hgext/convert/cvs.py

hgweb: refactor 304 handling code

We had generic code in wsgirequest for handling HTTP 304 responses.
We also had a special case for it in the catch all exception handler
in the WSGI application.

We only ever raise 304 in one place. So, we don't need to treat it
specially in the catch all exception handler.

But it is useful to validate behavior of 304 responses. We port the
code that sends a 304 to use the new response API. We then move the
code for screening 304 sanity into the new response API.

As part of doing so, we discovered that we would send
Content-Length: 0. This is not allowed. So, we fix our response code
to not emit that header for empty response bodies.

Differential Revision: https://phab.mercurial-scm.org/D2794

# cvs.py: CVS conversion code inspired by hg-cvs-import and git-cvsimport
#
#  Copyright 2005-2009 Matt Mackall <[e-mail]> and others
#
# 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 re
import socket

from mercurial.i18n import _
from mercurial import (
    encoding,
    error,
    pycompat,
    util,
)
from mercurial.utils import dateutil

from . import (
    common,
    cvsps,
)

stringio = util.stringio
checktool = common.checktool
commit = common.commit
converter_source = common.converter_source
makedatetimestamp = common.makedatetimestamp
NoRepo = common.NoRepo

class convert_cvs(converter_source):
    def __init__(self, ui, repotype, path, revs=None):
        super(convert_cvs, self).__init__(ui, repotype, path, revs=revs)

        cvs = os.path.join(path, "CVS")
        if not os.path.exists(cvs):
            raise NoRepo(_("%s does not look like a CVS checkout") % path)

        checktool('cvs')

        self.changeset = None
        self.files = {}
        self.tags = {}
        self.lastbranch = {}
        self.socket = None
        self.cvsroot = open(os.path.join(cvs, "Root"), 'rb').read()[:-1]
        self.cvsrepo = open(os.path.join(cvs, "Repository"), 'rb').read()[:-1]
        self.encoding = encoding.encoding

        self._connect()

    def _parse(self):
        if self.changeset is not None:
            return
        self.changeset = {}

        maxrev = 0
        if self.revs:
            if len(self.revs) > 1:
                raise error.Abort(_('cvs source does not support specifying '
                                   'multiple revs'))
            # TODO: handle tags
            try:
                # patchset number?
                maxrev = int(self.revs[0])
            except ValueError:
                raise error.Abort(_('revision %s is not a patchset number')
                                 % self.revs[0])

        d = pycompat.getcwd()
        try:
            os.chdir(self.path)
            id = None

            cache = 'update'
            if not self.ui.configbool('convert', 'cvsps.cache'):
                cache = None
            db = cvsps.createlog(self.ui, cache=cache)
            db = cvsps.createchangeset(self.ui, db,
                fuzz=int(self.ui.config('convert', 'cvsps.fuzz')),
                mergeto=self.ui.config('convert', 'cvsps.mergeto'),
                mergefrom=self.ui.config('convert', 'cvsps.mergefrom'))

            for cs in db:
                if maxrev and cs.id > maxrev:
                    break
                id = str(cs.id)
                cs.author = self.recode(cs.author)
                self.lastbranch[cs.branch] = id
                cs.comment = self.recode(cs.comment)
                if self.ui.configbool('convert', 'localtimezone'):
                    cs.date = makedatetimestamp(cs.date[0])
                date = dateutil.datestr(cs.date, '%Y-%m-%d %H:%M:%S %1%2')
                self.tags.update(dict.fromkeys(cs.tags, id))

                files = {}
                for f in cs.entries:
                    files[f.file] = "%s%s" % ('.'.join([str(x)
                                                        for x in f.revision]),
                                              ['', '(DEAD)'][f.dead])

                # add current commit to set
                c = commit(author=cs.author, date=date,
                           parents=[str(p.id) for p in cs.parents],
                           desc=cs.comment, branch=cs.branch or '')
                self.changeset[id] = c
                self.files[id] = files

            self.heads = self.lastbranch.values()
        finally:
            os.chdir(d)

    def _connect(self):
        root = self.cvsroot
        conntype = None
        user, host = None, None
        cmd = ['cvs', 'server']

        self.ui.status(_("connecting to %s\n") % root)

        if root.startswith(":pserver:"):
            root = root[9:]
            m = re.match(r'(?:(.*?)(?::(.*?))?@)?([^:\/]*)(?::(\d*))?(.*)',
                         root)
            if m:
                conntype = "pserver"
                user, passw, serv, port, root = m.groups()
                if not user:
                    user = "anonymous"
                if not port:
                    port = 2401
                else:
                    port = int(port)
                format0 = ":pserver:%s@%s:%s" % (user, serv, root)
                format1 = ":pserver:%s@%s:%d%s" % (user, serv, port, root)

                if not passw:
                    passw = "A"
                    cvspass = os.path.expanduser("~/.cvspass")
                    try:
                        pf = open(cvspass, 'rb')
                        for line in pf.read().splitlines():
                            part1, part2 = line.split(' ', 1)
                            # /1 :pserver:[e-mail]:2401/cvsroot/foo
                            # Ah<Z
                            if part1 == '/1':
                                part1, part2 = part2.split(' ', 1)
                                format = format1
                            # :pserver:[e-mail]:/cvsroot/foo Ah<Z
                            else:
                                format = format0
                            if part1 == format:
                                passw = part2
                                break
                        pf.close()
                    except IOError as inst:
                        if inst.errno != errno.ENOENT:
                            if not getattr(inst, 'filename', None):
                                inst.filename = cvspass
                            raise

                sck = socket.socket()
                sck.connect((serv, port))
                sck.send("\n".join(["BEGIN AUTH REQUEST", root, user, passw,
                                    "END AUTH REQUEST", ""]))
                if sck.recv(128) != "I LOVE YOU\n":
                    raise error.Abort(_("CVS pserver authentication failed"))

                self.writep = self.readp = sck.makefile('r+')

        if not conntype and root.startswith(":local:"):
            conntype = "local"
            root = root[7:]

        if not conntype:
            # :ext:user@host/home/user/path/to/cvsroot
            if root.startswith(":ext:"):
                root = root[5:]
            m = re.match(br'(?:([^@:/]+)@)?([^:/]+):?(.*)', root)
            # Do not take Windows path "c:\foo\bar" for a connection strings
            if os.path.isdir(root) or not m:
                conntype = "local"
            else:
                conntype = "rsh"
                user, host, root = m.group(1), m.group(2), m.group(3)

        if conntype != "pserver":
            if conntype == "rsh":
                rsh = encoding.environ.get("CVS_RSH") or "ssh"
                if user:
                    cmd = [rsh, '-l', user, host] + cmd
                else:
                    cmd = [rsh, host] + cmd

            # popen2 does not support argument lists under Windows
            cmd = [util.shellquote(arg) for arg in cmd]
            cmd = util.quotecommand(' '.join(cmd))
            self.writep, self.readp = util.popen2(cmd)

        self.realroot = root

        self.writep.write("Root %s\n" % root)
        self.writep.write("Valid-responses ok error Valid-requests Mode"
                          " M Mbinary E Checked-in Created Updated"
                          " Merged Removed\n")
        self.writep.write("valid-requests\n")
        self.writep.flush()
        r = self.readp.readline()
        if not r.startswith("Valid-requests"):
            raise error.Abort(_('unexpected response from CVS server '
                               '(expected "Valid-requests", but got %r)')
                             % r)
        if "UseUnchanged" in r:
            self.writep.write("UseUnchanged\n")
            self.writep.flush()
            r = self.readp.readline()

    def getheads(self):
        self._parse()
        return self.heads

    def getfile(self, name, rev):

        def chunkedread(fp, count):
            # file-objects returned by socket.makefile() do not handle
            # large read() requests very well.
            chunksize = 65536
            output = stringio()
            while count > 0:
                data = fp.read(min(count, chunksize))
                if not data:
                    raise error.Abort(_("%d bytes missing from remote file")
                                     % count)
                count -= len(data)
                output.write(data)
            return output.getvalue()

        self._parse()
        if rev.endswith("(DEAD)"):
            return None, None

        args = ("-N -P -kk -r %s --" % rev).split()
        args.append(self.cvsrepo + '/' + name)
        for x in args:
            self.writep.write("Argument %s\n" % x)
        self.writep.write("Directory .\n%s\nco\n" % self.realroot)
        self.writep.flush()

        data = ""
        mode = None
        while True:
            line = self.readp.readline()
            if line.startswith("Created ") or line.startswith("Updated "):
                self.readp.readline() # path
                self.readp.readline() # entries
                mode = self.readp.readline()[:-1]
                count = int(self.readp.readline()[:-1])
                data = chunkedread(self.readp, count)
            elif line.startswith(" "):
                data += line[1:]
            elif line.startswith("M "):
                pass
            elif line.startswith("Mbinary "):
                count = int(self.readp.readline()[:-1])
                data = chunkedread(self.readp, count)
            else:
                if line == "ok\n":
                    if mode is None:
                        raise error.Abort(_('malformed response from CVS'))
                    return (data, "x" in mode and "x" or "")
                elif line.startswith("E "):
                    self.ui.warn(_("cvs server: %s\n") % line[2:])
                elif line.startswith("Remove"):
                    self.readp.readline()
                else:
                    raise error.Abort(_("unknown CVS response: %s") % line)

    def getchanges(self, rev, full):
        if full:
            raise error.Abort(_("convert from cvs does not support --full"))
        self._parse()
        return sorted(self.files[rev].iteritems()), {}, set()

    def getcommit(self, rev):
        self._parse()
        return self.changeset[rev]

    def gettags(self):
        self._parse()
        return self.tags

    def getchangedfiles(self, rev, i):
        self._parse()
        return sorted(self.files[rev])