[Experimental] CSSSerializer Proof-of-concept

third_party/WebKit/Source/core/css/serializer/CSSDeserializeStream.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/CSSDeserializeStream.h"
+
+#include "core/HTMLNames.h"
+#include "core/css/CSSProperty.h"
+#include "core/css/serializer/CSSSerializeStream.h" // FIXME: Remove
+#include "platform/weborigin/Referrer.h"
+
+namespace blink {
+
+inline void CSSDeserializeStream::padIfNeeded()
+{
+    uintptr_t misalign = reinterpret_cast<uintptr_t>(m_ptr) & 0x3;
+    if (!misalign)
+        return;
+    unsigned padding = 4 - static_cast<unsigned>(misalign);
+    CSDEBUG("padding %d\n", padding);
+    m_ptr += padding;
+}
+
+CSSDeserializeStream::CSSDeserializeStream(const char* data, size_t size)
+    : m_ptr(data)
+    , m_ptrEnd(data + size)
+{
+}
+
+inline size_t CSSDeserializeStream::unconsumedSize() const
+{
+    return m_ptrEnd - m_ptr;
+}
+
+CSSValue::ClassType CSSDeserializeStream::readClassType()
+{
+    CSDEBUG("read classType ");
+    return static_cast<CSSValue::ClassType>(readUnsigned());
+}
+
+Color CSSDeserializeStream::readColor()
+{
+    CSDEBUG("read color ");
+    return Color(static_cast<RGBA32>(readUnsigned()));
+}
+
+bool CSSDeserializeStream::readBool()
+{
+    RELEASE_ASSERT(unconsumedSize() >= 1);
+
+    char c = *reinterpret_cast<const char*>(m_ptr);
+    m_ptr += 1;
+    CSDEBUG("read bool %d\n", c);
+
+    return c;
+}
+
+int CSSDeserializeStream::readInt()
+{
+    padIfNeeded();
+    RELEASE_ASSERT(unconsumedSize() >= sizeof(int));
+
+    int n = *reinterpret_cast<const int*>(m_ptr);
+    m_ptr += sizeof(int);
+    CSDEBUG("read int %d %x\n", n, n);
+
+    return n;
+}
+
+unsigned CSSDeserializeStream::readUnsigned()
+{
+    padIfNeeded();
+    RELEASE_ASSERT(unconsumedSize() >= sizeof(unsigned));
+
+    unsigned u = *reinterpret_cast<const unsigned*>(m_ptr);
+    m_ptr += sizeof(unsigned);
+    CSDEBUG("read unsigned %u %x\n", u, u);
+
+    return u;
+}
+
+double CSSDeserializeStream::readDouble()
+{
+    padIfNeeded();
+    RELEASE_ASSERT(unconsumedSize() >= sizeof(double));
+
+    double d = *reinterpret_cast<const double*>(m_ptr);
+    m_ptr += sizeof(double);
+    CSDEBUG("read double %f\n", d);
+
+    return d;
+}
+
+UChar32 CSSDeserializeStream::readUChar32()
+{
+    padIfNeeded();
+    RELEASE_ASSERT(unconsumedSize() >= sizeof(UChar32));
+
+    UChar32 u = *reinterpret_cast<const UChar32*>(m_ptr);
+    m_ptr += sizeof(UChar32);
+    CSDEBUG("read UChar32 %u\n", u);
+
+    return u;
+}
+
+String CSSDeserializeStream::readString()
+{
+    unsigned length = readUnsigned();
+    if (!length) {
+        CSDEBUG("read String <empty>\n");
+        return emptyString(); 
+    } else if (length == 0xffffffff) {
+        CSDEBUG("read String <null>\n");
+        return String();
+    }
+    bool is8Bit = readUnsigned();
+
+    if (is8Bit) {
+        RELEASE_ASSERT(unconsumedSize() >= length);
+        String ret(reinterpret_cast<const LChar*>(m_ptr), length);
+        m_ptr += length;
+
+        CSDEBUG("read String "); CSSHOW(ret);
+        return ret;
+    } else {
+        RELEASE_ASSERT(unconsumedSize() >= length);
+        String ret(reinterpret_cast<const UChar*>(m_ptr), length);
+        m_ptr += length * 2;
+
+        CSDEBUG("read String "); CSSHOW(ret);
+        return ret;
+    }
+}
+
+AtomicString CSSDeserializeStream::readAtomicString()
+{
+    CSDEBUG("read AtomicString ");
+    String str = readString();
+    unsigned hash = readUnsigned();
+    if (hash)
+        str.impl()->setHash(hash);
+    return AtomicString(str);
+}
+
+static const HTMLQualifiedName** htmlTagsArray()
+{
+    DEFINE_STATIC_LOCAL(OwnPtr<const HTMLQualifiedName*[]>, array, ());
+    if (!array) {
+        array = HTMLNames::getHTMLTags();
+    }
+    return array.get();
+}
+
+QualifiedName CSSDeserializeStream::readQualifiedName()
+{
+    CSDEBUG("read QualifiedName ");
+
+    int id = readInt();
+    if (id >= 0) {
+        return *htmlTagsArray()[id];
+    }
+
+    AtomicString namespaceURI = starAtom;
+    AtomicString localName(readAtomicString());
+
+    return QualifiedName(nullAtom, localName, namespaceURI);
+}
+
+StylePropertyMetadata CSSDeserializeStream::readStylePropertyMetadata()
+{
+    CSDEBUG("read StylePropertyMetadata ");
+    unsigned u = readUnsigned();
+    return *reinterpret_cast<StylePropertyMetadata*>(&u);
+}
+
+Referrer CSSDeserializeStream::readReferrer()
+{
+    Referrer referrer;
+    referrer.referrer = readAtomicString();
+    referrer.referrerPolicy = readIntAsEnum<ReferrerPolicy>();
+    return referrer;
+}
+
+} // namespace blink