Mercurial > hg
view mercurial/hgweb/request.py @ 26375:3686fa2b8eee
windows: insert file positioning call between reads and writes
fopen() and fdopen() have a unique-to-Windows requirement that
transitions between read and write operations in files opened
in modes r+, w+, and a+ perform a file positioning call
(fsetpos, fseek, or rewind) in between. While the MSDN docs don't
say what will happen if this is not done, observations reveal
that Python raises an IOError with errno 0. Furthermore, I
/think/ this behavior isn't deterministic. But I can reproduce
it reliably with subsequent patches applied that open revlogs
in a+ mode and perform both reads and writes.
This patch introduces a proxy class for file handles opened
in r+, w+, and a+ mode on Windows. The class intercepts calls
and audits whether a file positioning function has been called
between read and write operations. If not, a dummy, no-op seek
to the current file position is performed. This appears to be
sufficient to "trick" Windows into allowing transitions between
read and writes without raising errors.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 27 Sep 2015 18:46:53 -0700 |
parents | 461e7b700fdf |
children | 7c1b4840c2cd |
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# hgweb/request.py - An http request from either CGI or the standalone server. # # Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net> # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. import socket, cgi, errno from mercurial import util from common import ErrorResponse, statusmessage, HTTP_NOT_MODIFIED 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 normalize(form): # first expand the shortcuts 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] # And strip the values for k, v in form.iteritems(): form[k] = [i.strip() for i in v] return form class wsgirequest(object): """Higher-level API for a WSGI request. WSGI applications are invoked with 2 arguments. They are used to instantiate instances of this class, which provides higher-level APIs for obtaining request parameters, writing HTTP output, etc. """ 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 = normalize(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') or 0) for s in util.filechunkiter(self.inp, limit=length): pass def respond(self, status, type, filename=None, body=None): if self._start_response is not None: self.headers.append(('Content-Type', type)) if filename: filename = (filename.split('/')[-1] .replace('\\', '\\\\').replace('"', '\\"')) self.headers.append(('Content-Disposition', 'inline; filename="%s"' % filename)) if body is not None: self.headers.append(('Content-Length', str(len(body)))) 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.headers.extend(status.headers) if status.code == HTTP_NOT_MODIFIED: # RFC 2616 Section 10.3.5: 304 Not Modified has cases where # it MUST NOT include any headers other than these and no # body self.headers = [(k, v) for (k, v) in self.headers if k in ('Date', 'ETag', 'Expires', 'Cache-Control', 'Vary')] status = statusmessage(status.code, str(status)) 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 = [] if body is not None: self.write(body) self.server_write = None def write(self, thing): if thing: try: self.server_write(thing) except socket.error as 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 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