Reapply "Move isolate loading to a separate loader isolate."

Source/bindings/dart/DartAsyncLoader.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 "bindings/dart/DartAsyncLoader.h"
+
+#include "FetchInitiatorTypeNames.h"
+#include "bindings/dart/DartUtilities.h"
+#include "bindings/v8/ScriptSourceCode.h"
+#include "core/dom/Document.h"
+#include "core/dom/ScriptLoader.h"
+#include "core/fetch/FetchRequest.h"
+#include "core/fetch/ResourceClient.h"
+#include "core/fetch/ResourceFetcher.h"
+#include "core/fetch/ScriptResource.h"
+#include "core/inspector/ScriptCallStack.h"
+
+#include <dart_api.h>
+
+namespace WebCore {
+
+static const unsigned dartTypeID = 0xDAADDAAD;
+
+void DartAsyncLoader::LoadCallback::reportError(const String& error, const String& url)
+{
+    m_originDocument->logExceptionToConsole(error + ": " + url, url, 0, 0, 0);
+    if (m_scriptLoader)
+        m_scriptLoader->dispatchErrorEvent();
+}
+
+ResourcePtr<ScriptResource> DartAsyncLoader::LoadCallback::requestScript(FetchRequest& request)
+{
+    return m_originDocument->fetcher()->requestScript(request);
+}
+
+
+DartAsyncLoader::DartAsyncLoader(const String& url, PassRefPtr<DartAsyncLoader::LoadCallback> loadCallback)
+    : m_loadCallback(loadCallback)
+    , m_mainScriptFetched(false)
+{
+    Document* document = m_loadCallback->document();
+    char* error;
+
+    const KURL canonical = KURL(document->baseURL(), url);
+    m_topUrl = canonical.string();
+
+    DartDOMData* domData = new DartDOMData(document, false);
+    domData->setAsyncLoader(adoptRef(this));
+
+    const uint8_t* snapshot = DartUtilities::fullSnapshot(document->frame());
+    m_parseIsolate = Dart_CreateIsolate("dartium.fetch", "", snapshot, domData, &error);
+    if (!m_parseIsolate)
+        m_loadCallback->reportError(error, url);
+
+    Dart_Handle result = Dart_SetLibraryTagHandler(&libraryTagHandlerCallback);
+    ASSERT(!Dart_IsError(result));
+    UNUSED_PARAM(result);
+
+    m_pendingLibraries.add(m_topUrl);
+}
+
+DartAsyncLoader::~DartAsyncLoader()
+{
+    m_loadCallback = 0;
+}
+
+void DartAsyncLoader::findDependences(const String& url, const String& source, intptr_t lineNumber)
+{
+    ASSERT(m_pendingLibraries.contains(url) || m_pendingSource.contains(url));
+
+    DartIsolateScope isolateScope(m_parseIsolate);
+    DartApiScope dartApiScope;
+
+    if (!m_mainScriptFetched) {
+        ASSERT(m_topUrl == url);
+        m_topSource = source;
+        m_lineNumber = lineNumber;
+        m_mainScriptFetched = true;
+    }
+
+    if (m_pendingLibraries.contains(url)) {
+        processLibrary(url, source);
+        m_pendingLibraries.remove(url);
+    } else {
+        ASSERT(m_pendingSource.contains(url));
+        // No imports or parts, so no need to process further.
+        m_pendingSource.remove(url);
+    }
+}
+
+void DartAsyncLoader::reportError(Dart_Handle error, const String& url)
+{
+    reportError(Dart_GetError(error), url);
+}
+
+void DartAsyncLoader::processLibrary(const String& url, const String& source)
+{
+    ASSERT(m_pendingLibraries.contains(url));
+
+    Dart_Handle result = Dart_LoadLibrary(DartUtilities::stringToDartString(url), DartUtilities::convertSourceString(source));
+    if (Dart_IsError(result))
+        reportError(result, url);
+}
+
+void DartAsyncLoader::process(const String& url, const String& source, intptr_t lineNumber)
+{
+    ASSERT(!m_urlSourceMap.contains(url));
+    m_urlSourceMap.add(url, source);
+
+    findDependences(url, source, lineNumber);
+    if (ready()) {
+        // All dependences are in.
+        RefPtr<DartAsyncLoader> guard(this);
+        m_loadCallback->ready(guard);
+
+        // Free this loader and its isolate.
+        Dart_EnterIsolate(m_parseIsolate);
+        DartDOMData::current()->setAsyncLoader(0);
+        Dart_ShutdownIsolate();
+    }
+}
+
+Dart_Handle DartAsyncLoader::libraryTagHandlerCallback(Dart_LibraryTag tag, Dart_Handle library, Dart_Handle urlHandle)
+{
+    ASSERT(Dart_CurrentIsolate());
+    ASSERT(Dart_IsLibrary(library));
+
+    const String url = DartUtilities::toString(urlHandle);
+
+    if (tag == Dart_kCanonicalizeUrl) {
+        // If a dart application calls spawnUri, the DartVM will call this
+        // libraryTagHandler to canonicalize the url.
+        // DartDOMData::current()->scriptLoader() may be 0 at this point.
+        return DartUtilities::canonicalizeUrl(library, urlHandle, url);
+    }
+
+    RefPtr<DartAsyncLoader> loader = DartDOMData::current()->asyncLoader();
+    ASSERT(loader);
+
+    if (!url.startsWith("dart:")) {
+        // Fetch non-system URLs.
+        if (tag == Dart_kImportTag) {
+            loader->m_pendingLibraries.add(url);
+        } else if (tag == Dart_kSourceTag) {
+            loader->m_pendingSource.add(url);
+        } else {
+            ASSERT_NOT_REACHED();
+        }
+        loader->fetchScriptResource(url);
+    }
+    return Dart_NewBoolean(true);
+}
+
+class ScriptLoadedCallback : public ResourceClient {
+public:
+    ScriptLoadedCallback(String url, PassRefPtr<DartAsyncLoader> loader, ResourcePtr<ScriptResource> scriptResource)
+        : m_url(url)
+        , m_loader(loader)
+        , m_scriptResource(scriptResource)
+    {
+    }
+
+    virtual void notifyFinished(Resource* cachedResource)
+    {
+        ASSERT(cachedResource->type() == Resource::Script);
+        ASSERT(cachedResource == m_scriptResource.get());
+        ASSERT(WTF::isMainThread());
+
+        if (cachedResource->errorOccurred()) {
+            m_loader->reportError(String("An error occurred loading file"), m_url);
+        } else if (cachedResource->wasCanceled()) {
+            // FIXME: shall we let VM know, so it can inform application some of its
+            // resources cannot be loaded?
+            m_loader->reportError(String("File request cancelled"), m_url);
+        } else {
+            ScriptSourceCode sourceCode(m_scriptResource.get());
+            // FIXME: Should we check for cached metadata?
+            // CachedMetadata* cachedMetadata = m_scriptResource->cachedMetadata(dartTypeID);
+
+            // Use the original url associated with the Script so that
+            // redirects do not break the DartScriptLoader.
+            // FIXME: is this the correct behavior? This functionality is
+            // very convenient when you want the source file to act as if
+            // it was from the original location but that isn't always
+            // what the user expects.
+            m_loader->process(m_url, sourceCode.source(), 0);
+        }
+
+        m_scriptResource->removeClient(this);
+        delete this;
+    }
+
+private:
+    String m_url;
+    RefPtr<DartAsyncLoader> m_loader;
+    ResourcePtr<ScriptResource> m_scriptResource;
+};
+
+static String resolveUrl(String mainLibraryURL, const String& url)
+{
+    if (!url.startsWith("package:") || url.startsWith("package://"))
+        return url;
+
+    String packageRoot;
+    String packageUrl;
+    if (const char* packageRootOverride = getenv("DART_PACKAGE_ROOT")) {
+        // Resolve with respect to the override. Append a
+        // slash to ensure that resolution is against this
+        // path and not its parent.
+        packageRoot = String(packageRootOverride) + "/";
+        // Strip the 'package:' prefix.
+        packageUrl = url.substring(8);
+    } else {
+        // Resolve with respect to the entry point's URL. Note, the
+        // trailing file name in the entry point URL (e.g.,
+        // 'rootpath/mainapp.dart') is stripped by the KURL
+        // constructor below.
+        packageRoot = mainLibraryURL;
+        packageUrl = String("packages/") + url.substring(8);
+    }
+    return KURL(KURL(KURL(), packageRoot), packageUrl).string();
+}
+
+void DartAsyncLoader::fetchScriptResource(const String& url)
+{
+    // Request loading of script dependencies.
+    FetchRequest request(m_loadCallback->completeURL(resolveUrl(m_topUrl, url)),
+        FetchInitiatorTypeNames::document, "utf8");
+    // FIXME: what about charset for this script, maybe use charset of initial script tag?
+    ResourcePtr<ScriptResource> scriptResource = m_loadCallback->requestScript(request);
+    if (scriptResource)
+        scriptResource->addClient(new ScriptLoadedCallback(m_loadCallback->completeURL(url), this, scriptResource));
+    else
+        m_loadCallback->reportError(String("File request error"), url);
+}
+
+}