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1 /*
2     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
3     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
4     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
5     Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
6 
7     This library is free software; you can redistribute it and/or
8     modify it under the terms of the GNU Library General Public
9     License as published by the Free Software Foundation; either
10     version 2 of the License, or (at your option) any later version.
11 
12     This library is distributed in the hope that it will be useful,
13     but WITHOUT ANY WARRANTY; without even the implied warranty of
14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15     Library General Public License for more details.
16 
17     You should have received a copy of the GNU Library General Public License
18     along with this library; see the file COPYING.LIB.  If not, write to
19     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20     Boston, MA 02110-1301, USA.
21 */
22 
23 #include "config.h"
24 #include "core/fetch/MemoryCache.h"
25 
26 #include "core/dom/CrossThreadTask.h"
27 #include "core/dom/Document.h"
28 #include "core/fetch/ResourcePtr.h"
29 #include "core/frame/FrameView.h"
30 #include "core/workers/WorkerGlobalScope.h"
31 #include "core/workers/WorkerLoaderProxy.h"
32 #include "core/workers/WorkerThread.h"
33 #include "platform/Logging.h"
34 #include "platform/TraceEvent.h"
35 #include "platform/weborigin/SecurityOrigin.h"
36 #include "platform/weborigin/SecurityOriginHash.h"
37 #include "public/platform/Platform.h"
38 #include "wtf/Assertions.h"
39 #include "wtf/CurrentTime.h"
40 #include "wtf/MathExtras.h"
41 #include "wtf/TemporaryChange.h"
42 #include "wtf/text/CString.h"
43 
44 using namespace std;
45 
46 namespace WebCore {
47 
48 static MemoryCache* gMemoryCache;
49 
50 static const unsigned cDefaultCacheCapacity = 8192 * 1024;
51 static const unsigned cDeferredPruneDeadCapacityFactor = 2;
52 static const int cMinDelayBeforeLiveDecodedPrune = 1; // Seconds.
53 static const double cMaxPruneDeferralDelay = 0.5; // Seconds.
54 static const float cTargetPrunePercentage = .95f; // Percentage of capacity toward which we prune, to avoid immediately pruning again.
55 
memoryCache()56 MemoryCache* memoryCache()
57 {
58     ASSERT(WTF::isMainThread());
59     if (!gMemoryCache)
60         gMemoryCache = new MemoryCache();
61     return gMemoryCache;
62 }
63 
setMemoryCacheForTesting(MemoryCache * memoryCache)64 void setMemoryCacheForTesting(MemoryCache* memoryCache)
65 {
66     gMemoryCache = memoryCache;
67 }
68 
MemoryCache()69 MemoryCache::MemoryCache()
70     : m_inPruneResources(false)
71     , m_prunePending(false)
72     , m_maxPruneDeferralDelay(cMaxPruneDeferralDelay)
73     , m_capacity(cDefaultCacheCapacity)
74     , m_minDeadCapacity(0)
75     , m_maxDeadCapacity(cDefaultCacheCapacity)
76     , m_maxDeferredPruneDeadCapacity(cDeferredPruneDeadCapacityFactor * cDefaultCacheCapacity)
77     , m_delayBeforeLiveDecodedPrune(cMinDelayBeforeLiveDecodedPrune)
78     , m_liveSize(0)
79     , m_deadSize(0)
80 #ifdef MEMORY_CACHE_STATS
81     , m_statsTimer(this, &MemoryCache::dumpStats)
82 #endif
83 {
84 #ifdef MEMORY_CACHE_STATS
85     const double statsIntervalInSeconds = 15;
86     m_statsTimer.startRepeating(statsIntervalInSeconds);
87 #endif
88     m_pruneTimeStamp = m_pruneFrameTimeStamp = FrameView::currentFrameTimeStamp();
89 }
90 
~MemoryCache()91 MemoryCache::~MemoryCache()
92 {
93     if (m_prunePending)
94         blink::Platform::current()->currentThread()->removeTaskObserver(this);
95 }
96 
removeFragmentIdentifierIfNeeded(const KURL & originalURL)97 KURL MemoryCache::removeFragmentIdentifierIfNeeded(const KURL& originalURL)
98 {
99     if (!originalURL.hasFragmentIdentifier())
100         return originalURL;
101     // Strip away fragment identifier from HTTP URLs.
102     // Data URLs must be unmodified. For file and custom URLs clients may expect resources
103     // to be unique even when they differ by the fragment identifier only.
104     if (!originalURL.protocolIsInHTTPFamily())
105         return originalURL;
106     KURL url = originalURL;
107     url.removeFragmentIdentifier();
108     return url;
109 }
110 
add(Resource * resource)111 void MemoryCache::add(Resource* resource)
112 {
113     ASSERT(WTF::isMainThread());
114     m_resources.set(resource->url(), resource);
115     resource->setInCache(true);
116     resource->updateForAccess();
117 
118     WTF_LOG(ResourceLoading, "MemoryCache::add Added '%s', resource %p\n", resource->url().string().latin1().data(), resource);
119 }
120 
replace(Resource * newResource,Resource * oldResource)121 void MemoryCache::replace(Resource* newResource, Resource* oldResource)
122 {
123     evict(oldResource);
124     ASSERT(!m_resources.get(newResource->url()));
125     m_resources.set(newResource->url(), newResource);
126     newResource->setInCache(true);
127     insertInLRUList(newResource);
128     int delta = newResource->size();
129     if (newResource->decodedSize() && newResource->hasClients())
130         insertInLiveDecodedResourcesList(newResource);
131     if (delta)
132         adjustSize(newResource->hasClients(), delta);
133 }
134 
resourceForURL(const KURL & resourceURL)135 Resource* MemoryCache::resourceForURL(const KURL& resourceURL)
136 {
137     ASSERT(WTF::isMainThread());
138     KURL url = removeFragmentIdentifierIfNeeded(resourceURL);
139     Resource* resource = m_resources.get(url);
140     if (resource && !resource->makePurgeable(false)) {
141         ASSERT(!resource->hasClients());
142         evict(resource);
143         return 0;
144     }
145     return resource;
146 }
147 
deadCapacity() const148 size_t MemoryCache::deadCapacity() const
149 {
150     // Dead resource capacity is whatever space is not occupied by live resources, bounded by an independent minimum and maximum.
151     size_t capacity = m_capacity - min(m_liveSize, m_capacity); // Start with available capacity.
152     capacity = max(capacity, m_minDeadCapacity); // Make sure it's above the minimum.
153     capacity = min(capacity, m_maxDeadCapacity); // Make sure it's below the maximum.
154     return capacity;
155 }
156 
liveCapacity() const157 size_t MemoryCache::liveCapacity() const
158 {
159     // Live resource capacity is whatever is left over after calculating dead resource capacity.
160     return m_capacity - deadCapacity();
161 }
162 
pruneLiveResources()163 void MemoryCache::pruneLiveResources()
164 {
165     ASSERT(!m_prunePending);
166     size_t capacity = liveCapacity();
167     if (!m_liveSize || (capacity && m_liveSize <= capacity))
168         return;
169 
170     size_t targetSize = static_cast<size_t>(capacity * cTargetPrunePercentage); // Cut by a percentage to avoid immediately pruning again.
171 
172     // Destroy any decoded data in live objects that we can.
173     // Start from the tail, since this is the lowest priority
174     // and least recently accessed of the objects.
175 
176     // The list might not be sorted by the m_lastDecodedFrameTimeStamp. The impact
177     // of this weaker invariant is minor as the below if statement to check the
178     // elapsedTime will evaluate to false as the current time will be a lot
179     // greater than the current->m_lastDecodedFrameTimeStamp.
180     // For more details see: https://bugs.webkit.org/show_bug.cgi?id=30209
181 
182     // Start pruning from the lowest priority list.
183     for (int priority = Resource::CacheLiveResourcePriorityLow; priority <= Resource::CacheLiveResourcePriorityHigh; ++priority) {
184         Resource* current = m_liveDecodedResources[priority].m_tail;
185         while (current) {
186             Resource* prev = current->m_prevInLiveResourcesList;
187             ASSERT(current->hasClients());
188             if (current->isLoaded() && current->decodedSize()) {
189                 // Check to see if the remaining resources are too new to prune.
190                 double elapsedTime = m_pruneFrameTimeStamp - current->m_lastDecodedAccessTime;
191                 if (elapsedTime < m_delayBeforeLiveDecodedPrune)
192                     return;
193 
194                 // Destroy our decoded data. This will remove us from
195                 // m_liveDecodedResources, and possibly move us to a different LRU
196                 // list in m_allResources.
197                 current->destroyDecodedData();
198 
199                 if (targetSize && m_liveSize <= targetSize)
200                     return;
201             }
202             current = prev;
203         }
204     }
205 }
206 
pruneDeadResources()207 void MemoryCache::pruneDeadResources()
208 {
209     size_t capacity = deadCapacity();
210     if (!m_deadSize || (capacity && m_deadSize <= capacity))
211         return;
212 
213     size_t targetSize = static_cast<size_t>(capacity * cTargetPrunePercentage); // Cut by a percentage to avoid immediately pruning again.
214 
215     int size = m_allResources.size();
216 
217     // See if we have any purged resources we can evict.
218     for (int i = 0; i < size; i++) {
219         Resource* current = m_allResources[i].m_tail;
220         while (current) {
221             Resource* prev = current->m_prevInAllResourcesList;
222             if (current->wasPurged()) {
223                 ASSERT(!current->hasClients());
224                 ASSERT(!current->isPreloaded());
225                 evict(current);
226             }
227             current = prev;
228         }
229     }
230     if (targetSize && m_deadSize <= targetSize)
231         return;
232 
233     bool canShrinkLRULists = true;
234     for (int i = size - 1; i >= 0; i--) {
235         // Remove from the tail, since this is the least frequently accessed of the objects.
236         Resource* current = m_allResources[i].m_tail;
237 
238         // First flush all the decoded data in this queue.
239         while (current) {
240             // Protect 'previous' so it can't get deleted during destroyDecodedData().
241             ResourcePtr<Resource> previous = current->m_prevInAllResourcesList;
242             ASSERT(!previous || previous->inCache());
243             if (!current->hasClients() && !current->isPreloaded() && current->isLoaded()) {
244                 // Destroy our decoded data. This will remove us from
245                 // m_liveDecodedResources, and possibly move us to a different
246                 // LRU list in m_allResources.
247                 current->destroyDecodedData();
248 
249                 if (targetSize && m_deadSize <= targetSize)
250                     return;
251             }
252             // Decoded data may reference other resources. Stop iterating if 'previous' somehow got
253             // kicked out of cache during destroyDecodedData().
254             if (previous && !previous->inCache())
255                 break;
256             current = previous.get();
257         }
258 
259         // Now evict objects from this queue.
260         current = m_allResources[i].m_tail;
261         while (current) {
262             ResourcePtr<Resource> previous = current->m_prevInAllResourcesList;
263             ASSERT(!previous || previous->inCache());
264             if (!current->hasClients() && !current->isPreloaded() && !current->isCacheValidator()) {
265                 evict(current);
266                 if (targetSize && m_deadSize <= targetSize)
267                     return;
268             }
269             if (previous && !previous->inCache())
270                 break;
271             current = previous.get();
272         }
273 
274         // Shrink the vector back down so we don't waste time inspecting
275         // empty LRU lists on future prunes.
276         if (m_allResources[i].m_head)
277             canShrinkLRULists = false;
278         else if (canShrinkLRULists)
279             m_allResources.resize(i);
280     }
281 }
282 
setCapacities(size_t minDeadBytes,size_t maxDeadBytes,size_t totalBytes)283 void MemoryCache::setCapacities(size_t minDeadBytes, size_t maxDeadBytes, size_t totalBytes)
284 {
285     ASSERT(minDeadBytes <= maxDeadBytes);
286     ASSERT(maxDeadBytes <= totalBytes);
287     m_minDeadCapacity = minDeadBytes;
288     m_maxDeadCapacity = maxDeadBytes;
289     m_maxDeferredPruneDeadCapacity = cDeferredPruneDeadCapacityFactor * maxDeadBytes;
290     m_capacity = totalBytes;
291     prune();
292 }
293 
evict(Resource * resource)294 void MemoryCache::evict(Resource* resource)
295 {
296     ASSERT(WTF::isMainThread());
297     WTF_LOG(ResourceLoading, "Evicting resource %p for '%s' from cache", resource, resource->url().string().latin1().data());
298     // The resource may have already been removed by someone other than our caller,
299     // who needed a fresh copy for a reload. See <http://bugs.webkit.org/show_bug.cgi?id=12479#c6>.
300     if (resource->inCache()) {
301         // Remove from the resource map.
302         m_resources.remove(resource->url());
303         resource->setInCache(false);
304 
305         // Remove from the appropriate LRU list.
306         removeFromLRUList(resource);
307         removeFromLiveDecodedResourcesList(resource);
308         adjustSize(resource->hasClients(), -static_cast<ptrdiff_t>(resource->size()));
309     } else {
310         ASSERT(m_resources.get(resource->url()) != resource);
311     }
312 
313     resource->deleteIfPossible();
314 }
315 
lruListFor(Resource * resource)316 MemoryCache::LRUList* MemoryCache::lruListFor(Resource* resource)
317 {
318     unsigned accessCount = max(resource->accessCount(), 1U);
319     unsigned queueIndex = WTF::fastLog2(resource->size() / accessCount);
320 #ifndef NDEBUG
321     resource->m_lruIndex = queueIndex;
322 #endif
323     if (m_allResources.size() <= queueIndex)
324         m_allResources.grow(queueIndex + 1);
325     return &m_allResources[queueIndex];
326 }
327 
removeFromLRUList(Resource * resource)328 void MemoryCache::removeFromLRUList(Resource* resource)
329 {
330     // If we've never been accessed, then we're brand new and not in any list.
331     if (!resource->accessCount())
332         return;
333 
334 #if !ASSERT_DISABLED
335     unsigned oldListIndex = resource->m_lruIndex;
336 #endif
337 
338     LRUList* list = lruListFor(resource);
339 
340 #if !ASSERT_DISABLED
341     // Verify that the list we got is the list we want.
342     ASSERT(resource->m_lruIndex == oldListIndex);
343 
344     // Verify that we are in fact in this list.
345     bool found = false;
346     for (Resource* current = list->m_head; current; current = current->m_nextInAllResourcesList) {
347         if (current == resource) {
348             found = true;
349             break;
350         }
351     }
352     ASSERT(found);
353 #endif
354 
355     Resource* next = resource->m_nextInAllResourcesList;
356     Resource* prev = resource->m_prevInAllResourcesList;
357 
358     if (!next && !prev && list->m_head != resource)
359         return;
360 
361     resource->m_nextInAllResourcesList = 0;
362     resource->m_prevInAllResourcesList = 0;
363 
364     if (next)
365         next->m_prevInAllResourcesList = prev;
366     else if (list->m_tail == resource)
367         list->m_tail = prev;
368 
369     if (prev)
370         prev->m_nextInAllResourcesList = next;
371     else if (list->m_head == resource)
372         list->m_head = next;
373 }
374 
insertInLRUList(Resource * resource)375 void MemoryCache::insertInLRUList(Resource* resource)
376 {
377     // Make sure we aren't in some list already.
378     ASSERT(!resource->m_nextInAllResourcesList && !resource->m_prevInAllResourcesList);
379     ASSERT(resource->inCache());
380     ASSERT(resource->accessCount() > 0);
381 
382     LRUList* list = lruListFor(resource);
383 
384     resource->m_nextInAllResourcesList = list->m_head;
385     if (list->m_head)
386         list->m_head->m_prevInAllResourcesList = resource;
387     list->m_head = resource;
388 
389     if (!resource->m_nextInAllResourcesList)
390         list->m_tail = resource;
391 
392 #if !ASSERT_DISABLED
393     // Verify that we are in now in the list like we should be.
394     list = lruListFor(resource);
395     bool found = false;
396     for (Resource* current = list->m_head; current; current = current->m_nextInAllResourcesList) {
397         if (current == resource) {
398             found = true;
399             break;
400         }
401     }
402     ASSERT(found);
403 #endif
404 
405 }
406 
removeFromLiveDecodedResourcesList(Resource * resource)407 void MemoryCache::removeFromLiveDecodedResourcesList(Resource* resource)
408 {
409     // If we've never been accessed, then we're brand new and not in any list.
410     if (!resource->m_inLiveDecodedResourcesList)
411         return;
412     resource->m_inLiveDecodedResourcesList = false;
413 
414     LRUList* list = &m_liveDecodedResources[resource->cacheLiveResourcePriority()];
415 
416 #if !ASSERT_DISABLED
417     // Verify that we are in fact in this list.
418     bool found = false;
419     for (Resource* current = list->m_head; current; current = current->m_nextInLiveResourcesList) {
420         if (current == resource) {
421             found = true;
422             break;
423         }
424     }
425     ASSERT(found);
426 #endif
427 
428     Resource* next = resource->m_nextInLiveResourcesList;
429     Resource* prev = resource->m_prevInLiveResourcesList;
430 
431     if (!next && !prev && list->m_head != resource)
432         return;
433 
434     resource->m_nextInLiveResourcesList = 0;
435     resource->m_prevInLiveResourcesList = 0;
436 
437     if (next)
438         next->m_prevInLiveResourcesList = prev;
439     else if (list->m_tail == resource)
440         list->m_tail = prev;
441 
442     if (prev)
443         prev->m_nextInLiveResourcesList = next;
444     else if (list->m_head == resource)
445         list->m_head = next;
446 }
447 
insertInLiveDecodedResourcesList(Resource * resource)448 void MemoryCache::insertInLiveDecodedResourcesList(Resource* resource)
449 {
450     // Make sure we aren't in the list already.
451     ASSERT(!resource->m_nextInLiveResourcesList && !resource->m_prevInLiveResourcesList && !resource->m_inLiveDecodedResourcesList);
452     resource->m_inLiveDecodedResourcesList = true;
453 
454     LRUList* list = &m_liveDecodedResources[resource->cacheLiveResourcePriority()];
455     resource->m_nextInLiveResourcesList = list->m_head;
456     if (list->m_head)
457         list->m_head->m_prevInLiveResourcesList = resource;
458     list->m_head = resource;
459 
460     if (!resource->m_nextInLiveResourcesList)
461         list->m_tail = resource;
462 
463 #if !ASSERT_DISABLED
464     // Verify that we are in now in the list like we should be.
465     bool found = false;
466     for (Resource* current = list->m_head; current; current = current->m_nextInLiveResourcesList) {
467         if (current == resource) {
468             found = true;
469             break;
470         }
471     }
472     ASSERT(found);
473 #endif
474 
475 }
476 
addToLiveResourcesSize(Resource * resource)477 void MemoryCache::addToLiveResourcesSize(Resource* resource)
478 {
479     ASSERT(m_deadSize >= resource->size());
480     m_liveSize += resource->size();
481     m_deadSize -= resource->size();
482 }
483 
removeFromLiveResourcesSize(Resource * resource)484 void MemoryCache::removeFromLiveResourcesSize(Resource* resource)
485 {
486     ASSERT(m_liveSize >= resource->size());
487     m_liveSize -= resource->size();
488     m_deadSize += resource->size();
489 }
490 
adjustSize(bool live,ptrdiff_t delta)491 void MemoryCache::adjustSize(bool live, ptrdiff_t delta)
492 {
493     if (live) {
494         ASSERT(delta >= 0 || m_liveSize >= static_cast<size_t>(-delta) );
495         m_liveSize += delta;
496     } else {
497         ASSERT(delta >= 0 || m_deadSize >= static_cast<size_t>(-delta) );
498         m_deadSize += delta;
499     }
500 }
501 
removeURLFromCache(ExecutionContext * context,const KURL & url)502 void MemoryCache::removeURLFromCache(ExecutionContext* context, const KURL& url)
503 {
504     if (context->isWorkerGlobalScope()) {
505         WorkerGlobalScope* workerGlobalScope = toWorkerGlobalScope(context);
506         workerGlobalScope->thread()->workerLoaderProxy().postTaskToLoader(createCallbackTask(&removeURLFromCacheInternal, url));
507         return;
508     }
509     removeURLFromCacheInternal(context, url);
510 }
511 
removeURLFromCacheInternal(ExecutionContext *,const KURL & url)512 void MemoryCache::removeURLFromCacheInternal(ExecutionContext*, const KURL& url)
513 {
514     if (Resource* resource = memoryCache()->resourceForURL(url))
515         memoryCache()->remove(resource);
516 }
517 
addResource(Resource * o)518 void MemoryCache::TypeStatistic::addResource(Resource* o)
519 {
520     bool purged = o->wasPurged();
521     bool purgeable = o->isPurgeable() && !purged;
522     size_t pageSize = (o->encodedSize() + o->overheadSize() + 4095) & ~4095;
523     count++;
524     size += purged ? 0 : o->size();
525     liveSize += o->hasClients() ? o->size() : 0;
526     decodedSize += o->decodedSize();
527     encodedSize += o->encodedSize();
528     encodedSizeDuplicatedInDataURLs += o->url().protocolIsData() ? o->encodedSize() : 0;
529     purgeableSize += purgeable ? pageSize : 0;
530     purgedSize += purged ? pageSize : 0;
531 }
532 
getStatistics()533 MemoryCache::Statistics MemoryCache::getStatistics()
534 {
535     Statistics stats;
536     ResourceMap::iterator e = m_resources.end();
537     for (ResourceMap::iterator i = m_resources.begin(); i != e; ++i) {
538         Resource* resource = i->value;
539         switch (resource->type()) {
540         case Resource::Image:
541             stats.images.addResource(resource);
542             break;
543         case Resource::CSSStyleSheet:
544             stats.cssStyleSheets.addResource(resource);
545             break;
546         case Resource::Script:
547             stats.scripts.addResource(resource);
548             break;
549         case Resource::XSLStyleSheet:
550             stats.xslStyleSheets.addResource(resource);
551             break;
552         case Resource::Font:
553             stats.fonts.addResource(resource);
554             break;
555         default:
556             stats.other.addResource(resource);
557             break;
558         }
559     }
560     return stats;
561 }
562 
evictResources()563 void MemoryCache::evictResources()
564 {
565     for (;;) {
566         ResourceMap::iterator i = m_resources.begin();
567         if (i == m_resources.end())
568             break;
569         evict(i->value);
570     }
571 }
572 
prune(Resource * justReleasedResource)573 void MemoryCache::prune(Resource* justReleasedResource)
574 {
575     TRACE_EVENT0("renderer", "MemoryCache::prune()");
576 
577     if (m_inPruneResources)
578         return;
579     if (m_liveSize + m_deadSize <= m_capacity && m_maxDeadCapacity && m_deadSize <= m_maxDeadCapacity) // Fast path.
580         return;
581 
582     // To avoid burdening the current thread with repetitive pruning jobs,
583     // pruning is postponed until the end of the current task. If it has
584     // been more that m_maxPruneDeferralDelay since the last prune,
585     // then we prune immediately.
586     // If the current thread's run loop is not active, then pruning will happen
587     // immediately only if it has been over m_maxPruneDeferralDelay
588     // since the last prune.
589     double currentTime = WTF::currentTime();
590     if (m_prunePending) {
591         if (currentTime - m_pruneTimeStamp >= m_maxPruneDeferralDelay) {
592             pruneNow(currentTime);
593         }
594     } else {
595         if (currentTime - m_pruneTimeStamp >= m_maxPruneDeferralDelay) {
596             pruneNow(currentTime); // Delay exceeded, prune now.
597         } else {
598             // Defer.
599             blink::Platform::current()->currentThread()->addTaskObserver(this);
600             m_prunePending = true;
601         }
602     }
603 
604     if (m_prunePending && m_deadSize > m_maxDeferredPruneDeadCapacity && justReleasedResource) {
605         // The following eviction does not respect LRU order, but it can be done
606         // immediately in constant time, as opposed to pruneDeadResources, which
607         // we would rather defer because it is O(N), which would make tear-down of N
608         // objects O(N^2) if we pruned immediately. This immediate eviction is a
609         // safeguard against runaway memory consumption by dead resources
610         // while a prune is pending.
611         evict(justReleasedResource);
612 
613         // As a last resort, prune immediately
614         if (m_deadSize > m_maxDeferredPruneDeadCapacity)
615             pruneNow(currentTime);
616     }
617 }
618 
willProcessTask()619 void MemoryCache::willProcessTask()
620 {
621 }
622 
didProcessTask()623 void MemoryCache::didProcessTask()
624 {
625     // Perform deferred pruning
626     ASSERT(m_prunePending);
627     pruneNow(WTF::currentTime());
628 }
629 
pruneNow(double currentTime)630 void MemoryCache::pruneNow(double currentTime)
631 {
632     if (m_prunePending) {
633         m_prunePending = false;
634         blink::Platform::current()->currentThread()->removeTaskObserver(this);
635     }
636 
637     TemporaryChange<bool> reentrancyProtector(m_inPruneResources, true);
638     pruneDeadResources(); // Prune dead first, in case it was "borrowing" capacity from live.
639     pruneLiveResources();
640     m_pruneFrameTimeStamp = FrameView::currentFrameTimeStamp();
641     m_pruneTimeStamp = currentTime;
642 }
643 
644 #ifdef MEMORY_CACHE_STATS
645 
dumpStats(Timer<MemoryCache> *)646 void MemoryCache::dumpStats(Timer<MemoryCache>*)
647 {
648     Statistics s = getStatistics();
649     printf("%-13s %-13s %-13s %-13s %-13s %-13s %-13s\n", "", "Count", "Size", "LiveSize", "DecodedSize", "PurgeableSize", "PurgedSize");
650     printf("%-13s %-13s %-13s %-13s %-13s %-13s %-13s\n", "-------------", "-------------", "-------------", "-------------", "-------------", "-------------", "-------------");
651     printf("%-13s %13d %13d %13d %13d %13d %13d\n", "Images", s.images.count, s.images.size, s.images.liveSize, s.images.decodedSize, s.images.purgeableSize, s.images.purgedSize);
652     printf("%-13s %13d %13d %13d %13d %13d %13d\n", "CSS", s.cssStyleSheets.count, s.cssStyleSheets.size, s.cssStyleSheets.liveSize, s.cssStyleSheets.decodedSize, s.cssStyleSheets.purgeableSize, s.cssStyleSheets.purgedSize);
653     printf("%-13s %13d %13d %13d %13d %13d %13d\n", "XSL", s.xslStyleSheets.count, s.xslStyleSheets.size, s.xslStyleSheets.liveSize, s.xslStyleSheets.decodedSize, s.xslStyleSheets.purgeableSize, s.xslStyleSheets.purgedSize);
654     printf("%-13s %13d %13d %13d %13d %13d %13d\n", "JavaScript", s.scripts.count, s.scripts.size, s.scripts.liveSize, s.scripts.decodedSize, s.scripts.purgeableSize, s.scripts.purgedSize);
655     printf("%-13s %13d %13d %13d %13d %13d %13d\n", "Fonts", s.fonts.count, s.fonts.size, s.fonts.liveSize, s.fonts.decodedSize, s.fonts.purgeableSize, s.fonts.purgedSize);
656     printf("%-13s %13d %13d %13d %13d %13d %13d\n", "Other", s.other.count, s.other.size, s.other.liveSize, s.other.decodedSize, s.other.purgeableSize, s.other.purgedSize);
657     printf("%-13s %-13s %-13s %-13s %-13s %-13s %-13s\n\n", "-------------", "-------------", "-------------", "-------------", "-------------", "-------------", "-------------");
658 
659     printf("Duplication of encoded data from data URLs\n");
660     printf("%-13s %13d of %13d\n", "Images",     s.images.encodedSizeDuplicatedInDataURLs,         s.images.encodedSize);
661     printf("%-13s %13d of %13d\n", "CSS",        s.cssStyleSheets.encodedSizeDuplicatedInDataURLs, s.cssStyleSheets.encodedSize);
662     printf("%-13s %13d of %13d\n", "XSL",        s.xslStyleSheets.encodedSizeDuplicatedInDataURLs, s.xslStyleSheets.encodedSize);
663     printf("%-13s %13d of %13d\n", "JavaScript", s.scripts.encodedSizeDuplicatedInDataURLs,        s.scripts.encodedSize);
664     printf("%-13s %13d of %13d\n", "Fonts",      s.fonts.encodedSizeDuplicatedInDataURLs,          s.fonts.encodedSize);
665     printf("%-13s %13d of %13d\n", "Other",      s.other.encodedSizeDuplicatedInDataURLs,          s.other.encodedSize);
666 }
667 
dumpLRULists(bool includeLive) const668 void MemoryCache::dumpLRULists(bool includeLive) const
669 {
670     printf("LRU-SP lists in eviction order (Kilobytes decoded, Kilobytes encoded, Access count, Referenced, isPurgeable, wasPurged):\n");
671 
672     int size = m_allResources.size();
673     for (int i = size - 1; i >= 0; i--) {
674         printf("\n\nList %d: ", i);
675         Resource* current = m_allResources[i].m_tail;
676         while (current) {
677             Resource* prev = current->m_prevInAllResourcesList;
678             if (includeLive || !current->hasClients())
679                 printf("(%.1fK, %.1fK, %uA, %dR, %d, %d); ", current->decodedSize() / 1024.0f, (current->encodedSize() + current->overheadSize()) / 1024.0f, current->accessCount(), current->hasClients(), current->isPurgeable(), current->wasPurged());
680 
681             current = prev;
682         }
683     }
684 }
685 
686 #endif // MEMORY_CACHE_STATS
687 
688 } // namespace WebCore
689