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/*
Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#include "config.h"
#include "loader.h"
#include "Cache.h"
#include "CachedImage.h"
#include "CachedResource.h"
#include "CString.h"
#include "DocLoader.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "HTMLDocument.h"
#include "Request.h"
#include "ResourceHandle.h"
#include "ResourceRequest.h"
#include "ResourceResponse.h"
#include "SecurityOrigin.h"
#include "SubresourceLoader.h"
#include <wtf/Assertions.h>
#include <wtf/Vector.h>
#define REQUEST_MANAGEMENT_ENABLED 1
#define REQUEST_DEBUG 0
namespace WebCore {
#if REQUEST_MANAGEMENT_ENABLED
// Match the parallel connection count used by the networking layer
static unsigned maxRequestsInFlightPerHost;
// Having a limit might still help getting more important resources first
static const unsigned maxRequestsInFlightForNonHTTPProtocols = 20;
#else
static const unsigned maxRequestsInFlightPerHost = 10000;
static const unsigned maxRequestsInFlightForNonHTTPProtocols = 10000;
#endif
Loader::Loader()
: m_requestTimer(this, &Loader::requestTimerFired)
, m_isSuspendingPendingRequests(false)
{
m_nonHTTPProtocolHost = Host::create(AtomicString(), maxRequestsInFlightForNonHTTPProtocols);
#if REQUEST_MANAGEMENT_ENABLED
maxRequestsInFlightPerHost = initializeMaximumHTTPConnectionCountPerHost();
#endif
}
Loader::~Loader()
{
ASSERT_NOT_REACHED();
}
Loader::Priority Loader::determinePriority(const CachedResource* resource) const
{
#if REQUEST_MANAGEMENT_ENABLED
switch (resource->type()) {
case CachedResource::CSSStyleSheet:
#if ENABLE(XSLT)
case CachedResource::XSLStyleSheet:
#endif
#if ENABLE(XBL)
case CachedResource::XBL:
#endif
return High;
case CachedResource::Script:
case CachedResource::FontResource:
return Medium;
case CachedResource::ImageResource:
return Low;
}
ASSERT_NOT_REACHED();
return Low;
#else
return High;
#endif
}
void Loader::load(DocLoader* docLoader, CachedResource* resource, bool incremental, bool skipCanLoadCheck, bool sendResourceLoadCallbacks)
{
ASSERT(docLoader);
Request* request = new Request(docLoader, resource, incremental, skipCanLoadCheck, sendResourceLoadCallbacks);
RefPtr<Host> host;
KURL url(resource->url());
if (url.protocolInHTTPFamily()) {
AtomicString hostName = url.host();
host = m_hosts.get(hostName.impl());
if (!host) {
host = Host::create(hostName, maxRequestsInFlightPerHost);
m_hosts.add(hostName.impl(), host);
}
} else
host = m_nonHTTPProtocolHost;
bool hadRequests = host->hasRequests();
Priority priority = determinePriority(resource);
host->addRequest(request, priority);
docLoader->incrementRequestCount();
if (priority > Low || !url.protocolInHTTPFamily() || !hadRequests) {
// Try to request important resources immediately
host->servePendingRequests(priority);
} else {
// Handle asynchronously so early low priority requests don't get scheduled before later high priority ones
scheduleServePendingRequests();
}
}
void Loader::scheduleServePendingRequests()
{
if (!m_requestTimer.isActive())
m_requestTimer.startOneShot(0);
}
void Loader::requestTimerFired(Timer<Loader>*)
{
servePendingRequests();
}
void Loader::servePendingRequests(Priority minimumPriority)
{
if (m_isSuspendingPendingRequests)
return;
m_requestTimer.stop();
m_nonHTTPProtocolHost->servePendingRequests(minimumPriority);
Vector<Host*> hostsToServe;
HostMap::iterator i = m_hosts.begin();
HostMap::iterator end = m_hosts.end();
for (;i != end; ++i)
hostsToServe.append(i->second.get());
for (unsigned n = 0; n < hostsToServe.size(); ++n) {
Host* host = hostsToServe[n];
if (host->hasRequests())
host->servePendingRequests(minimumPriority);
else if (!host->processingResource()){
AtomicString name = host->name();
m_hosts.remove(name.impl());
}
}
}
void Loader::suspendPendingRequests()
{
ASSERT(!m_isSuspendingPendingRequests);
m_isSuspendingPendingRequests = true;
}
void Loader::resumePendingRequests()
{
ASSERT(m_isSuspendingPendingRequests);
m_isSuspendingPendingRequests = false;
if (!m_hosts.isEmpty() || m_nonHTTPProtocolHost->hasRequests())
scheduleServePendingRequests();
}
void Loader::cancelRequests(DocLoader* docLoader)
{
docLoader->clearPendingPreloads();
if (m_nonHTTPProtocolHost->hasRequests())
m_nonHTTPProtocolHost->cancelRequests(docLoader);
Vector<Host*> hostsToCancel;
HostMap::iterator i = m_hosts.begin();
HostMap::iterator end = m_hosts.end();
for (;i != end; ++i)
hostsToCancel.append(i->second.get());
for (unsigned n = 0; n < hostsToCancel.size(); ++n) {
Host* host = hostsToCancel[n];
if (host->hasRequests())
host->cancelRequests(docLoader);
}
scheduleServePendingRequests();
ASSERT(docLoader->requestCount() == (docLoader->loadInProgress() ? 1 : 0));
}
Loader::Host::Host(const AtomicString& name, unsigned maxRequestsInFlight)
: m_name(name)
, m_maxRequestsInFlight(maxRequestsInFlight)
, m_numResourcesProcessing(0)
{
}
Loader::Host::~Host()
{
ASSERT(m_requestsLoading.isEmpty());
for (unsigned p = 0; p <= High; p++)
ASSERT(m_requestsPending[p].isEmpty());
}
void Loader::Host::addRequest(Request* request, Priority priority)
{
m_requestsPending[priority].append(request);
}
bool Loader::Host::hasRequests() const
{
if (!m_requestsLoading.isEmpty())
return true;
for (unsigned p = 0; p <= High; p++) {
if (!m_requestsPending[p].isEmpty())
return true;
}
return false;
}
void Loader::Host::servePendingRequests(Loader::Priority minimumPriority)
{
if (cache()->loader()->isSuspendingPendingRequests())
return;
bool serveMore = true;
for (int priority = High; priority >= minimumPriority && serveMore; --priority)
servePendingRequests(m_requestsPending[priority], serveMore);
}
void Loader::Host::servePendingRequests(RequestQueue& requestsPending, bool& serveLowerPriority)
{
while (!requestsPending.isEmpty()) {
Request* request = requestsPending.first();
DocLoader* docLoader = request->docLoader();
bool resourceIsCacheValidator = request->cachedResource()->isCacheValidator();
// If the document is fully parsed and there are no pending stylesheets there won't be any more
// resources that we would want to push to the front of the queue. Just hand off the remaining resources
// to the networking layer.
bool parsedAndStylesheetsKnown = !docLoader->doc()->parsing() && docLoader->doc()->haveStylesheetsLoaded();
if (!parsedAndStylesheetsKnown && !resourceIsCacheValidator && m_requestsLoading.size() >= m_maxRequestsInFlight) {
serveLowerPriority = false;
return;
}
requestsPending.removeFirst();
ResourceRequest resourceRequest(request->cachedResource()->url());
if (!request->cachedResource()->accept().isEmpty())
resourceRequest.setHTTPAccept(request->cachedResource()->accept());
// Do not set the referrer or HTTP origin here. That's handled by SubresourceLoader::create.
if (resourceIsCacheValidator) {
CachedResource* resourceToRevalidate = request->cachedResource()->resourceToRevalidate();
ASSERT(resourceToRevalidate->canUseCacheValidator());
ASSERT(resourceToRevalidate->isLoaded());
const String& lastModified = resourceToRevalidate->response().httpHeaderField("Last-Modified");
const String& eTag = resourceToRevalidate->response().httpHeaderField("ETag");
if (!lastModified.isEmpty() || !eTag.isEmpty()) {
ASSERT(docLoader->cachePolicy() != CachePolicyReload);
if (docLoader->cachePolicy() == CachePolicyRevalidate)
resourceRequest.setHTTPHeaderField("Cache-Control", "max-age=0");
if (!lastModified.isEmpty())
resourceRequest.setHTTPHeaderField("If-Modified-Since", lastModified);
if (!eTag.isEmpty())
resourceRequest.setHTTPHeaderField("If-None-Match", eTag);
}
}
RefPtr<SubresourceLoader> loader = SubresourceLoader::create(docLoader->doc()->frame(),
this, resourceRequest, request->shouldSkipCanLoadCheck(), request->sendResourceLoadCallbacks());
if (loader) {
m_requestsLoading.add(loader.release(), request);
request->cachedResource()->setRequestedFromNetworkingLayer();
#if REQUEST_DEBUG
printf("HOST %s COUNT %d LOADING %s\n", resourceRequest.url().host().latin1().data(), m_requestsLoading.size(), request->cachedResource()->url().latin1().data());
#endif
} else {
docLoader->decrementRequestCount();
docLoader->setLoadInProgress(true);
request->cachedResource()->error();
docLoader->setLoadInProgress(false);
delete request;
}
}
}
void Loader::Host::didFinishLoading(SubresourceLoader* loader)
{
RefPtr<Host> myProtector(this);
RequestMap::iterator i = m_requestsLoading.find(loader);
if (i == m_requestsLoading.end())
return;
Request* request = i->second;
m_requestsLoading.remove(i);
DocLoader* docLoader = request->docLoader();
// Prevent the document from being destroyed before we are done with
// the docLoader that it will delete when the document gets deleted.
DocPtr<Document> protector(docLoader->doc());
if (!request->isMultipart())
docLoader->decrementRequestCount();
CachedResource* resource = request->cachedResource();
ASSERT(!resource->resourceToRevalidate());
// If we got a 4xx response, we're pretending to have received a network
// error, so we can't send the successful data() and finish() callbacks.
if (!resource->errorOccurred()) {
docLoader->setLoadInProgress(true);
resource->data(loader->resourceData(), true);
resource->finish();
}
delete request;
docLoader->setLoadInProgress(false);
docLoader->checkForPendingPreloads();
#if REQUEST_DEBUG
KURL u(resource->url());
printf("HOST %s COUNT %d RECEIVED %s\n", u.host().latin1().data(), m_requestsLoading.size(), resource->url().latin1().data());
#endif
servePendingRequests();
}
void Loader::Host::didFail(SubresourceLoader* loader, const ResourceError&)
{
didFail(loader);
}
void Loader::Host::didFail(SubresourceLoader* loader, bool cancelled)
{
RefPtr<Host> myProtector(this);
loader->clearClient();
RequestMap::iterator i = m_requestsLoading.find(loader);
if (i == m_requestsLoading.end())
return;
Request* request = i->second;
m_requestsLoading.remove(i);
DocLoader* docLoader = request->docLoader();
// Prevent the document from being destroyed before we are done with
// the docLoader that it will delete when the document gets deleted.
DocPtr<Document> protector(docLoader->doc());
if (!request->isMultipart())
docLoader->decrementRequestCount();
CachedResource* resource = request->cachedResource();
if (resource->resourceToRevalidate())
cache()->revalidationFailed(resource);
if (!cancelled) {
docLoader->setLoadInProgress(true);
resource->error();
}
docLoader->setLoadInProgress(false);
if (cancelled || !resource->isPreloaded())
cache()->remove(resource);
delete request;
docLoader->checkForPendingPreloads();
servePendingRequests();
}
void Loader::Host::didReceiveResponse(SubresourceLoader* loader, const ResourceResponse& response)
{
RefPtr<Host> protector(this);
Request* request = m_requestsLoading.get(loader);
// FIXME: This is a workaround for <rdar://problem/5236843>
// If a load starts while the frame is still in the provisional state
// (this can be the case when loading the user style sheet), committing the load then causes all
// requests to be removed from the m_requestsLoading map. This means that request might be null here.
// In that case we just return early.
// ASSERT(request);
if (!request)
return;
CachedResource* resource = request->cachedResource();
if (resource->isCacheValidator()) {
if (response.httpStatusCode() == 304) {
// 304 Not modified / Use local copy
m_requestsLoading.remove(loader);
loader->clearClient();
request->docLoader()->decrementRequestCount();
// Existing resource is ok, just use it updating the expiration time.
cache()->revalidationSucceeded(resource, response);
if (request->docLoader()->frame())
request->docLoader()->frame()->loader()->checkCompleted();
delete request;
servePendingRequests();
return;
}
// Did not get 304 response, continue as a regular resource load.
cache()->revalidationFailed(resource);
}
resource->setResponse(response);
String encoding = response.textEncodingName();
if (!encoding.isNull())
resource->setEncoding(encoding);
if (request->isMultipart()) {
ASSERT(resource->isImage());
static_cast<CachedImage*>(resource)->clear();
if (request->docLoader()->frame())
request->docLoader()->frame()->loader()->checkCompleted();
} else if (response.isMultipart()) {
request->setIsMultipart(true);
// We don't count multiParts in a DocLoader's request count
request->docLoader()->decrementRequestCount();
// If we get a multipart response, we must have a handle
ASSERT(loader->handle());
if (!resource->isImage())
loader->handle()->cancel();
}
}
void Loader::Host::didReceiveData(SubresourceLoader* loader, const char* data, int size)
{
RefPtr<Host> protector(this);
Request* request = m_requestsLoading.get(loader);
if (!request)
return;
CachedResource* resource = request->cachedResource();
ASSERT(!resource->isCacheValidator());
if (resource->errorOccurred())
return;
if (resource->response().httpStatusCode() / 100 == 4) {
// Treat a 4xx response like a network error for all resources but images (which will ignore the error and continue to load for
// legacy compatibility).
resource->httpStatusCodeError();
return;
}
// Set the data.
if (request->isMultipart()) {
// The loader delivers the data in a multipart section all at once, send eof.
// The resource data will change as the next part is loaded, so we need to make a copy.
RefPtr<SharedBuffer> copiedData = SharedBuffer::create(data, size);
resource->data(copiedData.release(), true);
} else if (request->isIncremental())
resource->data(loader->resourceData(), false);
}
void Loader::Host::cancelPendingRequests(RequestQueue& requestsPending, DocLoader* docLoader)
{
RequestQueue remaining;
RequestQueue::iterator end = requestsPending.end();
for (RequestQueue::iterator it = requestsPending.begin(); it != end; ++it) {
Request* request = *it;
if (request->docLoader() == docLoader) {
cache()->remove(request->cachedResource());
delete request;
docLoader->decrementRequestCount();
} else
remaining.append(request);
}
requestsPending.swap(remaining);
}
void Loader::Host::cancelRequests(DocLoader* docLoader)
{
for (unsigned p = 0; p <= High; p++)
cancelPendingRequests(m_requestsPending[p], docLoader);
Vector<SubresourceLoader*, 256> loadersToCancel;
RequestMap::iterator end = m_requestsLoading.end();
for (RequestMap::iterator i = m_requestsLoading.begin(); i != end; ++i) {
Request* r = i->second;
if (r->docLoader() == docLoader)
loadersToCancel.append(i->first.get());
}
for (unsigned i = 0; i < loadersToCancel.size(); ++i) {
SubresourceLoader* loader = loadersToCancel[i];
didFail(loader, true);
}
}
} //namespace WebCore
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