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

Source/bindings/dart/DartApplicationLoader.cpp

Index: Source/bindings/dart/DartApplicationLoader.cpp
diff --git a/Source/bindings/dart/DartApplicationLoader.cpp b/Source/bindings/dart/DartApplicationLoader.cpp
index d1170ca17862fdc471ac56cd0a69b9b50f588d2f..b95a191319c4a7f126210f81ff878f7ece6b4e37 100644
--- a/Source/bindings/dart/DartApplicationLoader.cpp
+++ b/Source/bindings/dart/DartApplicationLoader.cpp
@@ -60,18 +60,15 @@ DartApplicationLoader::DartApplicationLoader(
     Dart_Isolate isolate,
     Document* document,
     PassRefPtr<ErrorEventDispatcher> errorEventDispatcher,
-    PassRefPtr<VoidCallback> applicationLoadedCallback,
+    PassRefPtr<DartAsyncLoader> asyncLoader,
     bool domEnabled)
     : m_isolate(isolate)
     , m_originDocument(document)
     , m_errorEventDispatcher(errorEventDispatcher)
     , m_libraryUrl()
-    , m_importedLibraries()
-    , m_importersForSource()
-    , m_mainScriptHasBeenLoaded(false)
     , m_scriptHasError(false)
-    , m_applicationLoadedCallback(applicationLoadedCallback)
     , m_domEnabled(domEnabled)
+    , m_asyncLoader(asyncLoader)
 {
     ASSERT(m_originDocument);
 }
@@ -95,117 +92,68 @@ Dart_Handle DartApplicationLoader::libraryTagHandlerCallback(Dart_LibraryTag tag
         // If a dart application calls spawnUri, the DartVM will call this
         // libraryTagHandler to canonicalize the url.
         // DartDOMData::current()->applicationLoader() may be 0 at this point.
-        return DartApplicationLoader::CanonicalizeUrl(library, urlHandle, url);
+        return DartUtilities::canonicalizeUrl(library, urlHandle, url);
     }
 
     ASSERT(DartDOMData::current()->applicationLoader());
     return DartDOMData::current()->applicationLoader()->libraryTagHandler(tag, library, urlHandle, url);
 }
 
-Dart_Handle DartApplicationLoader::CanonicalizeUrl(Dart_Handle library, Dart_Handle urlHandle, String url)
-{
-    if (url.startsWith("dart:") || url.startsWith("package:"))
-        return urlHandle;
-
-    Dart_Handle libraryURLHandle = Dart_LibraryUrl(library);
-    ASSERT(!Dart_IsError(libraryURLHandle));
-    String libraryURL = DartUtilities::toString(libraryURLHandle);
-
-    bool packageScheme = false;
-
-    const char* kPackagePrefix = "package:";
-    const int kPackagePrefixLength = strlen(kPackagePrefix);
-
-    const char* kHttpPrefix = "http://";
-    const int kHttpPrefixLength = strlen(kHttpPrefix);
-
-    if (libraryURL.startsWith(kPackagePrefix)) {
-        // KURL has problems concating package:foo/bar (without slashes right after colon)
-        // and relative urls. Therefore pretend to be a standard absolute URL.
-        packageScheme = true;
-        libraryURL = kHttpPrefix + libraryURL.substring(kPackagePrefixLength);
-    }
-
-    const KURL canonical = KURL(KURL(KURL(), libraryURL), url);
-    String result = canonical.string();
-    if (packageScheme)
-        result = kPackagePrefix + result.substring(kHttpPrefixLength);
-    return DartUtilities::stringToDartString(result);
-}
-
 Dart_Handle DartApplicationLoader::libraryTagHandler(Dart_LibraryTag tag, Dart_Handle library, Dart_Handle urlHandle, String url)
 {
-    ASSERT(url != "dart:html");
-
-    // Record the importer.
-    if (tag == Dart_kImportTag)
-        m_importedLibraries.add(url);
-    else if (tag == Dart_kSourceTag) {
-        Dart_Handle libraryURLHandle = Dart_LibraryUrl(library);
-        ASSERT(!Dart_IsError(libraryURLHandle));
-        String libraryURL = DartUtilities::toString(libraryURLHandle);
-
-        add(m_importersForSource, url, libraryURL);
-    } else
+    ASSERT(m_asyncLoader->contains(url));
+    const String& source = m_asyncLoader->get(url);
+
+    Dart_Handle import;
+    if (tag == Dart_kImportTag) {
+        import = Dart_LoadLibrary(DartUtilities::stringToDartString(url), DartUtilities::convertSourceString(source));
+    } else if (tag == Dart_kSourceTag) {
+        import = Dart_LoadSource(library, DartUtilities::stringToDartString(url), DartUtilities::convertSourceString(source));
+    } else {
         ASSERT_NOT_REACHED();
+        DartUtilities::reportProblem(m_originDocument, "Invalid import tag");
+        return Dart_NewBoolean(false);
+    }
+
+    if (Dart_IsError(import)) {
+        reportDartError(import);
+        return Dart_NewBoolean(false);
+    }
 
-    loadScriptResource(url);
     return Dart_NewBoolean(true);
 }
 
-void DartApplicationLoader::load(const String& url, const String& source, WTF::OrdinalNumber startLineNumber)
+void DartApplicationLoader::load(const String& url, const String& source, int startLineNumber)
 {
     DartIsolateScope isolateScope(m_isolate);
     DartApiScope dartApiScope;
-    if (m_importedLibraries.isEmpty() && m_importersForSource.isEmpty()) {
-        m_libraryUrl = url;
-        loadMainScript(url, source, startLineNumber);
-        m_mainScriptHasBeenLoaded = true;
-    } else {
-        ASSERT(m_importedLibraries.contains(url) || m_importersForSource.contains(url));
-        if (m_importedLibraries.contains(url)) {
-            loadLibrary(url, source);
-            m_importedLibraries.remove(url);
-        }
-
-        if (m_importersForSource.contains(url)) {
-            loadSource(url, source);
-            m_importersForSource.remove(url);
-        }
+    m_libraryUrl = url;
+    loadMainScript(url, source, startLineNumber);
+
+    uint8_t* buffer;
+    intptr_t size;
+    Dart_Handle result = Dart_CreateScriptSnapshot(&buffer, &size);
+    if (Dart_IsError(result)) {
+        reportDartError(result);
+        // FIXME: exiting early might be not the best option if error is due to snapshot
+        // creation proper (and not due to compilation), even though it's unlikely.
+        // Consider other options like Dart_CompileAll.
+        return;
     }
 
-    if (m_importedLibraries.isEmpty() && m_importersForSource.isEmpty() && m_mainScriptHasBeenLoaded) {
-        uint8_t* buffer;
-        intptr_t size;
-        Dart_Handle result = Dart_CreateScriptSnapshot(&buffer, &size);
-        if (Dart_IsError(result)) {
-            reportDartError(result);
-            // FIXME: exiting early might be not the best option if error is due to snapshot
-            // creation proper (and not due to compilation), even though it's unlikely.
-            // Consider other options like Dart_CompileAll.
-            return;
-        }
-
-        Vector<uint8_t>* snapshot = DartDOMData::current()->applicationSnapshot();
-        ASSERT(snapshot->isEmpty());
-        snapshot->append(buffer, size);
-
-        if (isSnapshottingEnabled()) {
-            ResourceFetcher* loader = m_originDocument->fetcher();
-            FetchRequest request(m_originDocument->completeURL(mainLibraryURL()), FetchInitiatorTypeNames::document);
-            ResourcePtr<ScriptResource> scriptResource = loader->requestScript(request);
-            if (scriptResource && !scriptResource->cachedMetadata(dartTypeID))
-                scriptResource->setCachedMetadata(dartTypeID, reinterpret_cast<const char*>(buffer), size);
-        }
-
-        callEntryPoint();
+    Vector<uint8_t>* snapshot = DartDOMData::current()->applicationSnapshot();
+    ASSERT(snapshot->isEmpty());
+    snapshot->append(buffer, size);
+
+    if (isSnapshottingEnabled()) {
+        ResourceFetcher* loader = m_originDocument->fetcher();
+        FetchRequest request(m_originDocument->completeURL(mainLibraryURL()), FetchInitiatorTypeNames::document);
+        ResourcePtr<ScriptResource> scriptResource = loader->requestScript(request);
+        if (scriptResource && !scriptResource->cachedMetadata(dartTypeID))
+            scriptResource->setCachedMetadata(dartTypeID, reinterpret_cast<const char*>(buffer), size);
     }
-}
 
-static Dart_Handle convertSourceString(const String& source)
-{
-    const CString utf8encoded = source.utf8();
-    return Dart_NewStringFromCString(utf8encoded.data());
+    callEntryPoint();
 }
 
 void DartApplicationLoader::installLibraryTagHandlerForCurrentIsolate()
@@ -215,7 +163,7 @@ void DartApplicationLoader::installLibraryTagHandlerForCurrentIsolate()
     UNUSED_PARAM(result);
 }
 
-void DartApplicationLoader::loadMainScript(const String& url, const String& source, WTF::OrdinalNumber startLineNumber)
+void DartApplicationLoader::loadMainScript(const String& url, const String& source, int lineOffset)
 {
     // Associate application loader with current isolate, so we can retrieve it
     // in libraryTagHandlerCallback.
@@ -226,9 +174,10 @@ void DartApplicationLoader::loadMainScript(const String& url, const String& sour
     // inserted by the parser (e.g. it was inserted by JavaScript or Dart code.
     // We should not pass the Dart VM a negative line number so we fall back to
     // passing in line number zero for that case.
-    intptr_t lineOffset = startLineNumber == OrdinalNumber::beforeFirst() ? 0 : startLineNumber.zeroBasedInt();
+    if (lineOffset < 0)
+        lineOffset = 0;
 
-    Dart_Handle dartSource = convertSourceString(source);
+    Dart_Handle dartSource = DartUtilities::convertSourceString(source);
 
     if (m_domEnabled) {
         // The main page already should have an isolate. Load this script as a top-level library.
@@ -258,8 +207,6 @@ void DartApplicationLoader::loadMainScript(const String& url, const String& sour
 void DartApplicationLoader::loadScriptFromSnapshot(const String& url, const uint8_t* snapshot, intptr_t snapshotSize)
 {
     Timeline timeline(m_originDocument->frame(), String("loadSnapshot@") + m_libraryUrl);
-    ASSERT(m_importedLibraries.isEmpty());
-    ASSERT(m_importersForSource.isEmpty());
     m_libraryUrl = url;
     DartIsolateScope isolateScope(m_isolate);
     DartApiScope apiScope;
@@ -271,52 +218,28 @@ void DartApplicationLoader::loadScriptFromSnapshot(const String& url, const uint
     callEntryPoint();
 }
 
-void DartApplicationLoader::loadSource(const String& url, const String& source)
-{
-    ASSERT(m_importersForSource.contains(url));
-    const UrlSet* importers = m_importersForSource.find(url)->value;
-    Dart_Handle dartUrl = DartUtilities::stringToDartString(url);
-    Dart_Handle dartSource = convertSourceString(source);
-    for (UrlSet::iterator iter = importers->begin(); iter != importers->end(); ++iter) {
-        Dart_Handle library = Dart_LookupLibrary(DartUtilities::stringToDartString(*iter));
-        if (Dart_IsError(library)) {
-            reportDartError(library);
-            return;
-        }
-        Dart_Handle result = Dart_LoadSource(library, dartUrl, dartSource);
-        if (Dart_IsError(result)) {
-            reportDartError(result);
-            return;
-        }
-    }
-}
-
 void DartApplicationLoader::loadLibrary(const String& url, const String& source)
 {
-    ASSERT(m_importedLibraries.contains(url));
-    Dart_Handle result = Dart_LoadLibrary(DartUtilities::stringToDartString(url), convertSourceString(source));
+    Dart_Handle result = Dart_LoadLibrary(DartUtilities::stringToDartString(url), DartUtilities::convertSourceString(source));
     if (Dart_IsError(result))
         reportDartError(result);
 }
 
 void DartApplicationLoader::callEntryPoint()
 {
-    RefPtr<DartApplicationLoader> guard(this);
-
     Timeline timeline(m_originDocument->frame(), String("callEntryPoint@") + m_libraryUrl);
     ASSERT(m_originDocument->readyState() != "loading");
     if (m_domEnabled) {
       Timeline timeline(m_originDocument->frame(), String("notifyDebugServer@") + m_libraryUrl);
       DartDebugServer::shared().isolateLoaded();
     }
+
+    // FIXME: Do we still need this?
     if (m_scriptHasError) {
         // Errors have already been printed to console.
         return;
     }
 
-    if (m_applicationLoadedCallback)
-        m_applicationLoadedCallback->handleEvent();
-
     if (m_domEnabled) {
         V8Scope v8scope;
         Dart_Handle result = Dart_Invoke(topLevelLibrary(), Dart_NewStringFromCString("main"), 0, 0);
@@ -335,89 +258,6 @@ Dart_Handle DartApplicationLoader::topLevelLibrary()
     return library;
 }
 
-class ScriptLoadCallback : public ResourceClient {
-public:
-    ScriptLoadCallback(String url, PassRefPtr<DartApplicationLoader> 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->scriptLoadError(m_url);
-        else if (cachedResource->wasCanceled()) {
-            // FIXME: shall we let VM know, so it can inform application some of its
-            // resources cannot be loaded?
-        } else {
-            ScriptSourceCode sourceCode(m_scriptResource.get());
-            CachedMetadata* cachedMetadata = m_scriptResource->cachedMetadata(dartTypeID);
-            if (cachedMetadata)
-                m_loader->loadScriptFromSnapshot(sourceCode.url(), reinterpret_cast<const uint8_t*>(cachedMetadata->data()), static_cast<intptr_t>(cachedMetadata->size()));
-            else {
-                // Use the original url associated with the Script so that
-                // redirects do not break the DartApplicationLoader.
-                // 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->load(m_url, sourceCode.source(), WTF::OrdinalNumber::first());
-            }
-        }
-
-        m_scriptResource->removeClient(this);
-        delete this;
-    }
-
- private:
-    String m_url;
-    RefPtr<DartApplicationLoader> 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 DartApplicationLoader::loadScriptResource(const String& url)
-{
-    // Request loading of script dependencies.
-    FetchRequest request(m_originDocument->completeURL(resolveUrl(mainLibraryURL(), url)), FetchInitiatorTypeNames::document, "utf8");
-    // FIXME: what about charset for this script, maybe use charset of initial script tag?
-    ResourcePtr<ScriptResource> scriptResource = m_originDocument->fetcher()->requestScript(request);
-    if (scriptResource)
-        scriptResource->addClient(new ScriptLoadCallback(m_originDocument->completeURL(url), this, scriptResource));
-    else
-        scriptLoadError(url);
-}
-
 void DartApplicationLoader::scriptLoadError(String failedUrl)
 {
     // FIXME: try to dig out line number, -1 for now.
@@ -429,15 +269,4 @@ void DartApplicationLoader::scriptLoadError(String failedUrl)
     m_errorEventDispatcher->dispatchErrorEvent();
 }
 
-void DartApplicationLoader::add(UrlMultiMap& map, const String& key, const String& value)
-{
-    // We should never have a self dependence.
-    ASSERT(key != value);
-    UrlMultiMap::iterator iter = map.find(key);
-    if (iter == map.end())
-        iter = map.add(key, new UrlSet()).iterator;
-    UrlSet* set = iter->value;
-    set->add(value);
-}
-
 }