documentloader.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2006, 2007, 2008 Apple 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 "DocumentLoader.h"

#if ENABLE(OFFLINE_WEB_APPLICATIONS)
#include "ApplicationCache.h"
#include "ApplicationCacheGroup.h"
#include "ApplicationCacheResource.h"
#endif
#include "ArchiveFactory.h"
#include "ArchiveResourceCollection.h"
#include "CachedPage.h"
#include "DocLoader.h"
#include "Document.h"
#include "Event.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "FrameTree.h"
#include "HistoryItem.h"
#include "Logging.h"
#include "MainResourceLoader.h"
#include "Page.h"
#include "PlatformString.h"
#include "Settings.h"
#include "SharedBuffer.h"
#include "StringBuffer.h"
#include "XMLTokenizer.h"

#include <wtf/Assertions.h>
#include <wtf/unicode/Unicode.h>

namespace WebCore {

/*
 * Performs four operations:
 *  1. Convert backslashes to currency symbols
 *  2. Convert control characters to spaces
 *  3. Trim leading and trailing spaces
 *  4. Collapse internal whitespace.
 */
static inline String canonicalizedTitle(const String& title, Frame* frame)
{
    ASSERT(!title.isEmpty());

    const UChar* characters = title.characters();
    unsigned length = title.length();
    unsigned i;

    StringBuffer buffer(length);
    unsigned builderIndex = 0;

    // Skip leading spaces and leading characters that would convert to spaces
    for (i = 0; i < length; ++i) {
        UChar c = characters[i];
        if (!(c <= 0x20 || c == 0x7F))
            break;
    }

    if (i == length)
        return "";

    // Replace control characters with spaces, and backslashes with currency symbols, and collapse whitespace.
    bool previousCharWasWS = false;
    for (; i < length; ++i) {
        UChar c = characters[i];
        if (c <= 0x20 || c == 0x7F || (WTF::Unicode::category(c) & (WTF::Unicode::Separator_Line | WTF::Unicode::Separator_Paragraph))) {
            if (previousCharWasWS)
                continue;
            buffer[builderIndex++] = ' ';
            previousCharWasWS = true;
        } else {
            buffer[builderIndex++] = c;
            previousCharWasWS = false;
        }
    }

    // Strip trailing spaces
    while (builderIndex > 0) {
        --builderIndex;
        if (buffer[builderIndex] != ' ')
            break;
    }

    if (!builderIndex && buffer[builderIndex] == ' ')
        return "";

    buffer.shrink(builderIndex + 1);
    
    // Replace the backslashes with currency symbols if the encoding requires it.
    frame->document()->displayBufferModifiedByEncoding(buffer.characters(), buffer.length());

    return String::adopt(buffer);
}

static void cancelAll(const ResourceLoaderSet& loaders)
{
    const ResourceLoaderSet copy = loaders;
    ResourceLoaderSet::const_iterator end = copy.end();
    for (ResourceLoaderSet::const_iterator it = copy.begin(); it != end; ++it)
        (*it)->cancel();
}

static void setAllDefersLoading(const ResourceLoaderSet& loaders, bool defers)
{
    const ResourceLoaderSet copy = loaders;
    ResourceLoaderSet::const_iterator end = copy.end();
    for (ResourceLoaderSet::const_iterator it = copy.begin(); it != end; ++it)
        (*it)->setDefersLoading(defers);
}

DocumentLoader::DocumentLoader(const ResourceRequest& req, const SubstituteData& substituteData)
    : m_deferMainResourceDataLoad(true)
    , m_frame(0)
    , m_originalRequest(req)
    , m_substituteData(substituteData)
    , m_originalRequestCopy(req)
    , m_request(req)
    , m_committed(false)
    , m_isStopping(false)
    , m_loading(false)
    , m_gotFirstByte(false)
    , m_primaryLoadComplete(false)
    , m_isClientRedirect(false)
    , m_loadingFromCachedPage(false)
    , m_stopRecordingResponses(false)
    , m_substituteResourceDeliveryTimer(this, &DocumentLoader::substituteResourceDeliveryTimerFired)
    , m_didCreateGlobalHistoryEntry(false)
#if ENABLE(OFFLINE_WEB_APPLICATIONS)
    , m_candidateApplicationCacheGroup(0)
#endif
{
}

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

DocumentLoader::~DocumentLoader()
{
    ASSERT(!m_frame || frameLoader()->activeDocumentLoader() != this || !frameLoader()->isLoading());
    
#if ENABLE(OFFLINE_WEB_APPLICATIONS)
    if (m_applicationCache)
        m_applicationCache->group()->disassociateDocumentLoader(this);
    else if (m_candidateApplicationCacheGroup)
        m_candidateApplicationCacheGroup->disassociateDocumentLoader(this);
#endif
}

PassRefPtr<SharedBuffer> DocumentLoader::mainResourceData() const
{
    if (m_mainResourceData)
        return m_mainResourceData;
    if (m_mainResourceLoader)
        return m_mainResourceLoader->resourceData();
    return 0;
}

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

const ResourceRequest& DocumentLoader::originalRequestCopy() const
{
    return m_originalRequestCopy;
}

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

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

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

void DocumentLoader::replaceRequestURLForAnchorScroll(const KURL& url)
{
    m_originalRequestCopy.setURL(url);
    m_request.setURL(url);
}

void DocumentLoader::setRequest(const ResourceRequest& req)
{
    // Replacing an unreachable URL with alternate content looks like a server-side
    // redirect at this point, but we can replace a committed dataSource.
    bool handlingUnreachableURL = false;

    handlingUnreachableURL = m_substituteData.isValid() && !m_substituteData.failingURL().isEmpty();

    if (handlingUnreachableURL)
        m_committed = false;

    // We should never be getting a redirect callback after the data
    // source is committed, except in the unreachable URL case. It 
    // would be a WebFoundation bug if it sent a redirect callback after commit.
    ASSERT(!m_committed);

    KURL oldURL = m_request.url();
    m_request = req;

    // Only send webView:didReceiveServerRedirectForProvisionalLoadForFrame: if URL changed.
    // Also, don't send it when replacing unreachable URLs with alternate content.
    if (!handlingUnreachableURL && oldURL != req.url())
        frameLoader()->didReceiveServerRedirectForProvisionalLoadForFrame();
}

void DocumentLoader::setMainDocumentError(const ResourceError& error)
{
    m_mainDocumentError = error;    
    frameLoader()->setMainDocumentError(this, error);
 }

void DocumentLoader::clearErrors()
{
    m_mainDocumentError = ResourceError();
}

void DocumentLoader::mainReceivedError(const ResourceError& error, bool isComplete)
{
    ASSERT(!error.isNull());

#if ENABLE(OFFLINE_WEB_APPLICATIONS)
    ApplicationCacheGroup* group = m_candidateApplicationCacheGroup;
    if (!group && m_applicationCache) {
        ASSERT(!mainResourceApplicationCache()); // If the main resource were loaded from a cache, it wouldn't fail.
        group = m_applicationCache->group();
    }
    
    if (group)
        group->failedLoadingMainResource(this);
#endif
    
    if (!frameLoader())
        return;
    setMainDocumentError(error);
    if (isComplete)
        frameLoader()->mainReceivedCompleteError(this, error);
}

// 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()
{
    // In some rare cases, calling FrameLoader::stopLoading could set m_loading to 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 = m_loading;
    
    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(false);
    }

    // Always cancel multipart loaders
    cancelAll(m_multipartSubresourceLoaders);

    if (!loading)
        return;
    
    RefPtr<Frame> protectFrame(m_frame);
    RefPtr<DocumentLoader> protectLoader(this);

    m_isStopping = true;

    FrameLoader* frameLoader = DocumentLoader::frameLoader();
    
    if (m_mainResourceLoader)
        // Stop the main resource loader and let it send the cancelled message.
        m_mainResourceLoader->cancel();
    else if (!m_subresourceLoaders.isEmpty())
        // The main resource loader already finished loading. Set the cancelled error on the 
        // document and let the subresourceLoaders send individual cancelled messages below.
        setMainDocumentError(frameLoader->cancelledError(m_request));
    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(frameLoader->cancelledError(m_request), true);
    
    stopLoadingSubresources();
    stopLoadingPlugIns();
    
    m_isStopping = false;
}

void DocumentLoader::setupForReplace()
{
    frameLoader()->setupForReplace();
    m_committed = false;
}

void DocumentLoader::commitIfReady()
{
    if (m_gotFirstByte && !m_committed) {
        m_committed = true;
        frameLoader()->commitProvisionalLoad(0);
    }
}

void DocumentLoader::finishedLoading()
{
    m_gotFirstByte = true;   
    commitIfReady();
    if (FrameLoader* loader = frameLoader()) {
        loader->finishedLoadingDocument(this);
        loader->end();
    }
}

void DocumentLoader::commitLoad(const char* data, int length)
{
    // 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<DocumentLoader> protect(this);

    commitIfReady();
    if (FrameLoader* frameLoader = DocumentLoader::frameLoader())
        frameLoader->committedLoad(this, data, length);
}

bool DocumentLoader::doesProgressiveLoad(const String& MIMEType) const
{
    return !frameLoader()->isReplacing() || MIMEType == "text/html";
}

void DocumentLoader::receivedData(const char* data, int length)
{    
    m_gotFirstByte = true;
    if (doesProgressiveLoad(m_response.mimeType()))
        commitLoad(data, length);
}

void DocumentLoader::setupForReplaceByMIMEType(const String& newMIMEType)
{
    if (!m_gotFirstByte)
        return;
    
    String oldMIMEType = m_response.mimeType();
    
    if (!doesProgressiveLoad(oldMIMEType)) {
        frameLoader()->revertToProvisional(this);
        setupForReplace();
        RefPtr<SharedBuffer> resourceData = mainResourceData();
        commitLoad(resourceData->data(), resourceData->size());
    }
    
    frameLoader()->finishedLoadingDocument(this);
    m_frame->loader()->end();
    
    frameLoader()->setReplacing();
    m_gotFirstByte = false;
    
    if (doesProgressiveLoad(newMIMEType)) {
        frameLoader()->revertToProvisional(this);
        setupForReplace();
    }
    
    stopLoadingSubresources();
    stopLoadingPlugIns();
    clearArchiveResources();
}

void DocumentLoader::updateLoading()
{
    ASSERT(this == frameLoader()->activeDocumentLoader());
    setLoading(frameLoader()->isLoading());
}

void DocumentLoader::setFrame(Frame* frame)
{
    if (m_frame == frame)
        return;
    ASSERT(frame && !m_frame);
    m_frame = frame;
    attachToFrame();
}

void DocumentLoader::attachToFrame()
{
    ASSERT(m_frame);
}

void DocumentLoader::detachFromFrame()
{
    ASSERT(m_frame);
    m_frame = 0;
}

void DocumentLoader::prepareForLoadStart()
{
    ASSERT(!m_isStopping);
    setPrimaryLoadComplete(false);
    ASSERT(frameLoader());
    clearErrors();
    
    setLoading(true);
    
    frameLoader()->prepareForLoadStart();
}

void DocumentLoader::setPrimaryLoadComplete(bool flag)
{
    m_primaryLoadComplete = flag;
    if (flag) {
        if (m_mainResourceLoader) {
            m_mainResourceData = m_mainResourceLoader->resourceData();
#if ENABLE(OFFLINE_WEB_APPLICATIONS)
            m_mainResourceApplicationCache = m_mainResourceLoader->applicationCache();
#endif
            m_mainResourceLoader = 0;
        }

        if (this == frameLoader()->activeDocumentLoader())
            updateLoading();
    }
}

bool DocumentLoader::isLoadingInAPISense() const
{
    // Once a frame has loaded, we no longer need to consider subresources,
    // but we still need to consider subframes.
    if (frameLoader()->state() != FrameStateComplete) {
        if (!m_primaryLoadComplete && isLoading())
            return true;
        if (!m_subresourceLoaders.isEmpty())
            return true;
        Document* doc = m_frame->document();
        if (doc->docLoader()->requestCount())
            return true;
        if (Tokenizer* tok = doc->tokenizer())
            if (tok->processingData())
                return true;