Source Code for Module commons.progress

  1  # -*- mode: python; tab-width: 4; indent-tabs-mode: nil; py-indent-offset: 4; -*- 
  2  # vim:ft=python:et:sw=4:ts=4 
  3   
  4  """ 
  5  Long-running processes and facilities to let them report their progress. 
  6  """ 
  7   
  8  from commons.log import * 
  9  from commons.seqs import * 
 10  import urllib2, sys 
 11   
 12 -def urlopen_progress( url, output_stream = None, fields = 'OoRrtcl', chunk_size = 4096 ): 
 13      """ 
 14      Progress reporter for urlopen(). This is a generator which, upon 
 15      receipt of each chunk of data, yields a tuple of values. This 
 16      tuple reports data about the progress of the download; the exact 
 17      values yielded can be configured. 
 18   
 19      Based on 
 20      U{http://mail.python.org/pipermail/python-list/2006-January/320635.html}. 
 21   
 22      @param url: The URL to fetch. 
 23      @type url: str 
 24   
 25      @param output_stream: The file-like stream object to write to. 
 26      @type output_stream: stream 
 27   
 28      @param fields: A set of characters indicating what data to 
 29      report. The following characters have meaning: 
 30          - O: offset where the first byte of the latest chunk is to be 
 31            written 
 32          - o: offset percentage 
 33          - R: received number of bytes (offset + length of latest 
 34            chunk) 
 35          - r: received percentage 
 36          - t: total number of bytes 
 37          - c: the latest chunk 
 38          - l: the length of the latest chunk 
 39      @type fields: str 
 40   
 41      @param chunk_size: The requested chunk size. 
 42      @type chunk_size: int 
 43      """ 
 44      chunk_size = 4096 
 45      result = urllib2.urlopen( url ) 
 46      headers = result.info() 
 47      total = int( headers[ 'Content-Length' ] ) 
 48      for offset, chunk in chunkify( result, chunk_size ): 
 49          if output_stream is not None: 
 50              output_stream.write( chunk ) 
 51          values = [] 
 52          offset_ratio = float(offset)/float(total) 
 53          received = offset + len( chunk ) 
 54          received_ratio = float(received)/float(total) 
 55          if 'O' in fields: 
 56              values.append( offset ) 
 57          if 'o' in fields: 
 58              values.append( offset_ratio ) 
 59          if 'R' in fields: 
 60              values.append( received ) 
 61          if 'r' in fields: 
 62              values.append( received_ratio ) 
 63          if 't' in fields: 
 64              values.append( total ) 
 65          if 'c' in fields: 
 66              values.append( chunk ) 
 67          if 'l' in fields: 
 68              values.append( len( chunk ) ) 
 69          # TODO allow caller to customize the yields 
 70          yield tuple( values ) 
 71      debug( 'urlopen_progress', 'R', received, 'r', received_ratio, 't', total ) 
 72      result.close() 
 73   
 74  # TODO enable printing to a different stream 
 75  # TODO enable index/total/block interface 
 76 -def render_progress( caption, ratio, width ): #  index = None, total = None, block = None ): 
 77      """ 
 78      Draws a progress bar on the console. First prints a carriage 
 79      return, so this function can be called repeatedly to create an 
 80      "animated" progress bar. 
 81   
 82      @param caption: The label printed to the left of the bar. 
 83      @type caption: str 
 84   
 85      @param ratio: The percentage progress. 
 86      @type ratio: float 
 87   
 88      @param width: The width of the progress bar, in characters. 
 89      @type width: int 
 90      """ 
 91      sys.stdout.write( interp( '\r$caption: [' ) ) 
 92      thresh = ratio * width 
 93      for cursor in range( width ): 
 94          if cursor < thresh: 
 95              sys.stdout.write( '=' ) 
 96          else: 
 97              sys.stdout.write( ' ' ) 
 98      sys.stdout.write( interp( '] $ratio' ) ) 
 99      if ratio == 1.0: 
100          sys.stdout.write( '\n' ) 
101      #if index % block == 0: 
102      #    print interp( '\r$caption: |' ) 
103      #    for counter in range( total / block ): 
104      #        if counter < index / block: 
105      #            print '.' 
106      #        else: 
107      #            print ' ' 
108      #    print "| " 
109