[Experimental] CSSSerializer Proof-of-concept

third_party/WebKit/Source/core/css/serializer/CSSSerializeStream.cpp

+// Copyright 2015 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 "core/css/serializer/CSSSerializeStream.h"
+
+#include "core/HTMLNames.h"
+#include "core/css/CSSProperty.h"
+#include "platform/weborigin/Referrer.h"
+
+namespace blink {
+
+inline void CSSSerializeStream::padIfNeeded()
+{
+    uintptr_t misalign = m_buffer.size() & 0x3;
+    if (misalign) {
+        unsigned padding = 4 - static_cast<unsigned>(misalign);
+        CSDEBUG("padding %d\n", padding);
+        m_buffer.grow(m_buffer.size() + padding);
+    }
+}
+
+void CSSSerializeStream::writeClassType(CSSValue::ClassType classType)
+{
+    CSDEBUG("write classType ");
+    writeUnsigned(classType);
+}
+
+void CSSSerializeStream::writeColor(Color color)
+{
+    CSDEBUG("write color ");
+    writeUnsigned(color.rgb());
+}
+
+void CSSSerializeStream::writeBool(bool b)
+{
+    CSDEBUG("write bool %d\n", b);
+    m_buffer.append(reinterpret_cast<char*>(&b), 1);
+}
+
+void CSSSerializeStream::writeInt(int n)
+{
+    CSDEBUG("write signed %d %x\n", n, n);
+    padIfNeeded();
+    m_buffer.append(reinterpret_cast<char*>(&n), sizeof(int));
+}
+
+void CSSSerializeStream::writeUnsigned(unsigned u)
+{
+    CSDEBUG("write unsigned %u %x\n", u, u);
+    padIfNeeded();
+    m_buffer.append(reinterpret_cast<char*>(&u), sizeof(unsigned));
+}
+
+void CSSSerializeStream::writeDouble(double d)
+{
+    CSDEBUG("write double %f\n", d);
+    padIfNeeded();
+    m_buffer.append(reinterpret_cast<char*>(&d), sizeof(double));
+}
+
+void CSSSerializeStream::writeUChar32(UChar32 u)
+{
+    CSDEBUG("write UChar32 %u\n", u);
+    padIfNeeded();
+    m_buffer.append(reinterpret_cast<char*>(&u), sizeof(UChar32));
+}
+
+void CSSSerializeStream::writeString(const String& str)
+{
+    // FIXME: emptyString vs. emptyString16???
+    CSDEBUG("write String ");
+    CSSHOW(str);
+    if (str.isNull()) {
+        writeUnsigned(0xffffffff);
+        return;
+    }
+
+    writeUnsigned(str.length());
+    if (str.length()) {
+        writeUnsigned(str.is8Bit());
+        if (str.is8Bit()) {
+            m_buffer.append(str.characters8(), str.length());
+        } else {
+            m_buffer.append(str.characters16(), str.length() * 2);
+        }
+    }
+}
+
+void CSSSerializeStream::writeAtomicString(const AtomicString& str)
+{
+    CSDEBUG("write AtomicString ");
+    writeString(str.string());
+    writeUnsigned(str.impl() ? str.impl()->hash() : 0);
+}
+
+using QualifiedNameIntMap = HashMap<QualifiedName, int>; 
+static const QualifiedNameIntMap& htmlTagNameToInt()
+{
+    DEFINE_STATIC_LOCAL(QualifiedNameIntMap, map, ());
+    if (map.isEmpty()) {
+        OwnPtr<const HTMLQualifiedName*[]> qualifiedNames = HTMLNames::getHTMLTags();
+        for (size_t i = 0; i < HTMLNames::HTMLTagsCount; ++i) {
+            map.set(*qualifiedNames[i], i);
+        }
+    }
+     
+    return map;
+}
+
+void CSSSerializeStream::writeQualifiedName(const QualifiedName& name)
+{
+    // FIXME
+    CSDEBUG("write QualifiedName ");
+    
+    const QualifiedNameIntMap& map = htmlTagNameToInt();
+    auto it = map.find(name);
+    if (it != map.end()) {
+        int id = it->value;
+        CSDEBUG("Tag %d", id);
+        writeInt(id); 
+        return;
+    }
+
+    writeInt(-1);
+    RELEASE_ASSERT(!name.hasPrefix());
+    // name.namespaceURI().show();
+    // RELEASE_ASSERT(name.namespaceURI().isEmpty());
+    writeAtomicString(name.localName());
+}
+
+void CSSSerializeStream::writeStylePropertyMetadata(StylePropertyMetadata metadata)
+{
+    CSDEBUG("write StylePropertyMetadata ");
+    static_assert(sizeof(StylePropertyMetadata) == sizeof(uint16_t), "uint16 hack is unapplicable");
+    writeUnsigned(*reinterpret_cast<uint16_t*>(&metadata));
+}
+
+void CSSSerializeStream::writeReferrer(const Referrer& referrer)
+{
+    writeAtomicString(referrer.referrer);
+    writeInt(referrer.referrerPolicy);
+}
+
+} // namespace blink