view mercurial/hgweb/protocol.py @ 31294:c134a33b1d73

treemanifest: make node reuse match flat manifest behavior

In a flat manifest, a node with the same content but different parents is still
considered a new node. In the current tree manifests however, if the content is
the same, we ignore the parents entirely and just reuse the existing node.

In our external treemanifest extension, we want to allow having one treemanifest
for every flat manifests, as a way of easeing the migration to treemanifests. To
make this possible, let's change the root node treemanifest behavior to match
the behavior for flat manifests, so we can have a 1:1 relationship.

While this sounds like a BC breakage, it's not actually a state users can
normally get in because: A) you can't make empty commits, and B) even if you try
to make an empty commit (by making a commit then amending it's changes away),
the higher level commit logic in localrepo.commitctx() forces the commit to use
the original p1 manifest node if no files were changed. So this would only
affect extensions and automation that reached passed the normal
localrepo.commit() logic straight into the manifest logic.

#
# 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 cgi
import struct

from .common import (
    HTTP_OK,
)

from .. import (
    util,
    wireproto,
)
stringio = util.stringio

urlerr = util.urlerr
urlreq = util.urlreq

HGTYPE = 'application/mercurial-0.1'
HGTYPE2 = 'application/mercurial-0.2'
HGERRTYPE = 'application/hg-error'

def decodevaluefromheaders(req, headerprefix):
    """Decode a long value from multiple HTTP request headers."""
    chunks = []
    i = 1
    while True:
        v = req.env.get('HTTP_%s_%d' % (
            headerprefix.upper().replace('-', '_'), i))
        if v is None:
            break
        chunks.append(v)
        i += 1

    return ''.join(chunks)

class webproto(wireproto.abstractserverproto):
    def __init__(self, req, ui):
        self.req = req
        self.response = ''
        self.ui = ui
        self.name = 'http'

    def getargs(self, args):
        knownargs = self._args()
        data = {}
        keys = args.split()
        for k in keys:
            if k == '*':
                star = {}
                for key in knownargs.keys():
                    if key != 'cmd' and key not in keys:
                        star[key] = knownargs[key][0]
                data['*'] = star
            else:
                data[k] = knownargs[k][0]
        return [data[k] for k in keys]
    def _args(self):
        args = self.req.form.copy()
        postlen = int(self.req.env.get('HTTP_X_HGARGS_POST', 0))
        if postlen:
            args.update(cgi.parse_qs(
                self.req.read(postlen), keep_blank_values=True))
            return args

        argvalue = decodevaluefromheaders(self.req, 'X-HgArg')
        args.update(cgi.parse_qs(argvalue, keep_blank_values=True))
        return args
    def getfile(self, fp):
        length = int(self.req.env['CONTENT_LENGTH'])
        for s in util.filechunkiter(self.req, limit=length):
            fp.write(s)
    def redirect(self):
        self.oldio = self.ui.fout, self.ui.ferr
        self.ui.ferr = self.ui.fout = stringio()
    def restore(self):
        val = self.ui.fout.getvalue()
        self.ui.ferr, self.ui.fout = self.oldio
        return val

    def _client(self):
        return 'remote:%s:%s:%s' % (
            self.req.env.get('wsgi.url_scheme') or 'http',
            urlreq.quote(self.req.env.get('REMOTE_HOST', '')),
            urlreq.quote(self.req.env.get('REMOTE_USER', '')))

    def responsetype(self, v1compressible=False):
        """Determine the appropriate response type and compression settings.

        The ``v1compressible`` argument states whether the response with
        application/mercurial-0.1 media types should be zlib compressed.

        Returns a tuple of (mediatype, compengine, engineopts).
        """
        # For now, if it isn't compressible in the old world, it's never
        # compressible. We can change this to send uncompressed 0.2 payloads
        # later.
        if not v1compressible:
            return HGTYPE, None, None

        # Determine the response media type and compression engine based
        # on the request parameters.
        protocaps = decodevaluefromheaders(self.req, 'X-HgProto').split(' ')

        if '0.2' in protocaps:
            # Default as defined by wire protocol spec.
            compformats = ['zlib', 'none']
            for cap in protocaps:
                if cap.startswith('comp='):
                    compformats = cap[5:].split(',')
                    break

            # Now find an agreed upon compression format.
            for engine in wireproto.supportedcompengines(self.ui, self,
                                                         util.SERVERROLE):
                if engine.wireprotosupport().name in compformats:
                    opts = {}
                    level = self.ui.configint('server',
                                              '%slevel' % engine.name())
                    if level is not None:
                        opts['level'] = level

                    return HGTYPE2, engine, opts

            # No mutually supported compression format. Fall back to the
            # legacy protocol.

        # Don't allow untrusted settings because disabling compression or
        # setting a very high compression level could lead to flooding
        # the server's network or CPU.
        opts = {'level': self.ui.configint('server', 'zliblevel', -1)}
        return HGTYPE, util.compengines['zlib'], opts

def iscmd(cmd):
    return cmd in wireproto.commands

def call(repo, req, cmd):
    p = webproto(req, repo.ui)

    def genversion2(gen, compress, engine, engineopts):
        # application/mercurial-0.2 always sends a payload header
        # identifying the compression engine.
        name = engine.wireprotosupport().name
        assert 0 < len(name) < 256
        yield struct.pack('B', len(name))
        yield name

        if compress:
            for chunk in engine.compressstream(gen, opts=engineopts):
                yield chunk
        else:
            for chunk in gen:
                yield chunk

    rsp = wireproto.dispatch(repo, p, cmd)
    if isinstance(rsp, str):
        req.respond(HTTP_OK, HGTYPE, body=rsp)
        return []
    elif isinstance(rsp, wireproto.streamres):
        if rsp.reader:
            gen = iter(lambda: rsp.reader.read(32768), '')
        else:
            gen = rsp.gen

        # This code for compression should not be streamres specific. It
        # is here because we only compress streamres at the moment.
        mediatype, engine, engineopts = p.responsetype(rsp.v1compressible)

        if mediatype == HGTYPE and rsp.v1compressible:
            gen = engine.compressstream(gen, engineopts)
        elif mediatype == HGTYPE2:
            gen = genversion2(gen, rsp.v1compressible, engine, engineopts)

        req.respond(HTTP_OK, mediatype)
        return gen
    elif isinstance(rsp, wireproto.pushres):
        val = p.restore()
        rsp = '%d\n%s' % (rsp.res, val)
        req.respond(HTTP_OK, HGTYPE, body=rsp)
        return []
    elif isinstance(rsp, wireproto.pusherr):
        # drain the incoming bundle
        req.drain()
        p.restore()
        rsp = '0\n%s\n' % rsp.res
        req.respond(HTTP_OK, HGTYPE, body=rsp)
        return []
    elif isinstance(rsp, wireproto.ooberror):
        rsp = rsp.message
        req.respond(HTTP_OK, HGERRTYPE, body=rsp)
        return []