mercurial/hgweb/request.py

hgweb: send proper error messages to the client

Fixes a bug in protocol which caused an exception during exception handling in
some cases on Windows. Also makes sure the server error message is correctly
propagated to the client, instead of being thrown away.

# hgweb/request.py - An http request from either CGI or the standalone server.
#
# Copyright 21 May 2005 - (c) 2005 Jake Edge <[e-mail]>
# Copyright 2005, 2006 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.

import socket, cgi, errno
from mercurial import util
from common import ErrorResponse, statusmessage

shortcuts = {
    'cl': [('cmd', ['changelog']), ('rev', None)],
    'sl': [('cmd', ['shortlog']), ('rev', None)],
    'cs': [('cmd', ['changeset']), ('node', None)],
    'f': [('cmd', ['file']), ('filenode', None)],
    'fl': [('cmd', ['filelog']), ('filenode', None)],
    'fd': [('cmd', ['filediff']), ('node', None)],
    'fa': [('cmd', ['annotate']), ('filenode', None)],
    'mf': [('cmd', ['manifest']), ('manifest', None)],
    'ca': [('cmd', ['archive']), ('node', None)],
    'tags': [('cmd', ['tags'])],
    'tip': [('cmd', ['changeset']), ('node', ['tip'])],
    'static': [('cmd', ['static']), ('file', None)]
}

def expand(form):
    for k in shortcuts.iterkeys():
        if k in form:
            for name, value in shortcuts[k]:
                if value is None:
                    value = form[k]
                form[name] = value
            del form[k]
    return form

class wsgirequest(object):
    def __init__(self, wsgienv, start_response):
        version = wsgienv['wsgi.version']
        if (version < (1, 0)) or (version >= (2, 0)):
            raise RuntimeError("Unknown and unsupported WSGI version %d.%d"
                               % version)
        self.inp = wsgienv['wsgi.input']
        self.err = wsgienv['wsgi.errors']
        self.threaded = wsgienv['wsgi.multithread']
        self.multiprocess = wsgienv['wsgi.multiprocess']
        self.run_once = wsgienv['wsgi.run_once']
        self.env = wsgienv
        self.form = expand(cgi.parse(self.inp, self.env, keep_blank_values=1))
        self._start_response = start_response
        self.server_write = None
        self.headers = []

    def __iter__(self):
        return iter([])

    def read(self, count=-1):
        return self.inp.read(count)

    def drain(self):
        '''need to read all data from request, httplib is half-duplex'''
        length = int(self.env.get('CONTENT_LENGTH', 0))
        for s in util.filechunkiter(self.inp, limit=length):
            pass

    def respond(self, status, type=None, filename=None, length=0):
        if self._start_response is not None:

            self.httphdr(type, filename, length)
            if not self.headers:
                raise RuntimeError("request.write called before headers sent")

            for k, v in self.headers:
                if not isinstance(v, str):
                    raise TypeError('header value must be string: %r' % v)

            if isinstance(status, ErrorResponse):
                self.header(status.headers)
                status = statusmessage(status.code, status.message)
            elif status == 200:
                status = '200 Script output follows'
            elif isinstance(status, int):
                status = statusmessage(status)

            self.server_write = self._start_response(status, self.headers)
            self._start_response = None
            self.headers = []

    def write(self, thing):
        if hasattr(thing, "__iter__"):
            for part in thing:
                self.write(part)
        else:
            thing = str(thing)
            try:
                self.server_write(thing)
            except socket.error, inst:
                if inst[0] != errno.ECONNRESET:
                    raise

    def writelines(self, lines):
        for line in lines:
            self.write(line)

    def flush(self):
        return None

    def close(self):
        return None

    def header(self, headers=[('Content-Type','text/html')]):
        self.headers.extend(headers)

    def httphdr(self, type=None, filename=None, length=0, headers={}):
        headers = headers.items()
        if type is not None:
            headers.append(('Content-Type', type))
        if filename:
            filename = (filename.split('/')[-1]
                        .replace('\\', '\\\\').replace('"', '\\"'))
            headers.append(('Content-Disposition',
                            'inline; filename="%s"' % filename))
        if length:
            headers.append(('Content-Length', str(length)))
        self.header(headers)

def wsgiapplication(app_maker):
    '''For compatibility with old CGI scripts. A plain hgweb() or hgwebdir()
    can and should now be used as a WSGI application.'''
    application = app_maker()
    def run_wsgi(env, respond):
        return application(env, respond)
    return run_wsgi