inspector/scripts/jsmin.py

   1 # This code is original from jsmin by Douglas Crockford, it was translated to
   2 # Python by Baruch Even. It was rewritten by Dave St.Germain for speed.
   3 #
   4 # The MIT License (MIT)
   5 #
   6 # Copyright (c) 2013 Dave St.Germain
   7 #
   8 # Permission is hereby granted, free of charge, to any person obtaining a copy
   9 # of this software and associated documentation files (the "Software"), to deal
  10 # in the Software without restriction, including without limitation the rights
  11 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 # copies of the Software, and to permit persons to whom the Software is
  13 # furnished to do so, subject to the following conditions:
  14 #
  15 # The above copyright notice and this permission notice shall be included in
  16 # all copies or substantial portions of the Software.
  17 #
  18 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24 # THE SOFTWARE.
  25
  26
  27 import sys
  28 is_3 = sys.version_info >= (3, 0)
  29 if is_3:
  30     import io
  31 else:
  32     import StringIO
  33     try:
  34         import cStringIO
  35     except ImportError:
  36         cStringIO = None
  37
  38
  39 __all__ = ['jsmin', 'JavascriptMinify']
  40 __version__ = '2.0.9'
  41
  42
  43 def jsmin(js):
  44     """
  45     returns a minified version of the javascript string
  46     """
  47     if not is_3:
  48         if cStringIO and not isinstance(js, unicode):
  49             # strings can use cStringIO for a 3x performance
  50             # improvement, but unicode (in python2) cannot
  51             klass = cStringIO.StringIO
  52         else:
  53             klass = StringIO.StringIO
  54     else:
  55         klass = io.StringIO
  56     ins = klass(js)
  57     outs = klass()
  58     JavascriptMinify(ins, outs).minify()
  59     return outs.getvalue()
  60
  61
  62 class JavascriptMinify(object):
  63     """
  64     Minify an input stream of javascript, writing
  65     to an output stream
  66     """
  67
  68     def __init__(self, instream=None, outstream=None):
  69         self.ins = instream
  70         self.outs = outstream
  71
  72     def minify(self, instream=None, outstream=None):
  73         if instream and outstream:
  74             self.ins, self.outs = instream, outstream
  75
  76         self.is_return = False
  77         self.return_buf = ''
  78
  79         def write(char):
  80             # all of this is to support literal regular expressions.
  81             # sigh
  82             if char in 'return':
  83                 self.return_buf += char
  84                 self.is_return = self.return_buf == 'return'
  85             self.outs.write(char)
  86             if self.is_return:
  87                 self.return_buf = ''
  88
  89         read = self.ins.read
  90
  91         space_strings = "abcdefghijklmnopqrstuvwxyz"\
  92         "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_$\\"
  93         starters, enders = '{[(+-', '}])+-"\''
  94         newlinestart_strings = starters + space_strings
  95         newlineend_strings = enders + space_strings
  96         do_newline = False
  97         do_space = False
  98         escape_slash_count = 0
  99         doing_single_comment = False
 100         previous_before_comment = ''
 101         doing_multi_comment = False
 102         in_re = False
 103         in_quote = ''
 104         quote_buf = []
 105
 106         previous = read(1)
 107         if previous == '\\':
 108             escape_slash_count += 1
 109         next1 = read(1)
 110         if previous == '/':
 111             if next1 == '/':
 112                 doing_single_comment = True
 113             elif next1 == '*':
 114                 doing_multi_comment = True
 115                 previous = next1
 116                 next1 = read(1)
 117             else:
 118                 write(previous)
 119         elif not previous:
 120             return
 121         elif previous >= '!':
 122             if previous in "'\"":
 123                 in_quote = previous
 124             write(previous)
 125             previous_non_space = previous
 126         else:
 127             previous_non_space = ' '
 128         if not next1:
 129             return
 130
 131         while 1:
 132             next2 = read(1)
 133             if not next2:
 134                 last = next1.strip()
 135                 if not (doing_single_comment or doing_multi_comment)\
 136                     and last not in ('', '/'):
 137                     if in_quote:
 138                         write(''.join(quote_buf))
 139                     write(last)
 140                 break
 141             if doing_multi_comment:
 142                 if next1 == '*' and next2 == '/':
 143                     doing_multi_comment = False
 144                     next2 = read(1)
 145             elif doing_single_comment:
 146                 if next1 in '\r\n':
 147                     doing_single_comment = False
 148                     while next2 in '\r\n':
 149                         next2 = read(1)
 150                         if not next2:
 151                             break
 152                     if previous_before_comment in ')}]':
 153                         do_newline = True
 154                     elif previous_before_comment in space_strings:
 155                         write('\n')
 156             elif in_quote:
 157                 quote_buf.append(next1)
 158
 159                 if next1 == in_quote:
 160                     numslashes = 0
 161                     for c in reversed(quote_buf[:-1]):
 162                         if c != '\\':
 163                             break
 164                         else:
 165                             numslashes += 1
 166                     if numslashes % 2 == 0:
 167                         in_quote = ''
 168                         write(''.join(quote_buf))
 169             elif next1 in '\r\n':
 170                 if previous_non_space in newlineend_strings \
 171                     or previous_non_space > '~':
 172                     while 1:
 173                         if next2 < '!':
 174                             next2 = read(1)
 175                             if not next2:
 176                                 break
 177                         else:
 178                             if next2 in newlinestart_strings \
 179                                 or next2 > '~' or next2 == '/':
 180                                 do_newline = True
 181                             break
 182             elif next1 < '!' and not in_re:
 183                 if (previous_non_space in space_strings \
 184                     or previous_non_space > '~') \
 185                     and (next2 in space_strings or next2 > '~'):
 186                     do_space = True
 187                 elif previous_non_space in '-+' and next2 == previous_non_space:
 188                     # protect against + ++ or - -- sequences
 189                     do_space = True
 190                 elif self.is_return and next2 == '/':
 191                     # returning a regex...
 192                     write(' ')
 193             elif next1 == '/':
 194                 if do_space:
 195                     write(' ')
 196                 if in_re:
 197                     if previous != '\\' or (not escape_slash_count % 2) or next2 in 'gimy':
 198                         in_re = False
 199                     write('/')
 200                 elif next2 == '/':
 201                     doing_single_comment = True
 202                     previous_before_comment = previous_non_space
 203                 elif next2 == '*':
 204                     doing_multi_comment = True
 205                     previous = next1
 206                     next1 = next2
 207                     next2 = read(1)
 208                 else:
 209                     in_re = previous_non_space in '(,=:[?!&|' or self.is_return  # literal regular expression
 210                     write('/')
 211             else:
 212                 if do_space:
 213                     do_space = False
 214                     write(' ')
 215                 if do_newline:
 216                     write('\n')
 217                     do_newline = False
 218
 219                 write(next1)
 220                 if not in_re and next1 in "'\"":
 221                     in_quote = next1
 222                     quote_buf = []
 223
 224             previous = next1
 225             next1 = next2
 226
 227             if previous >= '!':
 228                 previous_non_space = previous
 229
 230             if previous == '\\':
 231                 escape_slash_count += 1
 232             else:
 233                 escape_slash_count = 0
 234
 235 if __name__ == '__main__':
 236     minifier = JavascriptMinify(sys.stdin, sys.stdout)
 237     minifier.minify()
 238     sys.stdout.write('\n')