transaction: allow registering a temporary transaction file
During the transaction, files may be created to store or expose data
involved in the transaction (eg: changelog index data are written in
a 'changelog.i.a' for hooks). But we do not have an official way to
record such file creation and make sure they are cleaned up. The lack
of clean-up is currently okay because there is a single file involved
and a single producer/consumer.
However, as we want to expose more data (bookmarks, phases, obsmarker)
we need something more solid. The 'backupentries' mechanism could
handle that. Temporary files can be encoded as a backup of nothing
'('', <temporarypath>)'. We "need" to attach it to the same mechanism
as we use to be able to use temporary transaction files outside of
.'store/' and 'backupentries' is expected to gain such feature.
This changeset makes it clear that we should rename 'backupentries' to
something more generic.
Tests if hgweb can run without touching sys.stdin, as is required
by the WSGI standard and strictly implemented by mod_wsgi.
$ hg init repo
$ cd repo
$ echo foo > bar
$ hg add bar
$ hg commit -m "test"
$ cat > request.py <<EOF
> from mercurial import dispatch
> from mercurial.hgweb.hgweb_mod import hgweb
> from mercurial.ui import ui
> from mercurial import hg
> from StringIO import StringIO
> import os, sys
>
> class FileLike(object):
> def __init__(self, real):
> self.real = real
> def fileno(self):
> print >> sys.__stdout__, 'FILENO'
> return self.real.fileno()
> def read(self):
> print >> sys.__stdout__, 'READ'
> return self.real.read()
> def readline(self):
> print >> sys.__stdout__, 'READLINE'
> return self.real.readline()
>
> sys.stdin = FileLike(sys.stdin)
> errors = StringIO()
> input = StringIO()
> output = StringIO()
>
> def startrsp(status, headers):
> print '---- STATUS'
> print status
> print '---- HEADERS'
> print [i for i in headers if i[0] != 'ETag']
> print '---- DATA'
> return output.write
>
> env = {
> 'wsgi.version': (1, 0),
> 'wsgi.url_scheme': 'http',
> 'wsgi.errors': errors,
> 'wsgi.input': input,
> 'wsgi.multithread': False,
> 'wsgi.multiprocess': False,
> 'wsgi.run_once': False,
> 'REQUEST_METHOD': 'GET',
> 'SCRIPT_NAME': '',
> 'PATH_INFO': '',
> 'QUERY_STRING': '',
> 'SERVER_NAME': '127.0.0.1',
> 'SERVER_PORT': os.environ['HGPORT'],
> 'SERVER_PROTOCOL': 'HTTP/1.0'
> }
>
> i = hgweb('.')
> i(env, startrsp)
> print '---- ERRORS'
> print errors.getvalue()
> print '---- OS.ENVIRON wsgi variables'
> print sorted([x for x in os.environ if x.startswith('wsgi')])
> print '---- request.ENVIRON wsgi variables'
> print sorted([x for x in i.repo.ui.environ if x.startswith('wsgi')])
> EOF
$ python request.py
---- STATUS
200 Script output follows
---- HEADERS
[('Content-Type', 'text/html; charset=ascii')]
---- DATA
---- ERRORS
---- OS.ENVIRON wsgi variables
[]
---- request.ENVIRON wsgi variables
['wsgi.errors', 'wsgi.input', 'wsgi.multiprocess', 'wsgi.multithread', 'wsgi.run_once', 'wsgi.url_scheme', 'wsgi.version']
$ cd ..