Mercurial > hg
view mercurial/hgweb/wsgicgi.py @ 26755:bb0b955d050d
streamclone: support for producing and consuming stream clone bundles
Up to this point, stream clones only existed as a dynamically generated
data format produced and consumed during streaming clones. In order to
support this efficient cloning format with the clone bundles feature, we
need a more formal, on disk representation of the streaming clone data.
This patch introduces a new "bundle" type for streaming clones. Unlike
existing bundles, it does not contain changegroup data. It does,
however, share the same concepts like the 4 byte header which identifies
the type of data that follows and the 2 byte abbreviation for
compression types (of which only "UN" is currently supported).
The new bundle format is essentially the existing stream clone version 1
data format with some headers at the beginning.
Content negotiation at stream clone request time checked for repository
format/requirements compatibility before initiating a stream clone. We
can't do active content negotiation when using clone bundles. So, we put
this set of requirements inside the payload so consumers have a built-in
mechanism for checking compatibility before reading and applying lots of
data. Of course, we will also advertise this requirements set in clone
bundles. But that's for another patch.
We currently don't have a mechanism to produce and consume this new
bundle format. This will be implemented in upcoming patches.
It's worth noting that if a legacy client attempts to `hg unbundle` a
stream clone bundle (with the "HGS1" header), it will abort with:
"unknown bundle version S1," which seems appropriate.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sat, 17 Oct 2015 11:14:52 -0700 |
parents | e8efcc8ff5c0 |
children | 37fcfe52c68c |
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# hgweb/wsgicgi.py - CGI->WSGI translator # # Copyright 2006 Eric Hopper <hopper@omnifarious.org> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. # # 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 from mercurial.hgweb import common def launch(application): util.setbinary(sys.stdin) util.setbinary(sys.stdout) environ = dict(os.environ.iteritems()) environ.setdefault('PATH_INFO', '') if environ.get('SERVER_SOFTWARE', '').startswith('Microsoft-IIS'): # IIS includes script_name in PATH_INFO scriptname = environ['SCRIPT_NAME'] if environ['PATH_INFO'].startswith(scriptname): environ['PATH_INFO'] = environ['PATH_INFO'][len(scriptname):] stdin = sys.stdin if environ.get('HTTP_EXPECT', '').lower() == '100-continue': stdin = common.continuereader(stdin, sys.stdout.write) environ['wsgi.input'] = 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 content = application(environ, start_response) try: for chunk in content: write(chunk) if not headers_sent: write('') # send headers now if body was empty finally: getattr(content, 'close', lambda : None)()