C++ DocLoader类代码示例

void Loader::didFail(SubresourceLoader* loader, bool cancelled)
{
    RequestMap::iterator i = m_requestsLoading.find(loader);
    if (i == m_requestsLoading.end())
        return;

    Request* req = i->second;
    m_requestsLoading.remove(i);
    DocLoader* docLoader = req->docLoader();
    if (!req->isMultipart())
        docLoader->decrementRequestCount();

    CachedResource* object = req->cachedResource();

    if (!cancelled) {
        docLoader->setLoadInProgress(true);
        object->error();
    }
    
    docLoader->setLoadInProgress(false);
    cache()->remove(object);

    delete req;

    servePendingRequests();
}

static void* openFunc(const char* uri)
{
    ASSERT(XMLTokenizerScope::currentDocLoader);
    ASSERT(currentThread() == libxmlLoaderThread);

    KURL url(KURL(), uri);

    if (!shouldAllowExternalLoad(url))
        return &globalDescriptor;

    ResourceError error;
    ResourceResponse response;
    Vector<char> data;


    {
        DocLoader* docLoader = XMLTokenizerScope::currentDocLoader;
        XMLTokenizerScope scope(0);
        // FIXME: We should restore the original global error handler as well.

        if (docLoader->frame()) 
            docLoader->frame()->loader()->loadResourceSynchronously(url, AllowStoredCredentials, error, response, data);
    }

    // We have to check the URL again after the load to catch redirects.
    // See <https://bugs.webkit.org/show_bug.cgi?id=21963>.
    if (!shouldAllowExternalLoad(response.url()))
        return &globalDescriptor;

    return new OffsetBuffer(data);
}

void Loader::Host::didFail(SubresourceLoader* loader, bool cancelled)
{
    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();
    if (!request->isMultipart())
        docLoader->decrementRequestCount();

    CachedResource* resource = request->cachedResource();

    if (!cancelled) {
        docLoader->setLoadInProgress(true);
        resource->error();
    }
    
    docLoader->setLoadInProgress(false);
    if (cancelled || !resource->isPreloaded())
        cache()->remove(resource);
    
    delete request;

    servePendingRequests();
}

void Loader::Host::didFinishLoading(SubresourceLoader* loader)
{
    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();
    if (!request->isMultipart())
        docLoader->decrementRequestCount();

    CachedResource* resource = request->cachedResource();

    // 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);

#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::servePendingRequests(RequestQueue& requestsPending, bool& serveLowerPriority)
{
    while (!requestsPending.isEmpty()) {        
        Request* request = requestsPending.first();
        DocLoader* docLoader = request->docLoader();
        bool resourceIsCacheValidator = request->cachedResource()->isCacheValidator();

        // For named hosts - which are only http(s) hosts - we should always enforce the connection limit.
        // For non-named hosts - everything but http(s) - we should only enforce the limit if the document isn't done parsing 
        // and we don't know all stylesheets yet.
        bool shouldLimitRequests = !m_name.isNull() || docLoader->doc()->parsing() || !docLoader->doc()->haveStylesheetsLoaded();
        if (shouldLimitRequests && m_requestsLoading.size() + m_nonCachedRequestsInFlight >= m_maxRequestsInFlight) {
            serveLowerPriority = false;
            cache()->loader()->scheduleServePendingRequests();
            return;
        }
        requestsPending.removeFirst();
        
        ResourceRequest resourceRequest(request->cachedResource()->url());
        resourceRequest.setTargetType(cachedResourceTypeToTargetType(request->cachedResource()->type()));
        
        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->shouldDoSecurityCheck(), 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::servePendingRequests(RequestQueue& requestsPending)
{
    while (m_requestsLoading.size() < m_maxRequestsInFlight && !requestsPending.isEmpty()) {        
        Request* request = requestsPending.first();
        requestsPending.removeFirst();

        DocLoader* docLoader = request->docLoader();
        
        ResourceRequest resourceRequest(request->cachedResource()->url());
        
        if (!request->cachedResource()->accept().isEmpty())
            resourceRequest.setHTTPAccept(request->cachedResource()->accept());
        
        KURL referrer = docLoader->doc()->url();
        if ((referrer.protocolIs("http") || referrer.protocolIs("https")) && referrer.path().isEmpty())
            referrer.setPath("/");
        resourceRequest.setHTTPReferrer(referrer.string());

        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 CSSImportRule::insertedIntoParent()
{
    CSSStyleSheet* parentSheet = parentStyleSheet();
    if (!parentSheet)
        return;

    DocLoader* docLoader = parentSheet->doc()->docLoader();
    if (!docLoader)
        return;

    String absHref = m_strHref;
    if (!parentSheet->finalURL().isNull())
        // use parent styleheet's URL as the base URL
        absHref = KURL(parentSheet->finalURL(), m_strHref).string();

    // Check for a cycle in our import chain.  If we encounter a stylesheet
    // in our parent chain with the same URL, then just bail.
    StyleBase* root = this;
    for (StyleBase* curr = parent(); curr; curr = curr->parent()) {
        // FIXME: This is wrong if the finalURL was updated via document::updateBaseURL. 
        if (curr->isCSSStyleSheet() && absHref == static_cast<CSSStyleSheet*>(curr)->finalURL().string())
            return;
        root = curr;
    }

    if (parentSheet->isUserStyleSheet())
        m_cachedSheet = docLoader->requestUserCSSStyleSheet(absHref, parentSheet->charset());
    else
        m_cachedSheet = docLoader->requestCSSStyleSheet(absHref, parentSheet->charset());
    if (m_cachedSheet) {
        // if the import rule is issued dynamically, the sheet may be
        // removed from the pending sheet count, so let the doc know
        // the sheet being imported is pending.
        if (parentSheet && parentSheet->loadCompleted() && root == parentSheet)
            parentSheet->doc()->addPendingSheet();
        m_loading = true;
        m_cachedSheet->addClient(this);
    }
}

void Loader::didFinishLoading(SubresourceLoader* loader)
{
    RequestMap::iterator i = m_requestsLoading.find(loader);
    if (i == m_requestsLoading.end())
        return;

    Request* req = i->second;
    m_requestsLoading.remove(i);
    DocLoader* docLoader = req->docLoader();
    if (!req->isMultipart())
        docLoader->decrementRequestCount();

    CachedResource* object = req->cachedResource();

    docLoader->setLoadInProgress(true);
    object->data(loader->resourceData(), true);
    docLoader->setLoadInProgress(false);
    object->finish();

    delete req;

    servePendingRequests();
}

void Loader::servePendingRequests()
{
    while (!m_requestsPending.isEmpty()) {
        // get the first pending request
        Request* req = m_requestsPending.take(0);
        DocLoader* dl = req->docLoader();
        dl->decrementRequestCount();

        ResourceRequest request(req->cachedResource()->url());

        if (!req->cachedResource()->accept().isEmpty())
            request.setHTTPAccept(req->cachedResource()->accept());

        KURL r = dl->doc()->URL();
        if (r.protocol().startsWith("http") && r.path().isEmpty())
            r.setPath("/");
        request.setHTTPReferrer(r.url());
        DeprecatedString domain = r.host();
        if (dl->doc()->isHTMLDocument())
            domain = static_cast<HTMLDocument*>(dl->doc())->domain().deprecatedString();
        
        RefPtr<SubresourceLoader> loader = SubresourceLoader::create(dl->doc()->frame(),
            this, request, req->shouldSkipCanLoadCheck(), req->sendResourceLoadCallbacks());

        if (loader) {
            m_requestsLoading.add(loader.release(), req);
            dl->incrementRequestCount();
            break;
        }

        dl->setLoadInProgress(true);
        req->cachedResource()->error();
        dl->setLoadInProgress(false);

        delete req;
    }
}

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.
    RefPtr<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(ParsedURLString, 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::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());
        
        KURL referrer = docLoader->doc()->url();
        if ((referrer.protocolIs("http") || referrer.protocolIs("https")) && referrer.path().isEmpty())
            referrer.setPath("/");
        resourceRequest.setHTTPReferrer(referrer.string());
        FrameLoader::addHTTPOriginIfNeeded(resourceRequest, docLoader->doc()->securityOrigin()->toString());
        
        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;
        }
    }
}

bool DragController::concludeEditDrag(DragData* dragData)
{
    ASSERT(dragData);
    ASSERT(!m_isHandlingDrag);

    if (!m_documentUnderMouse)
        return false;

    IntPoint point = m_documentUnderMouse->view()->windowToContents(dragData->clientPosition());
    Element* element = elementUnderMouse(m_documentUnderMouse, point);
    Frame* innerFrame = element->ownerDocument()->frame();
    ASSERT(innerFrame);

    if (dragData->containsColor()) {
        Color color = dragData->asColor();
        if (!color.isValid())
            return false;
        if (!innerFrame)
            return false;
        RefPtr<Range> innerRange = innerFrame->selection()->toNormalizedRange();
        RefPtr<CSSStyleDeclaration> style = m_documentUnderMouse->createCSSStyleDeclaration();
        ExceptionCode ec;
        style->setProperty("color", color.name(), ec);
        if (!innerFrame->editor()->shouldApplyStyle(style.get(), innerRange.get()))
            return false;
        m_client->willPerformDragDestinationAction(DragDestinationActionEdit, dragData);
        innerFrame->editor()->applyStyle(style.get(), EditActionSetColor);
        return true;
    }

    if (!m_page->dragController()->canProcessDrag(dragData)) {
        m_page->dragCaretController()->clear();
        return false;
    }

    if (HTMLInputElement* fileInput = asFileInput(element)) {
        if (!fileInput->isEnabledFormControl())
            return false;

        if (!dragData->containsFiles())
            return false;

        Vector<String> filenames;
        dragData->asFilenames(filenames);
        if (filenames.isEmpty())
            return false;

        // Ugly. For security none of the APIs available to us can set the input value
        // on file inputs. Even forcing a change in HTMLInputElement doesn't work as
        // RenderFileUploadControl clears the file when doing updateFromElement().
        RenderFileUploadControl* renderer = toRenderFileUploadControl(fileInput->renderer());
        if (!renderer)
            return false;

        renderer->receiveDroppedFiles(filenames);
        return true;
    }

    VisibleSelection dragCaret(m_page->dragCaretController()->selection());
    m_page->dragCaretController()->clear();
    RefPtr<Range> range = dragCaret.toNormalizedRange();

    // For range to be null a WebKit client must have done something bad while
    // manually controlling drag behaviour
    if (!range)
        return false;
    DocLoader* loader = range->ownerDocument()->docLoader();
    loader->setAllowStaleResources(true);
    if (dragIsMove(innerFrame->selection()) || dragCaret.isContentRichlyEditable()) {
        bool chosePlainText = false;
        RefPtr<DocumentFragment> fragment = documentFragmentFromDragData(dragData, range, true, chosePlainText);
        if (!fragment || !innerFrame->editor()->shouldInsertFragment(fragment, range, EditorInsertActionDropped)) {
            loader->setAllowStaleResources(false);
            return false;
        }

        m_client->willPerformDragDestinationAction(DragDestinationActionEdit, dragData);
        if (dragIsMove(innerFrame->selection())) {
            bool smartMove = innerFrame->selectionGranularity() == WordGranularity
                          && innerFrame->editor()->smartInsertDeleteEnabled()
                          && dragData->canSmartReplace();
            applyCommand(MoveSelectionCommand::create(fragment, dragCaret.base(), smartMove));
        } else {
            if (setSelectionToDragCaret(innerFrame, dragCaret, range, point))
                applyCommand(ReplaceSelectionCommand::create(m_documentUnderMouse, fragment, true, dragData->canSmartReplace(), chosePlainText));
        }
    } else {
        String text = dragData->asPlainText();
        if (text.isEmpty() || !innerFrame->editor()->shouldInsertText(text, range.get(), EditorInsertActionDropped)) {
            loader->setAllowStaleResources(false);
            return false;
        }

        m_client->willPerformDragDestinationAction(DragDestinationActionEdit, dragData);
        if (setSelectionToDragCaret(innerFrame, dragCaret, range, point))
            applyCommand(ReplaceSelectionCommand::create(m_documentUnderMouse, createFragmentFromText(range.get(), text), true, false, true));
    }
    loader->setAllowStaleResources(false);

    return true;
//.........这里部分代码省略.........