Add Streams API support to XMLHttpRequest

Source/core/xml/XMLHttpRequest.cpp

 /*
  *  Copyright (C) 2004, 2006, 2008 Apple Inc. All rights reserved.
  *  Copyright (C) 2005-2007 Alexey Proskuryakov <ap@webkit.org>
  *  Copyright (C) 2007, 2008 Julien Chaffraix <jchaffraix@webkit.org>
  *  Copyright (C) 2008, 2011 Google Inc. All rights reserved.
  *  Copyright (C) 2012 Intel Corporation
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Lesser General Public License for more details.
  *
  *  You should have received a copy of the GNU Lesser General Public
  *  License along with this library; if not, write to the Free Software
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 #include "config.h"
 #include "core/xml/XMLHttpRequest.h"
 
-#include <wtf/ArrayBuffer.h>
-#include <wtf/ArrayBufferView.h>
-#include <wtf/RefCountedLeakCounter.h>
-#include <wtf/StdLibExtras.h>
-#include <wtf/text/CString.h>
-#include <wtf/UnusedParam.h>
+#include "RuntimeEnabledFeatures.h"
 #include "core/dom/ContextFeatures.h"
 #include "core/dom/DOMImplementation.h"
 #include "core/dom/Event.h"
 #include "core/dom/EventListener.h"
 #include "core/dom/EventNames.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/WebCoreMemoryInstrumentation.h"
 #include "core/editing/markup.h"
 #include "core/fileapi/Blob.h"
 #include "core/fileapi/File.h"
+#include "core/fileapi/Stream.h"
 #include "core/html/DOMFormData.h"
 #include "core/html/HTMLDocument.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/loader/CrossOriginAccessControl.h"
 #include "core/loader/TextResourceDecoder.h"
 #include "core/loader/ThreadableLoader.h"
 #include "core/loader/cache/CachedResourceRequestInitiators.h"
 #include "core/page/ContentSecurityPolicy.h"
 #include "core/page/Settings.h"
 #include "core/platform/HistogramSupport.h"
 #include "core/platform/SharedBuffer.h"
 #include "core/platform/network/BlobData.h"
 #include "core/platform/network/HTTPParsers.h"
 #include "core/platform/network/ParsedContentType.h"
 #include "core/platform/network/ResourceError.h"
 #include "core/platform/network/ResourceRequest.h"
 #include "core/xml/XMLHttpRequestProgressEvent.h"
 #include "core/xml/XMLHttpRequestUpload.h"
 #include "weborigin/SecurityOrigin.h"
+#include "wtf/ArrayBuffer.h"
+#include "wtf/ArrayBufferView.h"
+#include "wtf/RefCountedLeakCounter.h"
+#include "wtf/StdLibExtras.h"
+#include "wtf/UnusedParam.h"
+#include "wtf/text/CString.h"
 
 namespace WebCore {
 
 DEFINE_DEBUG_ONLY_GLOBAL(WTF::RefCountedLeakCounter, xmlHttpRequestCounter, ("XMLHttpRequest"));
 
 // Histogram enum to see when we can deprecate xhr.send(ArrayBuffer).
 enum XMLHttpRequestSendArrayBufferOrView {
     XMLHttpRequestSendArrayBuffer,
     XMLHttpRequestSendArrayBufferView,
     XMLHttpRequestSendArrayBufferOrViewMax,
@@ skipping 235 matching lines @@
         return 0;
 
     if (!m_responseArrayBuffer.get() && m_binaryResponseBuilder.get() && m_binaryResponseBuilder->size() > 0) {
         m_responseArrayBuffer = m_binaryResponseBuilder->getAsArrayBuffer();
         m_binaryResponseBuilder.clear();
     }
 
     return m_responseArrayBuffer.get();
 }
 
+Stream* XMLHttpRequest::responseStream(ExceptionCode& ec)
+{
+    if (m_responseTypeCode != ResponseTypeStream) {
+        ec = InvalidStateError;
+        return 0;
+    }
+
+    if (m_error || (m_state != LOADING && m_state != DONE))
+        return 0;
+
+    return m_responseStream.get();
+}
+
 void XMLHttpRequest::setTimeout(unsigned long timeout, ExceptionCode& ec)
 {
     // FIXME: Need to trigger or update the timeout Timer here, if needed. http://webkit.org/b/98156
     // XHR2 spec, 4.7.3. "This implies that the timeout attribute can be set while fetching is in progress. If that occurs it will still be measured relative to the start of fetching."
     if (scriptExecutionContext()->isDocument() && !m_async) {
         logConsoleError(scriptExecutionContext(), "XMLHttpRequest.timeout cannot be set for synchronous HTTP(S) requests made from the window context.");
         ec = InvalidAccessError;
         return;
     }
     m_timeoutMilliseconds = timeout;
 }
 
 void XMLHttpRequest::setResponseType(const String& responseType, ExceptionCode& ec)
 {
     if (m_state >= LOADING) {
         ec = InvalidStateError;
         return;
     }
 
     // Newer functionality is not available to synchronous requests in window contexts, as a spec-mandated
     // attempt to discourage synchronous XHR use. responseType is one such piece of functionality.
     // We'll only disable this functionality for HTTP(S) requests since sync requests for local protocols
     // such as file: and data: still make sense to allow.
     if (!m_async && scriptExecutionContext()->isDocument() && m_url.protocolIsInHTTPFamily()) {
         logConsoleError(scriptExecutionContext(), "XMLHttpRequest.responseType cannot be changed for synchronous HTTP(S) requests made from the window context.");
         ec = InvalidAccessError;
         return;
     }
 
-    if (responseType == "")
+    if (responseType == "") {
         m_responseTypeCode = ResponseTypeDefault;
-    else if (responseType == "text")
+    } else if (responseType == "text") {
         m_responseTypeCode = ResponseTypeText;
-    else if (responseType == "document")
+    } else if (responseType == "document") {
         m_responseTypeCode = ResponseTypeDocument;
-    else if (responseType == "blob")
+    } else if (responseType == "blob") {
         m_responseTypeCode = ResponseTypeBlob;
-    else if (responseType == "arraybuffer")
+    } else if (responseType == "arraybuffer") {
         m_responseTypeCode = ResponseTypeArrayBuffer;
-    else
+    } else if (responseType == "stream") {
+        if (RuntimeEnabledFeatures::streamEnabled())
+            m_responseTypeCode = ResponseTypeStream;
+        else
+            return;
+    } else {
         ASSERT_NOT_REACHED();
+    }
 }
 
 String XMLHttpRequest::responseType()
 {
     switch (m_responseTypeCode) {
     case ResponseTypeDefault:
-        return "";
+        return ASCIILiteral("");
     case ResponseTypeText:
-        return "text";
+        return ASCIILiteral("text");
     case ResponseTypeDocument:
-        return "document";
+        return ASCIILiteral("document");
     case ResponseTypeBlob:
-        return "blob";
+        return ASCIILiteral("blob");
     case ResponseTypeArrayBuffer:
-        return "arraybuffer";
+        return ASCIILiteral("arraybuffer");
+    case ResponseTypeStream:
+        return ASCIILiteral("stream");
     }
-    return "";
+    return ASCIILiteral("");
 }
 
 XMLHttpRequestUpload* XMLHttpRequest::upload()
 {
     if (!m_upload)
         m_upload = XMLHttpRequestUpload::create(this);
     return m_upload.get();
 }
 
 void XMLHttpRequest::changeState(State newState)
@@ skipping 547 matching lines @@
 
 String XMLHttpRequest::getRequestHeader(const AtomicString& name) const
 {
     return m_requestHeaders.get(name);
 }
 
 String XMLHttpRequest::getAllResponseHeaders(ExceptionCode& ec) const
 {
     if (m_state < HEADERS_RECEIVED) {
         ec = InvalidStateError;
-        return "";
+        return ASCIILiteral("");
     }
 
     StringBuilder stringBuilder;
 
     HTTPHeaderSet accessControlExposeHeaderSet;
     parseAccessControlExposeHeadersAllowList(m_response.httpHeaderField("Access-Control-Expose-Headers"), accessControlExposeHeaderSet);
     HTTPHeaderMap::const_iterator end = m_response.httpHeaderFields().end();
     for (HTTPHeaderMap::const_iterator it = m_response.httpHeaderFields().begin(); it!= end; ++it) {
         // Hide Set-Cookie header fields from the XMLHttpRequest client for these reasons:
         //     1) If the client did have access to the fields, then it could read HTTP-only
@@ skipping 127 matching lines @@
         return;
 
     if (m_state < HEADERS_RECEIVED)
         changeState(HEADERS_RECEIVED);
 
     if (m_decoder)
         m_responseText = m_responseText.concatenateWith(m_decoder->flush());
 
     InspectorInstrumentation::didFinishXHRLoading(scriptExecutionContext(), this, identifier, m_responseText, m_url, m_lastSendURL, m_lastSendLineNumber);
 
+    if (m_responseStream)
+        m_responseStream->finalize();
+
     bool hadLoader = m_loader;
     m_loader = 0;
 
     changeState(DONE);
     m_decoder = 0;
 
     if (hadLoader)
         dropProtection();
 }
 
@@ skipping 56 matching lines @@
     if (len == -1)
         len = strlen(data);
 
     if (useDecoder)
         m_responseText = m_responseText.concatenateWith(m_decoder->decode(data, len));
     else if (m_responseTypeCode == ResponseTypeArrayBuffer || m_responseTypeCode == ResponseTypeBlob) {
         // Buffer binary data.
         if (!m_binaryResponseBuilder)
             m_binaryResponseBuilder = SharedBuffer::create();
         m_binaryResponseBuilder->append(data, len);
+    } else if (m_responseTypeCode == ResponseTypeStream) {
+        if (!m_responseStream)
+            m_responseStream = Stream::create(responseMIMEType());
+        m_responseStream->addData(data, len);

[michaeln, 2013/07/24 03:57:22]

Also, it it a desired characteristic of this implementation that the network be
gated such that it run too far ahead of the stream consumer? And if so, is that
flow control an important characteristic? If that is the behavior we want, I
think this approach (stuffing data into the stream at this callsite) makes that
more challenging to achieve then some alternatives (that would stuff data into
the stream in the browser process).

     }
 
     if (!m_error) {
         long long expectedLength = m_response.expectedContentLength();
         m_receivedLength += len;
 
         if (m_async) {
             bool lengthComputable = expectedLength > 0 && m_receivedLength <= expectedLength;
             unsigned long long total = lengthComputable ? expectedLength : 0;
             m_progressEventThrottle.dispatchProgressEvent(lengthComputable, m_receivedLength, total);
@@ skipping 101 matching lines @@
     info.addMember(m_responseDocument, "responseDocument");
     info.addMember(m_binaryResponseBuilder, "binaryResponseBuilder");
     info.addMember(m_responseArrayBuffer, "responseArrayBuffer");
     info.addMember(m_lastSendURL, "lastSendURL");
     info.addMember(m_eventTargetData, "eventTargetData");
     info.addMember(m_progressEventThrottle, "progressEventThrottle");
     info.addMember(m_securityOrigin, "securityOrigin");
 }
 
 } // namespace WebCore