void DocumentLoader::dataReceived(Resource* resource,
const char* data,
size_t length) {
DCHECK(data);
DCHECK(length);
DCHECK_EQ(resource, m_mainResource);
DCHECK(!m_response.isNull());
DCHECK(!m_frame->page()->defersLoading());
if (m_inDataReceived) {
// If this function is reentered, defer processing of the additional data to
// the top-level invocation. Reentrant calls can occur because of web
// platform (mis-)features that require running a nested message loop:
// - alert(), confirm(), prompt()
// - Detach of plugin elements.
// - Synchronous XMLHTTPRequest
m_dataBuffer->append(data, length);
return;
}
AutoReset<bool> reentrancyProtector(&m_inDataReceived, true);
processData(data, length);
// Process data received in reentrant invocations. Note that the invocations
// of processData() may queue more data in reentrant invocations, so iterate
// until it's empty.
const char* segment;
size_t pos = 0;
while (size_t length = m_dataBuffer->getSomeData(segment, pos)) {
processData(segment, length);
pos += length;
}
// All data has been consumed, so flush the buffer.
m_dataBuffer->clear();
}
void MemoryCache::prune()
{
if (m_liveSize + m_deadSize <= m_capacity && m_maxDeadCapacity && m_deadSize <= m_maxDeadCapacity) // Fast path.
return;
if (m_inPruneResources)
return;
TemporaryChange<bool> reentrancyProtector(m_inPruneResources, true);
pruneDeadResources(); // Prune dead first, in case it was "borrowing" capacity from live.
pruneLiveResources();
}
void MemoryCache::pruneNow(double currentTime)
{
if (m_prunePending) {
m_prunePending = false;
blink::Platform::current()->currentThread()->removeTaskObserver(this);
}
TemporaryChange<bool> reentrancyProtector(m_inPruneResources, true);
pruneDeadResources(); // Prune dead first, in case it was "borrowing" capacity from live.
pruneLiveResources();
m_pruneFrameTimeStamp = FrameView::currentFrameTimeStamp();
m_pruneTimeStamp = currentTime;
}
void MemoryCache::pruneLiveResourcesToSize(unsigned targetSize, bool shouldDestroyDecodedDataForAllLiveResources)
{
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 = monotonicallyIncreasingTime();
// Destroy any decoded data in live objects that we can.
// Start from the head, 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
auto it = m_liveDecodedResources.begin();
while (it != m_liveDecodedResources.end()) {
auto* current = *it;
// Increment the iterator now because the call to destroyDecodedData() below
// may cause a call to ListHashSet::remove() and invalidate the current
// iterator. Note that this is safe because unlike iteration of most
// WTF Hash data structures, iteration is guaranteed safe against mutation
// of the ListHashSet, except for removal of the item currently pointed to
// by a given iterator.
++it;
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 (!shouldDestroyDecodedDataForAllLiveResources && elapsedTime < cMinDelayBeforeLiveDecodedPrune)
return;
if (current->decodedDataIsPurgeable())
continue;
// 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;
}
}
}
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);
}
}
void MemoryCache::pruneDeadResourcesToSize(unsigned targetSize)
{
if (m_inPruneResources)
return;
TemporaryChange<bool> reentrancyProtector(m_inPruneResources, true);
if (targetSize && m_deadSize <= targetSize)
return;
bool canShrinkLRULists = true;
for (int i = m_allResources.size() - 1; i >= 0; i--) {
LRUList& list = *m_allResources[i];
// First flush all the decoded data in this queue.
// Remove from the head, since this is the least frequently accessed of the objects.
auto it = list.begin();
while (it != list.end()) {
CachedResource& current = **it;
// Increment the iterator now as the call to destroyDecodedData() below may
// invalidate the current iterator.
++it;
// Protect 'next' so it can't get deleted during destroyDecodedData().
CachedResourceHandle<CachedResource> next = it != list.end() ? *it : nullptr;
ASSERT(!next || next->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 'next' somehow got
// kicked out of cache during destroyDecodedData().
if (next && !next->inCache())
break;
}
// Now evict objects from this list.
// Remove from the head, since this is the least frequently accessed of the objects.
it = list.begin();
while (it != list.end()) {
CachedResource& current = **it;
// Increment the iterator now as the call to remove() below will
// invalidate the current iterator.
++it;
CachedResourceHandle<CachedResource> next = it != list.end() ? *it : nullptr;
ASSERT(!next || next->inCache());
if (!current.hasClients() && !current.isPreloaded() && !current.isCacheValidator()) {
remove(current);
if (targetSize && m_deadSize <= targetSize)
return;
}
if (next && !next->inCache())
break;
}
// Shrink the vector back down so we don't waste time inspecting
// empty LRU lists on future prunes.
if (!m_allResources[i]->isEmpty())
canShrinkLRULists = false;
else if (canShrinkLRULists)
m_allResources.shrink(i);
}
}