DevTools: Extract CSS resources preloading from css agent to page agent controlled loader.

Source/core/inspector/InspectorResourceContentLoader.cpp

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/inspector/InspectorResourceContentLoader.h"
+
+#include "FetchInitiatorTypeNames.h"
+#include "core/css/CSSStyleSheet.h"
+#include "core/css/StyleSheetContents.h"
+#include "core/fetch/CSSStyleSheetResource.h"
+#include "core/fetch/Resource.h"
+#include "core/fetch/ResourceFetcher.h"
+#include "core/fetch/ResourcePtr.h"
+#include "core/fetch/StyleSheetResourceClient.h"
+#include "core/frame/LocalFrame.h"
+#include "core/html/VoidCallback.h"
+#include "core/inspector/InspectorCSSAgent.h"
+#include "core/inspector/InspectorPageAgent.h"
+#include "core/page/Page.h"
+
+namespace WebCore {
+
+class InspectorResourceContentLoader::ResourceClient FINAL : private StyleSheetResourceClient {
+public:
+    ResourceClient(InspectorResourceContentLoader* loader)
+        : m_loader(loader)
+    {
+    }
+
+    void waitForResource(Resource* resource)
+    {
+        resource->addClient(this);
+    }
+
+private:
+    InspectorResourceContentLoader* m_loader;
+
+    virtual void setCSSStyleSheet(const String&, const KURL&, const String&, const CSSStyleSheetResource*) OVERRIDE;
+
+    friend class InspectorResourceContentLoader;
+};
+
+void InspectorResourceContentLoader::ResourceClient::setCSSStyleSheet(const String&, const KURL& url, const String&, const CSSStyleSheetResource* resource)
+{
+    if (m_loader)
+        m_loader->resourceFinished(this);
+    const_cast<CSSStyleSheetResource*>(resource)->removeClient(this);
+    delete this;
+}
+
+InspectorResourceContentLoader::InspectorResourceContentLoader(Page* page)
+    : m_allRequestsStarted(false)
+{
+    Vector<Document*> documents;
+    for (Frame* frame = page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
+        if (!frame->isLocalFrame())
+            continue;
+        LocalFrame* localFrame = toLocalFrame(frame);
+        documents.append(localFrame->document());
+        documents.appendVector(InspectorPageAgent::importsForFrame(localFrame));
+    }
+    for (Vector<Document*>::const_iterator documentIt = documents.begin(); documentIt != documents.end(); ++documentIt) {
+        Document* document = *documentIt;
+
+        HashSet<String> urlsToFetch;
+        Vector<CSSStyleSheet*> styleSheets;
+        InspectorCSSAgent::collectAllDocumentStyleSheets(document, styleSheets);
+        for (Vector<CSSStyleSheet*>::const_iterator stylesheetIt = styleSheets.begin(); stylesheetIt != styleSheets.end(); ++stylesheetIt) {
+            CSSStyleSheet* styleSheet = *stylesheetIt;
+            if (styleSheet->isInline() || !styleSheet->contents()->loadCompleted())
+                continue;
+            String url = styleSheet->baseURL().string();
+            if (url.isEmpty() || urlsToFetch.contains(url))
+                continue;
+            urlsToFetch.add(url);
+            FetchRequest request(ResourceRequest(url), FetchInitiatorTypeNames::internal);
+            ResourcePtr<Resource> resource = document->fetcher()->fetchCSSStyleSheet(request);
+            // Prevent garbage collection by holding a reference to this resource.
+            m_resources.append(resource.get());
+            ResourceClient* resourceClient = new ResourceClient(this);
+            m_pendingResourceClients.add(resourceClient);
+            resourceClient->waitForResource(resource.get());
+        }
+    }
+
+    m_allRequestsStarted = true;
+    checkDone();
+}
+
+void InspectorResourceContentLoader::addListener(PassOwnPtr<VoidCallback> callback)
+{
+    m_callbacks.append(callback);
+    checkDone();
+}
+
+InspectorResourceContentLoader::~InspectorResourceContentLoader()
+{
+    stop();
+}
+
+void InspectorResourceContentLoader::stop()
+{
+    HashSet<ResourceClient*> pendingResourceClients;
+    m_pendingResourceClients.swap(pendingResourceClients);
+    for (HashSet<ResourceClient*>::const_iterator it = pendingResourceClients.begin(); it != pendingResourceClients.end(); ++it)
+        (*it)->m_loader = 0;
+    m_resources.clear();
+    // Make sure all callbacks are called to prevent infinite waiting time.
+    checkDone();
+}
+
+bool InspectorResourceContentLoader::hasFinished()
+{
+    return m_allRequestsStarted && m_pendingResourceClients.size() == 0;
+}
+
+void InspectorResourceContentLoader::checkDone()
+{
+    if (!hasFinished())
+        return;
+    Vector<OwnPtr<VoidCallback> > callbacks;
+    callbacks.swap(m_callbacks);
+    for (Vector<OwnPtr<VoidCallback> >::const_iterator it = callbacks.begin(); it != callbacks.end(); ++it)
+        (*it)->handleEvent();
+}
+
+void InspectorResourceContentLoader::resourceFinished(ResourceClient* client)
+{
+    m_pendingResourceClients.remove(client);
+    checkDone();
+}
+
+} // namespace WebCore