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# -*- Mode: Python -*-
#
# Author: Sam Rushing <rushing@nightmare.com>
# Copyright 1997 by Sam Rushing
# All Rights Reserved.
#
# standard python modules
import mimetypes
import re
import stat
import string
# medusa modules
import http_date
import http_server
import status_handler
import producers
unquote = http_server.unquote
# This is the 'default' handler. it implements the base set of
# features expected of a simple file-delivering HTTP server. file
# services are provided through a 'filesystem' object, the very same
# one used by the FTP server.
#
# You can replace or modify this handler if you want a non-standard
# HTTP server. You can also derive your own handler classes from
# it.
#
# support for handling POST requests is available in the derived
# class <default_with_post_handler>, defined below.
#
from counter import counter
class default_handler:
valid_commands = ['GET', 'HEAD']
IDENT = 'Default HTTP Request Handler'
# Pathnames that are tried when a URI resolves to a directory name
directory_defaults = [
'index.html',
'default.html'
]
default_file_producer = producers.file_producer
def __init__ (self, filesystem):
self.filesystem = filesystem
# count total hits
self.hit_counter = counter()
# count file deliveries
self.file_counter = counter()
# count cache hits
self.cache_counter = counter()
hit_counter = 0
def __repr__ (self):
return '<%s (%s hits) at %x>' % (
self.IDENT,
self.hit_counter,
id (self)
)
# always match, since this is a default
def match (self, request):
return 1
# handle a file request, with caching.
def handle_request (self, request):
if request.command not in self.valid_commands:
request.error (400) # bad request
return
self.hit_counter.increment()
path, params, query, fragment = request.split_uri()
if '%' in path:
path = unquote (path)
# strip off all leading slashes
while path and path[0] == '/':
path = path[1:]
if self.filesystem.isdir (path):
if path and path[-1] != '/':
request['Location'] = 'http://%s/%s/' % (
request.channel.server.server_name,
path
)
request.error (301)
return
# we could also generate a directory listing here,
# may want to move this into another method for that
# purpose
found = 0
if path and path[-1] != '/':
path = path + '/'
for default in self.directory_defaults:
p = path + default
if self.filesystem.isfile (p):
path = p
found = 1
break
if not found:
request.error (404) # Not Found
return
elif not self.filesystem.isfile (path):
request.error (404) # Not Found
return
file_length = self.filesystem.stat (path)[stat.ST_SIZE]
ims = get_header_match (IF_MODIFIED_SINCE, request.header)
length_match = 1
if ims:
length = ims.group (4)
if length:
try:
length = string.atoi (length)
if length != file_length:
length_match = 0
except:
pass
ims_date = 0
if ims:
ims_date = http_date.parse_http_date (ims.group (1))
try:
mtime = self.filesystem.stat (path)[stat.ST_MTIME]
except:
request.error (404)
return
if length_match and ims_date:
if mtime <= ims_date:
request.reply_code = 304
request.done()
self.cache_counter.increment()
return
try:
file = self.filesystem.open (path, 'rb')
except IOError:
request.error (404)
return
request['Last-Modified'] = http_date.build_http_date (mtime)
request['Content-Length'] = file_length
self.set_content_type (path, request)
if request.command == 'GET':
request.push (self.default_file_producer (file))
self.file_counter.increment()
request.done()
def set_content_type (self, path, request):
ext = string.lower (get_extension (path))
typ, encoding = mimetypes.guess_type(path)
if typ is not None:
request['Content-Type'] = typ
else:
# TODO: test a chunk off the front of the file for 8-bit
# characters, and use application/octet-stream instead.
request['Content-Type'] = 'text/plain'
def status (self):
return producers.simple_producer (
'<li>%s' % status_handler.html_repr (self)
+ '<ul>'
+ ' <li><b>Total Hits:</b> %s' % self.hit_counter
+ ' <li><b>Files Delivered:</b> %s' % self.file_counter
+ ' <li><b>Cache Hits:</b> %s' % self.cache_counter
+ '</ul>'
)
# HTTP/1.0 doesn't say anything about the "; length=nnnn" addition
# to this header. I suppose its purpose is to avoid the overhead
# of parsing dates...
IF_MODIFIED_SINCE = re.compile (
'If-Modified-Since: ([^;]+)((; length=([0-9]+)$)|$)',
re.IGNORECASE
)
USER_AGENT = re.compile ('User-Agent: (.*)', re.IGNORECASE)
CONTENT_TYPE = re.compile (
r'Content-Type: ([^;]+)((; boundary=([A-Za-z0-9\'\(\)+_,./:=?-]+)$)|$)',
re.IGNORECASE
)
get_header = http_server.get_header
get_header_match = http_server.get_header_match
def get_extension (path):
dirsep = string.rfind (path, '/')
dotsep = string.rfind (path, '.')
if dotsep > dirsep:
return path[dotsep+1:]
else:
return ''
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