Module rjsmin

Source Code for Module rjsmin

  1  #!/usr/bin/env python 
  2  # -*- coding: ascii -*- 
  3  # 
  4  # Copyright 2011, 2012 
  5  # Andr\xe9 Malo or his licensors, as applicable 
  6  # 
  7  # Licensed under the Apache License, Version 2.0 (the "License"); 
  8  # you may not use this file except in compliance with the License. 
  9  # You may obtain a copy of the License at 
 10  # 
 11  #     http://www.apache.org/licenses/LICENSE-2.0 
 12  # 
 13  # Unless required by applicable law or agreed to in writing, software 
 14  # distributed under the License is distributed on an "AS IS" BASIS, 
 15  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 16  # See the License for the specific language governing permissions and 
 17  # limitations under the License. 
 18  r""" 
 19  ===================== 
 20   Javascript Minifier 
 21  ===================== 
 22   
 23  rJSmin is a javascript minifier written in python. 
 24   
 25  The minifier is based on the semantics of `jsmin.c by Douglas Crockford`_\. 
 26   
 27  The module is a re-implementation aiming for speed, so it can be used at 
 28  runtime (rather than during a preprocessing step). Usually it produces the 
 29  same results as the original ``jsmin.c``. It differs in the following ways: 
 30   
 31  - there is no error detection: unterminated string, regex and comment 
 32    literals are treated as regular javascript code and minified as such. 
 33  - Control characters inside string and regex literals are left untouched; they 
 34    are not converted to spaces (nor to \n) 
 35  - Newline characters are not allowed inside string and regex literals, except 
 36    for line continuations in string literals (ECMA-5). 
 37  - "return /regex/" is recognized correctly. 
 38  - "+ +" and "- -" sequences are not collapsed to '++' or '--' 
 39  - Newlines before ! operators are removed more sensibly 
 40  - rJSmin does not handle streams, but only complete strings. (However, the 
 41    module provides a "streamy" interface). 
 42   
 43  Since most parts of the logic are handled by the regex engine it's way 
 44  faster than the original python port of ``jsmin.c`` by Baruch Even. The speed 
 45  factor varies between about 6 and 55 depending on input and python version 
 46  (it gets faster the more compressed the input already is). Compared to the 
 47  speed-refactored python port by Dave St.Germain the performance gain is less 
 48  dramatic but still between 1.2 and 7. See the docs/BENCHMARKS file for 
 49  details. 
 50   
 51  rjsmin.c is a reimplementation of rjsmin.py in C and speeds it up even more. 
 52   
 53  Both python 2 and python 3 are supported. 
 54   
 55  .. _jsmin.c by Douglas Crockford: 
 56     http://www.crockford.com/javascript/jsmin.c 
 57  """ 
 58  __author__ = "Andr\xe9 Malo" 
 59  __author__ = getattr(__author__, 'decode', lambda x: __author__)('latin-1') 
 60  __docformat__ = "restructuredtext en" 
 61  __license__ = "Apache License, Version 2.0" 
 62  __version__ = '1.0.6' 
 63  __all__ = ['jsmin'] 
 64   
 65  import re as _re 
 66   
 67   
68 -def _make_jsmin(python_only=False):
69 """ 70 Generate JS minifier based on `jsmin.c by Douglas Crockford`_ 71 72 .. _jsmin.c by Douglas Crockford: 73 http://www.crockford.com/javascript/jsmin.c 74 75 :Parameters: 76 `python_only` : ``bool`` 77 Use only the python variant. If true, the c extension is not even 78 tried to be loaded. 79 80 :Return: Minifier 81 :Rtype: ``callable`` 82 """ 83 # pylint: disable = R0912, R0914, W0612 84 if not python_only: 85 try: 86 import _rjsmin 87 except ImportError: 88 pass 89 else: 90 return _rjsmin.jsmin 91 try: 92 xrange 93 except NameError: 94 xrange = range # pylint: disable = W0622 95 96 space_chars = r'[\000-\011\013\014\016-\040]' 97 98 line_comment = r'(?://[^\r\n]*)' 99 space_comment = r'(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/)' 100 string1 = \ 101 r'(?:\047[^\047\\\r\n]*(?:\\(?:[^\r\n]|\r?\n|\r)[^\047\\\r\n]*)*\047)' 102 string2 = r'(?:"[^"\\\r\n]*(?:\\(?:[^\r\n]|\r?\n|\r)[^"\\\r\n]*)*")' 103 strings = r'(?:%s|%s)' % (string1, string2) 104 105 charclass = r'(?:\[[^\\\]\r\n]*(?:\\[^\r\n][^\\\]\r\n]*)*\])' 106 nospecial = r'[^/\\\[\r\n]' 107 regex = r'(?:/(?![\r\n/*])%s*(?:(?:\\[^\r\n]|%s)%s*)*/)' % ( 108 nospecial, charclass, nospecial 109 ) 110 space = r'(?:%s|%s)' % (space_chars, space_comment) 111 newline = r'(?:%s?[\r\n])' % line_comment 112 113 def fix_charclass(result): 114 """ Fixup string of chars to fit into a regex char class """ 115 pos = result.find('-') 116 if pos >= 0: 117 result = r'%s%s-' % (result[:pos], result[pos + 1:]) 118 119 def sequentize(string): 120 """ 121 Notate consecutive characters as sequence 122 123 (1-4 instead of 1234) 124 """ 125 first, last, result = None, None, [] 126 for char in map(ord, string): 127 if last is None: 128 first = last = char 129 elif last + 1 == char: 130 last = char 131 else: 132 result.append((first, last)) 133 first = last = char 134 if last is not None: 135 result.append((first, last)) 136 return ''.join(['%s%s%s' % ( 137 chr(first), 138 last > first + 1 and '-' or '', 139 last != first and chr(last) or '' 140 ) for first, last in result])
141 142 return _re.sub(r'([\000-\040\047])', # for better portability 143 lambda m: '\\%03o' % ord(m.group(1)), (sequentize(result) 144 .replace('\\', '\\\\') 145 .replace('[', '\\[') 146 .replace(']', '\\]') 147 ) 148 ) 149 150 def id_literal_(what): 151 """ Make id_literal like char class """ 152 match = _re.compile(what).match 153 result = ''.join([ 154 chr(c) for c in xrange(127) if not match(chr(c)) 155 ]) 156 return '[^%s]' % fix_charclass(result) 157 158 def not_id_literal_(keep): 159 """ Make negated id_literal like char class """ 160 match = _re.compile(id_literal_(keep)).match 161 result = ''.join([ 162 chr(c) for c in xrange(127) if not match(chr(c)) 163 ]) 164 return r'[%s]' % fix_charclass(result) 165 166 not_id_literal = not_id_literal_(r'[a-zA-Z0-9_$]') 167 preregex1 = r'[(,=:\[!&|?{};\r\n]' 168 preregex2 = r'%(not_id_literal)sreturn' % locals() 169 170 id_literal = id_literal_(r'[a-zA-Z0-9_$]') 171 id_literal_open = id_literal_(r'[a-zA-Z0-9_${\[(!+-]') 172 id_literal_close = id_literal_(r'[a-zA-Z0-9_$}\])"\047+-]') 173 174 space_sub = _re.compile(( 175 r'([^\047"/\000-\040]+)' 176 r'|(%(strings)s[^\047"/\000-\040]*)' 177 r'|(?:(?<=%(preregex1)s)%(space)s*(%(regex)s[^\047"/\000-\040]*))' 178 r'|(?:(?<=%(preregex2)s)%(space)s*(%(regex)s[^\047"/\000-\040]*))' 179 r'|(?<=%(id_literal_close)s)' 180 r'%(space)s*(?:(%(newline)s)%(space)s*)+' 181 r'(?=%(id_literal_open)s)' 182 r'|(?<=%(id_literal)s)(%(space)s)+(?=%(id_literal)s)' 183 r'|(?<=\+)(%(space)s)+(?=\+)' 184 r'|(?<=-)(%(space)s)+(?=-)' 185 r'|%(space)s+' 186 r'|(?:%(newline)s%(space)s*)+' 187 ) % locals()).sub 188 #print space_sub.__self__.pattern 189 190 def space_subber(match): 191 """ Substitution callback """ 192 # pylint: disable = C0321, R0911 193 groups = match.groups() 194 if groups[0]: return groups[0] 195 elif groups[1]: return groups[1] 196 elif groups[2]: return groups[2] 197 elif groups[3]: return groups[3] 198 elif groups[4]: return '\n' 199 elif groups[5] or groups[6] or groups[7]: return ' ' 200 else: return '' 201 202 def jsmin(script): # pylint: disable = W0621 203 r""" 204 Minify javascript based on `jsmin.c by Douglas Crockford`_\. 205 206 Instead of parsing the stream char by char, it uses a regular 207 expression approach which minifies the whole script with one big 208 substitution regex. 209 210 .. _jsmin.c by Douglas Crockford: 211 http://www.crockford.com/javascript/jsmin.c 212 213 :Parameters: 214 `script` : ``str`` 215 Script to minify 216 217 :Return: Minified script 218 :Rtype: ``str`` 219 """ 220 return space_sub(space_subber, '\n%s\n' % script).strip() 221 222 return jsmin 223 224 jsmin = _make_jsmin() 225 226
227 -def jsmin_for_posers(script):
228 r""" 229 Minify javascript based on `jsmin.c by Douglas Crockford`_\. 230 231 Instead of parsing the stream char by char, it uses a regular 232 expression approach which minifies the whole script with one big 233 substitution regex. 234 235 .. _jsmin.c by Douglas Crockford: 236 http://www.crockford.com/javascript/jsmin.c 237 238 :Warning: This function is the digest of a _make_jsmin() call. It just 239 utilizes the resulting regex. It's just for fun here and may 240 vanish any time. Use the `jsmin` function instead. 241 242 :Parameters: 243 `script` : ``str`` 244 Script to minify 245 246 :Return: Minified script 247 :Rtype: ``str`` 248 """ 249 def subber(match): 250 """ Substitution callback """ 251 groups = match.groups() 252 return ( 253 groups[0] or 254 groups[1] or 255 groups[2] or 256 groups[3] or 257 (groups[4] and '\n') or 258 (groups[5] and ' ') or 259 (groups[6] and ' ') or 260 (groups[7] and ' ') or 261 '' 262 )
263 264 return _re.sub( 265 r'([^\047"/\000-\040]+)|((?:(?:\047[^\047\\\r\n]*(?:\\(?:[^\r\n]|\r?' 266 r'\n|\r)[^\047\\\r\n]*)*\047)|(?:"[^"\\\r\n]*(?:\\(?:[^\r\n]|\r?\n|' 267 r'\r)[^"\\\r\n]*)*"))[^\047"/\000-\040]*)|(?:(?<=[(,=:\[!&|?{};\r\n]' 268 r')(?:[\000-\011\013\014\016-\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/' 269 r'))*((?:/(?![\r\n/*])[^/\\\[\r\n]*(?:(?:\\[^\r\n]|(?:\[[^\\\]\r\n]*' 270 r'(?:\\[^\r\n][^\\\]\r\n]*)*\]))[^/\\\[\r\n]*)*/)[^\047"/\000-\040]*' 271 r'))|(?:(?<=[\000-#%-,./:-@\[-^`{-~-]return)(?:[\000-\011\013\014\01' 272 r'6-\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/))*((?:/(?![\r\n/*])[^/' 273 r'\\\[\r\n]*(?:(?:\\[^\r\n]|(?:\[[^\\\]\r\n]*(?:\\[^\r\n][^\\\]\r\n]' 274 r'*)*\]))[^/\\\[\r\n]*)*/)[^\047"/\000-\040]*))|(?<=[^\000-!#%&(*,./' 275 r':-@\[\\^`{|~])(?:[\000-\011\013\014\016-\040]|(?:/\*[^*]*\*+(?:[^/' 276 r'*][^*]*\*+)*/))*(?:((?:(?://[^\r\n]*)?[\r\n]))(?:[\000-\011\013\01' 277 r'4\016-\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/))*)+(?=[^\000-\040"#' 278 r'%-\047)*,./:-@\\-^`|-~])|(?<=[^\000-#%-,./:-@\[-^`{-~-])((?:[\000-' 279 r'\011\013\014\016-\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/)))+(?=[^' 280 r'\000-#%-,./:-@\[-^`{-~-])|(?<=\+)((?:[\000-\011\013\014\016-\040]|' 281 r'(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/)))+(?=\+)|(?<=-)((?:[\000-\011\0' 282 r'13\014\016-\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/)))+(?=-)|(?:[\0' 283 r'00-\011\013\014\016-\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/))+|(?:' 284 r'(?:(?://[^\r\n]*)?[\r\n])(?:[\000-\011\013\014\016-\040]|(?:/\*[^*' 285 r']*\*+(?:[^/*][^*]*\*+)*/))*)+', subber, '\n%s\n' % script 286 ).strip() 287 288 289 if __name__ == '__main__': 290 import sys as _sys 291 _sys.stdout.write(jsmin(_sys.stdin.read())) 292