view mercurial/hgweb/wsgicgi.py @ 6858:8f256bf98219

Add support for multiple possible bisect results (issue1228, issue1182)

The real reason for both issue is that bisect can not handle cases where there
are multiple possibilities for the result.

Example (from issue1228):
rev 0 -> good
rev 1 -> skipped
rev 2 -> skipped
rev 3 -> skipped
rev 4 -> bad

Note that this patch does not only fix the reported Assertion Error but also
the problem of a non converging bisect:

hg init
for i in `seq 3`; do echo $i > $i; hg add $i; hg ci -m$i; done
hg bisect -b 2
hg bisect -g 0
hg bisect -s

From this state on, you can:
 a) mark as bad forever (non converging!)
 b) mark as good to get an inconsistent state
 c) skip for the Assertion Error

Minor description and code edits by pmezard.

# hgweb/wsgicgi.py - CGI->WSGI translator
#
# Copyright 2006 Eric Hopper <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.
#
# This was originally copied from the public domain code at
# http://www.python.org/dev/peps/pep-0333/#the-server-gateway-side

import os, sys
from mercurial import util

def launch(application):
    util.set_binary(sys.stdin)
    util.set_binary(sys.stdout)

    environ = dict(os.environ.items())
    environ.setdefault('PATH_INFO', '')
    environ['wsgi.input'] = sys.stdin
    environ['wsgi.errors'] = sys.stderr
    environ['wsgi.version'] = (1, 0)
    environ['wsgi.multithread'] = False
    environ['wsgi.multiprocess'] = True
    environ['wsgi.run_once'] = True

    if environ.get('HTTPS','off').lower() in ('on','1','yes'):
        environ['wsgi.url_scheme'] = 'https'
    else:
        environ['wsgi.url_scheme'] = 'http'

    headers_set = []
    headers_sent = []
    out = sys.stdout

    def write(data):
        if not headers_set:
            raise AssertionError("write() before start_response()")

        elif not headers_sent:
            # Before the first output, send the stored headers
            status, response_headers = headers_sent[:] = headers_set
            out.write('Status: %s\r\n' % status)
            for header in response_headers:
                out.write('%s: %s\r\n' % header)
            out.write('\r\n')

        out.write(data)
        out.flush()

    def start_response(status, response_headers, exc_info=None):
        if exc_info:
            try:
                if headers_sent:
                    # Re-raise original exception if headers sent
                    raise exc_info[0], exc_info[1], exc_info[2]
            finally:
                exc_info = None     # avoid dangling circular ref
        elif headers_set:
            raise AssertionError("Headers already set!")

        headers_set[:] = [status, response_headers]
        return write

    application(environ, start_response)