Minimize bundled user-agent CSS: html.css

third_party/WebKit/Source/build/scripts/minimize_css.py

+#!/usr/bin/env python
+# 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.
+
+import functools
+import os.path
+import re
+import sys
+
+import in_generator
+
+
+class CSSMinimizer(object):
+
+    INITIAL = 0
+    MAYBE_COMMENT_START = 1
+    INSIDE_COMMENT = 2
+    MAYBE_COMMENT_END = 3
+    INSIDE_SINGLE_QUOTE = 4
+    INSIDE_SINGLE_QUOTE_ESCAPE = 5
+    INSIDE_DOUBLE_QUOTE = 6
+    INSIDE_DOUBLE_QUOTE_ESCAPE = 7
+
+    def __init__(self):
+        self._output = ''
+        self._codeblock = ''
+
+    def flush_codeblock(self):
+        stripped = re.sub(r"\s+", ' ', self._codeblock)
+        stripped = re.sub(r";?\s*(?P<op>[{};])\s*", r'\g<op>', stripped)
+        self._output += stripped
+        self._codeblock = ''
+
+    def parse(self, content):
+        state = self.INITIAL
+        for char in content:
+            if state == self.INITIAL:
+                if char == '/':
+                    state = self.MAYBE_COMMENT_START
+                elif char == "'":
+                    self.flush_codeblock()
+                    self._output += char
+                    state = self.INSIDE_SINGLE_QUOTE
+                elif char == '"':
+                    self.flush_codeblock()
+                    self._output += char
+                    state = self.INSIDE_DOUBLE_QUOTE
+                else:
+                    self._codeblock += char
+            elif state == self.MAYBE_COMMENT_START:
+                if char == '*':
+                    self.flush_codeblock()
+                    state = self.INSIDE_COMMENT
+                else:
+                    self._codeblock += '/' + char
+                    state = self.INITIAL
+            elif state == self.INSIDE_COMMENT:
+                if char == '*':
+                    state = self.MAYBE_COMMENT_END
+                else:
+                    pass
+            elif state == self.MAYBE_COMMENT_END:
+                if char == '/':
+                    state = self.INITIAL
+                else:
+                    state = self.INSIDE_COMMENT
+            elif state == self.INSIDE_SINGLE_QUOTE:
+                if char == '\\':
+                    self._output += char
+                    state = self.INSIDE_SINGLE_QUOTE_ESCAPE
+                elif char == "'":
+                    self._output += char
+                    state = self.INITIAL
+                else:
+                    self._output += char
+            elif state == self.INSIDE_SINGLE_QUOTE_ESCAPE:
+                self._output += char
+                state = self.INSIDE_SINGLE_QUOTE
+            elif state == self.INSIDE_DOUBLE_QUOTE:
+                if char == '\\':
+                    self._output += char
+                    state = self.INSIDE_DOUBLE_QUOTE_ESCAPE
+                elif char == '"':
+                    self._output += char
+                    state = self.INITIAL
+                else:
+                    self._output += char
+            elif state == self.INSIDE_DOUBLE_QUOTE_ESCAPE:
+                self._output += char
+                state = self.INSIDE_DOUBLE_QUOTE
+
+        self.flush_codeblock()
+        self._output = self._output.strip()
+        return self._output
+
+    @classmethod
+    def minimize_css(cls, content):
+        minimizer = CSSMinimizer()
+        return minimizer.parse(content)
+
+
+class CSSMinimizerWriter(in_generator.GenericWriter):
+
+    def __init__(self, in_file_paths):
+        super(CSSMinimizerWriter, self).__init__(in_file_paths)
+
+        self._outputs = {}
+        for in_file_path in in_file_paths:
+            out_path = os.path.basename(in_file_path)
+            self._outputs[out_path] = functools.partial(self.generate_implementation, in_file_path)
+
+    def generate_implementation(self, in_file_path):
+        content = ''
+        with open(os.path.abspath(in_file_path)) as in_file:
+            content = in_file.read()
+        return CSSMinimizer.minimize_css(content)
+
+
+if __name__ == '__main__':
+    in_generator.Maker(CSSMinimizerWriter).main(sys.argv)