORS files for details. | |
6a566b9c | 7 | */ |
8 | ||
bbc27441 AJ |
9 | /* DEBUG: none LRU Removal Policy */ |
10 | ||
582c2af2 | 11 | #include "squid.h" |
528b2c61 | 12 | #include "MemObject.h" |
985c86bc | 13 | #include "SquidTime.h" |
602d9612 | 14 | #include "Store.h" |
6a566b9c | 15 | |
ed6e9fb9 AJ |
16 | /* because LruNode use explicit memory alloc()/freeOne() calls. |
17 | * XXX: convert to MEMPROXY_CLASS() API | |
18 | */ | |
19 | #include "mem/Pool.h" | |
20 | ||
6a566b9c | 21 | REMOVALPOLICYCREATE createRemovalPolicy_lru; |
22 | ||
26ac0430 | 23 | struct LruPolicyData { |
e6ccf245 | 24 | void setPolicyNode (StoreEntry *, void *) const; |
6a566b9c | 25 | RemovalPolicy *policy; |
26 | dlink_list list; | |
27 | int count; | |
28 | int nwalkers; | |
9f913cf1 | 29 | enum heap_entry_type { |
62e76326 | 30 | TYPE_UNKNOWN = 0, TYPE_STORE_ENTRY, TYPE_STORE_MEM |
9f913cf1 | 31 | } type; |
6a566b9c | 32 | }; |
33 | ||
34 | /* Hack to avoid having to remember the RemovalPolicyNode location. | |
35 | * Needed by the purge walker to clear the policy information | |
36 | */ | |
e6ccf245 | 37 | static enum LruPolicyData::heap_entry_type |
6a566b9c | 38 | repl_guessType(StoreEntry * entry, RemovalPolicyNode * node) |
39 | { | |
40 | if (node == &entry->repl) | |
62e76326 | 41 | return LruPolicyData::TYPE_STORE_ENTRY; |
42 | ||
6a566b9c | 43 | if (entry->mem_obj && node == &entry->mem_obj->repl) |
62e76326 | 44 | return LruPolicyData::TYPE_STORE_MEM; |
45 | ||
6a566b9c | 46 | fatal("Heap Replacement: Unknown StoreEntry node type"); |
62e76326 | 47 | |
e6ccf245 | 48 | return LruPolicyData::TYPE_UNKNOWN; |
6a566b9c | 49 | } |
e6ccf245 | 50 | |
51 | void | |
52 | LruPolicyData::setPolicyNode (StoreEntry *entry, void *value) const | |
53 | { | |
54 | switch (type) { | |
62e76326 | 55 | |
56 | case TYPE_STORE_ENTRY: | |
57 | entry->repl.data = value; | |
58 | break ; | |
59 | ||
60 | case TYPE_STORE_MEM: | |
61 | entry->mem_obj->repl.data = value ; | |
62 | break ; | |
63 | ||
64 | default: | |
65 | break; | |
6a566b9c | 66 | } |
e6ccf245 | 67 | } |
6a566b9c | 68 | |
69 | typedef struct _LruNode LruNode; | |
62e76326 | 70 | |
26ac0430 | 71 | struct _LruNode { |
6a566b9c | 72 | /* Note: the dlink_node MUST be the first member of the LruNode |
73 | * structure. This member is later pointer typecasted to LruNode *. | |
74 | */ | |
75 | dlink_node node; | |
76 | }; | |
77 | ||
04eb0689 | 78 | static MemAllocator *lru_node_pool = NULL; |
6a566b9c | 79 | static int nr_lru_policies = 0; |
80 | ||
81 | static void | |
82 | lru_add(RemovalPolicy * policy, StoreEntry * entry, RemovalPolicyNode * node) | |
83 | { | |
e6ccf245 | 84 | LruPolicyData *lru = (LruPolicyData *)policy->_data; |
6a566b9c | 85 | LruNode *lru_node; |
86 | assert(!node->data); | |
b001e822 | 87 | node->data = lru_node = (LruNode *)lru_node_pool->alloc(); |
6a566b9c | 88 | dlinkAddTail(entry, &lru_node->node, &lru->list); |
89 | lru->count += 1; | |
62e76326 | 90 | |
6a566b9c | 91 | if (!lru->type) |
62e76326 | 92 | lru->type = repl_guessType(entry, node); |
6a566b9c | 93 | } |
94 | ||
95 | static void | |
96 | lru_remove(RemovalPolicy * policy, StoreEntry * entry, RemovalPolicyNode * node) | |
97 | { | |
e6ccf245 | 98 | LruPolicyData *lru = (LruPolicyData *)policy->_data; |
99 | LruNode *lru_node = (LruNode *)node->data; | |
62e76326 | 100 | |
6a566b9c | 101 | if (!lru_node) |
62e76326 | 102 | return; |
103 | ||
75240ca9 | 104 | /* |
105 | * It seems to be possible for an entry to exist in the hash | |
106 | * but not be in the LRU list, so check for that case rather | |
107 | * than suffer a NULL pointer access. | |
108 | */ | |
109 | if (NULL == lru_node->node.data) | |
62e76326 | 110 | return; |
111 | ||
6a566b9c | 112 | assert(lru_node->node.data == entry); |
62e76326 | 113 | |
6a566b9c | 114 | node->data = NULL; |
62e76326 | 115 | |
6a566b9c | 116 | dlinkDelete(&lru_node->node, &lru->list); |
62e76326 | 117 | |
dc47f531 | 118 | lru_node_pool->freeOne(lru_node); |
62e76326 | 119 | |
6a566b9c | 120 | lru->count -= 1; |
121 | } | |
122 | ||
123 | static void | |
124 | lru_referenced(RemovalPolicy * policy, const StoreEntry * entry, | |
62e76326 | 125 | RemovalPolicyNode * node) |
6a566b9c | 126 | { |
e6ccf245 | 127 | LruPolicyData *lru = (LruPolicyData *)policy->_data; |
128 | LruNode *lru_node = (LruNode *)node->data; | |
62e76326 | 129 | |
6a566b9c | 130 | if (!lru_node) |
62e76326 | 131 | return; |
132 | ||
6a566b9c | 133 | dlinkDelete(&lru_node->node, &lru->list); |
62e76326 | 134 | |
6a566b9c | 135 | dlinkAddTail((void *) entry, &lru_node->node, &lru->list); |
136 | } | |
137 | ||
138 | /** RemovalPolicyWalker **/ | |
139 | ||
140 | typedef struct _LruWalkData LruWalkData; | |
62e76326 | 141 | |
26ac0430 | 142 | struct _LruWalkData { |
6a566b9c | 143 | LruNode *current; |
144 | }; | |
145 | ||
2d72d4fd | 146 | static const StoreEntry * |
6a566b9c | 147 | lru_walkNext(RemovalPolicyWalker * walker) |
148 | { | |
e6ccf245 | 149 | LruWalkData *lru_walk = (LruWalkData *)walker->_data; |
6a566b9c | 150 | LruNode *lru_node = lru_walk->current; |
62e76326 | 151 | |
6a566b9c | 152 | if (!lru_node) |
62e76326 | 153 | return NULL; |
154 | ||
6a566b9c | 155 | lru_walk->current = (LruNode *) lru_node->node.next; |
62e76326 | 156 | |
6a566b9c | 157 | return (StoreEntry *) lru_node->node.data; |
158 | } | |
159 | ||
160 | static void | |
161 | lru_walkDone(RemovalPolicyWalker * walker) | |
162 | { | |
163 | RemovalPolicy *policy = walker->_policy; | |
e6ccf245 | 164 | LruPolicyData *lru = (LruPolicyData *)policy->_data; |
6a566b9c | 165 | assert(strcmp(policy->_type, "lru") == 0); |
166 | assert(lru->nwalkers > 0); | |
167 | lru->nwalkers -= 1; | |
168 | safe_free(walker->_data); | |
aa839030 | 169 | delete walker; |
6a566b9c | 170 | } |
171 | ||
172 | static RemovalPolicyWalker * | |
173 | lru_walkInit(RemovalPolicy * policy) | |
174 | { | |
e6ccf245 | 175 | LruPolicyData *lru = (LruPolicyData *)policy->_data; |
6a566b9c | 176 | RemovalPolicyWalker *walker; |
177 | LruWalkData *lru_walk; | |
178 | lru->nwalkers += 1; | |
aa839030 | 179 | walker = new RemovalPolicyWalker; |
e6ccf245 | 180 | lru_walk = (LruWalkData *)xcalloc(1, sizeof(*lru_walk)); |
6a566b9c | 181 | walker->_policy = policy; |
182 | walker->_data = lru_walk; | |
183 | walker->Next = lru_walkNext; | |
184 | walker->Done = lru_walkDone; | |
185 | lru_walk->current = (LruNode *) lru->list.head; | |
6a566b9c | 186 | return walker; |
187 | } | |
188 | ||
189 | /** RemovalPurgeWalker **/ | |
190 | ||
191 | typedef struct _LruPurgeData LruPurgeData; | |
62e76326 | 192 | |
26ac0430 | 193 | struct _LruPurgeData { |
6a566b9c | 194 | LruNode *current; |
195 | LruNode *start; | |
196 | }; | |
197 | ||
198 | static StoreEntry * | |
199 | lru_purgeNext(RemovalPurgeWalker * walker) | |
200 | { | |
e6ccf245 | 201 | LruPurgeData *lru_walker = (LruPurgeData *)walker->_data; |
6a566b9c | 202 | RemovalPolicy *policy = walker->_policy; |
e6ccf245 | 203 | LruPolicyData *lru = (LruPolicyData *)policy->_data; |
6a566b9c | 204 | LruNode *lru_node; |
205 | StoreEntry *entry; | |
62e76326 | 206 | |
207 | try_again: | |
6a566b9c | 208 | lru_node = lru_walker->current; |
62e76326 | 209 | |
6a566b9c | 210 | if (!lru_node || walker->scanned >= walker->max_scan) |
62e76326 | 211 | return NULL; |
212 | ||
6a566b9c | 213 | walker->scanned += 1; |
62e76326 | 214 | |
6a566b9c | 215 | lru_walker->current = (LruNode *) lru_node->node.next; |
62e76326 | 216 | |
6a566b9c | 217 | if (lru_walker->current == lru_walker->start) { |
62e76326 | 218 | /* Last node found */ |
219 | lru_walker->current = NULL; | |
6a566b9c | 220 | } |
62e76326 | 221 | |
6a566b9c | 222 | entry = (StoreEntry *) lru_node->node.data; |
223 | dlinkDelete(&lru_node->node, &lru->list); | |
62e76326 | 224 | |
3900307b | 225 | if (entry->locked()) { |
62e76326 | 226 | /* Shit, it is locked. we can't return this one */ |
d7ae3534 | 227 | ++ walker->locked; |
62e76326 | 228 | dlinkAddTail(entry, &lru_node->node, &lru->list); |
229 | goto try_again; | |
6a566b9c | 230 | } |
62e76326 | 231 | |
dc47f531 | 232 | lru_node_pool->freeOne(lru_node); |
6a566b9c | 233 | lru->count -= 1; |
e6ccf245 | 234 | lru->setPolicyNode(entry, NULL); |
6a566b9c | 235 | return entry; |
236 | } | |
237 | ||
238 | static void | |
239 | lru_purgeDone(RemovalPurgeWalker * walker) | |
240 | { | |
241 | RemovalPolicy *policy = walker->_policy; | |
e6ccf245 | 242 | LruPolicyData *lru = (LruPolicyData *)policy->_data; |
6a566b9c | 243 | assert(strcmp(policy->_type, "lru") == 0); |
244 | assert(lru->nwalkers > 0); | |
245 | lru->nwalkers -= 1; | |
246 | safe_free(walker->_data); | |
aa839030 | 247 | delete walker; |
6a566b9c | 248 | } |
249 | ||
250 | static RemovalPurgeWalker * | |
251 | lru_purgeInit(RemovalPolicy * policy, int max_scan) | |
252 | { | |
e6ccf245 | 253 | LruPolicyData *lru = (LruPolicyData *)policy->_data; |
6a566b9c | 254 | RemovalPurgeWalker *walker; |
255 | LruPurgeData *lru_walk; | |
256 | lru->nwalkers += 1; | |
aa839030 | 257 | walker = new RemovalPurgeWalker; |
e6ccf245 | 258 | lru_walk = (LruPurgeData *)xcalloc(1, sizeof(*lru_walk)); |
6a566b9c | 259 | walker->_policy = policy; |
260 | walker->_data = lru_walk; | |
261 | walker->max_scan = max_scan; | |
262 | walker->Next = lru_purgeNext; | |
263 | walker->Done = lru_purgeDone; | |
264 | lru_walk->start = lru_walk->current = (LruNode *) lru->list.head; | |
6a566b9c | 265 | return walker; |
266 | } | |
267 | ||
8a3e7d9e | 268 | static void |
269 | lru_stats(RemovalPolicy * policy, StoreEntry * sentry) | |
270 | { | |
e6ccf245 | 271 | LruPolicyData *lru = (LruPolicyData *)policy->_data; |
b671cc68 | 272 | LruNode *lru_node = (LruNode *) lru->list.head; |
8a3e7d9e | 273 | |
62e76326 | 274 | again: |
275 | ||
8a3e7d9e | 276 | if (lru_node) { |
62e76326 | 277 | StoreEntry *entry = (StoreEntry *) lru_node->node.data; |
278 | ||
3900307b | 279 | if (entry->locked()) { |
62e76326 | 280 | lru_node = (LruNode *) lru_node->node.next; |
281 | goto again; | |
282 | } | |
283 | ||
284 | storeAppendPrintf(sentry, "LRU reference age: %.2f days\n", (double) (squid_curtime - entry->lastref) / (double) (24 * 60 * 60)); | |
8a3e7d9e | 285 | } |
286 | } | |
287 | ||
6a566b9c | 288 | static void |
289 | lru_free(RemovalPolicy * policy) | |
290 | { | |
e6ccf245 | 291 | LruPolicyData *lru = (LruPolicyData *)policy->_data; |
6a566b9c | 292 | /* Make some verification of the policy state */ |
293 | assert(strcmp(policy->_type, "lru") == 0); | |
294 | assert(lru->nwalkers); | |
295 | assert(lru->count); | |
296 | /* Ok, time to destroy this policy */ | |
e4a67a80 | 297 | safe_free(lru); |
6a566b9c | 298 | memset(policy, 0, sizeof(*policy)); |
aa839030 | 299 | delete policy; |
6a566b9c | 300 | } |
301 | ||
302 | RemovalPolicy * | |
9f913cf1 | 303 | createRemovalPolicy_lru(wordlist * args) |
6a566b9c | 304 | { |
305 | RemovalPolicy *policy; | |
306 | LruPolicyData *lru_data; | |
307 | /* no arguments expected or understood */ | |
308 | assert(!args); | |
309 | /* Initialize */ | |
62e76326 | 310 | |
d96ceb8e | 311 | if (!lru_node_pool) { |
b001e822 | 312 | /* Must be chunked */ |
04eb0689 | 313 | lru_node_pool = memPoolCreate("LRU policy node", sizeof(LruNode)); |
b001e822 | 314 | lru_node_pool->setChunkSize(512 * 1024); |
d96ceb8e | 315 | } |
62e76326 | 316 | |
6a566b9c | 317 | /* Allocate the needed structures */ |
e6ccf245 | 318 | lru_data = (LruPolicyData *)xcalloc(1, sizeof(*lru_data)); |
62e76326 | 319 | |
aa839030 | 320 | policy = new RemovalPolicy; |
62e76326 | 321 | |
6a566b9c | 322 | /* Initialize the URL data */ |
323 | lru_data->policy = policy; | |
62e76326 | 324 | |
6a566b9c | 325 | /* Populate the policy structure */ |
326 | policy->_type = "lru"; | |
62e76326 | 327 | |
6a566b9c | 328 | policy->_data = lru_data; |
62e76326 | 329 | |
6a566b9c | 330 | policy->Free = lru_free; |
62e76326 | 331 | |
6a566b9c | 332 | policy->Add = lru_add; |
62e76326 | 333 | |
6a566b9c | 334 | policy->Remove = lru_remove; |
62e76326 | 335 | |
6a566b9c | 336 | policy->Referenced = lru_referenced; |
62e76326 | 337 | |
6a566b9c | 338 | policy->Dereferenced = lru_referenced; |
62e76326 | 339 | |
6a566b9c | 340 | policy->WalkInit = lru_walkInit; |
62e76326 | 341 | |
6a566b9c | 342 | policy->PurgeInit = lru_purgeInit; |
62e76326 | 343 | |
8a3e7d9e | 344 | policy->Stats = lru_stats; |
62e76326 | 345 | |
6a566b9c | 346 | /* Increase policy usage count */ |
347 | nr_lru_policies += 0; | |
62e76326 | 348 | |
6a566b9c | 349 | return policy; |
350 | } | |
f53969cc | 351 |