A thread-safe Media Query Parser

Source/core/css/parser/MediaQueryTokenizer.h

+/*
+ * Copyright (C) 2013 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef MediaQueryTokenizer_h
+#define MediaQueryTokenizer_h
+
+#include "core/css/parser/CSSToken.h"
+#include "core/html/parser/InputStreamPreprocessor.h"
+#include "wtf/text/WTFString.h"
+
+#define CODE_POINTS_NUM 128
+
+namespace WebCore {
+
+class CSSInputStream;
+
+class MediaQueryTokenizer {
+    WTF_MAKE_NONCOPYABLE(MediaQueryTokenizer);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    MediaQueryTokenizer();
+
+    CSSToken nextToken(CSSInputStream&);
+    static void tokenize(String, Vector<CSSToken>&);
+
+private:
+    UChar consume();
+    void consume(unsigned);
+    void reconsume(UChar);
+
+    CSSToken consumeNumericToken();
+    CSSToken consumeIdentLikeToken();
+    CSSToken consumeNumber();
+
+    void consumeUntilNotWhitespace();
+
+    bool consumeIfNext(UChar);
+    String consumeName();
+    UChar consumeEscape();
+
+    bool nextTwoCharsAreValidEscape();
+    bool nextCharsAreNumber();
+    bool nextCharsAreIdentifier();
+
+    typedef CSSToken (MediaQueryTokenizer::*CodePoint)(UChar);
+
+    class CodePoints {
+    public:
+        CodePoint codePoints[CODE_POINTS_NUM];
+
+        CodePoints()
+        {
+            memset(codePoints, 0, CODE_POINTS_NUM);
+            codePoints['\n'] = &MediaQueryTokenizer::whiteSpace;
+            codePoints['\r'] = &MediaQueryTokenizer::whiteSpace;
+            codePoints['\t'] = &MediaQueryTokenizer::whiteSpace;
+            codePoints[' '] = &MediaQueryTokenizer::whiteSpace;
+            codePoints['\f'] = &MediaQueryTokenizer::whiteSpace;
+            codePoints['('] = &MediaQueryTokenizer::leftParen;
+            codePoints[')'] = &MediaQueryTokenizer::rightParen;
+            codePoints['+'] = &MediaQueryTokenizer::plusOrFullStop;
+            codePoints['.'] = &MediaQueryTokenizer::plusOrFullStop;
+            codePoints[','] = &MediaQueryTokenizer::comma;
+            codePoints['-'] = &MediaQueryTokenizer::hyphenMinus;
+            codePoints['/'] = &MediaQueryTokenizer::solidus;
+            codePoints[':'] = &MediaQueryTokenizer::colon;
+            codePoints[';'] = &MediaQueryTokenizer::semiColon;
+            codePoints['\\'] = &MediaQueryTokenizer::reverseSolidus;
+            for (char digit = '0'; digit <= '9'; ++digit)
+                codePoints[digit] = &MediaQueryTokenizer::asciiDigit;
+            for (char alpha = 'a'; alpha <= 'z'; ++alpha)
+                codePoints[alpha] = &MediaQueryTokenizer::nameStart;
+            for (char alpha = 'A'; alpha <= 'Z'; ++alpha)
+                codePoints[alpha] = &MediaQueryTokenizer::nameStart;
+            codePoints['_'] = &MediaQueryTokenizer::nameStart;
+            codePoints[kEndOfFileMarker] = &MediaQueryTokenizer::endOfFile;
+        }
+    };
+
+    CodePoints* getCodePoints()
+    {
+        static CodePoints codePoints;
+        return &codePoints;
+    }
+
+    CSSToken whiteSpace(UChar);
+    CSSToken leftParen(UChar);
+    CSSToken rightParen(UChar);
+    CSSToken plusOrFullStop(UChar);
+    CSSToken comma(UChar);
+    CSSToken hyphenMinus(UChar);
+    CSSToken solidus(UChar);
+    CSSToken colon(UChar);
+    CSSToken semiColon(UChar);
+    CSSToken reverseSolidus(UChar);
+    CSSToken asciiDigit(UChar);
+    CSSToken nameStart(UChar);
+    CSSToken endOfFile(UChar);
+
+    CSSInputStream* m_input;
+};
+
+
+
+} // namespace WebCore
+
+#endif // MediaQueryTokenizer_h