First step of HTMLImports

Source/core/html/HTMLImports.cpp

+/*
+ * Copyright (C) 2013 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:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * 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.
+ *     * Neither the name of Google Inc. 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 THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
+ * OWNER OR 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/html/HTMLImports.h"
+
+#include "core/dom/DocumentFragment.h"
+#include "core/dom/Range.h"
+#include "core/html/HTMLDocument.h"
+#include "core/html/HTMLLinkElement.h"
+#include "core/loader/cache/CachedResourceLoader.h"
+#include "weborigin/SecurityOrigin.h"
+
+namespace WebCore {
+
+PassRefPtr<LinkImport> LinkImport::create(HTMLLinkElement* owner)
+{
+    return adoptRef(new LinkImport(owner));
+}
+
+LinkImport::LinkImport(HTMLLinkElement* owner)
+    : LinkResource(owner)
+    , m_imports(0)
+    , m_ofSameLocation(0)
+    , m_state(StatePreparing)
+{
+}
+
+LinkImport::~LinkImport()
+{
+    if (m_cachedDocument)
+        m_cachedDocument->removeClient(this);
+}
+
+LinkImport::State LinkImport::finish()
+{
+    if (!m_imports || !m_cachedDocument->document())
+        return StateDone;
+
+    if (!m_imports->securityOrigin()->canRequest(m_cachedDocument->response().url())
+        && !m_cachedDocument->passesAccessControlCheck(m_imports->securityOrigin()))
+        return StateDone;
+
+    m_importedFragment = m_imports->createFragmentFrom(m_cachedDocument->document());
+    return StateDone;
+}
+
+void LinkImport::notifyFinished(CachedResource*)
+{
+    setState(finish());
+}
+
+void LinkImport::setState(State state)
+{
+    if (m_state == state)
+        return;
+    m_state = state;
+    if (m_state == StateDone && m_imports)
+        m_imports->didLoad();
+}
+
+LinkImport::State LinkImport::startRequest()
+{
+    ASSERT(m_owner);
+    ASSERT(m_state == StatePreparing);
+
+    // FIXME(morrita): Should take care of sub-imports whose document doesn't have frame.
+    if (!m_owner->document()->frame())
+        return StateDone;
+
+    LinkRequestBuilder builder(m_owner);
+    if (!builder.isValid())
+        return StateDone;
+
+    m_imports = m_owner->document()->imports();
+    if (RefPtr<LinkImport> found = m_imports->findLinkFor(builder.url())) {
+        m_ofSameLocation = found.get();
+        return StateDone;
+    }
+
+    // XXX: take care of CORS and cookies
+    CachedResourceRequest request = builder.build(true);
+    m_cachedDocument = m_owner->document()->cachedResourceLoader()->requestHTMLDocument(request);

[dglazkov, 2013/05/23 18:32:00]

I don't know if we need to be creating a new document for each load. Do we have
to?

[Hajime Morrita, 2013/05/24 02:28:27]

That's what I've been wondering, too. There are some tradeoff.

- Using CachedDocument means the Document is cached. we don't need to re-parse
it when the cache is hit.
   We cannot do it with DocumetFragment because we cannot define the
ownerDocument of cached DocumentFragment.
- If we're going to do progressive parsing later, we can do it using
DocumetWriter. DocumentWriter produces Document.
- Caching Document will be memory-heavy. So it might better off not do that.

My feeling is that we can use CachedDocument to keep CL small, then come back
later to explore better option.

[dglazkov, 2013/05/24 03:15:16]

Can you explain why?
Maybe we should invent DocumentFragmentWriter? :)
My only worry here is that if we do this later, we won't be able to explore
feasibility of the better option, and then we'll be stuck with a terrible spec
:)

+    if (!m_cachedDocument)
+        return StateDone;
+
+    m_cachedDocument->addClient(this);
+    m_url = builder.url();
+    m_imports->addLink(this);
+
+    return StateStarted;
+}
+
+DocumentFragment* LinkImport::importedFragment() const
+{
+    if (!m_owner)
+        return 0;
+
+    if (m_ofSameLocation) {
+        ASSERT(!m_importedFragment);
+        return m_ofSameLocation->importedFragment();
+    }
+
+    return m_importedFragment.get();
+}
+
+void LinkImport::process()
+{
+    if (StatePreparing != m_state)
+        return;
+    setState(startRequest());
+}
+
+void LinkImport::ownerRemoved()
+{
+    m_owner = 0;
+}
+
+void LinkImport::importDestroyed()
+{
+    m_imports = 0;
+    m_importedFragment.clear();
+}
+
+PassOwnPtr<HTMLImports> HTMLImports::create(HTMLImportsHost* host)
+{
+    return adoptPtr(new HTMLImports(host));
+}
+
+HTMLImports::HTMLImports(HTMLImportsHost* host)
+    : m_host(host)
+    , m_owner(HTMLDocument::create(0, KURL()))
+{
+}
+
+HTMLImports::~HTMLImports()
+{
+    for (size_t i = 0; i < m_links.size(); ++i)
+        m_links[i]->importDestroyed();
+}
+
+void HTMLImports::addLink(PassRefPtr<LinkImport> link)
+{
+    ASSERT(!link->url().isEmpty() && link->url().isValid());
+    m_links.append(link);
+}
+
+void HTMLImports::didLoad()
+{
+    if (haveLoaded())
+        m_host->didLoadAllImports();
+}
+
+PassRefPtr<DocumentFragment> HTMLImports::createFragmentFrom(Document* source) const
+{
+    RefPtr<Range> toClone = Range::create(source);
+    toClone->setStartBefore(source->documentElement(), ASSERT_NO_EXCEPTION);
+    toClone->setEndAfter(source->documentElement(), ASSERT_NO_EXCEPTION);
+    RefPtr<DocumentFragment> created = toClone->cloneContents(ASSERT_NO_EXCEPTION);
+    m_owner->adoptNode(created, ASSERT_NO_EXCEPTION);
+    return created.release();
+}
+
+PassRefPtr<LinkImport> HTMLImports::findLinkFor(const KURL& url) const
+{
+    for (size_t i = 0; i < m_links.size(); ++i) {
+        if (m_links[i]->url() == url)
+            return m_links[i];
+    }
+
+    return 0;
+}
+
+SecurityOrigin* HTMLImports::securityOrigin() const
+{
+    return m_host->importsContext()->securityOrigin();
+}
+
+bool HTMLImports::haveLoaded() const
+{
+    for (size_t i = 0; i < m_links.size(); ++i) {
+        if (!m_links[i]->isDone())
+            return false;
+    }
+
+    return true;
+}
+
+} // namespace WebCore