Source Code for Module web2py.gluon.streamer

  1  #!/usr/bin/env python 
  2  # -*- coding: utf-8 -*- 
  3   
  4  """ 
  5  This file is part of the web2py Web Framework 
  6  Copyrighted by Massimo Di Pierro <mdipierro@cs.depaul.edu> 
  7  License: LGPLv3 (http://www.gnu.org/licenses/lgpl.html) 
  8  """ 
  9   
 10  import os 
 11  import stat 
 12  import time 
 13  import re 
 14  import errno 
 15  import rewrite 
 16  from http import HTTP 
 17  from contenttype import contenttype 
 18   
 19   
 20  regex_start_range = re.compile('\d+(?=\-)') 
 21  regex_stop_range = re.compile('(?<=\-)\d+') 
 22   
 23  DEFAULT_CHUNK_SIZE = 64*1024 
 24   
 25 -def streamer(stream, chunk_size = DEFAULT_CHUNK_SIZE, bytes = None): 
 26      offset = 0 
 27      while bytes == None or offset < bytes: 
 28          if bytes != None and bytes - offset < chunk_size: 
 29              chunk_size = bytes - offset 
 30          data = stream.read(chunk_size) 
 31          length = len(data) 
 32          if not length: 
 33              break 
 34          else: 
 35              yield data 
 36          if length < chunk_size: 
 37              break 
 38          offset += length 
 39      stream.close() 
 40   
 41 -def stream_file_or_304_or_206( 
 42      static_file, 
 43      chunk_size = DEFAULT_CHUNK_SIZE, 
 44      request = None, 
 45      headers = {}, 
 46      error_message = None, 
 47      ): 
 48      if error_message is None: 
 49          error_message = rewrite.thread.routes.error_message % 'invalid request' 
 50      try: 
 51          fp = open(static_file) 
 52      except IOError, e: 
 53          if e[0] == errno.EISDIR: 
 54              raise HTTP(403, error_message, web2py_error='file is a directory') 
 55          elif e[0] == errno.EACCES: 
 56              raise HTTP(403, error_message, web2py_error='inaccessible file') 
 57          else: 
 58              raise HTTP(404, error_message, web2py_error='invalid file') 
 59      else: 
 60          fp.close() 
 61      stat_file = os.stat(static_file) 
 62      fsize = stat_file[stat.ST_SIZE] 
 63      mtime = time.strftime('%a, %d %b %Y %H:%M:%S GMT', 
 64                            time.gmtime(stat_file[stat.ST_MTIME])) 
 65      headers['Content-Type'] = contenttype(static_file) 
 66      headers['Last-Modified'] = mtime 
 67      headers['Pragma'] = 'cache' 
 68      headers['Cache-Control'] = 'private' 
 69   
 70      if request and request.env.http_if_modified_since == mtime: 
 71          raise HTTP(304, **{'Content-Type': headers['Content-Type']}) 
 72   
 73      elif request and request.env.http_range: 
 74          start_items = regex_start_range.findall(request.env.http_range) 
 75          if not start_items: 
 76              start_items = [0] 
 77          stop_items = regex_stop_range.findall(request.env.http_range) 
 78          if not stop_items or int(stop_items[0]) > fsize - 1: 
 79              stop_items = [fsize - 1] 
 80          part = (int(start_items[0]), int(stop_items[0]), fsize) 
 81          bytes = part[1] - part[0] + 1 
 82          try: 
 83              stream = open(static_file, 'rb') 
 84          except IOError, e: 
 85              if e[0] in (errno.EISDIR, errno.EACCES): 
 86                  raise HTTP(403) 
 87              else: 
 88                  raise HTTP(404) 
 89          stream.seek(part[0]) 
 90          headers['Content-Range'] = 'bytes %i-%i/%i' % part 
 91          headers['Content-Length'] = '%i' % bytes 
 92          status = 206 
 93      else: 
 94          try: 
 95              stream = open(static_file, 'rb') 
 96          except IOError, e: 
 97              if e[0] in (errno.EISDIR, errno.EACCES): 
 98                  raise HTTP(403) 
 99              else: 
100                  raise HTTP(404) 
101          headers['Content-Length'] = fsize 
102          bytes = None 
103          status = 200 
104      if request and request.env.web2py_use_wsgi_file_wrapper: 
105          wrapped = request.env.wsgi_file_wrapper(stream, chunk_size) 
106      else: 
107          wrapped = streamer(stream, chunk_size=chunk_size, bytes=bytes) 
108      raise HTTP(status, wrapped, **headers) 
109