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6a566b9c | 1 | |
2 | /* | |
b9ae18aa | 3 | * $Id: store_repl_heap.cc,v 1.17 2004/12/20 16:30:47 robertc Exp $ |
6a566b9c | 4 | * |
5 | * DEBUG: section ? HEAP based removal policies | |
6 | * AUTHOR: Henrik Nordstrom | |
7 | * | |
b6a7f52c | 8 | * Based on the ideas of the heap policy implemented by John Dilley of |
6095abfe | 9 | * Hewlett Packard. Rewritten from scratch when modularizing the removal |
10 | * policy implementation of Squid. | |
b6a7f52c | 11 | * |
12 | * For details on the original heap policy work and the thinking behind see | |
13 | * http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html | |
14 | * | |
6095abfe | 15 | * |
2b6662ba | 16 | * SQUID Web Proxy Cache http://www.squid-cache.org/ |
6a566b9c | 17 | * ---------------------------------------------------------- |
18 | * | |
2b6662ba | 19 | * Squid is the result of efforts by numerous individuals from |
20 | * the Internet community; see the CONTRIBUTORS file for full | |
21 | * details. Many organizations have provided support for Squid's | |
22 | * development; see the SPONSORS file for full details. Squid is | |
23 | * Copyrighted (C) 2001 by the Regents of the University of | |
24 | * California; see the COPYRIGHT file for full details. Squid | |
25 | * incorporates software developed and/or copyrighted by other | |
26 | * sources; see the CREDITS file for full details. | |
6a566b9c | 27 | * |
28 | * This program is free software; you can redistribute it and/or modify | |
29 | * it under the terms of the GNU General Public License as published by | |
30 | * the Free Software Foundation; either version 2 of the License, or | |
31 | * (at your option) any later version. | |
32 | * | |
33 | * This program is distributed in the hope that it will be useful, | |
34 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
35 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
36 | * GNU General Public License for more details. | |
37 | * | |
38 | * You should have received a copy of the GNU General Public License | |
39 | * along with this program; if not, write to the Free Software | |
40 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. | |
41 | * | |
42 | */ | |
43 | ||
44 | #include "squid.h" | |
45 | #include "heap.h" | |
46 | #include "store_heap_replacement.h" | |
e6ccf245 | 47 | #include "Store.h" |
528b2c61 | 48 | #include "MemObject.h" |
6a566b9c | 49 | |
50 | REMOVALPOLICYCREATE createRemovalPolicy_heap; | |
51 | ||
52 | static int nr_heap_policies = 0; | |
53 | ||
62e76326 | 54 | struct HeapPolicyData |
55 | { | |
e6ccf245 | 56 | void setPolicyNode (StoreEntry *, void *) const; |
6a566b9c | 57 | RemovalPolicy *policy; |
e6ccf245 | 58 | heap *theHeap; |
6a566b9c | 59 | heap_key_func *keyfunc; |
60 | int count; | |
61 | int nwalkers; | |
be1ed2a4 | 62 | enum heap_entry_type { |
62e76326 | 63 | TYPE_UNKNOWN = 0, TYPE_STORE_ENTRY, TYPE_STORE_MEM |
be1ed2a4 | 64 | } type; |
6a566b9c | 65 | }; |
66 | ||
67 | /* Hack to avoid having to remember the RemovalPolicyNode location. | |
68 | * Needed by the purge walker. | |
69 | */ | |
e6ccf245 | 70 | static enum HeapPolicyData::heap_entry_type |
6a566b9c | 71 | heap_guessType(StoreEntry * entry, RemovalPolicyNode * node) |
72 | { | |
73 | if (node == &entry->repl) | |
62e76326 | 74 | return HeapPolicyData::TYPE_STORE_ENTRY; |
75 | ||
6a566b9c | 76 | if (entry->mem_obj && node == &entry->mem_obj->repl) |
62e76326 | 77 | return HeapPolicyData::TYPE_STORE_MEM; |
78 | ||
6a566b9c | 79 | fatal("Heap Replacement: Unknown StoreEntry node type"); |
62e76326 | 80 | |
e6ccf245 | 81 | return HeapPolicyData::TYPE_UNKNOWN; |
6a566b9c | 82 | } |
e6ccf245 | 83 | |
84 | void | |
85 | HeapPolicyData::setPolicyNode (StoreEntry *entry, void *value) const | |
86 | { | |
87 | switch (type) { | |
62e76326 | 88 | |
89 | case TYPE_STORE_ENTRY: | |
90 | entry->repl.data = value; | |
91 | break ; | |
92 | ||
93 | case TYPE_STORE_MEM: | |
94 | entry->mem_obj->repl.data = value ; | |
95 | break ; | |
96 | ||
97 | default: | |
98 | break; | |
6a566b9c | 99 | } |
e6ccf245 | 100 | } |
6a566b9c | 101 | |
102 | static void | |
103 | heap_add(RemovalPolicy * policy, StoreEntry * entry, RemovalPolicyNode * node) | |
104 | { | |
e6ccf245 | 105 | HeapPolicyData *heap = (HeapPolicyData *)policy->_data; |
6a566b9c | 106 | assert(!node->data); |
62e76326 | 107 | |
6a566b9c | 108 | if (EBIT_TEST(entry->flags, ENTRY_SPECIAL)) |
62e76326 | 109 | return; /* We won't manage these.. they messes things up */ |
110 | ||
e6ccf245 | 111 | node->data = heap_insert(heap->theHeap, entry); |
62e76326 | 112 | |
6a566b9c | 113 | heap->count += 1; |
62e76326 | 114 | |
6a566b9c | 115 | if (!heap->type) |
62e76326 | 116 | heap->type = heap_guessType(entry, node); |
117 | ||
6a566b9c | 118 | /* Add a little more variance to the aging factor */ |
e6ccf245 | 119 | heap->theHeap->age += heap->theHeap->age / 100000000; |
6a566b9c | 120 | } |
121 | ||
122 | static void | |
123 | heap_remove(RemovalPolicy * policy, StoreEntry * entry, | |
62e76326 | 124 | RemovalPolicyNode * node) |
6a566b9c | 125 | { |
e6ccf245 | 126 | HeapPolicyData *heap = (HeapPolicyData *)policy->_data; |
127 | heap_node *hnode = (heap_node *)node->data; | |
62e76326 | 128 | |
6a566b9c | 129 | if (!hnode) |
62e76326 | 130 | return; |
131 | ||
e6ccf245 | 132 | heap_delete(heap->theHeap, hnode); |
62e76326 | 133 | |
6a566b9c | 134 | node->data = NULL; |
62e76326 | 135 | |
6a566b9c | 136 | heap->count -= 1; |
137 | } | |
138 | ||
139 | static void | |
140 | heap_referenced(RemovalPolicy * policy, const StoreEntry * entry, | |
62e76326 | 141 | RemovalPolicyNode * node) |
6a566b9c | 142 | { |
e6ccf245 | 143 | HeapPolicyData *heap = (HeapPolicyData *)policy->_data; |
144 | heap_node *hnode = (heap_node *)node->data; | |
62e76326 | 145 | |
6a566b9c | 146 | if (!hnode) |
62e76326 | 147 | return; |
148 | ||
e6ccf245 | 149 | heap_update(heap->theHeap, hnode, (StoreEntry *) entry); |
6a566b9c | 150 | } |
151 | ||
152 | /** RemovalPolicyWalker **/ | |
153 | ||
154 | typedef struct _HeapWalkData HeapWalkData; | |
62e76326 | 155 | |
156 | struct _HeapWalkData | |
157 | { | |
e6ccf245 | 158 | size_t current; |
6a566b9c | 159 | }; |
160 | ||
2d72d4fd | 161 | static const StoreEntry * |
6a566b9c | 162 | heap_walkNext(RemovalPolicyWalker * walker) |
163 | { | |
e6ccf245 | 164 | HeapWalkData *heap_walk = (HeapWalkData *)walker->_data; |
6a566b9c | 165 | RemovalPolicy *policy = walker->_policy; |
e6ccf245 | 166 | HeapPolicyData *heap = (HeapPolicyData *)policy->_data; |
6a566b9c | 167 | StoreEntry *entry; |
62e76326 | 168 | |
e6ccf245 | 169 | if (heap_walk->current >= heap_nodes(heap->theHeap)) |
62e76326 | 170 | return NULL; /* done */ |
171 | ||
e6ccf245 | 172 | entry = (StoreEntry *) heap_peep(heap->theHeap, heap_walk->current++); |
62e76326 | 173 | |
6a566b9c | 174 | return entry; |
175 | } | |
176 | ||
177 | static void | |
178 | heap_walkDone(RemovalPolicyWalker * walker) | |
179 | { | |
180 | RemovalPolicy *policy = walker->_policy; | |
e6ccf245 | 181 | HeapPolicyData *heap = (HeapPolicyData *)policy->_data; |
6a566b9c | 182 | assert(strcmp(policy->_type, "heap") == 0); |
183 | assert(heap->nwalkers > 0); | |
184 | heap->nwalkers -= 1; | |
185 | safe_free(walker->_data); | |
186 | cbdataFree(walker); | |
187 | } | |
188 | ||
189 | static RemovalPolicyWalker * | |
190 | heap_walkInit(RemovalPolicy * policy) | |
191 | { | |
e6ccf245 | 192 | HeapPolicyData *heap = (HeapPolicyData *)policy->_data; |
6a566b9c | 193 | RemovalPolicyWalker *walker; |
194 | HeapWalkData *heap_walk; | |
195 | heap->nwalkers += 1; | |
72711e31 | 196 | walker = cbdataAlloc(RemovalPolicyWalker); |
e6ccf245 | 197 | heap_walk = (HeapWalkData *)xcalloc(1, sizeof(*heap_walk)); |
6a566b9c | 198 | heap_walk->current = 0; |
199 | walker->_policy = policy; | |
200 | walker->_data = heap_walk; | |
201 | walker->Next = heap_walkNext; | |
202 | walker->Done = heap_walkDone; | |
6a566b9c | 203 | return walker; |
204 | } | |
205 | ||
206 | /** RemovalPurgeWalker **/ | |
207 | ||
208 | typedef struct _HeapPurgeData HeapPurgeData; | |
62e76326 | 209 | |
210 | struct _HeapPurgeData | |
211 | { | |
6a566b9c | 212 | link_list *locked_entries; |
213 | heap_key min_age; | |
214 | }; | |
215 | ||
216 | static StoreEntry * | |
217 | heap_purgeNext(RemovalPurgeWalker * walker) | |
218 | { | |
e6ccf245 | 219 | HeapPurgeData *heap_walker = (HeapPurgeData *)walker->_data; |
6a566b9c | 220 | RemovalPolicy *policy = walker->_policy; |
e6ccf245 | 221 | HeapPolicyData *heap = (HeapPolicyData *)policy->_data; |
6a566b9c | 222 | StoreEntry *entry; |
223 | heap_key age; | |
62e76326 | 224 | |
225 | try_again: | |
226 | ||
e6ccf245 | 227 | if (!heap_nodes(heap->theHeap) > 0) |
62e76326 | 228 | return NULL; /* done */ |
229 | ||
e6ccf245 | 230 | age = heap_peepminkey(heap->theHeap); |
62e76326 | 231 | |
e6ccf245 | 232 | entry = (StoreEntry *)heap_extractmin(heap->theHeap); |
62e76326 | 233 | |
6a566b9c | 234 | if (storeEntryLocked(entry)) { |
c540a303 | 235 | storeLockObject(entry); |
62e76326 | 236 | linklistPush(&heap_walker->locked_entries, entry); |
237 | goto try_again; | |
6a566b9c | 238 | } |
62e76326 | 239 | |
6a566b9c | 240 | heap_walker->min_age = age; |
e6ccf245 | 241 | heap->setPolicyNode(entry, NULL); |
6a566b9c | 242 | return entry; |
243 | } | |
244 | ||
245 | static void | |
246 | heap_purgeDone(RemovalPurgeWalker * walker) | |
247 | { | |
e6ccf245 | 248 | HeapPurgeData *heap_walker = (HeapPurgeData *)walker->_data; |
6a566b9c | 249 | RemovalPolicy *policy = walker->_policy; |
e6ccf245 | 250 | HeapPolicyData *heap = (HeapPolicyData *)policy->_data; |
6a566b9c | 251 | StoreEntry *entry; |
252 | assert(strcmp(policy->_type, "heap") == 0); | |
253 | assert(heap->nwalkers > 0); | |
254 | heap->nwalkers -= 1; | |
62e76326 | 255 | |
6a566b9c | 256 | if (heap_walker->min_age > 0) { |
62e76326 | 257 | heap->theHeap->age = heap_walker->min_age; |
258 | debug(81, 3) ("heap_purgeDone: Heap age set to %f\n", | |
259 | (double) heap->theHeap->age); | |
6a566b9c | 260 | } |
62e76326 | 261 | |
6a566b9c | 262 | /* |
263 | * Reinsert the locked entries | |
264 | */ | |
e6ccf245 | 265 | while ((entry = (StoreEntry *)linklistShift(&heap_walker->locked_entries))) { |
62e76326 | 266 | heap_node *node = heap_insert(heap->theHeap, entry); |
267 | heap->setPolicyNode(entry, node); | |
c540a303 | 268 | storeUnlockObject(entry); |
6a566b9c | 269 | } |
62e76326 | 270 | |
6a566b9c | 271 | safe_free(walker->_data); |
272 | cbdataFree(walker); | |
273 | } | |
274 | ||
275 | static RemovalPurgeWalker * | |
276 | heap_purgeInit(RemovalPolicy * policy, int max_scan) | |
277 | { | |
e6ccf245 | 278 | HeapPolicyData *heap = (HeapPolicyData *)policy->_data; |
6a566b9c | 279 | RemovalPurgeWalker *walker; |
280 | HeapPurgeData *heap_walk; | |
281 | heap->nwalkers += 1; | |
72711e31 | 282 | walker = cbdataAlloc(RemovalPurgeWalker); |
e6ccf245 | 283 | heap_walk = (HeapPurgeData *)xcalloc(1, sizeof(*heap_walk)); |
6a566b9c | 284 | heap_walk->min_age = 0.0; |
285 | heap_walk->locked_entries = NULL; | |
286 | walker->_policy = policy; | |
287 | walker->_data = heap_walk; | |
288 | walker->max_scan = max_scan; | |
289 | walker->Next = heap_purgeNext; | |
290 | walker->Done = heap_purgeDone; | |
6a566b9c | 291 | return walker; |
292 | } | |
293 | ||
294 | static void | |
295 | heap_free(RemovalPolicy * policy) | |
296 | { | |
e6ccf245 | 297 | HeapPolicyData *heap = (HeapPolicyData *)policy->_data; |
6a566b9c | 298 | /* Make some verification of the policy state */ |
299 | assert(strcmp(policy->_type, "heap") == 0); | |
300 | assert(heap->nwalkers); | |
301 | assert(heap->count); | |
302 | /* Ok, time to destroy this policy */ | |
e4a67a80 | 303 | safe_free(heap); |
6a566b9c | 304 | memset(policy, 0, sizeof(*policy)); |
305 | cbdataFree(policy); | |
306 | } | |
307 | ||
308 | RemovalPolicy * | |
309 | createRemovalPolicy_heap(wordlist * args) | |
310 | { | |
311 | RemovalPolicy *policy; | |
312 | HeapPolicyData *heap_data; | |
c193c972 | 313 | const char *keytype; |
6a566b9c | 314 | /* Allocate the needed structures */ |
72711e31 | 315 | policy = cbdataAlloc(RemovalPolicy); |
e6ccf245 | 316 | heap_data = (HeapPolicyData *)xcalloc(1, sizeof(*heap_data)); |
6a566b9c | 317 | /* Initialize the policy data */ |
318 | heap_data->policy = policy; | |
62e76326 | 319 | |
6a566b9c | 320 | if (args) { |
62e76326 | 321 | keytype = args->key; |
322 | args = args->next; | |
6a566b9c | 323 | } else { |
62e76326 | 324 | debug(81, 1) ("createRemovalPolicy_heap: No key type specified. Using LRU\n"); |
325 | keytype = "LRU"; | |
6a566b9c | 326 | } |
62e76326 | 327 | |
6a566b9c | 328 | if (!strcmp(keytype, "GDSF")) |
62e76326 | 329 | heap_data->keyfunc = HeapKeyGen_StoreEntry_GDSF; |
6a566b9c | 330 | else if (!strcmp(keytype, "LFUDA")) |
62e76326 | 331 | heap_data->keyfunc = HeapKeyGen_StoreEntry_LFUDA; |
6a566b9c | 332 | else if (!strcmp(keytype, "LRU")) |
62e76326 | 333 | heap_data->keyfunc = HeapKeyGen_StoreEntry_LRU; |
6a566b9c | 334 | else { |
62e76326 | 335 | debug(81, 0) ("createRemovalPolicy_heap: Unknown key type \"%s\". Using LRU\n", |
336 | keytype); | |
337 | heap_data->keyfunc = HeapKeyGen_StoreEntry_LRU; | |
6a566b9c | 338 | } |
62e76326 | 339 | |
6a566b9c | 340 | /* No additional arguments expected */ |
341 | assert(!args); | |
62e76326 | 342 | |
e6ccf245 | 343 | heap_data->theHeap = new_heap(1000, heap_data->keyfunc); |
62e76326 | 344 | |
e6ccf245 | 345 | heap_data->theHeap->age = 1.0; |
62e76326 | 346 | |
6a566b9c | 347 | /* Populate the policy structure */ |
348 | policy->_type = "heap"; | |
62e76326 | 349 | |
6a566b9c | 350 | policy->_data = heap_data; |
62e76326 | 351 | |
6a566b9c | 352 | policy->Free = heap_free; |
62e76326 | 353 | |
6a566b9c | 354 | policy->Add = heap_add; |
62e76326 | 355 | |
6a566b9c | 356 | policy->Remove = heap_remove; |
62e76326 | 357 | |
6a566b9c | 358 | policy->Referenced = NULL; |
62e76326 | 359 | |
6a566b9c | 360 | policy->Dereferenced = heap_referenced; |
62e76326 | 361 | |
6a566b9c | 362 | policy->WalkInit = heap_walkInit; |
62e76326 | 363 | |
6a566b9c | 364 | policy->PurgeInit = heap_purgeInit; |
62e76326 | 365 | |
6a566b9c | 366 | /* Increase policy usage count */ |
367 | nr_heap_policies += 0; | |
62e76326 | 368 | |
6a566b9c | 369 | return policy; |
370 | } |