mercurial/hgweb/protocol.py

revset: add optional offset argument to limit() predicate

It's common for GUI or web frontend to fetch chunk of revisions per batch
size. Previously it was possible only if revisions were sorted by revision
number.

  $ hg log -r 'limit({revspec} & :{last_known}, 101)'

So this patch introduces a general way to retrieve chunk of revisions after
skipping offset revisions.

  $ hg log -r 'limit({revspec}, 100, {last_count})'

This is a dumb implementation. We can optimize it for baseset and spanset
later.

#
# 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 cgi, cStringIO, zlib, urllib
from mercurial import util, wireproto
from common import HTTP_OK

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

class webproto(wireproto.abstractserverproto):
    def __init__(self, req, ui):
        self.req = req
        self.response = ''
        self.ui = ui
    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()
        chunks = []
        i = 1
        while True:
            h = self.req.env.get('HTTP_X_HGARG_' + str(i))
            if h is None:
                break
            chunks += [h]
            i += 1
        args.update(cgi.parse_qs(''.join(chunks), 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 = cStringIO.StringIO()
    def restore(self):
        val = self.ui.fout.getvalue()
        self.ui.ferr, self.ui.fout = self.oldio
        return val
    def groupchunks(self, cg):
        z = zlib.compressobj()
        while True:
            chunk = cg.read(4096)
            if not chunk:
                break
            yield z.compress(chunk)
        yield z.flush()
    def _client(self):
        return 'remote:%s:%s:%s' % (
            self.req.env.get('wsgi.url_scheme') or 'http',
            urllib.quote(self.req.env.get('REMOTE_HOST', '')),
            urllib.quote(self.req.env.get('REMOTE_USER', '')))

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

def call(repo, req, cmd):
    p = webproto(req, repo.ui)
    rsp = wireproto.dispatch(repo, p, cmd)
    if isinstance(rsp, str):
        req.respond(HTTP_OK, HGTYPE, body=rsp)
        return []
    elif isinstance(rsp, wireproto.streamres):
        req.respond(HTTP_OK, HGTYPE)
        return rsp.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 []