view mercurial/hgweb/server.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.

# hgweb/server.py - The standalone hg web server.
#
# Copyright 21 May 2005 - (c) 2005 Jake Edge <[e-mail]>
# Copyright 2005-2007 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import os, sys, errno, urllib, BaseHTTPServer, socket, SocketServer, traceback
from mercurial import util, error
from mercurial.hgweb import common
from mercurial.i18n import _

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 urllib.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(BaseHTTPServer.BaseHTTPRequestHandler):

    url_scheme = 'http'

    @staticmethod
    def preparehttpserver(httpserver, ssl_cert):
        """Prepare .socket of new HTTPServer instance"""
        pass

    def __init__(self, *args, **kargs):
        self.protocol_version = 'HTTP/1.1'
        BaseHTTPServer.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 _httprequesthandleropenssl(_httprequesthandler):
    """HTTPS handler based on pyOpenSSL"""

    url_scheme = 'https'

    @staticmethod
    def preparehttpserver(httpserver, ssl_cert):
        try:
            import OpenSSL
            OpenSSL.SSL.Context
        except ImportError:
            raise error.Abort(_("SSL support is unavailable"))
        ctx = OpenSSL.SSL.Context(OpenSSL.SSL.TLSv1_METHOD)
        ctx.use_privatekey_file(ssl_cert)
        ctx.use_certificate_file(ssl_cert)
        sock = socket.socket(httpserver.address_family, httpserver.socket_type)
        httpserver.socket = OpenSSL.SSL.Connection(ctx, sock)
        httpserver.server_bind()
        httpserver.server_activate()

    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)

    def do_write(self):
        import OpenSSL
        try:
            _httprequesthandler.do_write(self)
        except OpenSSL.SSL.SysCallError as inst:
            if inst.args[0] != errno.EPIPE:
                raise

    def handle_one_request(self):
        import OpenSSL
        try:
            _httprequesthandler.handle_one_request(self)
        except (OpenSSL.SSL.SysCallError, OpenSSL.SSL.ZeroReturnError):
            self.close_connection = True
            pass

class _httprequesthandlerssl(_httprequesthandler):
    """HTTPS handler based on Python's ssl module"""

    url_scheme = 'https'

    @staticmethod
    def preparehttpserver(httpserver, ssl_cert):
        try:
            import ssl
            ssl.wrap_socket
        except ImportError:
            raise error.Abort(_("SSL support is unavailable"))
        httpserver.socket = ssl.wrap_socket(
            httpserver.socket, server_side=True,
            certfile=ssl_cert, ssl_version=ssl.PROTOCOL_TLSv1)

    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:
    from threading import activeCount
    activeCount() # silence pyflakes
    _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(object, _mixin, BaseHTTPServer.HTTPServer):

    # SO_REUSEADDR has broken semantics on windows
    if os.name == 'nt':
        allow_reuse_address = 0

    def __init__(self, ui, app, addr, handler, **kwargs):
        BaseHTTPServer.HTTPServer.__init__(self, addr, handler, **kwargs)
        self.daemon_threads = True
        self.application = app

        handler.preparehttpserver(self, ui.config('web', 'certificate'))

        prefix = ui.config('web', 'prefix', '')
        if prefix:
            prefix = '/' + prefix.strip('/')
        self.prefix = prefix

        alog = openlog(ui.config('web', 'accesslog', '-'), sys.stdout)
        elog = openlog(ui.config('web', 'errorlog', '-'), sys.stderr)
        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'):
        if sys.version_info >= (2, 6):
            handler = _httprequesthandlerssl
        else:
            handler = _httprequesthandleropenssl
    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]))