void DocumentThreadableLoader::loadRequest(const ResourceRequest& request, SecurityCheckPolicy securityCheck)
{
    // Any credential should have been removed from the cross-site requests.
    const KURL& requestURL = request.url();
    ASSERT(m_sameOriginRequest || requestURL.user().isEmpty());
    ASSERT(m_sameOriginRequest || requestURL.pass().isEmpty());

    if (m_async) {
        // Don't sniff content or send load callbacks for the preflight request.
        bool sendLoadCallbacks = m_options.sendLoadCallbacks && !m_actualRequest;
        bool sniffContent = m_options.sniffContent && !m_actualRequest;
        // Keep buffering the data for the preflight request.
        bool shouldBufferData = m_options.shouldBufferData || m_actualRequest;

        // Clear the loader so that any callbacks from SubresourceLoader::create will not have the old loader.
        m_loader = 0;
        m_loader = resourceLoadScheduler()->scheduleSubresourceLoad(m_document->frame(), this, request, ResourceLoadPriorityMedium, securityCheck, sendLoadCallbacks,
                                                                    sniffContent, m_optionalOutgoingReferrer, shouldBufferData);
        return;
    }
    
    // FIXME: ThreadableLoaderOptions.sniffContent is not supported for synchronous requests.
    StoredCredentials storedCredentials = m_options.allowCredentials ? AllowStoredCredentials : DoNotAllowStoredCredentials;

    Vector<char> data;
    ResourceError error;
    ResourceResponse response;
    unsigned long identifier = std::numeric_limits<unsigned long>::max();
    if (m_document->frame())
        identifier = m_document->frame()->loader()->loadResourceSynchronously(request, storedCredentials, error, response, data);

    // No exception for file:/// resources, see <rdar://problem/4962298>.
    // Also, if we have an HTTP response, then it wasn't a network error in fact.
    if (!error.isNull() && !requestURL.isLocalFile() && response.httpStatusCode() <= 0) {
        m_client->didFail(error);
        return;
    }

    // FIXME: FrameLoader::loadSynchronously() does not tell us whether a redirect happened or not, so we guess by comparing the
    // request and response URLs. This isn't a perfect test though, since a server can serve a redirect to the same URL that was
    // requested. Also comparing the request and response URLs as strings will fail if the requestURL still has its credentials.
    if (requestURL != response.url() && !isAllowedRedirect(response.url())) {
        m_client->didFailRedirectCheck();
        return;
    }

    didReceiveResponse(0, response);

    const char* bytes = static_cast<const char*>(data.data());
    int len = static_cast<int>(data.size());
    didReceiveData(0, bytes, len);

    didFinishLoading(identifier, 0.0);
}

void MultipartHandle::contentEnded()
{
    // Process the leftover data.
    while (processContent()) { }

    if (m_state != End) {
        // It seems we are still not at the end of the processing.
        // Push out the remaining data.
        didReceiveData(m_buffer.size());
        m_state = End;
    }

    m_buffer.clear();
}

void PluginStream::sendJavaScriptStream(const KURL& requestURL, const CString& resultString)
{
    didReceiveResponse(0, ResourceResponse(requestURL, "text/plain", resultString.length(), "", ""));

    if (m_streamState == StreamStopped)
        return;

    if (!resultString.isNull()) {
        didReceiveData(0, resultString.data(), resultString.length());
        if (m_streamState == StreamStopped)
            return;
    }

    m_loader = 0;

    destroyStream(resultString.isNull() ? NPRES_NETWORK_ERR : NPRES_DONE);
}

void ResourceLoader::didReceiveData(ResourceHandle*, const char* data, int length, int lengthReceived)
{
#if ENABLE(INSPECTOR)
    if (InspectorTimelineAgent::instanceCount()) {
        InspectorTimelineAgent* timelineAgent = m_frame->page() ? m_frame->page()->inspectorTimelineAgent() : 0;
        if (timelineAgent)
            timelineAgent->willReceiveResourceData(identifier());
    }
#endif
    didReceiveData(data, length, lengthReceived, false);
#if ENABLE(INSPECTOR)
    if (InspectorTimelineAgent::instanceCount()) {
        InspectorTimelineAgent* timelineAgent = m_frame->page() ? m_frame->page()->inspectorTimelineAgent() : 0;
        if (timelineAgent)
            timelineAgent->didReceiveResourceData();
    }
#endif
}

void InspectorResourceAgent::didReceiveResponse(unsigned long identifier, DocumentLoader* loader, const ResourceResponse& response, ResourceLoader* resourceLoader)
{
    String requestId = IdentifiersFactory::requestId(identifier);
    RefPtr<TypeBuilder::Network::Response> resourceResponse = buildObjectForResourceResponse(response, loader);
    InspectorPageAgent::ResourceType type = InspectorPageAgent::OtherResource;
    long cachedResourceSize = 0;

    bool isNotModified = response.httpStatusCode() == 304;
    if (loader) {
        CachedResource* cachedResource = 0;
        if (resourceLoader && resourceLoader->isSubresourceLoader() && !isNotModified)
            cachedResource = static_cast<SubresourceLoader*>(resourceLoader)->cachedResource();
        if (!cachedResource)
            cachedResource = InspectorPageAgent::cachedResource(loader->frame(), response.url());
        if (cachedResource) {
            type = InspectorPageAgent::cachedResourceType(*cachedResource);
            cachedResourceSize = cachedResource->encodedSize();
            // Use mime type from cached resource in case the one in response is empty.
            if (resourceResponse && response.mimeType().isEmpty())
                resourceResponse->setString(TypeBuilder::Network::Response::MimeType, cachedResource->response().mimeType());

            m_resourcesData->addCachedResource(requestId, cachedResource);
        }
        if (m_loadingXHRSynchronously || m_resourcesData->resourceType(requestId) == InspectorPageAgent::XHRResource)
            type = InspectorPageAgent::XHRResource;
        else if (m_resourcesData->resourceType(requestId) == InspectorPageAgent::ScriptResource)
            type = InspectorPageAgent::ScriptResource;
        else if (equalIgnoringFragmentIdentifier(response.url(), loader->frameLoader()->icon()->url()))
            type = InspectorPageAgent::ImageResource;
        else if (equalIgnoringFragmentIdentifier(response.url(), loader->url()) && !loader->isCommitted())
            type = InspectorPageAgent::DocumentResource;

        m_resourcesData->responseReceived(requestId, m_pageAgent->frameId(loader->frame()), response);
    }
    m_resourcesData->setResourceType(requestId, type);
    m_frontend->responseReceived(requestId, m_pageAgent->frameId(loader->frame()), m_pageAgent->loaderId(loader), currentTime(), InspectorPageAgent::resourceTypeJson(type), resourceResponse);
    // If we revalidated the resource and got Not modified, send content length following didReceiveResponse
    // as there will be no calls to didReceiveData from the network stack.
    if (cachedResourceSize && isNotModified)
        didReceiveData(identifier, 0, cachedResourceSize, 0);
}

void InspectorResourceAgent::didReceiveResponse(unsigned long identifier, DocumentLoader* loader, const ResourceResponse& response, ResourceLoader* resourceLoader)
{
    if (m_hiddenRequestIdentifiers.contains(identifier))
        return;

    String requestId = IdentifiersFactory::requestId(identifier);
    RefPtr<Inspector::Protocol::Network::Response> resourceResponse = buildObjectForResourceResponse(response, loader);

    bool isNotModified = response.httpStatusCode() == 304;

    CachedResource* cachedResource = nullptr;
    if (resourceLoader && resourceLoader->isSubresourceLoader() && !isNotModified)
        cachedResource = static_cast<SubresourceLoader*>(resourceLoader)->cachedResource();
    if (!cachedResource)
        cachedResource = InspectorPageAgent::cachedResource(loader->frame(), response.url());

    if (cachedResource) {
        // Use mime type from cached resource in case the one in response is empty.
        if (resourceResponse && response.mimeType().isEmpty())
            resourceResponse->setString(Inspector::Protocol::Network::Response::MimeType, cachedResource->response().mimeType());
        m_resourcesData->addCachedResource(requestId, cachedResource);
    }

    InspectorPageAgent::ResourceType type = m_resourcesData->resourceType(requestId);
    InspectorPageAgent::ResourceType newType = cachedResource ? InspectorPageAgent::cachedResourceType(*cachedResource) : type;

    // FIXME: XHRResource is returned for CachedResource::RawResource, it should be OtherResource unless it truly is an XHR.
    // RawResource is used for loading worker scripts, and those should stay as ScriptResource and not change to XHRResource.
    if (type != newType && newType != InspectorPageAgent::XHRResource && newType != InspectorPageAgent::OtherResource)
        type = newType;

    m_resourcesData->responseReceived(requestId, m_pageAgent->frameId(loader->frame()), response);
    m_resourcesData->setResourceType(requestId, type);

    m_frontendDispatcher->responseReceived(requestId, m_pageAgent->frameId(loader->frame()), m_pageAgent->loaderId(loader), currentTime(), InspectorPageAgent::resourceTypeJson(type), resourceResponse);

    // If we revalidated the resource and got Not modified, send content length following didReceiveResponse
    // as there will be no calls to didReceiveData from the network stack.
    if (isNotModified && cachedResource && cachedResource->encodedSize())
        didReceiveData(identifier, nullptr, cachedResource->encodedSize(), 0);
}

void ResourceLoader::didReceiveData(ResourceHandle*, const char* data, unsigned length, int encodedDataLength)
{
    didReceiveData(data, length, encodedDataLength, DataPayloadBytes);
}

void DocumentThreadableLoader::dataReceived(Resource* resource, const char* data, int dataLength)
{
    ASSERT(resource == this->resource());
    didReceiveData(resource->identifier(), data, dataLength);
}

void MainResourceLoader::continueAfterContentPolicy(PolicyAction contentPolicy, const ResourceResponse& r)
{
    KURL url = request().url();
    const String& mimeType = r.mimeType();
    
    switch (contentPolicy) {
    case PolicyUse: {
        // Prevent remote web archives from loading because they can claim to be from any domain and thus avoid cross-domain security checks (4120255).
        bool isRemoteWebArchive = (equalIgnoringCase("application/x-webarchive", mimeType) || equalIgnoringCase("multipart/related", mimeType))
            && !m_substituteData.isValid() && !url.isLocalFile();
        if (!frameLoader()->client()->canShowMIMEType(mimeType) || isRemoteWebArchive) {
            frameLoader()->policyChecker()->cannotShowMIMEType(r);
            // Check reachedTerminalState since the load may have already been cancelled inside of _handleUnimplementablePolicyWithErrorCode::.
            if (!reachedTerminalState())
                stopLoadingForPolicyChange();
            return;
        }
        break;
    }

    case PolicyDownload:
        // m_handle can be null, e.g. when loading a substitute resource from application cache.
        if (!m_handle) {
            receivedError(cannotShowURLError());
            return;
        }
        frameLoader()->client()->download(m_handle.get(), request(), m_handle.get()->firstRequest(), r);
        // It might have gone missing
        if (frameLoader())
            receivedError(interruptedForPolicyChangeError());
        return;

    case PolicyIgnore:
        stopLoadingForPolicyChange();
        return;
    
    default:
        ASSERT_NOT_REACHED();
    }

    RefPtr<MainResourceLoader> protect(this);

    if (r.isHTTP()) {
        int status = r.httpStatusCode();
        if (status < 200 || status >= 300) {
            bool hostedByObject = frameLoader()->isHostedByObjectElement();

            frameLoader()->handleFallbackContent();
            // object elements are no longer rendered after we fallback, so don't
            // keep trying to process data from their load

            if (hostedByObject)
                cancel();
        }
    }

    // we may have cancelled this load as part of switching to fallback content
    if (!reachedTerminalState())
        ResourceLoader::didReceiveResponse(r);

    if (frameLoader() && !frameLoader()->isStopping()) {
        if (m_substituteData.isValid()) {
            if (m_substituteData.content()->size())
                didReceiveData(m_substituteData.content()->data(), m_substituteData.content()->size(), m_substituteData.content()->size(), true);
            if (frameLoader() && !frameLoader()->isStopping()) 
                didFinishLoading(0);
        } else if (shouldLoadAsEmptyDocument(url) || frameLoader()->client()->representationExistsForURLScheme(url.protocol()))
            didFinishLoading(0);
    }
}

void DocumentThreadableLoader::dataReceived(Resource* resource, const char* data, int dataLength)
{
    ASSERT_UNUSED(resource, resource == this->resource());
    didReceiveData(data, dataLength);
}

void DocumentThreadableLoader::loadRequest(const ResourceRequest& request)
{
    // Any credential should have been removed from the cross-site requests.
    const KURL& requestURL = request.url();
    ASSERT(m_sameOriginRequest || requestURL.user().isEmpty());
    ASSERT(m_sameOriginRequest || requestURL.pass().isEmpty());

    ThreadableLoaderOptions options = m_options;
    if (m_async) {
        if (m_actualRequest) {
            options.sniffContent = DoNotSniffContent;
            options.dataBufferingPolicy = BufferData;
        }

        if (m_options.timeoutMilliseconds > 0)
            m_timeoutTimer.startOneShot(m_options.timeoutMilliseconds / 1000.0);

        FetchRequest newRequest(request, m_options.initiator, options);
        ASSERT(!resource());
        setResource(m_document->fetcher()->fetchRawResource(newRequest));
        if (resource() && resource()->loader()) {
            unsigned long identifier = resource()->identifier();
            InspectorInstrumentation::documentThreadableLoaderStartedLoadingForClient(m_document, identifier, m_client);
        }
        return;
    }

    FetchRequest fetchRequest(request, m_options.initiator, options);
    ResourcePtr<Resource> resource = m_document->fetcher()->fetchSynchronously(fetchRequest);
    ResourceResponse response = resource ? resource->response() : ResourceResponse();
    unsigned long identifier = resource ? resource->identifier() : std::numeric_limits<unsigned long>::max();
    ResourceError error = resource ? resource->resourceError() : ResourceError();

    InspectorInstrumentation::documentThreadableLoaderStartedLoadingForClient(m_document, identifier, m_client);

    if (!resource) {
        m_client->didFail(error);
        return;
    }

    // No exception for file:/// resources, see <rdar://problem/4962298>.
    // Also, if we have an HTTP response, then it wasn't a network error in fact.
    if (!error.isNull() && !requestURL.isLocalFile() && response.httpStatusCode() <= 0) {
        m_client->didFail(error);
        return;
    }

    // FIXME: A synchronous request does not tell us whether a redirect happened or not, so we guess by comparing the
    // request and response URLs. This isn't a perfect test though, since a server can serve a redirect to the same URL that was
    // requested. Also comparing the request and response URLs as strings will fail if the requestURL still has its credentials.
    if (requestURL != response.url() && (!isAllowedByPolicy(response.url()) || !isAllowedRedirect(response.url()))) {
        m_client->didFailRedirectCheck();
        return;
    }

    didReceiveResponse(identifier, response);

    SharedBuffer* data = resource->resourceBuffer();
    if (data)
        didReceiveData(data->data(), data->size());

    didFinishLoading(identifier, 0.0);
}

void ResourceHandleClient::didReceiveBuffer(ResourceHandle* handle, PassRefPtr<SharedBuffer> buffer, int encodedDataLength)
{
    didReceiveData(handle, buffer->data(), buffer->size(), encodedDataLength);
}

void ResourceLoader::didReceiveData(ResourceHandle*, const char* data, int length, int lengthReceived)
{
    didReceiveData(data, length, lengthReceived, false);
}

void DocumentThreadableLoader::loadRequest(const ResourceRequest& request, SecurityCheckPolicy securityCheck)
{
    // Any credential should have been removed from the cross-site requests.
    const KURL& requestURL = request.url();
    m_options.securityCheck = securityCheck;
    ASSERT(m_sameOriginRequest || requestURL.user().isEmpty());
    ASSERT(m_sameOriginRequest || requestURL.pass().isEmpty());

    if (m_async) {
        ThreadableLoaderOptions options = m_options;
        options.clientCredentialPolicy = DoNotAskClientForCrossOriginCredentials;
        if (m_actualRequest) {
            // Don't sniff content or send load callbacks for the preflight request.
            options.sendLoadCallbacks = DoNotSendCallbacks;
            options.sniffContent = DoNotSniffContent;
            // Keep buffering the data for the preflight request.
            options.dataBufferingPolicy = BufferData;
        }

        CachedResourceRequest newRequest(request, options);
#if ENABLE(RESOURCE_TIMING)
        newRequest.setInitiator(m_options.initiator);
#endif
        ASSERT(!m_resource);
        m_resource = m_document->cachedResourceLoader()->requestRawResource(newRequest);
        if (m_resource) {
#if ENABLE(INSPECTOR)
            if (m_resource->loader()) {
                unsigned long identifier = m_resource->loader()->identifier();
                InspectorInstrumentation::documentThreadableLoaderStartedLoadingForClient(m_document, identifier, m_client);
            }
#endif
            m_resource->addClient(this);
        }
        return;
    }
    
    // FIXME: ThreadableLoaderOptions.sniffContent is not supported for synchronous requests.
    Vector<char> data;
    ResourceError error;
    ResourceResponse response;
    unsigned long identifier = std::numeric_limits<unsigned long>::max();
    if (m_document->frame())
        identifier = m_document->frame()->loader()->loadResourceSynchronously(request, m_options.allowCredentials, m_options.clientCredentialPolicy, error, response, data);

    InspectorInstrumentation::documentThreadableLoaderStartedLoadingForClient(m_document, identifier, m_client);

    // No exception for file:/// resources, see <rdar://problem/4962298>.
    // Also, if we have an HTTP response, then it wasn't a network error in fact.
    if (!error.isNull() && !requestURL.isLocalFile() && response.httpStatusCode() <= 0) {
        m_client->didFail(error);
        return;
    }

    // FIXME: FrameLoader::loadSynchronously() does not tell us whether a redirect happened or not, so we guess by comparing the
    // request and response URLs. This isn't a perfect test though, since a server can serve a redirect to the same URL that was
    // requested. Also comparing the request and response URLs as strings will fail if the requestURL still has its credentials.
    if (requestURL != response.url() && !isAllowedRedirect(response.url())) {
        m_client->didFailRedirectCheck();
        return;
    }

    didReceiveResponse(identifier, response);

    const char* bytes = static_cast<const char*>(data.data());
    int len = static_cast<int>(data.size());
    didReceiveData(identifier, bytes, len);

    didFinishLoading(identifier, 0.0);
}

bool MultipartHandle::processContent()
{
/*
    The allowed transitions between the states:
         Check Boundary
               |
      /-- In Boundary <----\
     |         |            |
     |     In Header        |
     |         |            |
     |     In Content       |
     |         |            |
     |    End Boundary ----/
     |         |
      \-----> End

*/
    switch (m_state) {
    case CheckBoundary: {
        if (m_buffer.size() < m_boundaryLength) {
            // We don't have enough data, so just skip.
            return false;
        }

        // Check for the boundary string.
        size_t boundaryStart;
        size_t lastPartialMatch;

        if (!checkForBoundary(boundaryStart, lastPartialMatch) && boundaryStart == notFound) {
            // Did not find the boundary start in this chunk.
            // Skip ahead to the last valid looking boundary character and start again.
            m_buffer.remove(0, lastPartialMatch);
            return false;
        }

        // Found the boundary start.
        // Consume everything before that and also the boundary
        m_buffer.remove(0, boundaryStart + m_boundaryLength);
        m_state = InBoundary;
    }
    // Fallthrough.
    case InBoundary: {
        // Now the first two characters should be: \r\n
        if (m_buffer.size() < 2)
            return false;

        const char* content = m_buffer.data();
        // By default we'll remove 2 characters at the end.
        // The \r and \n as stated in the multipart RFC.
        size_t removeCount = 2;

        if (content[0] != '\r' || content[1] != '\n') {
            // There should be a \r and a \n but it seems that's not the case.
            // So we'll check for a simple \n. Not really RFC compatible but servers do tricky things.
            if (content[0] != '\n') {
                // Also no \n so just go to the end.
                m_state = End;
                return false;
            }

            // Found a simple \n so remove just that.
            removeCount = 1;
        }

        // Consume the characters.
        m_buffer.remove(0, removeCount);
        m_headers.clear();
        m_state = InHeader;
    }
    // Fallthrough.
    case InHeader: {
        // Process the headers.
        if (!parseHeadersIfPossible()) {
            // Parsing of headers failed, try again later.
            return false;
        }

        didReceiveResponse();
        m_state = InContent;
    }
    // Fallthrough.
    case InContent: {
        if (m_buffer.isEmpty())
            return false;

        size_t boundaryStart = notFound;
        size_t lastPartialMatch;

        if (!checkForBoundary(boundaryStart, lastPartialMatch) && boundaryStart == notFound) {
            // Did not find the boundary start, all data up to the lastPartialMatch is ok.
            didReceiveData(lastPartialMatch);
            m_buffer.remove(0, lastPartialMatch);
            return false;
        }

        // There was a boundary start (or end we'll check that later), push out part of the data.
        didReceiveData(boundaryStart);
        m_buffer.remove(0, boundaryStart + m_boundaryLength);
        m_state = EndBoundary;
    }
//.........这里部分代码省略.........