Source/core/loader/DocumentLoader.cpp

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
isArchiveMIMEType
m_applicationCacheHost
frameLoader
mainResourceLoader
mainResourceIdentifier
document
originalRequest
request
url
updateForSameDocumentNavigation
urlForHistory
setMainDocumentError
mainReceivedError
stopLoading
commitIfReady
isLoading
notifyFinished
finishedLoading
isRedirectAfterPost
shouldContinueForNavigationPolicy
redirectReceived
updateRequest
isFormSubmission
willSendRequest
canShowMIMEType
shouldContinueForResponse
responseReceived
ensureWriter
commitData
dataReceived
checkLoadComplete
clearRedirectChain
appendRedirect
detachFromFrame
clearMainResourceLoader
clearMainResourceHandle
maybeCreateArchive
addAllArchiveResources
prepareSubframeArchiveLoadIfNeeded
scheduleArchiveLoad
responseMIMEType
unreachableURL
setDefersLoading
maybeLoadEmpty
startLoadingMainResource
cancelMainResourceLoad
attachThreadedDataReceiver
endWriting
createWriterFor
mimeType
setUserChosenEncoding
replaceDocument
/*
 * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
 * Copyright (C) 2011 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "core/loader/DocumentLoader.h"

#include "FetchInitiatorTypeNames.h"
#include "core/dom/Document.h"
#include "core/dom/DocumentParser.h"
#include "core/events/Event.h"
#include "core/fetch/MemoryCache.h"
#include "core/fetch/ResourceFetcher.h"
#include "core/fetch/ResourceLoader.h"
#include "core/html/HTMLFrameOwnerElement.h"
#include "core/html/parser/TextResourceDecoder.h"
#include "core/inspector/InspectorInstrumentation.h"
#include "core/loader/FrameLoader.h"
#include "core/loader/FrameLoaderClient.h"
#include "core/loader/UniqueIdentifier.h"
#include "core/loader/appcache/ApplicationCacheHost.h"
#include "core/frame/DOMWindow.h"
#include "core/frame/LocalFrame.h"
#include "core/frame/csp/ContentSecurityPolicy.h"
#include "core/page/FrameTree.h"
#include "core/page/Page.h"
#include "core/frame/Settings.h"
#include "platform/Logging.h"
#include "platform/UserGestureIndicator.h"
#include "platform/mhtml/ArchiveResourceCollection.h"
#include "platform/mhtml/MHTMLArchive.h"
#include "platform/plugins/PluginData.h"
#include "platform/weborigin/SchemeRegistry.h"
#include "platform/weborigin/SecurityPolicy.h"
#include "public/platform/Platform.h"
#include "public/platform/WebMimeRegistry.h"
#include "public/platform/WebThreadedDataReceiver.h"
#include "wtf/Assertions.h"
#include "wtf/text/WTFString.h"

namespace WebCore {

static bool isArchiveMIMEType(const String& mimeType)
{
    return mimeType == "multipart/related";
}

DocumentLoader::DocumentLoader(LocalFrame* frame, const ResourceRequest& req, const SubstituteData& substituteData)
    : m_frame(frame)
    , m_fetcher(ResourceFetcher::create(this))
    , m_originalRequest(req)
    , m_substituteData(substituteData)
    , m_request(req)
    , m_committed(false)
    , m_isClientRedirect(false)
    , m_replacesCurrentHistoryItem(false)
    , m_loadingMainResource(false)
    , m_timeOfLastDataReceived(0.0)
    , m_applicationCacheHost(adoptPtr(new ApplicationCacheHost(this)))
{
}

FrameLoader* DocumentLoader::frameLoader() const
{
    if (!m_frame)
        return 0;
    return &m_frame->loader();
}

ResourceLoader* DocumentLoader::mainResourceLoader() const
{
    return m_mainResource ? m_mainResource->loader() : 0;
}

DocumentLoader::~DocumentLoader()
{
    ASSERT(!m_frame || !isLoading());
    m_fetcher->clearDocumentLoader();
    clearMainResourceHandle();
}

unsigned long DocumentLoader::mainResourceIdentifier() const
{
    return m_mainResource ? m_mainResource->identifier() : 0;
}

Document* DocumentLoader::document() const
{
    if (m_frame && m_frame->loader().documentLoader() == this)
        return m_frame->document();
    return 0;
}

const ResourceRequest& DocumentLoader::originalRequest() const
{
    return m_originalRequest;
}

const ResourceRequest& DocumentLoader::request() const
{
    return m_request;
}

const KURL& DocumentLoader::url() const
{
    return m_request.url();
}

void DocumentLoader::updateForSameDocumentNavigation(const KURL& newURL)
{
    KURL oldURL = m_request.url();
    m_originalRequest.setURL(newURL);
    m_request.setURL(newURL);
    clearRedirectChain();
    if (m_isClientRedirect)
        appendRedirect(oldURL);
    appendRedirect(newURL);
}

const KURL& DocumentLoader::urlForHistory() const
{
    return unreachableURL().isEmpty() ? url() : unreachableURL();
}

void DocumentLoader::setMainDocumentError(const ResourceError& error)
{
    m_mainDocumentError = error;
}

void DocumentLoader::mainReceivedError(const ResourceError& error)
{
    ASSERT(!error.isNull());
    ASSERT(!mainResourceLoader() || !mainResourceLoader()->defersLoading() || InspectorInstrumentation::isDebuggerPaused(m_frame));
    m_applicationCacheHost->failedLoadingMainResource();
    if (!frameLoader())
        return;
    setMainDocumentError(error);
    clearMainResourceLoader();
    frameLoader()->receivedMainResourceError(error);
    clearMainResourceHandle();
}

// Cancels the data source's pending loads.  Conceptually, a data source only loads
// one document at a time, but one document may have many related resources.
// stopLoading will stop all loads initiated by the data source,
// but not loads initiated by child frames' data sources -- that's the WebFrame's job.
void DocumentLoader::stopLoading()
{
    RefPtr<LocalFrame> protectFrame(m_frame);
    RefPtr<DocumentLoader> protectLoader(this);

    // In some rare cases, calling FrameLoader::stopLoading could cause isLoading() to return false.
    // (This can happen when there's a single XMLHttpRequest currently loading and stopLoading causes it
    // to stop loading. Because of this, we need to save it so we don't return early.
    bool loading = isLoading();

    if (m_committed) {
        // Attempt to stop the frame if the document loader is loading, or if it is done loading but
        // still  parsing. Failure to do so can cause a world leak.
        Document* doc = m_frame->document();

        if (loading || doc->parsing())
            m_frame->loader().stopLoading();
    }

    if (!loading)
        return;

    if (m_loadingMainResource) {
        // Stop the main resource loader and let it send the cancelled message.
        cancelMainResourceLoad(ResourceError::cancelledError(m_request.url()));
    } else if (m_fetcher->isFetching()) {
        // The main resource loader already finished loading. Set the cancelled error on the
        // document and let the resourceLoaders send individual cancelled messages below.
        setMainDocumentError(ResourceError::cancelledError(m_request.url()));
    } else {
        // If there are no resource loaders, we need to manufacture a cancelled message.
        // (A back/forward navigation has no resource loaders because its resources are cached.)
        mainReceivedError(ResourceError::cancelledError(m_request.url()));
    }

    m_fetcher->stopFetching();
}

void DocumentLoader::commitIfReady()
{
    if (!m_committed) {
        m_committed = true;
        frameLoader()->commitProvisionalLoad();
    }
}

bool DocumentLoader::isLoading() const
{
    if (document() && document()->hasActiveParser())
        return true;

    return m_loadingMainResource || m_fetcher->isFetching();
}

void DocumentLoader::notifyFinished(Resource* resource)
{
    ASSERT_UNUSED(resource, m_mainResource == resource);
    ASSERT(m_mainResource);

    RefPtr<DocumentLoader> protect(this);

    if (!m_mainResource->errorOccurred() && !m_mainResource->wasCanceled()) {
        finishedLoading(m_mainResource->loadFinishTime());
        return;
    }

    mainReceivedError(m_mainResource->resourceError());
}

void DocumentLoader::finishedLoading(double finishTime)
{
    ASSERT(!mainResourceLoader() || !mainResourceLoader()->defersLoading() || InspectorInstrumentation::isDebuggerPaused(m_frame));

    RefPtr<DocumentLoader> protect(this);

    double responseEndTime = finishTime;
    if (!responseEndTime)
        responseEndTime = m_timeOfLastDataReceived;
    if (!responseEndTime)
        responseEndTime = monotonicallyIncreasingTime();
    timing()->setResponseEnd(responseEndTime);

    commitIfReady();
    if (!frameLoader())
        return;

    if (!maybeCreateArchive()) {
        // If this is an empty document, it will not have actually been created yet. Commit dummy data so that
        // DocumentWriter::begin() gets called and creates the Document.
        if (!m_writer)
            commitData(0, 0);
    }

    endWriting(m_writer.get());

    if (!m_mainDocumentError.isNull())
        return;
    clearMainResourceLoader();
    if (!frameLoader()->stateMachine()->creatingInitialEmptyDocument())
        frameLoader()->checkLoadComplete();

    // If the document specified an application cache manifest, it violates the author's intent if we store it in the memory cache
    // and deny the appcache the chance to intercept it in the future, so remove from the memory cache.
    if (m_frame) {
        if (m_mainResource && m_frame->document()->hasManifest())
            memoryCache()->remove(m_mainResource.get());
    }
    m_applicationCacheHost->finishedLoadingMainResource();
    clearMainResourceHandle();
}

bool DocumentLoader::isRedirectAfterPost(const ResourceRequest& newRequest, const ResourceResponse& redirectResponse)
{
    int status = redirectResponse.httpStatusCode();
    if (((status >= 301 && status <= 303) || status == 307)
        && m_originalRequest.httpMethod() == "POST")
        return true;

    return false;
}

bool DocumentLoader::shouldContinueForNavigationPolicy(const ResourceRequest& request)
{
    // Don't ask if we are loading an empty URL.
    if (request.url().isEmpty() || m_substituteData.isValid())
        return true;

    // If we're loading content into a subframe, check against the parent's Content Security Policy
    // and kill the load if that check fails.
    if (m_frame->ownerElement() && !m_frame->ownerElement()->document().contentSecurityPolicy()->allowChildFrameFromSource(request.url())) {
        // Fire a load event, as timing attacks would otherwise reveal that the
        // frame was blocked. This way, it looks like every other cross-origin
        // page load.
        m_frame->document()->enforceSandboxFlags(SandboxOrigin);
        m_frame->ownerElement()->dispatchEvent(Event::create(EventTypeNames::load));
        return false;
    }

    NavigationPolicy policy = m_triggeringAction.policy();
    policy = frameLoader()->client()->decidePolicyForNavigation(request, this, policy);
    if (policy == NavigationPolicyCurrentTab)
        return true;
    if (policy == NavigationPolicyIgnore)
        return false;
    if (!DOMWindow::allowPopUp(*m_frame) && !UserGestureIndicator::processingUserGesture())
        return false;
    frameLoader()->client()->loadURLExternally(request, policy);
    return false;
}

void DocumentLoader::redirectReceived(Resource* resource, ResourceRequest& request, const ResourceResponse& redirectResponse)
{
    ASSERT_UNUSED(resource, resource == m_mainResource);
    willSendRequest(request, redirectResponse);
}

void DocumentLoader::updateRequest(Resource* resource, const ResourceRequest& request)
{
    ASSERT_UNUSED(resource, resource == m_mainResource);
    m_request = request;
}

static bool isFormSubmission(NavigationType type)
{
    return type == NavigationTypeFormSubmitted || type == NavigationTypeFormResubmitted;
}

void DocumentLoader::willSendRequest(ResourceRequest& newRequest, const ResourceResponse& redirectResponse)
{
    // Note that there are no asserts here as there are for the other callbacks. This is due to the
    // fact that this "callback" is sent when starting every load, and the state of callback
    // deferrals plays less of a part in this function in preventing the bad behavior deferring
    // callbacks is meant to prevent.
    ASSERT(!newRequest.isNull());
    if (isFormSubmission(m_triggeringAction.type()) && !m_frame->document()->contentSecurityPolicy()->allowFormAction(newRequest.url())) {
        cancelMainResourceLoad(ResourceError::cancelledError(newRequest.url()));
        return;
    }

    ASSERT(timing()->fetchStart());
    if (!redirectResponse.isNull()) {
        // If the redirecting url is not allowed to display content from the target origin,
        // then block the redirect.
        RefPtr<SecurityOrigin> redirectingOrigin = SecurityOrigin::create(redirectResponse.url());
        if (!redirectingOrigin->canDisplay(newRequest.url())) {
            FrameLoader::reportLocalLoadFailed(m_frame, newRequest.url().string());
            cancelMainResourceLoad(ResourceError::cancelledError(newRequest.url()));
            return;
        }
        timing()->addRedirect(redirectResponse.url(), newRequest.url());
    }

    // Update cookie policy base URL as URL changes, except for subframes, which use the
    // URL of the main frame which doesn't change when we redirect.
    if (frameLoader()->isLoadingMainFrame())
        newRequest.setFirstPartyForCookies(newRequest.url());

    // If we're fielding a redirect in response to a POST, force a load from origin, since
    // this is a common site technique to return to a page viewing some data that the POST
    // just modified.
    if (newRequest.cachePolicy() == UseProtocolCachePolicy && isRedirectAfterPost(newRequest, redirectResponse))
        newRequest.setCachePolicy(ReloadIgnoringCacheData);

    // If this is a sub-frame, check for mixed content blocking against the top frame.
    if (m_frame->tree().parent()) {
        LocalFrame* top = m_frame->tree().top();
        if (!top->loader().mixedContentChecker()->canRunInsecureContent(top->document()->securityOrigin(), newRequest.url())) {
            cancelMainResourceLoad(ResourceError::cancelledError(newRequest.url()));
            return;
        }
    }

    m_request = newRequest;

    if (redirectResponse.isNull())
        return;

    appendRedirect(newRequest.url());
    frameLoader()->client()->dispatchDidReceiveServerRedirectForProvisionalLoad();
    if (!shouldContinueForNavigationPolicy(newRequest))
        cancelMainResourceLoad(ResourceError::cancelledError(m_request.url()));
}

static bool canShowMIMEType(const String& mimeType, Page* page)
{
    if (blink::Platform::current()->mimeRegistry()->supportsMIMEType(mimeType) == blink::WebMimeRegistry::IsSupported)
        return true;
    PluginData* pluginData = page->pluginData();
    return !mimeType.isEmpty() && pluginData && pluginData->supportsMimeType(mimeType);
}

bool DocumentLoader::shouldContinueForResponse() const
{
    if (m_substituteData.isValid())
        return true;

    int statusCode = m_response.httpStatusCode();
    if (statusCode == 204 || statusCode == 205) {
        // The server does not want us to replace the page contents.
        return false;
    }

    if (contentDispositionType(m_response.httpHeaderField("Content-Disposition")) == ContentDispositionAttachment) {
        // The server wants us to download instead of replacing the page contents.
        // Downloading is handled by the embedder, but we still get the initial
        // response so that we can ignore it and clean up properly.
        return false;
    }

    if (!canShowMIMEType(m_response.mimeType(), m_frame->page()))
        return false;

    // Prevent remote web archives from loading because they can claim to be from any domain and thus avoid cross-domain security checks.
    if (equalIgnoringCase("multipart/related", m_response.mimeType()) && !SchemeRegistry::shouldTreatURLSchemeAsLocal(m_request.url().protocol()))
        return false;

    return true;
}

void DocumentLoader::responseReceived(Resource* resource, const ResourceResponse& response)
{
    ASSERT_UNUSED(resource, m_mainResource == resource);
    RefPtr<DocumentLoader> protect(this);

    m_applicationCacheHost->didReceiveResponseForMainResource(response);

    // The memory cache doesn't understand the application cache or its caching rules. So if a main resource is served
    // from the application cache, ensure we don't save the result for future use. All responses loaded
    // from appcache will have a non-zero appCacheID().
    if (response.appCacheID())
        memoryCache()->remove(m_mainResource.get());

    DEFINE_STATIC_LOCAL(AtomicString, xFrameOptionHeader, ("x-frame-options", AtomicString::ConstructFromLiteral));
    HTTPHeaderMap::const_iterator it = response.httpHeaderFields().find(xFrameOptionHeader);
    if (it != response.httpHeaderFields().end()) {
        String content = it->value;
        ASSERT(m_mainResource);
        unsigned long identifier = mainResourceIdentifier();
        ASSERT(identifier);
        if (frameLoader()->shouldInterruptLoadForXFrameOptions(content, response.url(), identifier)) {
            InspectorInstrumentation::continueAfterXFrameOptionsDenied(m_frame, this, identifier, response);
            String message = "Refused to display '" + response.url().elidedString() + "' in a frame because it set 'X-Frame-Options' to '" + content + "'.";
            frame()->document()->addConsoleMessageWithRequestIdentifier(SecurityMessageSource, ErrorMessageLevel, message, identifier);
            frame()->document()->enforceSandboxFlags(SandboxOrigin);
            if (HTMLFrameOwnerElement* ownerElement = frame()->ownerElement())
                ownerElement->dispatchEvent(Event::create(EventTypeNames::load));

            // The load event might have detached this frame. In that case, the load will already have been cancelled during detach.
            if (frameLoader())
                cancelMainResourceLoad(ResourceError::cancelledError(m_request.url()));
            return;
        }
    }

    ASSERT(!mainResourceLoader() || !mainResourceLoader()->defersLoading());

    m_response = response;

    if (isArchiveMIMEType(m_response.mimeType()) && m_mainResource->dataBufferingPolicy() != BufferData)
        m_mainResource->setDataBufferingPolicy(BufferData);

    if (!shouldContinueForResponse()) {
        InspectorInstrumentation::continueWithPolicyIgnore(m_frame, this, m_mainResource->identifier(), m_response);
        cancelMainResourceLoad(ResourceError::cancelledError(m_request.url()));
        return;
    }

    if (m_response.isHTTP()) {
        int status = m_response.httpStatusCode();
        if ((status < 200 || status >= 300) && m_frame->ownerElement() && m_frame->ownerElement()->isObjectElement()) {
            m_frame->ownerElement()->renderFallbackContent();
            // object elements are no longer rendered after we fallback, so don't
            // keep trying to process data from their load
            cancelMainResourceLoad(ResourceError::cancelledError(m_request.url()));
        }
    }
}

void DocumentLoader::ensureWriter(const AtomicString& mimeType, const KURL& overridingURL)
{
    if (m_writer)
        return;

    const AtomicString& encoding = overrideEncoding().isNull() ? response().textEncodingName() : overrideEncoding();
    m_writer = createWriterFor(m_frame, 0, url(), mimeType, encoding, false, false);
    m_writer->setDocumentWasLoadedAsPartOfNavigation();
    // This should be set before receivedFirstData().
    if (!overridingURL.isEmpty())
        m_frame->document()->setBaseURLOverride(overridingURL);

    // Call receivedFirstData() exactly once per load.
    frameLoader()->receivedFirstData();
    m_frame->document()->maybeHandleHttpRefresh(m_response.httpHeaderField("Refresh"), Document::HttpRefreshFromHeader);
}

void DocumentLoader::commitData(const char* bytes, size_t length)
{
    ensureWriter(m_response.mimeType());
    ASSERT(m_frame->document()->parsing());
    m_writer->addData(bytes, length);
}

void DocumentLoader::dataReceived(Resource* resource, const char* data, int length)
{
    ASSERT(data);
    ASSERT(length);
    ASSERT_UNUSED(resource, resource == m_mainResource);
    ASSERT(!m_response.isNull());
    ASSERT(!mainResourceLoader() || !mainResourceLoader()->defersLoading());

    // Both unloading the old page and parsing the new page may execute JavaScript which destroys the datasource
    // by starting a new load, so retain temporarily.
    RefPtr<LocalFrame> protectFrame(m_frame);
    RefPtr<DocumentLoader> protectLoader(this);

    m_applicationCacheHost->mainResourceDataReceived(data, length);
    m_timeOfLastDataReceived = monotonicallyIncreasingTime();

    commitIfReady();
    if (!frameLoader())
        return;
    if (isArchiveMIMEType(response().mimeType()))
        return;
    commitData(data, length);

    // If we are sending data to MediaDocument, we should stop here
    // and cancel the request.
    if (m_frame && m_frame->document()->isMediaDocument())
        cancelMainResourceLoad(ResourceError::cancelledError(m_request.url()));
}

void DocumentLoader::checkLoadComplete()
{
    if (!m_frame || isLoading() || !m_committed)
        return;
    m_frame->domWindow()->finishedLoading();
}

void DocumentLoader::clearRedirectChain()
{
    m_redirectChain.clear();
}

void DocumentLoader::appendRedirect(const KURL& url)
{
    m_redirectChain.append(url);
}

void DocumentLoader::detachFromFrame()
{
    ASSERT(m_frame);
    RefPtr<LocalFrame> protectFrame(m_frame);
    RefPtr<DocumentLoader> protectLoader(this);

    // It never makes sense to have a document loader that is detached from its
    // frame have any loads active, so go ahead and kill all the loads.
    stopLoading();

    m_applicationCacheHost->setApplicationCache(0);
    InspectorInstrumentation::loaderDetachedFromFrame(m_frame, this);
    m_frame = 0;
}

void DocumentLoader::clearMainResourceLoader()
{
    m_loadingMainResource = false;
    checkLoadComplete();
}

void DocumentLoader::clearMainResourceHandle()
{
    if (!m_mainResource)
        return;
    m_mainResource->removeClient(this);
    m_mainResource = 0;
}

bool DocumentLoader::maybeCreateArchive()
{
    // Only the top-frame can load MHTML.
    if (m_frame->tree().parent())
        return false;

    // Give the archive machinery a crack at this document. If the MIME type is not an archive type, it will return 0.
    if (!isArchiveMIMEType(m_response.mimeType()))
        return false;

    ASSERT(m_mainResource);
    m_archive = MHTMLArchive::create(m_response.url(), m_mainResource->resourceBuffer());
    // Invalid MHTML.
    if (!m_archive || !m_archive->mainResource()) {
        m_archive.clear();
        return false;
    }

    addAllArchiveResources(m_archive.get());
    ArchiveResource* mainResource = m_archive->mainResource();

    // The origin is the MHTML file, we need to set the base URL to the document encoded in the MHTML so
    // relative URLs are resolved properly.
    ensureWriter(mainResource->mimeType(), m_archive->mainResource()->url());

    // The Document has now been created.
    document()->enforceSandboxFlags(SandboxAll);

    commitData(mainResource->data()->data(), mainResource->data()->size());
    return true;
}

void DocumentLoader::addAllArchiveResources(MHTMLArchive* archive)
{
    ASSERT(archive);
    if (!m_archiveResourceCollection)
        m_archiveResourceCollection = adoptPtr(new ArchiveResourceCollection);
    m_archiveResourceCollection->addAllResources(archive);
}

void DocumentLoader::prepareSubframeArchiveLoadIfNeeded()
{
    if (!m_frame->tree().parent())
        return;

    ArchiveResourceCollection* parentCollection = m_frame->tree().parent()->loader().documentLoader()->m_archiveResourceCollection.get();
    if (!parentCollection)
        return;

    m_archive = parentCollection->popSubframeArchive(m_frame->tree().uniqueName(), m_request.url());

    if (!m_archive)
        return;
    addAllArchiveResources(m_archive.get());

    ArchiveResource* mainResource = m_archive->mainResource();
    m_substituteData = SubstituteData(mainResource->data(), mainResource->mimeType(), mainResource->textEncoding(), KURL());
}

bool DocumentLoader::scheduleArchiveLoad(Resource* cachedResource, const ResourceRequest& request)
{
    if (!m_archive)
        return false;

    ASSERT(m_archiveResourceCollection);
    ArchiveResource* archiveResource = m_archiveResourceCollection->archiveResourceForURL(request.url());
    if (!archiveResource) {
        cachedResource->error(Resource::LoadError);
        return true;
    }

    cachedResource->setLoading(true);
    cachedResource->responseReceived(archiveResource->response());
    SharedBuffer* data = archiveResource->data();
    if (data)
        cachedResource->appendData(data->data(), data->size());
    cachedResource->finish();
    return true;
}

const AtomicString& DocumentLoader::responseMIMEType() const
{
    return m_response.mimeType();
}

const KURL& DocumentLoader::unreachableURL() const
{
    return m_substituteData.failingURL();
}

void DocumentLoader::setDefersLoading(bool defers)
{
    // Multiple frames may be loading the same main resource simultaneously. If deferral state changes,
    // each frame's DocumentLoader will try to send a setDefersLoading() to the same underlying ResourceLoader. Ensure only
    // the "owning" DocumentLoader does so, as setDefersLoading() is not resilient to setting the same value repeatedly.
    if (mainResourceLoader() && mainResourceLoader()->isLoadedBy(m_fetcher.get()))
        mainResourceLoader()->setDefersLoading(defers);

    m_fetcher->setDefersLoading(defers);
}

bool DocumentLoader::maybeLoadEmpty()
{
    bool shouldLoadEmpty = !m_substituteData.isValid() && (m_request.url().isEmpty() || SchemeRegistry::shouldLoadURLSchemeAsEmptyDocument(m_request.url().protocol()));
    if (!shouldLoadEmpty)
        return false;

    if (m_request.url().isEmpty() && !frameLoader()->stateMachine()->creatingInitialEmptyDocument())
        m_request.setURL(blankURL());
    m_response = ResourceResponse(m_request.url(), "text/html", 0, nullAtom, String());
    finishedLoading(monotonicallyIncreasingTime());
    return true;
}

void DocumentLoader::startLoadingMainResource()
{
    RefPtr<DocumentLoader> protect(this);
    m_mainDocumentError = ResourceError();
    timing()->markNavigationStart();
    ASSERT(!m_mainResource);
    ASSERT(!m_loadingMainResource);
    m_loadingMainResource = true;

    if (maybeLoadEmpty())
        return;

    ASSERT(timing()->navigationStart());
    ASSERT(!timing()->fetchStart());
    timing()->markFetchStart();
    willSendRequest(m_request, ResourceResponse());

    // willSendRequest() may lead to our LocalFrame being detached or cancelling the load via nulling the ResourceRequest.
    if (!m_frame || m_request.isNull())
        return;

    m_applicationCacheHost->willStartLoadingMainResource(m_request);
    prepareSubframeArchiveLoadIfNeeded();

    ResourceRequest request(m_request);
    DEFINE_STATIC_LOCAL(ResourceLoaderOptions, mainResourceLoadOptions,
        (SniffContent, DoNotBufferData, AllowStoredCredentials, ClientRequestedCredentials, CheckContentSecurityPolicy, DocumentContext));
    FetchRequest cachedResourceRequest(request, FetchInitiatorTypeNames::document, mainResourceLoadOptions);
    m_mainResource = m_fetcher->fetchMainResource(cachedResourceRequest, m_substituteData);
    if (!m_mainResource) {
        m_request = ResourceRequest();
        // If the load was aborted by clearing m_request, it's possible the ApplicationCacheHost
        // is now in a state where starting an empty load will be inconsistent. Replace it with
        // a new ApplicationCacheHost.
        m_applicationCacheHost = adoptPtr(new ApplicationCacheHost(this));
        maybeLoadEmpty();
        return;
    }
    m_mainResource->addClient(this);

    // A bunch of headers are set when the underlying ResourceLoader is created, and m_request needs to include those.
    if (mainResourceLoader())
        request = mainResourceLoader()->originalRequest();
    // If there was a fragment identifier on m_request, the cache will have stripped it. m_request should include
    // the fragment identifier, so add that back in.
    if (equalIgnoringFragmentIdentifier(m_request.url(), request.url()))
        request.setURL(m_request.url());
    m_request = request;
}

void DocumentLoader::cancelMainResourceLoad(const ResourceError& resourceError)
{
    RefPtr<DocumentLoader> protect(this);
    ResourceError error = resourceError.isNull() ? ResourceError::cancelledError(m_request.url()) : resourceError;

    if (mainResourceLoader())
        mainResourceLoader()->cancel(error);

    mainReceivedError(error);
}

void DocumentLoader::attachThreadedDataReceiver(PassOwnPtr<blink::WebThreadedDataReceiver> threadedDataReceiver)
{
    if (mainResourceLoader())
        mainResourceLoader()->attachThreadedDataReceiver(threadedDataReceiver);
}

void DocumentLoader::endWriting(DocumentWriter* writer)
{
    ASSERT_UNUSED(writer, m_writer == writer);
    m_writer->end();
    m_writer.clear();
}

PassRefPtr<DocumentWriter> DocumentLoader::createWriterFor(LocalFrame* frame, const Document* ownerDocument, const KURL& url, const AtomicString& mimeType, const AtomicString& encoding, bool userChosen, bool dispatch)
{
    // Create a new document before clearing the frame, because it may need to
    // inherit an aliased security context.
    DocumentInit init(url, frame);
    init.withNewRegistrationContext();

    // In some rare cases, we'll re-used a DOMWindow for a new Document. For example,
    // when a script calls window.open("..."), the browser gives JavaScript a window
    // synchronously but kicks off the load in the window asynchronously. Web sites
    // expect that modifications that they make to the window object synchronously
    // won't be blown away when the network load commits. To make that happen, we
    // "securely transition" the existing DOMWindow to the Document that results from
    // the network load. See also SecurityContext::isSecureTransitionTo.
    bool shouldReuseDefaultView = frame->loader().stateMachine()->isDisplayingInitialEmptyDocument() && frame->document()->isSecureTransitionTo(url);

    frame->loader().clear();

    if (frame->document())
        frame->document()->prepareForDestruction();

    if (!shouldReuseDefaultView)
        frame->setDOMWindow(DOMWindow::create(*frame));

    RefPtr<Document> document = frame->domWindow()->installNewDocument(mimeType, init);
    if (ownerDocument) {
        document->setCookieURL(ownerDocument->cookieURL());
        document->setSecurityOrigin(ownerDocument->securityOrigin());
    }

    frame->loader().didBeginDocument(dispatch);

    return DocumentWriter::create(document.get(), mimeType, encoding, userChosen);
}

const AtomicString& DocumentLoader::mimeType() const
{
    if (m_writer)
        return m_writer->mimeType();
    return m_response.mimeType();
}

void DocumentLoader::setUserChosenEncoding(const String& charset)
{
    if (m_writer)
        m_writer->setUserChosenEncoding(charset);
}

// This is only called by ScriptController::executeScriptIfJavaScriptURL
// and always contains the result of evaluating a javascript: url.
// This is the <iframe src="javascript:'html'"> case.
void DocumentLoader::replaceDocument(const String& source, Document* ownerDocument)
{
    m_frame->loader().stopAllLoaders();
    m_writer = createWriterFor(m_frame, ownerDocument, m_frame->document()->url(), mimeType(), m_writer ? m_writer->encoding() : emptyAtom,  m_writer ? m_writer->encodingWasChosenByUser() : false, true);
    if (!source.isNull())
        m_writer->appendReplacingData(source);
    endWriting(m_writer.get());
}

} // namespace WebCore
/* [<][>][^][v][top][bottom][index][help] */
root/Source/core/loader/DocumentLoader.cpp

DEFINITIONS
