~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005 Canonical Ltd

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
"""Implementation of Transport over http.
"""

import os, errno
from cStringIO import StringIO
import urllib, urllib2
import urlparse
from warnings import warn

import bzrlib
from bzrlib.transport import Transport, Server
from bzrlib.errors import (TransportNotPossible, NoSuchFile, 
                           TransportError, ConnectionError)
from bzrlib.errors import BzrError, BzrCheckError
from bzrlib.branch import Branch
from bzrlib.trace import mutter
from bzrlib.ui import ui_factory


def extract_auth(url, password_manager):
    """
    Extract auth parameters from am HTTP/HTTPS url and add them to the given
    password manager.  Return the url, minus those auth parameters (which
    confuse urllib2).
    """
    scheme, netloc, path, query, fragment = urlparse.urlsplit(url)
    assert (scheme == 'http') or (scheme == 'https')
    
    if '@' in netloc:
        auth, netloc = netloc.split('@', 1)
        if ':' in auth:
            username, password = auth.split(':', 1)
        else:
            username, password = auth, None
        if ':' in netloc:
            host = netloc.split(':', 1)[0]
        else:
            host = netloc
        username = urllib.unquote(username)
        if password is not None:
            password = urllib.unquote(password)
        else:
            password = ui_factory.get_password(prompt='HTTP %(user)@%(host) password',
                                               user=username, host=host)
        password_manager.add_password(None, host, username, password)
    url = urlparse.urlunsplit((scheme, netloc, path, query, fragment))
    return url


class Request(urllib2.Request):
    """Request object for urllib2 that allows the method to be overridden."""

    method = None

    def get_method(self):
        if self.method is not None:
            return self.method
        else:
            return urllib2.Request.get_method(self)


def get_url(url, method=None):
    import urllib2
    mutter("get_url %s", url)
    manager = urllib2.HTTPPasswordMgrWithDefaultRealm()
    url = extract_auth(url, manager)
    auth_handler = urllib2.HTTPBasicAuthHandler(manager)
    opener = urllib2.build_opener(auth_handler)

    request = Request(url)
    request.method = method
    request.add_header('User-Agent', 'bzr/%s' % bzrlib.__version__)
    response = opener.open(request)
    return response


class HttpTransport(Transport):
    """This is the transport agent for http:// access.
    
    TODO: Implement pipelined versions of all of the *_multi() functions.
    """

    def __init__(self, base):
        """Set the base path where files will be stored."""
        assert base.startswith('http://') or base.startswith('https://')
        if base[-1] != '/':
            base = base + '/'
        super(HttpTransport, self).__init__(base)
        # In the future we might actually connect to the remote host
        # rather than using get_url
        # self._connection = None
        (self._proto, self._host,
            self._path, self._parameters,
            self._query, self._fragment) = urlparse.urlparse(self.base)

    def should_cache(self):
        """Return True if the data pulled across should be cached locally.
        """
        return True

    def clone(self, offset=None):
        """Return a new HttpTransport with root at self.base + offset
        For now HttpTransport does not actually connect, so just return
        a new HttpTransport object.
        """
        if offset is None:
            return HttpTransport(self.base)
        else:
            return HttpTransport(self.abspath(offset))

    def abspath(self, relpath):
        """Return the full url to the given relative path.
        This can be supplied with a string or a list
        """
        assert isinstance(relpath, basestring)
        if isinstance(relpath, basestring):
            relpath_parts = relpath.split('/')
        else:
            # TODO: Don't call this with an array - no magic interfaces
            relpath_parts = relpath[:]
        if len(relpath_parts) > 1:
            if relpath_parts[0] == '':
                raise ValueError("path %r within branch %r seems to be absolute"
                                 % (relpath, self._path))
            if relpath_parts[-1] == '':
                raise ValueError("path %r within branch %r seems to be a directory"
                                 % (relpath, self._path))
        basepath = self._path.split('/')
        if len(basepath) > 0 and basepath[-1] == '':
            basepath = basepath[:-1]
        for p in relpath_parts:
            if p == '..':
                if len(basepath) == 0:
                    # In most filesystems, a request for the parent
                    # of root, just returns root.
                    continue
                basepath.pop()
            elif p == '.' or p == '':
                continue # No-op
            else:
                basepath.append(p)
        # Possibly, we could use urlparse.urljoin() here, but
        # I'm concerned about when it chooses to strip the last
        # portion of the path, and when it doesn't.
        path = '/'.join(basepath)
        return urlparse.urlunparse((self._proto,
                self._host, path, '', '', ''))

    def has(self, relpath):
        """Does the target location exist?

        TODO: This should be changed so that we don't use
        urllib2 and get an exception, the code path would be
        cleaner if we just do an http HEAD request, and parse
        the return code.
        """
        path = relpath
        try:
            path = self.abspath(relpath)
            f = get_url(path, method='HEAD')
            # Without the read and then close()
            # we tend to have busy sockets.
            f.read()
            f.close()
            return True
        except urllib2.URLError, e:
            mutter('url error code: %s for has url: %r', e.code, path)
            if e.code == 404:
                return False
            raise
        except IOError, e:
            mutter('io error: %s %s for has url: %r', 
                e.errno, errno.errorcode.get(e.errno), path)
            if e.errno == errno.ENOENT:
                return False
            raise TransportError(orig_error=e)

    def get(self, relpath, decode=False):
        """Get the file at the given relative path.

        :param relpath: The relative path to the file
        """
        path = relpath
        try:
            path = self.abspath(relpath)
            return get_url(path)
        except urllib2.HTTPError, e:
            mutter('url error code: %s for has url: %r', e.code, path)
            if e.code == 404:
                raise NoSuchFile(path, extra=e)
            raise
        except (BzrError, IOError), e:
            if hasattr(e, 'errno'):
                mutter('io error: %s %s for has url: %r', 
                    e.errno, errno.errorcode.get(e.errno), path)
                if e.errno == errno.ENOENT:
                    raise NoSuchFile(path, extra=e)
            raise ConnectionError(msg = "Error retrieving %s: %s" 
                             % (self.abspath(relpath), str(e)),
                             orig_error=e)

    def put(self, relpath, f, mode=None):
        """Copy the file-like or string object into the location.

        :param relpath: Location to put the contents, relative to base.
        :param f:       File-like or string object.
        """
        raise TransportNotPossible('http PUT not supported')

    def mkdir(self, relpath, mode=None):
        """Create a directory at the given path."""
        raise TransportNotPossible('http does not support mkdir()')

    def rmdir(self, relpath):
        """See Transport.rmdir."""
        raise TransportNotPossible('http does not support rmdir()')

    def append(self, relpath, f):
        """Append the text in the file-like object into the final
        location.
        """
        raise TransportNotPossible('http does not support append()')

    def copy(self, rel_from, rel_to):
        """Copy the item at rel_from to the location at rel_to"""
        raise TransportNotPossible('http does not support copy()')

    def copy_to(self, relpaths, other, mode=None, pb=None):
        """Copy a set of entries from self into another Transport.

        :param relpaths: A list/generator of entries to be copied.

        TODO: if other is LocalTransport, is it possible to
              do better than put(get())?
        """
        # At this point HttpTransport might be able to check and see if
        # the remote location is the same, and rather than download, and
        # then upload, it could just issue a remote copy_this command.
        if isinstance(other, HttpTransport):
            raise TransportNotPossible('http cannot be the target of copy_to()')
        else:
            return super(HttpTransport, self).copy_to(relpaths, other, mode=mode, pb=pb)

    def move(self, rel_from, rel_to):
        """Move the item at rel_from to the location at rel_to"""
        raise TransportNotPossible('http does not support move()')

    def delete(self, relpath):
        """Delete the item at relpath"""
        raise TransportNotPossible('http does not support delete()')

    def is_readonly(self):
        """See Transport.is_readonly."""
        return True

    def listable(self):
        """See Transport.listable."""
        return False

    def stat(self, relpath):
        """Return the stat information for a file.
        """
        raise TransportNotPossible('http does not support stat()')

    def lock_read(self, relpath):
        """Lock the given file for shared (read) access.
        :return: A lock object, which should be passed to Transport.unlock()
        """
        # The old RemoteBranch ignore lock for reading, so we will
        # continue that tradition and return a bogus lock object.
        class BogusLock(object):
            def __init__(self, path):
                self.path = path
            def unlock(self):
                pass
        return BogusLock(relpath)

    def lock_write(self, relpath):
        """Lock the given file for exclusive (write) access.
        WARNING: many transports do not support this, so trying avoid using it

        :return: A lock object, which should be passed to Transport.unlock()
        """
        raise TransportNotPossible('http does not support lock_write()')


#---------------- test server facilities ----------------
import BaseHTTPServer, SimpleHTTPServer, socket, time
import threading


class WebserverNotAvailable(Exception):
    pass


class BadWebserverPath(ValueError):
    def __str__(self):
        return 'path %s is not in %s' % self.args


class TestingHTTPRequestHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):

    def log_message(self, format, *args):
        self.server.test_case.log('webserver - %s - - [%s] %s "%s" "%s"',
                                  self.address_string(),
                                  self.log_date_time_string(),
                                  format % args,
                                  self.headers.get('referer', '-'),
                                  self.headers.get('user-agent', '-'))

    def handle_one_request(self):
        """Handle a single HTTP request.

        You normally don't need to override this method; see the class
        __doc__ string for information on how to handle specific HTTP
        commands such as GET and POST.

        """
        for i in xrange(1,11): # Don't try more than 10 times
            try:
                self.raw_requestline = self.rfile.readline()
            except socket.error, e:
                if e.args[0] in (errno.EAGAIN, errno.EWOULDBLOCK):
                    # omitted for now because some tests look at the log of
                    # the server and expect to see no errors.  see recent
                    # email thread. -- mbp 20051021. 
                    ## self.log_message('EAGAIN (%d) while reading from raw_requestline' % i)
                    time.sleep(0.01)
                    continue
                raise
            else:
                break
        if not self.raw_requestline:
            self.close_connection = 1
            return
        if not self.parse_request(): # An error code has been sent, just exit
            return
        mname = 'do_' + self.command
        if not hasattr(self, mname):
            self.send_error(501, "Unsupported method (%r)" % self.command)
            return
        method = getattr(self, mname)
        method()


class TestingHTTPServer(BaseHTTPServer.HTTPServer):
    def __init__(self, server_address, RequestHandlerClass, test_case):
        BaseHTTPServer.HTTPServer.__init__(self, server_address,
                                                RequestHandlerClass)
        self.test_case = test_case


class HttpServer(Server):
    """A test server for http transports."""

    def _http_start(self):
        httpd = None
        httpd = TestingHTTPServer(('localhost', 0),
                                  TestingHTTPRequestHandler,
                                  self)
        host, port = httpd.socket.getsockname()
        self._http_base_url = 'http://localhost:%s/' % port
        self._http_starting.release()
        httpd.socket.settimeout(0.1)

        while self._http_running:
            try:
                httpd.handle_request()
            except socket.timeout:
                pass

    def _get_remote_url(self, path):
        path_parts = path.split(os.path.sep)
        if os.path.isabs(path):
            if path_parts[:len(self._local_path_parts)] != \
                   self._local_path_parts:
                raise BadWebserverPath(path, self.test_dir)
            remote_path = '/'.join(path_parts[len(self._local_path_parts):])
        else:
            remote_path = '/'.join(path_parts)

        self._http_starting.acquire()
        self._http_starting.release()
        return self._http_base_url + remote_path

    def log(self, format, *args):
        """Capture Server log output."""
        self.logs.append(format % args)

    def setUp(self):
        """See bzrlib.transport.Server.setUp."""
        self._home_dir = os.getcwdu()
        self._local_path_parts = self._home_dir.split(os.path.sep)
        self._http_starting = threading.Lock()
        self._http_starting.acquire()
        self._http_running = True
        self._http_base_url = None
        self._http_thread = threading.Thread(target=self._http_start)
        self._http_thread.setDaemon(True)
        self._http_thread.start()
        self._http_proxy = os.environ.get("http_proxy")
        if self._http_proxy is not None:
            del os.environ["http_proxy"]
        self.logs = []

    def tearDown(self):
        """See bzrlib.transport.Server.tearDown."""
        self._http_running = False
        self._http_thread.join()
        if self._http_proxy is not None:
            import os
            os.environ["http_proxy"] = self._http_proxy

    def get_url(self):
        """See bzrlib.transport.Server.get_url."""
        return self._get_remote_url(self._home_dir)
        
    def get_bogus_url(self):
        """See bzrlib.transport.Server.get_bogus_url."""
        return 'http://jasldkjsalkdjalksjdkljasd'


def get_test_permutations():
    """Return the permutations to be used in testing."""
    warn("There are no HTTPS transport provider tests yet.")
    return [(HttpTransport, HttpServer),
            ]