# -*- coding: iso-8859-1 -*- # # Copyright (C) 2005 Edgewall Software # Copyright (C) 2005 Christopher Lenz # All rights reserved. # # This software is licensed as described in the file COPYING, which # you should have received as part of this distribution. The terms # are also available at http://trac.edgewall.com/license.html. # # This software consists of voluntary contributions made by many # individuals. For the exact contribution history, see the revision # history and logs, available at http://projects.edgewall.com/trac/. # # Author: Christopher Lenz from Cookie import SimpleCookie as Cookie import mimetypes import os import urlparse from trac.core import Interface from trac.util import http_date, TracError class RequestDone(Exception): """Marker exception that indicates whether request processing has completed and a response was sent. """ class Request(object): """This class is used to abstract the interface between different frontends. Trac modules must use this interface. It is not allowed to have frontend (cgi, tracd, mod_python) specific code in the modules. """ method = None scheme = None server_name = None server_port = None remote_addr = None remote_user = None args = None hdf = None authname = None perm = None session = None _headers = None # additional headers to send def __init__(self): self.incookie = Cookie() self.outcookie = Cookie() self._headers = [] def get_header(self, name): """Return the value of the specified HTTP header, or `None` if there's no such header in the request. """ raise NotImplementedError def send_response(self, code): """Set the status code of the response.""" raise NotImplementedError def send_header(self, name, value): """Send the response header with the specified name and value.""" raise NotImplementedError def end_headers(self): """Must be called after all headers have been sent and before the actual content is written. """ raise NotImplementedError def _send_cookie_headers(self): # Cookie values can not contain " ,;" characters, so escape them for name in self.outcookie.keys(): path = self.outcookie[name].get('path') if path: path = path.replace(' ', '%20') \ .replace(';', '%3B') \ .replace(',', '%3C') self.outcookie[name]['path'] = path cookies = self.outcookie.output(header='') for cookie in cookies.splitlines(): self.send_header('Set-Cookie', cookie.strip()) def check_modified(self, timesecs, extra=''): """Check the request "If-None-Match" header against an entity tag generated from the specified last modified time in seconds (`timesecs`), optionally appending an `extra` string to indicate variants of the requested resource. If the generated tag matches the "If-None-Match" header of the request, this method sends a "304 Not Modified" response to the client. Otherwise, it adds the entity tag as as "ETag" header to the response so that consequetive requests can be cached. """ etag = 'W"%s/%d/%s"' % (self.authname, timesecs, extra) inm = self.get_header('If-None-Match') if (not inm or inm != etag): self._headers.append(('ETag', etag)) else: self.send_response(304) self.end_headers() raise RequestDone() def redirect(self, url): """Send a redirect to the client, forwarding to the specified URL. The `url` may be relative or absolute, relative URLs will be translated appropriately. """ if self.session: self.session.save() # has to be done before the redirect is sent self.send_response(302) if not url.startswith('http://') and not url.startswith('https://'): # Make sure the URL is absolute url = absolute_url(self, url) self.send_header('Location', url) self.send_header('Content-Type', 'text/plain') self.send_header('Pragma', 'no-cache') self.send_header('Cache-control', 'no-cache') self.send_header('Expires', 'Fri, 01 Jan 1999 00:00:00 GMT') self._send_cookie_headers() self.end_headers() if self.method != 'HEAD': self.write('Redirecting...') raise RequestDone def display(self, template, content_type='text/html', response=200): """Render the response using the ClearSilver template given by the `template` parameter, which can be either the name of the template file, or an already parsed `neo_cs.CS` object. """ assert self.hdf, 'HDF dataset not available' if self.args.has_key('hdfdump'): # FIXME: the administrator should probably be able to disable HDF # dumps content_type = 'text/plain' data = str(self.hdf) else: data = self.hdf.render(template) self.send_response(response) self.send_header('Cache-control', 'must-revalidate') self.send_header('Expires', 'Fri, 01 Jan 1999 00:00:00 GMT') self.send_header('Content-Type', content_type + ';charset=utf-8') self.send_header('Content-Length', len(data)) for name, value in self._headers: self.send_header(name, value) self._send_cookie_headers() self.end_headers() if self.method != 'HEAD': self.write(data) raise RequestDone def send_file(self, path, mimetype=None): """Send a local file to the browser. This method includes the "Last-Modified", "Content-Type" and "Content-Length" headers in the response, corresponding to the file attributes. It also checks the last modification time of the local file against the "If-Modified-Since" provided by the user agent, and sends a "304 Not Modified" response if it matches. """ if not os.path.isfile(path): raise TracError, "File %s not found" % path stat = os.stat(path) last_modified = http_date(stat.st_mtime) if last_modified == self.get_header('If-Modified-Since'): self.send_response(304) self.end_headers() raise RequestDone self.send_response(200) if not mimetype: mimetype = mimetypes.guess_type(path)[0] self.send_header('Content-Type', mimetype) self.send_header('Content-Length', stat.st_size) self.send_header('Last-Modified', last_modified) for name, value in self._headers: self.send_header(name, value) self._send_cookie_headers() self.end_headers() if self.method != 'HEAD': try: fd = open(path, 'rb') while True: data = fd.read(4096) if not data: break self.write(data) finally: fd.close() raise RequestDone def read(self, size): """Read the specified number of bytes from the request body.""" raise NotImplementedError def write(self, data): """Write the given data to the response body.""" raise NotImplementedError class IAuthenticator(Interface): """Extension point interface for components that can provide the name of the remote user.""" def authenticate(req): """Return the name of the remote user, or `None` if the identity of the user is unknown.""" class IRequestHandler(Interface): """Extension point interface for request handlers.""" def match_request(req): """Return whether the handler wants to process the given request.""" def process_request(req): """Process the request. Should return a (template_name, content_type) tuple, where `template` is the ClearSilver template to use (either a `neo_cs.CS` object, or the file name of the template), and `content_type` is the MIME type of the content. If `content_type` is `None`, "text/html" is assumed. Note that if template processing should not occur, this method can simply send the response itself and not return anything. """ def absolute_url(req, path=None): """Reconstruct the absolute URL of the given request. If the `path` parameter is specified, the path is appended to the URL. Otherwise, only a URL with the components scheme, host and port is returned. """ if hasattr(req, 'base_url'): scheme, host, _, _, _, _ = urlparse.urlparse(req.base_url) else: scheme = req.scheme host = req.get_header('Host') if not host: # Missing host header, so reconstruct the host from the # server name and port default_port = {'http': 80, 'https': 443} if req.server_port and req.server_port != default_port[scheme]: host = '%s:%d' % (req.server_name, req.server_port) else: host = req.server_name if not path: path = req.cgi_location return urlparse.urlunparse((scheme, host, path, None, None, None))