Cleanups for VTTTokenizer

Source/core/html/track/vtt/VTTTokenizer.cpp

 /*
  * Copyright (C) 2011 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
@@ skipping 20 matching lines @@
 #include "config.h"
 
 #include "core/html/track/vtt/VTTTokenizer.h"
 
 #include "core/xml/parser/MarkupTokenizerInlines.h"
 #include "wtf/text/StringBuilder.h"
 #include "wtf/unicode/CharacterNames.h"
 
 namespace WebCore {
 
-#define WEBVTT_BEGIN_STATE(stateName) BEGIN_STATE(VTTTokenizerState, stateName)
-#define WEBVTT_ADVANCE_TO(stateName) ADVANCE_TO(VTTTokenizerState, stateName)
+#define WEBVTT_BEGIN_STATE(stateName) case stateName: stateName:
+#define WEBVTT_ADVANCE_TO(stateName)                               \
+    do {                                                           \
+        state = stateName;                                         \
+        ASSERT(!m_input.isEmpty());                                \
+        m_inputStreamPreprocessor.advance(m_input);                \
+        cc = m_inputStreamPreprocessor.nextInputCharacter();       \
+        goto stateName;                                            \
+    } while (false)
 
 template<unsigned charactersCount>
 ALWAYS_INLINE bool equalLiteral(const StringBuilder& s, const char (&characters)[charactersCount])
 {
     return WTF::equal(s, reinterpret_cast<const LChar*>(characters), charactersCount - 1);
 }
 
 static void addNewClass(StringBuilder& classes, const StringBuilder& newClass)
 {
     if (!classes.isEmpty())
         classes.append(' ');
     classes.append(newClass);
 }
 
+inline bool emitToken(VTTToken& resultToken, const VTTToken& token)
+{
+    resultToken = token;
+    return true;
+}
+
+inline bool advanceAndEmitToken(SegmentedString& source, VTTToken& resultToken, const VTTToken& token)
+{
+    source.advanceAndUpdateLineNumber();
+    return emitToken(resultToken, token);
+}
+
 VTTTokenizer::VTTTokenizer(const String& input)
     : m_input(input)
     , m_inputStreamPreprocessor(this)
 {
-    reset();
-
     // Append a EOF marker and close the input "stream".
     ASSERT(!m_input.isClosed());
     m_input.append(SegmentedString(String(&kEndOfFileMarker, 1)));
     m_input.close();
 }
 
-void VTTTokenizer::reset()
-{
-    m_token = 0;
-}
-
 bool VTTTokenizer::nextToken(VTTToken& token)
 {
-    // If we have a token in progress, then we're supposed to be called back
-    // with the same token so we can finish it.
-    ASSERT(!m_token || m_token == &token);
-    m_token = &token;
-
     if (m_input.isEmpty() || !m_inputStreamPreprocessor.peek(m_input))
-        return haveBufferedCharacterToken();
+        return false;
 
     UChar cc = m_inputStreamPreprocessor.nextInputCharacter();
     if (cc == kEndOfFileMarker) {
         m_inputStreamPreprocessor.advance(m_input);
         return false;
     }
 
     StringBuilder buffer;
     StringBuilder result;
     StringBuilder classes;
-    m_state = VTTTokenizerState::DataState;
-
-    // The ADVANCE_TO helper macros expect this name ('source') on the input variable.
-    SegmentedString& source = m_input;
+    enum {
+        DataState,
+        EscapeState,
+        TagState,
+        StartTagState,
+        StartTagClassState,
+        StartTagAnnotationState,
+        EndTagState,
+        TimestampTagState,
+    } state = DataState;
 
     // 4.8.10.13.4 WebVTT cue text tokenizer
-    switch (m_state) {
+    switch (state) {
         WEBVTT_BEGIN_STATE(DataState) {
             if (cc == '&') {
                 buffer.append(static_cast<LChar>(cc));
                 WEBVTT_ADVANCE_TO(EscapeState);
             } else if (cc == '<') {
                 if (result.isEmpty()) {
                     WEBVTT_ADVANCE_TO(TagState);
                 } else {
                     // We don't want to advance input or perform a state transition - just return a (new) token.
                     // (On the next call to nextToken we will see '<' again, but take the other branch in this if instead.)
-                    return emitToken(VTTToken::StringToken(result.toString()));
+                    return emitToken(token, VTTToken::StringToken(result.toString()));
                 }
             } else if (cc == kEndOfFileMarker) {
-                return advanceAndEmitToken(source, VTTToken::StringToken(result.toString()));
+                return advanceAndEmitToken(m_input, token, VTTToken::StringToken(result.toString()));
             } else {
                 result.append(cc);
                 WEBVTT_ADVANCE_TO(DataState);
             }
         }
         END_STATE()
 
         WEBVTT_BEGIN_STATE(EscapeState) {
             if (cc == ';') {
                 if (equalLiteral(buffer, "&amp")) {
@@ skipping 12 matching lines @@
                     buffer.append(static_cast<LChar>(cc));
                     result.append(buffer);
                 }
                 buffer.clear();
                 WEBVTT_ADVANCE_TO(DataState);
             } else if (isASCIIAlphanumeric(cc)) {
                 buffer.append(static_cast<LChar>(cc));
                 WEBVTT_ADVANCE_TO(EscapeState);
             } else if (cc == '<') {
                 result.append(buffer);
-                return emitToken(VTTToken::StringToken(result.toString()));
+                return emitToken(token, VTTToken::StringToken(result.toString()));
             } else if (cc == kEndOfFileMarker) {
                 result.append(buffer);
-                return advanceAndEmitToken(source, VTTToken::StringToken(result.toString()));
+                return advanceAndEmitToken(m_input, token, VTTToken::StringToken(result.toString()));
             } else {
                 result.append(buffer);
                 buffer.clear();
 
                 if (cc == '&') {
                     buffer.append(static_cast<LChar>(cc));
                     WEBVTT_ADVANCE_TO(EscapeState);
                 }
                 result.append(cc);
                 WEBVTT_ADVANCE_TO(DataState);
             }
         }
         END_STATE()
 
         WEBVTT_BEGIN_STATE(TagState) {
             if (isTokenizerWhitespace(cc)) {
                 ASSERT(result.isEmpty());
                 WEBVTT_ADVANCE_TO(StartTagAnnotationState);
             } else if (cc == '.') {
                 ASSERT(result.isEmpty());
                 WEBVTT_ADVANCE_TO(StartTagClassState);
             } else if (cc == '/') {
                 WEBVTT_ADVANCE_TO(EndTagState);
             } else if (WTF::isASCIIDigit(cc)) {
                 result.append(cc);
                 WEBVTT_ADVANCE_TO(TimestampTagState);
             } else if (cc == '>' || cc == kEndOfFileMarker) {
                 ASSERT(result.isEmpty());
-                return advanceAndEmitToken(source, VTTToken::StartTag(result.toString()));
+                return advanceAndEmitToken(m_input, token, VTTToken::StartTag(result.toString()));
             } else {
                 result.append(cc);
                 WEBVTT_ADVANCE_TO(StartTagState);
             }
         }
         END_STATE()
 
         WEBVTT_BEGIN_STATE(StartTagState) {
             if (isTokenizerWhitespace(cc)) {
                 WEBVTT_ADVANCE_TO(StartTagAnnotationState);
             } else if (cc == '.') {
                 WEBVTT_ADVANCE_TO(StartTagClassState);
             } else if (cc == '>' || cc == kEndOfFileMarker) {
-                return advanceAndEmitToken(source, VTTToken::StartTag(result.toString()));
+                return advanceAndEmitToken(m_input, token, VTTToken::StartTag(result.toString()));
             } else {
                 result.append(cc);
                 WEBVTT_ADVANCE_TO(StartTagState);
             }
         }
         END_STATE()
 
         WEBVTT_BEGIN_STATE(StartTagClassState) {
             if (isTokenizerWhitespace(cc)) {
                 addNewClass(classes, buffer);
                 buffer.clear();
                 WEBVTT_ADVANCE_TO(StartTagAnnotationState);
             } else if (cc == '.') {
                 addNewClass(classes, buffer);
                 buffer.clear();
                 WEBVTT_ADVANCE_TO(StartTagClassState);
             } else if (cc == '>' || cc == kEndOfFileMarker) {
                 addNewClass(classes, buffer);
                 buffer.clear();
-                return advanceAndEmitToken(source, VTTToken::StartTag(result.toString(), classes.toAtomicString()));
+                return advanceAndEmitToken(m_input, token, VTTToken::StartTag(result.toString(), classes.toAtomicString()));
             } else {
                 buffer.append(cc);
                 WEBVTT_ADVANCE_TO(StartTagClassState);
             }
         }
         END_STATE()
 
         WEBVTT_BEGIN_STATE(StartTagAnnotationState) {
             if (cc == '>' || cc == kEndOfFileMarker) {
-                return advanceAndEmitToken(source, VTTToken::StartTag(result.toString(), classes.toAtomicString(), buffer.toAtomicString()));
+                return advanceAndEmitToken(m_input, token, VTTToken::StartTag(result.toString(), classes.toAtomicString(), buffer.toAtomicString()));
             }
             buffer.append(cc);
             WEBVTT_ADVANCE_TO(StartTagAnnotationState);
         }
         END_STATE()
 
         WEBVTT_BEGIN_STATE(EndTagState) {
             if (cc == '>' || cc == kEndOfFileMarker)
-                return advanceAndEmitToken(source, VTTToken::EndTag(result.toString()));
+                return advanceAndEmitToken(m_input, token, VTTToken::EndTag(result.toString()));
             result.append(cc);
             WEBVTT_ADVANCE_TO(EndTagState);
         }
         END_STATE()
 
         WEBVTT_BEGIN_STATE(TimestampTagState) {
             if (cc == '>' || cc == kEndOfFileMarker)
-                return advanceAndEmitToken(source, VTTToken::TimestampTag(result.toString()));
+                return advanceAndEmitToken(m_input, token, VTTToken::TimestampTag(result.toString()));
             result.append(cc);
             WEBVTT_ADVANCE_TO(TimestampTagState);
         }
         END_STATE()
 
     }
 
     ASSERT_NOT_REACHED();
     return false;
 }
 
 }