view mercurial/hgweb/server.py @ 36876:97f44b0720e2

hgweb: port archive command to modern response API

Well, I tried to go with PEP 3333's recommendations and only allow
our WSGI application to emit data via a response generator.
Unfortunately, the "archive" command calls into the zipfile and
tarfile modules and these operator on file objects and must send
their data to an object with write(). There's no easy way turn
these write() calls into a generator.

So, we teach our response type how to expose a file object like
object that can be used to write() output. We try to keep the API
consistent with how things work currently: callers must call a
setbody*(), then sendresponse() to trigger sending of headers,
and only then can they get a handle on the object to perform
writing.

This required overloading the return value of @webcommand functions
even more. Fortunately, we're almost completely ported off the
legacy API. So we should be able to simplify matters in the near
future.

A test relying on this functionality has also been updated to use
the new API.

Differential Revision: https://phab.mercurial-scm.org/D2792

# 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.

from __future__ import absolute_import

import errno
import os
import socket
import sys
import traceback
import wsgiref.validate

from ..i18n import _

from .. import (
    encoding,
    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 r'?' in uri:
        path, query = uri.split(r'?', 1)
    else:
        path, query = uri, r''
    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"""

    def __init__(self, *args, **kargs):
        self.protocol_version = r'HTTP/1.1'
        httpservermod.basehttprequesthandler.__init__(self, *args, **kargs)

    def _log_any(self, fp, format, *args):
        fp.write(pycompat.sysbytes(
            r"%s - - [%s] %s" % (self.client_address[0],
                                 self.log_date_time_string(),
                                 format % args)) + '\n')
        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=r'-', size=r'-'):
        xheaders = []
        if util.safehasattr(self, 'headers'):
            xheaders = [h for h in self.headers.items()
                        if h[0].startswith(r'x-')]
        self.log_message(r'"%s" %s %s%s',
                         self.requestline, str(code), str(size),
                         r''.join([r' %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 = r"".join(traceback.format_exception(*sys.exc_info()))
            # We need a native-string newline to poke in the log
            # message, because we won't get a newline when using an
            # r-string. This is the easy way out.
            newline = chr(10)
            self.log_error(r"Exception happened during processing "
                           r"request '%s':%s%s", self.path, newline, tb)

    def do_GET(self):
        self.do_POST()

    def do_hgweb(self):
        self.sent_headers = False
        path, query = _splitURI(self.path)

        env = {}
        env[r'GATEWAY_INTERFACE'] = r'CGI/1.1'
        env[r'REQUEST_METHOD'] = self.command
        env[r'SERVER_NAME'] = self.server.server_name
        env[r'SERVER_PORT'] = str(self.server.server_port)
        env[r'REQUEST_URI'] = self.path
        env[r'SCRIPT_NAME'] = pycompat.sysstr(self.server.prefix)
        env[r'PATH_INFO'] = pycompat.sysstr(path[len(self.server.prefix):])
        env[r'REMOTE_HOST'] = self.client_address[0]
        env[r'REMOTE_ADDR'] = self.client_address[0]
        env[r'QUERY_STRING'] = query or r''

        if pycompat.ispy3:
            if self.headers.get_content_type() is None:
                env[r'CONTENT_TYPE'] = self.headers.get_default_type()
            else:
                env[r'CONTENT_TYPE'] = self.headers.get_content_type()
            length = self.headers.get('content-length')
        else:
            if self.headers.typeheader is None:
                env[r'CONTENT_TYPE'] = self.headers.type
            else:
                env[r'CONTENT_TYPE'] = self.headers.typeheader
            length = self.headers.getheader('content-length')
        if length:
            env[r'CONTENT_LENGTH'] = length
        for header in [h for h in self.headers.keys()
                       if h not in ('content-type', 'content-length')]:
            hkey = r'HTTP_' + header.replace(r'-', r'_').upper()
            hval = self.headers.get(header)
            hval = hval.replace(r'\n', r'').strip()
            if hval:
                env[hkey] = hval
        env[r'SERVER_PROTOCOL'] = self.request_version
        env[r'wsgi.version'] = (1, 0)
        env[r'wsgi.url_scheme'] = pycompat.sysstr(self.url_scheme)
        if env.get(r'HTTP_EXPECT', '').lower() == '100-continue':
            self.rfile = common.continuereader(self.rfile, self.wfile.write)

        env[r'wsgi.input'] = self.rfile
        env[r'wsgi.errors'] = _error_logger(self)
        env[r'wsgi.multithread'] = isinstance(self.server,
                                             socketserver.ThreadingMixIn)
        env[r'wsgi.multiprocess'] = isinstance(self.server,
                                              socketserver.ForkingMixIn)
        env[r'wsgi.run_once'] = 0

        wsgiref.validate.check_environ(env)

        self.saved_status = None
        self.saved_headers = []
        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(r'Transfer-Encoding', r'chunked')
            else:
                self.send_header(r'Connection', r'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 = self.request.makefile(r"rb", self.rbufsize)
        self.wfile = self.request.makefile(r"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, 'ab')
    return default

class MercurialHTTPServer(_mixin, httpservermod.httpserver, object):

    # SO_REUSEADDR has broken semantics on windows
    if pycompat.iswindows:
        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'))
    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, encoding.strtolocal(inst.args[1])))