revlog: flag processor
Add the ability for revlog objects to process revision flags and apply
registered transforms on read/write operations.
This patch introduces:
- the 'revlog._processflags()' method that looks at revision flags and applies
flag processors registered on them. Due to the need to handle non-commutative
operations, flag transforms are applied in stable order but the order in which
the transforms are applied is reversed between read and write operations.
- the 'addflagprocessor()' method allowing to register processors on flags.
Flag processors are defined as a 3-tuple of (read, write, raw) functions to be
applied depending on the operation being performed.
- an update on 'revlog.addrevision()' behavior. The current flagprocessor design
relies on extensions to wrap around 'addrevision()' to set flags on revision
data, and on the flagprocessor to perform the actual transformation of its
contents. In the lfs case, this means we need to process flags before we meet
the 2GB size check, leading to performing some operations before it happens:
- if flags are set on the revision data, we assume some extensions might be
modifying the contents using the flag processor next, and we compute the
node for the original revision data (still allowing extension to override
the node by wrapping around 'addrevision()').
- we then invoke the flag processor to apply registered transforms (in lfs's
case, drastically reducing the size of large blobs).
- finally, we proceed with the 2GB size check.
Note: In the case a cachedelta is passed to 'addrevision()' and we detect the
flag processor modified the revision data, we chose to trust the flag processor
and drop the cachedelta.
# hgweb/server.py - The standalone hg web server.
#
# Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net>
# Copyright 2005-2007 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.
from __future__ import absolute_import
import errno
import os
import socket
import sys
import traceback
from ..i18n import _
from .. import (
error,
pycompat,
util,
)
httpservermod = util.httpserver
socketserver = util.socketserver
urlerr = util.urlerr
urlreq = util.urlreq
from . import (
common,
)
def _splitURI(uri):
"""Return path and query that has been split from uri
Just like CGI environment, the path is unquoted, the query is
not.
"""
if '?' in uri:
path, query = uri.split('?', 1)
else:
path, query = uri, ''
return urlreq.unquote(path), query
class _error_logger(object):
def __init__(self, handler):
self.handler = handler
def flush(self):
pass
def write(self, str):
self.writelines(str.split('\n'))
def writelines(self, seq):
for msg in seq:
self.handler.log_error("HG error: %s", msg)
class _httprequesthandler(httpservermod.basehttprequesthandler):
url_scheme = 'http'
@staticmethod
def preparehttpserver(httpserver, ui):
"""Prepare .socket of new HTTPServer instance"""
pass
def __init__(self, *args, **kargs):
self.protocol_version = 'HTTP/1.1'
httpservermod.basehttprequesthandler.__init__(self, *args, **kargs)
def _log_any(self, fp, format, *args):
fp.write("%s - - [%s] %s\n" % (self.client_address[0],
self.log_date_time_string(),
format % args))
fp.flush()
def log_error(self, format, *args):
self._log_any(self.server.errorlog, format, *args)
def log_message(self, format, *args):
self._log_any(self.server.accesslog, format, *args)
def log_request(self, code='-', size='-'):
xheaders = []
if util.safehasattr(self, 'headers'):
xheaders = [h for h in self.headers.items()
if h[0].startswith('x-')]
self.log_message('"%s" %s %s%s',
self.requestline, str(code), str(size),
''.join([' %s:%s' % h for h in sorted(xheaders)]))
def do_write(self):
try:
self.do_hgweb()
except socket.error as inst:
if inst[0] != errno.EPIPE:
raise
def do_POST(self):
try:
self.do_write()
except Exception:
self._start_response("500 Internal Server Error", [])
self._write("Internal Server Error")
self._done()
tb = "".join(traceback.format_exception(*sys.exc_info()))
self.log_error("Exception happened during processing "
"request '%s':\n%s", self.path, tb)
def do_GET(self):
self.do_POST()
def do_hgweb(self):
path, query = _splitURI(self.path)
env = {}
env['GATEWAY_INTERFACE'] = 'CGI/1.1'
env['REQUEST_METHOD'] = self.command
env['SERVER_NAME'] = self.server.server_name
env['SERVER_PORT'] = str(self.server.server_port)
env['REQUEST_URI'] = self.path
env['SCRIPT_NAME'] = self.server.prefix
env['PATH_INFO'] = path[len(self.server.prefix):]
env['REMOTE_HOST'] = self.client_address[0]
env['REMOTE_ADDR'] = self.client_address[0]
if query:
env['QUERY_STRING'] = query
if self.headers.typeheader is None:
env['CONTENT_TYPE'] = self.headers.type
else:
env['CONTENT_TYPE'] = self.headers.typeheader
length = self.headers.getheader('content-length')
if length:
env['CONTENT_LENGTH'] = length
for header in [h for h in self.headers.keys()
if h not in ('content-type', 'content-length')]:
hkey = 'HTTP_' + header.replace('-', '_').upper()
hval = self.headers.getheader(header)
hval = hval.replace('\n', '').strip()
if hval:
env[hkey] = hval
env['SERVER_PROTOCOL'] = self.request_version
env['wsgi.version'] = (1, 0)
env['wsgi.url_scheme'] = self.url_scheme
if env.get('HTTP_EXPECT', '').lower() == '100-continue':
self.rfile = common.continuereader(self.rfile, self.wfile.write)
env['wsgi.input'] = self.rfile
env['wsgi.errors'] = _error_logger(self)
env['wsgi.multithread'] = isinstance(self.server,
socketserver.ThreadingMixIn)
env['wsgi.multiprocess'] = isinstance(self.server,
socketserver.ForkingMixIn)
env['wsgi.run_once'] = 0
self.saved_status = None
self.saved_headers = []
self.sent_headers = False
self.length = None
self._chunked = None
for chunk in self.server.application(env, self._start_response):
self._write(chunk)
if not self.sent_headers:
self.send_headers()
self._done()
def send_headers(self):
if not self.saved_status:
raise AssertionError("Sending headers before "
"start_response() called")
saved_status = self.saved_status.split(None, 1)
saved_status[0] = int(saved_status[0])
self.send_response(*saved_status)
self.length = None
self._chunked = False
for h in self.saved_headers:
self.send_header(*h)
if h[0].lower() == 'content-length':
self.length = int(h[1])
if (self.length is None and
saved_status[0] != common.HTTP_NOT_MODIFIED):
self._chunked = (not self.close_connection and
self.request_version == "HTTP/1.1")
if self._chunked:
self.send_header('Transfer-Encoding', 'chunked')
else:
self.send_header('Connection', 'close')
self.end_headers()
self.sent_headers = True
def _start_response(self, http_status, headers, exc_info=None):
code, msg = http_status.split(None, 1)
code = int(code)
self.saved_status = http_status
bad_headers = ('connection', 'transfer-encoding')
self.saved_headers = [h for h in headers
if h[0].lower() not in bad_headers]
return self._write
def _write(self, data):
if not self.saved_status:
raise AssertionError("data written before start_response() called")
elif not self.sent_headers:
self.send_headers()
if self.length is not None:
if len(data) > self.length:
raise AssertionError("Content-length header sent, but more "
"bytes than specified are being written.")
self.length = self.length - len(data)
elif self._chunked and data:
data = '%x\r\n%s\r\n' % (len(data), data)
self.wfile.write(data)
self.wfile.flush()
def _done(self):
if self._chunked:
self.wfile.write('0\r\n\r\n')
self.wfile.flush()
class _httprequesthandlerssl(_httprequesthandler):
"""HTTPS handler based on Python's ssl module"""
url_scheme = 'https'
@staticmethod
def preparehttpserver(httpserver, ui):
try:
from .. import sslutil
sslutil.modernssl
except ImportError:
raise error.Abort(_("SSL support is unavailable"))
certfile = ui.config('web', 'certificate')
# These config options are currently only meant for testing. Use
# at your own risk.
cafile = ui.config('devel', 'servercafile')
reqcert = ui.configbool('devel', 'serverrequirecert')
httpserver.socket = sslutil.wrapserversocket(httpserver.socket,
ui,
certfile=certfile,
cafile=cafile,
requireclientcert=reqcert)
def setup(self):
self.connection = self.request
self.rfile = socket._fileobject(self.request, "rb", self.rbufsize)
self.wfile = socket._fileobject(self.request, "wb", self.wbufsize)
try:
import threading
threading.activeCount() # silence pyflakes and bypass demandimport
_mixin = socketserver.ThreadingMixIn
except ImportError:
if util.safehasattr(os, "fork"):
_mixin = socketserver.ForkingMixIn
else:
class _mixin(object):
pass
def openlog(opt, default):
if opt and opt != '-':
return open(opt, 'a')
return default
class MercurialHTTPServer(_mixin, httpservermod.httpserver, object):
# SO_REUSEADDR has broken semantics on windows
if pycompat.osname == 'nt':
allow_reuse_address = 0
def __init__(self, ui, app, addr, handler, **kwargs):
httpservermod.httpserver.__init__(self, addr, handler, **kwargs)
self.daemon_threads = True
self.application = app
handler.preparehttpserver(self, ui)
prefix = ui.config('web', 'prefix', '')
if prefix:
prefix = '/' + prefix.strip('/')
self.prefix = prefix
alog = openlog(ui.config('web', 'accesslog', '-'), ui.fout)
elog = openlog(ui.config('web', 'errorlog', '-'), ui.ferr)
self.accesslog = alog
self.errorlog = elog
self.addr, self.port = self.socket.getsockname()[0:2]
self.fqaddr = socket.getfqdn(addr[0])
class IPv6HTTPServer(MercurialHTTPServer):
address_family = getattr(socket, 'AF_INET6', None)
def __init__(self, *args, **kwargs):
if self.address_family is None:
raise error.RepoError(_('IPv6 is not available on this system'))
super(IPv6HTTPServer, self).__init__(*args, **kwargs)
def create_server(ui, app):
if ui.config('web', 'certificate'):
handler = _httprequesthandlerssl
else:
handler = _httprequesthandler
if ui.configbool('web', 'ipv6'):
cls = IPv6HTTPServer
else:
cls = MercurialHTTPServer
# ugly hack due to python issue5853 (for threaded use)
try:
import mimetypes
mimetypes.init()
except UnicodeDecodeError:
# Python 2.x's mimetypes module attempts to decode strings
# from Windows' ANSI APIs as ascii (fail), then re-encode them
# as ascii (clown fail), because the default Python Unicode
# codec is hardcoded as ascii.
sys.argv # unwrap demand-loader so that reload() works
reload(sys) # resurrect sys.setdefaultencoding()
oldenc = sys.getdefaultencoding()
sys.setdefaultencoding("latin1") # or any full 8-bit encoding
mimetypes.init()
sys.setdefaultencoding(oldenc)
address = ui.config('web', 'address', '')
port = util.getport(ui.config('web', 'port', 8000))
try:
return cls(ui, app, (address, port), handler)
except socket.error as inst:
raise error.Abort(_("cannot start server at '%s:%d': %s")
% (address, port, inst.args[1]))