ppapi/generators/idl_outfile.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 """ Output file objects for generator. """
   7
   8 import difflib
   9 import os
  10 import time
  11 import sys
  12
  13 from idl_log import ErrOut, InfoOut, WarnOut
  14 from idl_option import GetOption, Option, ParseOptions
  15 from stat import *
  16
  17 Option('diff', 'Generate a DIFF when saving the file.')
  18
  19 def IsEquivalent(intext, outtext):
  20   if not intext: return False
  21   inlines = intext.split('\n')
  22   outlines = outtext.split('\n')
  23
  24   # If number of lines don't match, it's a mismatch
  25   if len(inlines) != len(outlines):  return False
  26
  27   for index in range(len(inlines)):
  28     inline = inlines[index]
  29     outline = outlines[index]
  30
  31     if inline == outline: continue
  32
  33     # If the line is not an exact match, check for comment deltas
  34     inwords = inline.split()
  35     outwords = outline.split()
  36
  37     if not inwords or not outwords: return False
  38     if inwords[0] != outwords[0] or inwords[0] not in ('/*', '*', '//'):
  39       return False
  40
  41     # Neither the year, nor the modified date need an exact match
  42     if inwords[1] == 'Copyright':
  43       if inwords[4:] == outwords[4:]: continue
  44     elif inwords[1] == 'From': # Un-wrapped modified date.
  45       if inwords[0:4] == outwords[0:4]: continue
  46     elif inwords[1] == 'modified': # Wrapped modified date.
  47       if inwords[0:2] == outwords[0:2]: continue
  48     return False
  49   return True
  50
  51
  52 #
  53 # IDLOutFile
  54 #
  55 # IDLOutFile provides a temporary output file.  By default, the object will
  56 # not write the output if the file already exists, and matches what will be
  57 # written.  This prevents the timestamp from changing to optimize cases where
  58 # the output files are used by a timestamp dependent build system
  59 #
  60 class IDLOutFile(object):
  61   def __init__(self, filename, always_write = False, create_dir = True):
  62     self.filename = filename
  63     self.always_write = always_write
  64     self.create_dir = create_dir
  65     self.outlist = []
  66     self.open = True
  67
  68   # Return the file name
  69   def Filename(self):
  70     return self.filename
  71
  72   # Append to the output if the file is still open
  73   def Write(self, string):
  74     if not self.open:
  75       raise RuntimeError('Could not write to closed file %s.' % self.filename)
  76     self.outlist.append(string)
  77
  78   # Close the file
  79   def Close(self):
  80     filename = os.path.realpath(self.filename)
  81     self.open = False
  82     outtext = ''.join(self.outlist)
  83     if not self.always_write:
  84       if os.path.isfile(filename):
  85         intext = open(filename, 'rb').read()
  86       else:
  87         intext = ''
  88
  89       if IsEquivalent(intext, outtext):
  90         if GetOption('verbose'):
  91           InfoOut.Log('Output %s unchanged.' % self.filename)
  92         return False
  93
  94     if GetOption('diff'):
  95       for line in difflib.unified_diff(intext.split('\n'), outtext.split('\n'),
  96                                        'OLD ' + self.filename,
  97                                        'NEW ' + self.filename,
  98                                        n=1, lineterm=''):
  99         ErrOut.Log(line)
 100
 101     try:
 102       # If the directory does not exit, try to create it, if we fail, we
 103       # still get the exception when the file is openned.
 104       basepath, leafname = os.path.split(filename)
 105       if basepath and not os.path.isdir(basepath) and self.create_dir:
 106         InfoOut.Log('Creating directory: %s\n' % basepath)
 107         os.makedirs(basepath)
 108
 109       if not GetOption('test'):
 110         outfile = open(filename, 'wb')
 111         outfile.write(outtext)
 112         InfoOut.Log('Output %s written.' % self.filename)
 113       return True
 114
 115     except IOError as (errno, strerror):
 116       ErrOut.Log("I/O error(%d): %s" % (errno, strerror))
 117     except:
 118       ErrOut.Log("Unexpected error: %s" % sys.exc_info()[0])
 119       raise
 120
 121     return False
 122
 123
 124 def TestFile(name, stringlist, force, update):
 125   errors = 0
 126
 127   # Get the old timestamp
 128   if os.path.exists(name):
 129     old_time = os.stat(filename)[ST_MTIME]
 130   else:
 131     old_time = 'NONE'
 132
 133   # Create the file and write to it
 134   out = IDLOutFile(filename, force)
 135   for item in stringlist:
 136     out.Write(item)
 137
 138   # We wait for flush to force the timestamp to change
 139   time.sleep(2)
 140
 141   wrote = out.Close()
 142   cur_time = os.stat(filename)[ST_MTIME]
 143   if update:
 144     if not wrote:
 145       ErrOut.Log('Failed to write output %s.' % filename)
 146       return 1
 147     if cur_time == old_time:
 148       ErrOut.Log('Failed to update timestamp for %s.' % filename)
 149       return 1
 150   else:
 151     if wrote:
 152       ErrOut.Log('Should not have writen output %s.' % filename)
 153       return 1
 154     if cur_time != old_time:
 155       ErrOut.Log('Should not have modified timestamp for %s.' % filename)
 156       return 1
 157   return 0
 158
 159
 160 def main():
 161   errors = 0
 162   stringlist = ['Test', 'Testing\n', 'Test']
 163   filename = 'outtest.txt'
 164
 165   # Test forcibly writing a file
 166   errors += TestFile(filename, stringlist, force=True, update=True)
 167
 168   # Test conditionally writing the file skipping
 169   errors += TestFile(filename, stringlist, force=False, update=False)
 170
 171   # Test conditionally writing the file updating
 172   errors += TestFile(filename, stringlist + ['X'], force=False, update=True)
 173
 174   # Clean up file
 175   os.remove(filename)
 176   if not errors: InfoOut.Log('All tests pass.')
 177   return errors
 178
 179
 180 if __name__ == '__main__':
 181   sys.exit(main())