[WIP] Streaming CSS parser

third_party/WebKit/Source/core/css/parser/CSSParserTokenStream.cpp

Index: third_party/WebKit/Source/core/css/parser/CSSParserTokenStream.cpp
diff --git a/third_party/WebKit/Source/core/css/parser/CSSParserTokenStream.cpp b/third_party/WebKit/Source/core/css/parser/CSSParserTokenStream.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..377f21ad22a00b0befa9ec08587d0a174adf4bf9
--- /dev/null
+++ b/third_party/WebKit/Source/core/css/parser/CSSParserTokenStream.cpp
@@ -0,0 +1,38 @@
+// Copyright 2016 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/parser/CSSParserTokenStream.h"
+
+namespace blink {
+
+CSSParserTokenStream::~CSSParserTokenStream() {
+  if (!m_isSubStream)
+    return;
+
+  // TODO(timloh): Should be using CSSTokenier::skipToBlockEnd() instead.

[Charlie Harrison, 2017/01/09 21:35:07]

s/CSSTokenier/CSSTokenizer

+  consumeUntilAtEndOrPeekedTypeIs<>();
+
+  if (m_tokenizer.m_tokens.size() == m_currentIndex) {

[Charlie Harrison, 2017/01/09 21:35:07]

could these conditions be re-written in terms of hasLookedAhead?

+    DCHECK(m_tokenizer.m_finishedTokenizing);
+    m_tokenizer.m_tokens.remove(m_startIndex, m_currentIndex - m_startIndex);
+  } else {
+    DCHECK_EQ(m_tokenizer.m_tokens.size(), m_currentIndex + 1);
+    DCHECK_EQ(m_tokenizer.m_tokens[m_currentIndex].getBlockType(),
+              CSSParserToken::BlockEnd);
+    m_tokenizer.m_tokens.remove(m_startIndex,
+                                m_currentIndex - m_startIndex + 1);
+  }
+}
+
+const CSSParserToken& CSSParserTokenStream::peekInternal() {

[Charlie Harrison, 2017/01/09 21:35:07]

If tokenizeSingle() returned a token, this could be rewritten to:

if (hasLookedAhead)
  return m_tokenizer.m_tokens[m_currentIndex]
return m_tokenizer.tokenizeSingle()


Assuming tokenizeSingle just returns the staticEOFToken on end.

+  DCHECK_LE(m_currentIndex, m_tokenizer.m_tokens.size());
+  if (m_currentIndex == m_tokenizer.m_tokens.size()) {
+    m_tokenizer.tokenizeSingle();
+    if (m_tokenizer.m_finishedTokenizing)
+      return staticEOFToken;
+  }
+  return m_tokenizer.m_tokens[m_currentIndex];
+}
+
+}  // namespace blink