Refactoring: Simplify DocumentWriter by reorganizing its lifetime.

Source/core/loader/DocumentWriter.cpp

Index: Source/core/loader/DocumentWriter.cpp
diff --git a/Source/core/loader/DocumentWriter.cpp b/Source/core/loader/DocumentWriter.cpp
index 3dc0282ab700ae5ba7eeefd6fcbfd5c8b2b8f0f2..9290db54effd2cdb9372b4e090123fe1e183a3d3 100644
--- a/Source/core/loader/DocumentWriter.cpp
+++ b/Source/core/loader/DocumentWriter.cpp
@@ -29,11 +29,10 @@
 #include "config.h"
 #include "core/loader/DocumentWriter.h"
 
-#include "core/dom/DOMImplementation.h"
+#include "core/dom/Document.h"
 #include "core/dom/ScriptableDocumentParser.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/FrameLoaderStateMachine.h"
-#include "core/loader/SinkDocument.h"
 #include "core/loader/TextResourceDecoder.h"
 #include "core/page/DOMWindow.h"
 #include "core/page/Frame.h"
@@ -41,118 +40,46 @@
 #include "core/page/Settings.h"
 #include "weborigin/KURL.h"
 #include "weborigin/SecurityOrigin.h"
+#include "wtf/PassOwnPtr.h"
 
 namespace WebCore {
 
-DocumentWriter::DocumentWriter(Frame* frame)
-    : m_frame(frame)
-    , m_hasReceivedSomeData(false)
-    , m_state(NotStartedWritingState)
-{
-}
-
-// This is only called by ScriptController::executeScriptIfJavaScriptURL
-// and always contains the result of evaluating a javascript: url.
-// This is the <iframe src="javascript:'html'"> case.
-void DocumentWriter::replaceDocument(const String& source, Document* ownerDocument)
+PassRefPtr<DocumentWriter> DocumentWriter::create(Document* document, const String& mimeType, const String& encoding, bool encodingUserChoosen)
 {
-    m_frame->loader()->stopAllLoaders();
-    begin(m_frame->document()->url(), true, ownerDocument);
-
-    if (!source.isNull()) {
-        if (!m_hasReceivedSomeData) {
-            m_hasReceivedSomeData = true;
-            m_frame->document()->setCompatibilityMode(Document::NoQuirksMode);
-        }
-
-        // FIXME: This should call DocumentParser::appendBytes instead of append
-        // to support RawDataDocumentParsers.
-        if (DocumentParser* parser = m_frame->document()->parser()) {
-            parser->pinToMainThread();
-            // Because we're pinned to the main thread we don't need to worry about
-            // passing ownership of the source string.
-            parser->append(source.impl());
-        }
-    }
-
-    end();
+    return adoptRef(new DocumentWriter(document, mimeType, encoding, encodingUserChoosen));
 }
 
-void DocumentWriter::clear()
-{
-    m_decoder = 0;
-    m_decoderBuilder.clear();
-    m_hasReceivedSomeData = false;
-}
-
-void DocumentWriter::begin()
+DocumentWriter::DocumentWriter(Document* document, const String& mimeType, const String& encoding, bool encodingUserChoosen)
+    : m_document(document)
+    , m_hasReceivedSomeData(false)
+    , m_decoderBuilder(mimeType, encoding, encodingUserChoosen)
+    // We grab a reference to the parser so that we'll always send data to the
+    // original parser, even if the document acquires a new parser (e.g., via
+    // document.open).
+    , m_parser(m_document->implicitOpen())
 {
-    begin(KURL());
+    if (FrameView* view = m_document->frame()->view())
+        view->setContentsSize(IntSize());
 }
 
-PassRefPtr<Document> DocumentWriter::createDocument(const KURL& url)
+DocumentWriter::~DocumentWriter()
 {
-    return DOMImplementation::createDocument(mimeType(), m_frame, url, m_frame->inViewSourceMode());
 }
 
-void DocumentWriter::begin(const KURL& urlReference, bool dispatch, Document* ownerDocument)
+void DocumentWriter::appendReplacingData(const String& source)
 {
-    // We grab a local copy of the URL because it's easy for callers to supply
-    // a URL that will be deallocated during the execution of this function.
-    // For example, see <https://bugs.webkit.org/show_bug.cgi?id=66360>.
-    KURL url = urlReference;
-
-    // Create a new document before clearing the frame, because it may need to
-    // inherit an aliased security context.
-    RefPtr<Document> document = createDocument(url);
-    
-    // If the new document is for a Plugin but we're supposed to be sandboxed from Plugins,
-    // then replace the document with one whose parser will ignore the incoming data (bug 39323)
-    if (document->isPluginDocument() && document->isSandboxed(SandboxPlugins))
-        document = SinkDocument::create(m_frame, url);
-
-    // FIXME: Do we need to consult the content security policy here about blocked plug-ins?
-
-    bool shouldReuseDefaultView = m_frame->loader()->stateMachine()->isDisplayingInitialEmptyDocument() && m_frame->document()->isSecureTransitionTo(url);
-
-    RefPtr<DOMWindow> originalDOMWindow;
-    if (shouldReuseDefaultView)
-        originalDOMWindow = m_frame->domWindow();
-    m_frame->loader()->clear(!shouldReuseDefaultView, !shouldReuseDefaultView);
-    clear();
-
-    if (!shouldReuseDefaultView)
-        m_frame->setDOMWindow(DOMWindow::create(m_frame));
-    else {
-        // Note that the old Document is still attached to the DOMWindow; the
-        // setDocument() call below will detach the old Document.
-        ASSERT(originalDOMWindow);
-        m_frame->setDOMWindow(originalDOMWindow);
-    }
-
-    m_frame->loader()->setOutgoingReferrer(url);
-    m_frame->domWindow()->setDocument(document);
-
-    if (m_decoder)
-        document->setDecoder(m_decoder.get());
-    if (ownerDocument) {
-        document->setCookieURL(ownerDocument->cookieURL());
-        document->setSecurityOrigin(ownerDocument->securityOrigin());
+    ASSERT(!m_hasReceivedSomeData);
+    m_hasReceivedSomeData = true;
+    m_document->setCompatibilityMode(Document::NoQuirksMode);
+
+    // FIXME: This should call DocumentParser::appendBytes instead of append
+    // to support RawDataDocumentParsers.
+    if (DocumentParser* parser = m_document->parser()) {
+        parser->pinToMainThread();
+        // Because we're pinned to the main thread we don't need to worry about
+        // passing ownership of the source string.
+        parser->append(source.impl());
     }
-
-    m_frame->loader()->didBeginDocument(dispatch);
-
-    document->implicitOpen();
-
-    // We grab a reference to the parser so that we'll always send data to the
-    // original parser, even if the document acquires a new parser (e.g., via
-    // document.open).
-    m_parser = document->parser();
-
-    if (m_frame->view())
-        m_frame->view()->setContentsSize(IntSize());
-
-    m_state = StartedWritingState;
 }
 
 void DocumentWriter::reportDataReceived()
@@ -162,22 +89,16 @@ void DocumentWriter::reportDataReceived()
         return;
     m_hasReceivedSomeData = true;
     if (m_decoder->encoding().usesVisualOrdering())
-        m_frame->document()->setVisuallyOrdered();
+        m_document->setVisuallyOrdered();
 }
 
 void DocumentWriter::addData(const char* bytes, size_t length)
 {
-    // Check that we're inside begin()/end().
-    // FIXME: Change these to ASSERT once https://bugs.webkit.org/show_bug.cgi?id=80427 has
-    // been resolved.
-    if (m_state == NotStartedWritingState)
-        CRASH();
-    if (m_state == FinishedWritingState)
-        CRASH();
-
     ASSERT(m_parser);
     if (!m_decoder && m_parser->needsDecoder() && 0 < length)
-        m_decoder = m_decoderBuilder.buildFor(m_frame->document());
+        m_decoder = m_decoderBuilder.buildFor(m_document);
+    // appendBytes() can result replacing DocumentLoader::m_writer.
+    RefPtr<DocumentWriter> protectingThis(this);
     size_t consumedChars = m_parser->appendBytes(bytes, length);
     if (consumedChars)
         reportDataReceived();
@@ -185,29 +106,29 @@ void DocumentWriter::addData(const char* bytes, size_t length)
 
 void DocumentWriter::end()
 {
-    ASSERT(m_frame->page());
-    ASSERT(m_frame->document());
-
-    // The parser is guaranteed to be released after this point. begin() would
-    // have to be called again before we can start writing more data.
-    m_state = FinishedWritingState;
+    ASSERT(m_document);
 
     // http://bugs.webkit.org/show_bug.cgi?id=10854
     // The frame's last ref may be removed and it can be deleted by checkCompleted(), 
     // so we'll add a protective refcount
-    RefPtr<Frame> protector(m_frame);
+    RefPtr<Frame> protector(m_document->frame());
 
     if (!m_parser)
         return;
+
     if (!m_decoder && m_parser->needsDecoder())
-        m_decoder = m_decoderBuilder.buildFor(m_frame->document());
+        m_decoder = m_decoderBuilder.buildFor(m_document);
+    // flush() can result replacing DocumentLoader::m_writer.
+    RefPtr<DocumentWriter> protectingThis(this);
     size_t consumedChars = m_parser->flush();
     if (consumedChars)
         reportDataReceived();
     if (!m_parser)
         return;
+
     m_parser->finish();
     m_parser = 0;
+    m_document = 0;
 }
 
 void DocumentWriter::setDocumentWasLoadedAsPartOfNavigation()