migrations/extract-views.py

   1 #!/usr/bin/env python
   2
   3 import sys
   4 import re
   5
   6 class Schema:
   7
   8     def __init__ (self,input,output=None):
   9         self.input=input
  10         self.output=output
  11
  12     # left part is non-greedy
  13     comment=re.compile("(.*?)--.*")
  14     spaces=re.compile("^\s+(\S.*)")
  15     view=re.compile("(?i)\s*create\s+(or\s+replace)?\s+view.*")
  16
  17     def parse (self):
  18         if self.output:
  19             outfile = open(self.output, "a")
  20         else:
  21             outfile = sys.stdout
  22         contents = file(self.input).read()
  23         parts=contents.split(";")
  24         for part in parts:
  25             # normalize: remove comments, linebreaks, trailing spaces..
  26             normalized=''
  27             lines=part.split('\n');
  28             out_lines=[]
  29             for line in lines:
  30                 # remove comment
  31                 match=Schema.comment.match(line)
  32                 if match:
  33                     line=match.group(1)
  34                 out_lines.append(line)
  35             # get them together
  36             out_line = " ".join(out_lines)
  37             # remove trailing spaces
  38             match=Schema.spaces.match(out_line)
  39             if match:
  40                 out_line=match.group(1)
  41             match=Schema.view.match(out_line)
  42             if match:
  43                 outfile.write("{};\n".format(out_line))
  44         if outfile != sys.stdout:
  45             outfile.close()
  46
  47 if __name__ == '__main__':
  48     if len(sys.argv) not in [2,3]:
  49         print 'Usage:',sys.argv[0],'input [output]'
  50         sys.exit(1)
  51     input=sys.argv[1]
  52     try:
  53         output=sys.argv[2]
  54     except:
  55         output=None
  56     Schema(input,output).parse()
  57