view mercurial/hgweb/protocol.py @ 35305:483b5dd0f1aa

push: restrict common discovery to the pushed set

This changeset make use of the ability of the set discovery to only search
common changeset for a subset of the repository. Restricting that search to the
pushed set avoid potential waste of time finding out the status of many
unrelated related revision.

Repository with many heads were especially badly affected by this. Here is an
example of findcommonhead discovery for pushing 11 outgoing changeset on a
repository with tens of thousand of unrelated heads. (discovery run over a ssh
link to localhost).

Before:
    queries: 92
    time:    44.1996s

After:
    queries: 3
    time:    0.6938s

A x63 speedup even with a network link without latency.

#
# 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 (
    error,
    pycompat,
    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.

    Returns the value as a bytes, not a str.
    """
    chunks = []
    i = 1
    prefix = headerprefix.upper().replace(r'-', r'_')
    while True:
        v = req.env.get(r'HTTP_%s_%d' % (prefix, i))
        if v is None:
            break
        chunks.append(pycompat.bytesurl(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()
        if pycompat.ispy3:
            args = {k.encode('ascii'): [v.encode('ascii') for v in vs]
                    for k, vs in args.items()}
        postlen = int(self.req.env.get(r'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, r'X-HgArg')
        args.update(cgi.parse_qs(argvalue, keep_blank_values=True))
        return args
    def getfile(self, fp):
        length = int(self.req.env[r'CONTENT_LENGTH'])
        # If httppostargs is used, we need to read Content-Length
        # minus the amount that was consumed by args.
        length -= int(self.req.env.get(r'HTTP_X_HGARGS_POST', 0))
        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, r'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')}
        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, bytes):
        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 []
    raise error.ProgrammingError('hgweb.protocol internal failure', rsp)