void MemoryCache::TypeStatistic::addResource(CachedResource& resource)
{
count++;
size += resource.size();
liveSize += resource.hasClients() ? resource.size() : 0;
decodedSize += resource.decodedSize();
}
void MemoryCache::remove(CachedResource& resource)
{
ASSERT(WTF::isMainThread());
LOG(ResourceLoading, "Evicting resource %p for '%s' from cache", &resource, resource.url().string().latin1().data());
// The resource may have already been removed by someone other than our caller,
// who needed a fresh copy for a reload. See <http://bugs.webkit.org/show_bug.cgi?id=12479#c6>.
if (auto* resources = sessionResourceMap(resource.sessionID())) {
#if ENABLE(CACHE_PARTITIONING)
auto key = std::make_pair(resource.url(), resource.cachePartition());
#else
auto& key = resource.url();
#endif
if (resource.inCache()) {
// Remove resource from the resource map.
resources->remove(key);
resource.setInCache(false);
// If the resource map is now empty, remove it from m_sessionResources.
if (resources->isEmpty())
m_sessionResources.remove(resource.sessionID());
// Remove from the appropriate LRU list.
removeFromLRUList(resource);
removeFromLiveDecodedResourcesList(resource);
adjustSize(resource.hasClients(), -static_cast<int>(resource.size()));
} else
ASSERT(resources->get(key) != &resource);
}
resource.deleteIfPossible();
}
void MemoryCache::revalidationSucceeded(CachedResource* revalidatingResource, const ResourceResponse& response)
{
CachedResource* resource = revalidatingResource->resourceToRevalidate();
ASSERT(resource);
ASSERT(!resource->inCache());
ASSERT(resource->isLoaded());
ASSERT(revalidatingResource->inCache());
// Calling evict() can potentially delete revalidatingResource, which we use
// below. This mustn't be the case since revalidation means it is loaded
// and so canDelete() is false.
ASSERT(!revalidatingResource->canDelete());
evict(revalidatingResource);
CachedResourceMap& resources = getSessionMap(resource->sessionID());
#if ENABLE(CACHE_PARTITIONING)
ASSERT(!resources.get(resource->url()) || !resources.get(resource->url())->get(resource->cachePartition()));
CachedResourceItem* originMap = resources.get(resource->url());
if (!originMap) {
originMap = new CachedResourceItem;
resources.set(resource->url(), adoptPtr(originMap));
}
originMap->set(resource->cachePartition(), resource);
#else
ASSERT(!resources.get(resource->url()));
resources.set(resource->url(), resource);
#endif
resource->setInCache(true);
resource->updateResponseAfterRevalidation(response);
insertInLRUList(resource);
int delta = resource->size();
if (resource->decodedSize() && resource->hasClients())
insertInLiveDecodedResourcesList(resource);
if (delta)
adjustSize(resource->hasClients(), delta);
revalidatingResource->switchClientsToRevalidatedResource();
ASSERT(!revalidatingResource->m_deleted);
// this deletes the revalidating resource
revalidatingResource->clearResourceToRevalidate();
}
CachedResource* MemoryCache::resourceForRequest(const ResourceRequest& request)
{
ASSERT(WTF::isMainThread());
KURL url = removeFragmentIdentifierIfNeeded(request.url());
#if ENABLE(CACHE_PARTITIONING)
CachedResourceItem* item = m_resources.get(url);
CachedResource* resource = 0;
if (item)
resource = item->get(request.cachePartition());
#else
CachedResource* resource = m_resources.get(url);
#endif
bool wasPurgeable = MemoryCache::shouldMakeResourcePurgeableOnEviction() && resource && resource->isPurgeable();
if (resource && !resource->makePurgeable(false)) {
ASSERT(!resource->hasClients());
evict(resource);
return 0;
}
// Add the size back since we had subtracted it when we marked the memory as purgeable.
if (wasPurgeable)
adjustSize(resource->hasClients(), resource->size());
return resource;
}
void MemoryCache::dumpLRULists(bool includeLive) const
{
printf("LRU-SP lists in eviction order (Kilobytes decoded, Kilobytes encoded, Access count, Referenced, isPurgeable, wasPurged):\n");
int size = m_allResources.size();
for (int i = size - 1; i >= 0; i--) {
printf("\n\nList %d: ", i);
CachedResource* current = m_allResources[i].m_tail;
while (current) {
CachedResource* prev = current->m_prevInAllResourcesList;
if (includeLive || !current->hasClients())
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());
current = prev;
}
}
}
void MemoryCache::resourceAccessed(CachedResource& resource)
{
ASSERT(resource.inCache());
// Need to make sure to remove before we increase the access count, since
// the queue will possibly change.
removeFromLRUList(resource);
// If this is the first time the resource has been accessed, adjust the size of the cache to account for its initial size.
if (!resource.accessCount())
adjustSize(resource.hasClients(), resource.size());
// Add to our access count.
resource.increaseAccessCount();
// Now insert into the new queue.
insertInLRUList(resource);
}
void MemoryCache::pruneLiveResourcesToSize(unsigned targetSize)
{
if (m_inPruneResources)
return;
TemporaryChange<bool> reentrancyProtector(m_inPruneResources, true);
double currentTime = FrameView::currentPaintTimeStamp();
if (!currentTime) // In case prune is called directly, outside of a Frame paint.
currentTime = WTF::currentTime();
// Destroy any decoded data in live objects that we can.
// Start from the tail, since this is the least recently accessed of the objects.
// The list might not be sorted by the m_lastDecodedAccessTime. The impact
// of this weaker invariant is minor as the below if statement to check the
// elapsedTime will evaluate to false as the currentTime will be a lot
// greater than the current->m_lastDecodedAccessTime.
// For more details see: https://bugs.webkit.org/show_bug.cgi?id=30209
CachedResource* current = m_liveDecodedResources.m_tail;
while (current) {
CachedResource* prev = current->m_prevInLiveResourcesList;
ASSERT(current->hasClients());
if (current->isLoaded() && current->decodedSize()) {
// Check to see if the remaining resources are too new to prune.
double elapsedTime = currentTime - current->m_lastDecodedAccessTime;
if (elapsedTime < cMinDelayBeforeLiveDecodedPrune)
return;
// Destroy our decoded data. This will remove us from
// m_liveDecodedResources, and possibly move us to a different LRU
// list in m_allResources.
current->destroyDecodedData();
if (targetSize && m_liveSize <= targetSize)
return;
}
current = prev;
}
}
void MemoryCache::pruneDeadResourcesToSize(unsigned targetSize)
{
if (m_inPruneResources)
return;
TemporaryChange<bool> reentrancyProtector(m_inPruneResources, true);
int size = m_allResources.size();
// See if we have any purged resources we can evict.
for (int i = 0; i < size; i++) {
CachedResource* current = m_allResources[i].m_tail;
while (current) {
CachedResource* prev = current->m_prevInAllResourcesList;
if (current->wasPurged()) {
ASSERT(!current->hasClients());
ASSERT(!current->isPreloaded());
evict(current);
}
current = prev;
}
}
if (targetSize && m_deadSize <= targetSize)
return;
bool canShrinkLRULists = true;
for (int i = size - 1; i >= 0; i--) {
// Remove from the tail, since this is the least frequently accessed of the objects.
CachedResource* current = m_allResources[i].m_tail;
// First flush all the decoded data in this queue.
while (current) {
// Protect 'previous' so it can't get deleted during destroyDecodedData().
CachedResourceHandle<CachedResource> previous = current->m_prevInAllResourcesList;
ASSERT(!previous || previous->inCache());
if (!current->hasClients() && !current->isPreloaded() && current->isLoaded()) {
// Destroy our decoded data. This will remove us from
// m_liveDecodedResources, and possibly move us to a different
// LRU list in m_allResources.
current->destroyDecodedData();
if (targetSize && m_deadSize <= targetSize)
return;
}
// Decoded data may reference other resources. Stop iterating if 'previous' somehow got
// kicked out of cache during destroyDecodedData().
if (previous && !previous->inCache())
break;
current = previous.get();
}
// Now evict objects from this queue.
current = m_allResources[i].m_tail;
while (current) {
CachedResourceHandle<CachedResource> previous = current->m_prevInAllResourcesList;
ASSERT(!previous || previous->inCache());
if (!current->hasClients() && !current->isPreloaded() && !current->isCacheValidator()) {
if (!makeResourcePurgeable(current))
evict(current);
if (targetSize && m_deadSize <= targetSize)
return;
}
if (previous && !previous->inCache())
break;
current = previous.get();
}
// Shrink the vector back down so we don't waste time inspecting
// empty LRU lists on future prunes.
if (m_allResources[i].m_head)
canShrinkLRULists = false;
else if (canShrinkLRULists)
m_allResources.resize(i);
}
}
