annotate mercurial/wireprotov1server.py @ 45892:06b64fabf91c

copies: cache the ancestor checking call when tracing copy

A good share of the time spent in this function is spent doing ancestors
checking. To avoid spending time in duplicated call, we cache the result of
calls.

In the slower case, this provide a quite significant performance boost. Below
are the result for a set of selected pairs (many of them pathological):

(And further down is another table that summarize the current state of filelog
based vs changeset base copy tracing)


The benchmark have been configured to be killed after 6 minutes of runtime,
which mean that any detect slower than 2 minutes will be marked as "killed".
This drop some useful information about how much slower these case are… but also
prevent 99% of the benchmark time to be spent on case that can be labelled "very
slow" anyway.


Repo            Case                                  Source-Rev   Dest-Rev         Old-Time      New-Time     Difference   Factor
------------------------------------------------------------------------------------------------------------------------------------
mercurial       x_revs_x_added_0_copies               ad6b123de1c7 39cfcef4f463 :   0.000044 s,   0.000044 s,  +0.000000 s, × 1.0000
mercurial       x_revs_x_added_x_copies               2b1c78674230 0c1d10351869 :   0.000138 s,   0.000138 s,  +0.000000 s, × 1.0000
mercurial       x000_revs_x000_added_x_copies         81f8ff2a9bf2 dd3267698d84 :   0.005067 s,   0.005052 s,  -0.000015 s, × 0.9970
pypy            x_revs_x_added_0_copies               aed021ee8ae8 099ed31b181b :   0.000218 s,   0.000219 s,  +0.000001 s, × 1.0046
pypy            x_revs_x000_added_0_copies            4aa4e1f8e19a 359343b9ac0e :   0.000053 s,   0.000055 s,  +0.000002 s, × 1.0377
pypy            x_revs_x_added_x_copies               ac52eb7bbbb0 72e022663155 :   0.000125 s,   0.000128 s,  +0.000003 s, × 1.0240
pypy            x_revs_x00_added_x_copies             c3b14617fbd7 ace7255d9a26 :   0.001098 s,   0.001089 s,  -0.000009 s, × 0.9918
pypy            x_revs_x000_added_x000_copies         df6f7a526b60 a83dc6a2d56f :   0.017546 s,   0.017407 s,  -0.000139 s, × 0.9921
pypy            x000_revs_xx00_added_0_copies         89a76aede314 2f22446ff07e :   0.096723 s,   0.094175 s,  -0.002548 s, × 0.9737
pypy            x000_revs_x000_added_x_copies         8a3b5bfd266e 2c68e87c3efe :   0.271796 s,   0.238009 s,  -0.033787 s, × 0.8757
pypy            x000_revs_x000_added_x000_copies      89a76aede314 7b3dda341c84 :   0.128602 s,   0.125876 s,  -0.002726 s, × 0.9788
pypy            x0000_revs_x_added_0_copies           d1defd0dc478 c9cb1334cc78 :   7.086742 s,   3.581556 s,  -3.505186 s, × 0.5054
pypy            x0000_revs_xx000_added_0_copies       bf2c629d0071 4ffed77c095c :   0.016634 s,   0.016721 s,  +0.000087 s, × 1.0052
pypy            x0000_revs_xx000_added_x000_copies    08ea3258278e d9fa043f30c0 :   0.254225 s,   0.242367 s,  -0.011858 s, × 0.9534
netbeans        x_revs_x_added_0_copies               fb0955ffcbcd a01e9239f9e7 :   0.000166 s,   0.000165 s,  -0.000001 s, × 0.9940
netbeans        x_revs_x000_added_0_copies            6f360122949f 20eb231cc7d0 :   0.000118 s,   0.000114 s,  -0.000004 s, × 0.9661
netbeans        x_revs_x_added_x_copies               1ada3faf6fb6 5a39d12eecf4 :   0.000296 s,   0.000296 s,  +0.000000 s, × 1.0000
netbeans        x_revs_x00_added_x_copies             35be93ba1e2c 9eec5e90c05f :   0.001137 s,   0.001124 s,  -0.000013 s, × 0.9886
netbeans        x000_revs_xx00_added_0_copies         eac3045b4fdd 51d4ae7f1290 :   0.014133 s,   0.013060 s,  -0.001073 s, × 0.9241
netbeans        x000_revs_x000_added_x_copies         e2063d266acd 6081d72689dc :   0.016988 s,   0.017112 s,  +0.000124 s, × 1.0073
netbeans        x000_revs_x000_added_x000_copies      ff453e9fee32 411350406ec2 :   0.676361 s,   0.660350 s,  -0.016011 s, × 0.9763
netbeans        x0000_revs_xx000_added_x000_copies    588c2d1ced70 1aad62e59ddd :  12.515149 s,  10.032499 s,  -2.482650 s, × 0.8016
mozilla-central x_revs_x_added_0_copies               3697f962bb7b 7015fcdd43a2 :   0.000186 s,   0.000189 s,  +0.000003 s, × 1.0161
mozilla-central x_revs_x000_added_0_copies            dd390860c6c9 40d0c5bed75d :   0.000459 s,   0.000462 s,  +0.000003 s, × 1.0065
mozilla-central x_revs_x_added_x_copies               8d198483ae3b 14207ffc2b2f :   0.000273 s,   0.000270 s,  -0.000003 s, × 0.9890
mozilla-central x_revs_x00_added_x_copies             98cbc58cc6bc 446a150332c3 :   0.001503 s,   0.001474 s,  -0.000029 s, × 0.9807
mozilla-central x_revs_x000_added_x000_copies         3c684b4b8f68 0a5e72d1b479 :   0.004862 s,   0.004806 s,  -0.000056 s, × 0.9885
mozilla-central x_revs_x0000_added_x0000_copies       effb563bb7e5 c07a39dc4e80 :   0.088291 s,   0.085150 s,  -0.003141 s, × 0.9644
mozilla-central x000_revs_xx00_added_0_copies         6100d773079a 04a55431795e :   0.007113 s,   0.007064 s,  -0.000049 s, × 0.9931
mozilla-central x000_revs_x000_added_x_copies         9f17a6fc04f9 2d37b966abed :   0.004687 s,   0.004741 s,  +0.000054 s, × 1.0115
mozilla-central x000_revs_x000_added_x000_copies      7c97034feb78 4407bd0c6330 :   0.198710 s,   0.190133 s,  -0.008577 s, × 0.9568
mozilla-central x0000_revs_xx000_added_0_copies       9eec5917337d 67118cc6dcad :   0.036068 s,   0.035651 s,  -0.000417 s, × 0.9884
mozilla-central x0000_revs_xx000_added_x000_copies    f78c615a656c 96a38b690156 :   0.465362 s,   0.440694 s,  -0.024668 s, × 0.9470
mozilla-central x00000_revs_x0000_added_x0000_copies  6832ae71433c 4c222a1d9a00 :  24.519684 s,  18.454163 s,  -6.065521 s, × 0.7526
mozilla-central x00000_revs_x00000_added_x000_copies  76caed42cf7c 1daa622bbe42 :  42.711897 s,  31.562719 s, -11.149178 s, × 0.7390
mozilla-try     x_revs_x_added_0_copies               aaf6dde0deb8 9790f499805a :   0.001201 s,   0.001189 s,  -0.000012 s, × 0.9900
mozilla-try     x_revs_x000_added_0_copies            d8d0222927b4 5bb8ce8c7450 :   0.001216 s,   0.001204 s,  -0.000012 s, × 0.9901
mozilla-try     x_revs_x_added_x_copies               092fcca11bdb 936255a0384a :   0.000595 s,   0.000586 s,  -0.000009 s, × 0.9849
mozilla-try     x_revs_x00_added_x_copies             b53d2fadbdb5 017afae788ec :   0.001856 s,   0.001845 s,  -0.000011 s, × 0.9941
mozilla-try     x_revs_x000_added_x000_copies         20408ad61ce5 6f0ee96e21ad :   0.064936 s,   0.063822 s,  -0.001114 s, × 0.9828
mozilla-try     x_revs_x0000_added_x0000_copies       effb563bb7e5 c07a39dc4e80 :   0.090601 s,   0.088038 s,  -0.002563 s, × 0.9717
mozilla-try     x000_revs_xx00_added_0_copies         6100d773079a 04a55431795e :   0.007510 s,   0.007389 s,  -0.000121 s, × 0.9839
mozilla-try     x000_revs_x000_added_x_copies         9f17a6fc04f9 2d37b966abed :   0.004911 s,   0.004868 s,  -0.000043 s, × 0.9912
mozilla-try     x000_revs_x000_added_x000_copies      1346fd0130e4 4c65cbdabc1f :   0.233231 s,   0.222450 s,  -0.010781 s, × 0.9538
mozilla-try     x0000_revs_x_added_0_copies           63519bfd42ee a36a2a865d92 :   0.419989 s,   0.370675 s,  -0.049314 s, × 0.8826
mozilla-try     x0000_revs_x_added_x_copies           9fe69ff0762d bcabf2a78927 :   0.401521 s,   0.358020 s,  -0.043501 s, × 0.8917
mozilla-try     x0000_revs_xx000_added_x_copies       156f6e2674f2 4d0f2c178e66 :   0.179555 s,   0.145235 s,  -0.034320 s, × 0.8089
mozilla-try     x0000_revs_xx000_added_0_copies       9eec5917337d 67118cc6dcad :   0.038004 s,   0.037606 s,  -0.000398 s, × 0.9895
mozilla-try     x0000_revs_xx000_added_x000_copies    89294cd501d9 7ccb2fc7ccb5 :  52.838482 s,   7.382439 s, -45.456043 s, × 0.1397
mozilla-try     x0000_revs_x0000_added_x0000_copies   e928c65095ed e951f4ad123a :   8.705874 s,   7.273506 s,  -1.432368 s, × 0.8355
mozilla-try     x00000_revs_x00000_added_0_copies     dc8a3ca7010e d16fde900c9c :   1.126708 s,   1.074593 s,  -0.052115 s, × 0.9537
mozilla-try     x00000_revs_x0000_added_x0000_copies  8d3fafa80d4b eb884023b810 :  83.854020 s,  27.746195 s, -56.107825 s, × 0.3309


Below is a table comparing the runtime of the current "filelog centric"
algorithm, with the "changeset centric" one, we just modified.

The changeset centric algorithm is a significant win in many scenario, but they
are still various cases where it is quite slower. When many revision  has to be
considered the cost of retrieving the copy information, creating new
dictionaries, merging dictionaries and checking if revision are ancestors of
each other can slow things down.

The rest of this series, will introduce a rust version of the copy tracing code
to deal with most of theses issues.


Repo            Case                                  Source-Rev   Dest-Rev         filelog     sidedata      Difference       Factor
---------------------------------------------------------------------------------------------------------------------------------------
mercurial       x_revs_x_added_0_copies               ad6b123de1c7 39cfcef4f463 :  0.000914 s,  0.000044 s, - 0.000870 s,    × 0.048140
mercurial       x_revs_x_added_x_copies               2b1c78674230 0c1d10351869 :  0.001812 s,  0.000138 s, - 0.001674 s,    × 0.076159
mercurial       x000_revs_x000_added_x_copies         81f8ff2a9bf2 dd3267698d84 :  0.017954 s,  0.005052 s, - 0.012902 s,    × 0.281386
pypy            x_revs_x_added_0_copies               aed021ee8ae8 099ed31b181b :  0.001509 s,  0.000219 s, - 0.001290 s,    × 0.145129
pypy            x_revs_x000_added_0_copies            4aa4e1f8e19a 359343b9ac0e :  0.206881 s,  0.000055 s, - 0.206826 s,    × 0.000266
pypy            x_revs_x_added_x_copies               ac52eb7bbbb0 72e022663155 :  0.016951 s,  0.000128 s, - 0.016823 s,    × 0.007551
pypy            x_revs_x00_added_x_copies             c3b14617fbd7 ace7255d9a26 :  0.019096 s,  0.001089 s, - 0.018007 s,    × 0.057028
pypy            x_revs_x000_added_x000_copies         df6f7a526b60 a83dc6a2d56f :  0.762506 s,  0.017407 s, - 0.745099 s,    × 0.022829
pypy            x000_revs_xx00_added_0_copies         89a76aede314 2f22446ff07e :  1.179211 s,  0.094175 s, - 1.085036 s,    × 0.079863
pypy            x000_revs_x000_added_x_copies         8a3b5bfd266e 2c68e87c3efe :  1.249058 s,  0.238009 s, - 1.011049 s,    × 0.190551
pypy            x000_revs_x000_added_x000_copies      89a76aede314 7b3dda341c84 :  1.614107 s,  0.125876 s, - 1.488231 s,    × 0.077985
pypy            x0000_revs_x_added_0_copies           d1defd0dc478 c9cb1334cc78 :  0.001064 s,  3.581556 s, + 3.580492 s, × 3366.124060
pypy            x0000_revs_xx000_added_0_copies       bf2c629d0071 4ffed77c095c :  1.061275 s,  0.016721 s, - 1.044554 s,    × 0.015756
pypy            x0000_revs_xx000_added_x000_copies    08ea3258278e d9fa043f30c0 :  1.341119 s,  0.242367 s, - 1.098752 s,    × 0.180720
netbeans        x_revs_x_added_0_copies               fb0955ffcbcd a01e9239f9e7 :  0.027803 s,  0.000165 s, - 0.027638 s,    × 0.005935
netbeans        x_revs_x000_added_0_copies            6f360122949f 20eb231cc7d0 :  0.130014 s,  0.000114 s, - 0.129900 s,    × 0.000877
netbeans        x_revs_x_added_x_copies               1ada3faf6fb6 5a39d12eecf4 :  0.024990 s,  0.000296 s, - 0.024694 s,    × 0.011845
netbeans        x_revs_x00_added_x_copies             35be93ba1e2c 9eec5e90c05f :  0.052201 s,  0.001124 s, - 0.051077 s,    × 0.021532
netbeans        x000_revs_xx00_added_0_copies         eac3045b4fdd 51d4ae7f1290 :  0.037642 s,  0.013060 s, - 0.024582 s,    × 0.346953
netbeans        x000_revs_x000_added_x_copies         e2063d266acd 6081d72689dc :  0.197086 s,  0.017112 s, - 0.179974 s,    × 0.086825
netbeans        x000_revs_x000_added_x000_copies      ff453e9fee32 411350406ec2 :  0.935148 s,  0.660350 s, - 0.274798 s,    × 0.706145
netbeans        x0000_revs_xx000_added_x000_copies    588c2d1ced70 1aad62e59ddd :  3.920674 s, 10.032499 s, + 6.111825 s,    × 2.558871
mozilla-central x_revs_x_added_0_copies               3697f962bb7b 7015fcdd43a2 :  0.024232 s,  0.000189 s, - 0.024043 s,    × 0.007800
mozilla-central x_revs_x000_added_0_copies            dd390860c6c9 40d0c5bed75d :  0.141483 s,  0.000462 s, - 0.141021 s,    × 0.003265
mozilla-central x_revs_x_added_x_copies               8d198483ae3b 14207ffc2b2f :  0.025775 s,  0.000270 s, - 0.025505 s,    × 0.010475
mozilla-central x_revs_x00_added_x_copies             98cbc58cc6bc 446a150332c3 :  0.084922 s,  0.001474 s, - 0.083448 s,    × 0.017357
mozilla-central x_revs_x000_added_x000_copies         3c684b4b8f68 0a5e72d1b479 :  0.194784 s,  0.004806 s, - 0.189978 s,    × 0.024673
mozilla-central x_revs_x0000_added_x0000_copies       effb563bb7e5 c07a39dc4e80 :  2.161103 s,  0.085150 s, - 2.075953 s,    × 0.039401
mozilla-central x000_revs_xx00_added_0_copies         6100d773079a 04a55431795e :  0.089347 s,  0.007064 s, - 0.082283 s,    × 0.079063
mozilla-central x000_revs_x000_added_x_copies         9f17a6fc04f9 2d37b966abed :  0.732171 s,  0.004741 s, - 0.727430 s,    × 0.006475
mozilla-central x000_revs_x000_added_x000_copies      7c97034feb78 4407bd0c6330 :  1.157287 s,  0.190133 s, - 0.967154 s,    × 0.164292
mozilla-central x0000_revs_xx000_added_0_copies       9eec5917337d 67118cc6dcad :  6.726568 s,  0.035651 s, - 6.690917 s,    × 0.005300
mozilla-central x0000_revs_xx000_added_x000_copies    f78c615a656c 96a38b690156 :  3.266229 s,  0.440694 s, - 2.825535 s,    × 0.134924
mozilla-central x00000_revs_x0000_added_x0000_copies  6832ae71433c 4c222a1d9a00 : 15.860534 s, 18.454163 s, + 2.593629 s,    × 1.163527
mozilla-central x00000_revs_x00000_added_x000_copies  76caed42cf7c 1daa622bbe42 : 20.450475 s, 31.562719 s, +11.112244 s,    × 1.543373
mozilla-try     x_revs_x_added_0_copies               aaf6dde0deb8 9790f499805a :  0.080442 s,  0.001189 s, - 0.079253 s,    × 0.014781
mozilla-try     x_revs_x000_added_0_copies            d8d0222927b4 5bb8ce8c7450 :  0.497672 s,  0.001204 s, - 0.496468 s,    × 0.002419
mozilla-try     x_revs_x_added_x_copies               092fcca11bdb 936255a0384a :  0.021183 s,  0.000586 s, - 0.020597 s,    × 0.027664
mozilla-try     x_revs_x00_added_x_copies             b53d2fadbdb5 017afae788ec :  0.230991 s,  0.001845 s, - 0.229146 s,    × 0.007987
mozilla-try     x_revs_x000_added_x000_copies         20408ad61ce5 6f0ee96e21ad :  1.118461 s,  0.063822 s, - 1.054639 s,    × 0.057062
mozilla-try     x_revs_x0000_added_x0000_copies       effb563bb7e5 c07a39dc4e80 :  2.206083 s,  0.088038 s, - 2.118045 s,    × 0.039907
mozilla-try     x000_revs_xx00_added_0_copies         6100d773079a 04a55431795e :  0.089404 s,  0.007389 s, - 0.082015 s,    × 0.082647
mozilla-try     x000_revs_x000_added_x_copies         9f17a6fc04f9 2d37b966abed :  0.733043 s,  0.004868 s, - 0.728175 s,    × 0.006641
mozilla-try     x000_revs_x000_added_x000_copies      1346fd0130e4 4c65cbdabc1f :  1.163367 s,  0.222450 s, - 0.940917 s,    × 0.191212
mozilla-try     x0000_revs_x_added_0_copies           63519bfd42ee a36a2a865d92 :  0.085456 s,  0.370675 s, + 0.285219 s,    × 4.337612
mozilla-try     x0000_revs_x_added_x_copies           9fe69ff0762d bcabf2a78927 :  0.083601 s,  0.358020 s, + 0.274419 s,    × 4.282485
mozilla-try     x0000_revs_xx000_added_x_copies       156f6e2674f2 4d0f2c178e66 :  7.366614 s,  0.145235 s, - 7.221379 s,    × 0.019715
mozilla-try     x0000_revs_xx000_added_0_copies       9eec5917337d 67118cc6dcad :  6.664464 s,  0.037606 s, - 6.626858 s,    × 0.005643
mozilla-try     x0000_revs_xx000_added_x000_copies    89294cd501d9 7ccb2fc7ccb5 :  7.467836 s,  7.382439 s, - 0.085397 s,    × 0.988565
mozilla-try     x0000_revs_x0000_added_x0000_copies   e928c65095ed e951f4ad123a :  9.801294 s,  7.273506 s, - 2.527788 s,    × 0.742097
mozilla-try     x00000_revs_x_added_0_copies          6a320851d377 1ebb79acd503 :  0.091886 s, killed
mozilla-try     x00000_revs_x00000_added_0_copies     dc8a3ca7010e d16fde900c9c : 26.491140 s,  1.074593 s, -25.416547 s,    × 0.040564
mozilla-try     x00000_revs_x_added_x_copies          5173c4b6f97c 95d83ee7242d :  0.092863 s, killed
mozilla-try     x00000_revs_x000_added_x_copies       9126823d0e9c ca82787bb23c :  0.226823 s, killed
mozilla-try     x00000_revs_x0000_added_x0000_copies  8d3fafa80d4b eb884023b810 : 18.914630 s, 27.746195 s, + 8.831565 s,    × 1.466917
mozilla-try     x00000_revs_x00000_added_x0000_copies 1b661134e2ca 1ae03d022d6d : 21.198903 s, killed
mozilla-try     x00000_revs_x00000_added_x000_copies  9b2a99adc05e 8e29777b48e6 : 24.952268 s, killed

Differential Revision: https://phab.mercurial-scm.org/D9296

# wireprotov1server.py - Wire protocol version 1 server functionality
#
# Copyright 2005-2010 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 binascii
import os

from .i18n import _
from .node import (
    hex,
    nullid,
)
from .pycompat import getattr

from . import (
    bundle2,
    bundlecaches,
    changegroup as changegroupmod,
    discovery,
    encoding,
    error,
    exchange,
    pushkey as pushkeymod,
    pycompat,
    streamclone,
    util,
    wireprototypes,
)

from .utils import (
    procutil,
    stringutil,
)

urlerr = util.urlerr
urlreq = util.urlreq

bundle2requiredmain = _(b'incompatible Mercurial client; bundle2 required')
bundle2requiredhint = _(
    b'see https://www.mercurial-scm.org/wiki/IncompatibleClient'
)
bundle2required = b'%s\n(%s)\n' % (bundle2requiredmain, bundle2requiredhint)


def clientcompressionsupport(proto):
    """Returns a list of compression methods supported by the client.

    Returns a list of the compression methods supported by the client
    according to the protocol capabilities. If no such capability has
    been announced, fallback to the default of zlib and uncompressed.
    """
    for cap in proto.getprotocaps():
        if cap.startswith(b'comp='):
            return cap[5:].split(b',')
    return [b'zlib', b'none']


# wire protocol command can either return a string or one of these classes.


def getdispatchrepo(repo, proto, command):
    """Obtain the repo used for processing wire protocol commands.

    The intent of this function is to serve as a monkeypatch point for
    extensions that need commands to operate on different repo views under
    specialized circumstances.
    """
    viewconfig = repo.ui.config(b'server', b'view')
    return repo.filtered(viewconfig)


def dispatch(repo, proto, command):
    repo = getdispatchrepo(repo, proto, command)

    func, spec = commands[command]
    args = proto.getargs(spec)

    return func(repo, proto, *args)


def options(cmd, keys, others):
    opts = {}
    for k in keys:
        if k in others:
            opts[k] = others[k]
            del others[k]
    if others:
        procutil.stderr.write(
            b"warning: %s ignored unexpected arguments %s\n"
            % (cmd, b",".join(others))
        )
    return opts


def bundle1allowed(repo, action):
    """Whether a bundle1 operation is allowed from the server.

    Priority is:

    1. server.bundle1gd.<action> (if generaldelta active)
    2. server.bundle1.<action>
    3. server.bundle1gd (if generaldelta active)
    4. server.bundle1
    """
    ui = repo.ui
    gd = b'generaldelta' in repo.requirements

    if gd:
        v = ui.configbool(b'server', b'bundle1gd.%s' % action)
        if v is not None:
            return v

    v = ui.configbool(b'server', b'bundle1.%s' % action)
    if v is not None:
        return v

    if gd:
        v = ui.configbool(b'server', b'bundle1gd')
        if v is not None:
            return v

    return ui.configbool(b'server', b'bundle1')


commands = wireprototypes.commanddict()


def wireprotocommand(name, args=None, permission=b'push'):
    """Decorator to declare a wire protocol command.

    ``name`` is the name of the wire protocol command being provided.

    ``args`` defines the named arguments accepted by the command. It is
    a space-delimited list of argument names. ``*`` denotes a special value
    that says to accept all named arguments.

    ``permission`` defines the permission type needed to run this command.
    Can be ``push`` or ``pull``. These roughly map to read-write and read-only,
    respectively. Default is to assume command requires ``push`` permissions
    because otherwise commands not declaring their permissions could modify
    a repository that is supposed to be read-only.
    """
    transports = {
        k for k, v in wireprototypes.TRANSPORTS.items() if v[b'version'] == 1
    }

    # Because SSHv2 is a mirror of SSHv1, we allow "batch" commands through to
    # SSHv2.
    # TODO undo this hack when SSH is using the unified frame protocol.
    if name == b'batch':
        transports.add(wireprototypes.SSHV2)

    if permission not in (b'push', b'pull'):
        raise error.ProgrammingError(
            b'invalid wire protocol permission; '
            b'got %s; expected "push" or "pull"' % permission
        )

    if args is None:
        args = b''

    if not isinstance(args, bytes):
        raise error.ProgrammingError(
            b'arguments for version 1 commands must be declared as bytes'
        )

    def register(func):
        if name in commands:
            raise error.ProgrammingError(
                b'%s command already registered for version 1' % name
            )
        commands[name] = wireprototypes.commandentry(
            func, args=args, transports=transports, permission=permission
        )

        return func

    return register


# TODO define a more appropriate permissions type to use for this.
@wireprotocommand(b'batch', b'cmds *', permission=b'pull')
def batch(repo, proto, cmds, others):
    unescapearg = wireprototypes.unescapebatcharg
    res = []
    for pair in cmds.split(b';'):
        op, args = pair.split(b' ', 1)
        vals = {}
        for a in args.split(b','):
            if a:
                n, v = a.split(b'=')
                vals[unescapearg(n)] = unescapearg(v)
        func, spec = commands[op]

        # Validate that client has permissions to perform this command.
        perm = commands[op].permission
        assert perm in (b'push', b'pull')
        proto.checkperm(perm)

        if spec:
            keys = spec.split()
            data = {}
            for k in keys:
                if k == b'*':
                    star = {}
                    for key in vals.keys():
                        if key not in keys:
                            star[key] = vals[key]
                    data[b'*'] = star
                else:
                    data[k] = vals[k]
            result = func(repo, proto, *[data[k] for k in keys])
        else:
            result = func(repo, proto)
        if isinstance(result, wireprototypes.ooberror):
            return result

        # For now, all batchable commands must return bytesresponse or
        # raw bytes (for backwards compatibility).
        assert isinstance(result, (wireprototypes.bytesresponse, bytes))
        if isinstance(result, wireprototypes.bytesresponse):
            result = result.data
        res.append(wireprototypes.escapebatcharg(result))

    return wireprototypes.bytesresponse(b';'.join(res))


@wireprotocommand(b'between', b'pairs', permission=b'pull')
def between(repo, proto, pairs):
    pairs = [wireprototypes.decodelist(p, b'-') for p in pairs.split(b" ")]
    r = []
    for b in repo.between(pairs):
        r.append(wireprototypes.encodelist(b) + b"\n")

    return wireprototypes.bytesresponse(b''.join(r))


@wireprotocommand(b'branchmap', permission=b'pull')
def branchmap(repo, proto):
    branchmap = repo.branchmap()
    heads = []
    for branch, nodes in pycompat.iteritems(branchmap):
        branchname = urlreq.quote(encoding.fromlocal(branch))
        branchnodes = wireprototypes.encodelist(nodes)
        heads.append(b'%s %s' % (branchname, branchnodes))

    return wireprototypes.bytesresponse(b'\n'.join(heads))


@wireprotocommand(b'branches', b'nodes', permission=b'pull')
def branches(repo, proto, nodes):
    nodes = wireprototypes.decodelist(nodes)
    r = []
    for b in repo.branches(nodes):
        r.append(wireprototypes.encodelist(b) + b"\n")

    return wireprototypes.bytesresponse(b''.join(r))


@wireprotocommand(b'clonebundles', b'', permission=b'pull')
def clonebundles(repo, proto):
    """Server command for returning info for available bundles to seed clones.

    Clients will parse this response and determine what bundle to fetch.

    Extensions may wrap this command to filter or dynamically emit data
    depending on the request. e.g. you could advertise URLs for the closest
    data center given the client's IP address.
    """
    return wireprototypes.bytesresponse(
        repo.vfs.tryread(bundlecaches.CB_MANIFEST_FILE)
    )


wireprotocaps = [
    b'lookup',
    b'branchmap',
    b'pushkey',
    b'known',
    b'getbundle',
    b'unbundlehash',
]


def _capabilities(repo, proto):
    """return a list of capabilities for a repo

    This function exists to allow extensions to easily wrap capabilities
    computation

    - returns a lists: easy to alter
    - change done here will be propagated to both `capabilities` and `hello`
      command without any other action needed.
    """
    # copy to prevent modification of the global list
    caps = list(wireprotocaps)

    # Command of same name as capability isn't exposed to version 1 of
    # transports. So conditionally add it.
    if commands.commandavailable(b'changegroupsubset', proto):
        caps.append(b'changegroupsubset')

    if streamclone.allowservergeneration(repo):
        if repo.ui.configbool(b'server', b'preferuncompressed'):
            caps.append(b'stream-preferred')
        requiredformats = repo.requirements & repo.supportedformats
        # if our local revlogs are just revlogv1, add 'stream' cap
        if not requiredformats - {b'revlogv1'}:
            caps.append(b'stream')
        # otherwise, add 'streamreqs' detailing our local revlog format
        else:
            caps.append(b'streamreqs=%s' % b','.join(sorted(requiredformats)))
    if repo.ui.configbool(b'experimental', b'bundle2-advertise'):
        capsblob = bundle2.encodecaps(bundle2.getrepocaps(repo, role=b'server'))
        caps.append(b'bundle2=' + urlreq.quote(capsblob))
    caps.append(b'unbundle=%s' % b','.join(bundle2.bundlepriority))

    if repo.ui.configbool(b'experimental', b'narrow'):
        caps.append(wireprototypes.NARROWCAP)
        if repo.ui.configbool(b'experimental', b'narrowservebrokenellipses'):
            caps.append(wireprototypes.ELLIPSESCAP)

    return proto.addcapabilities(repo, caps)


# If you are writing an extension and consider wrapping this function. Wrap
# `_capabilities` instead.
@wireprotocommand(b'capabilities', permission=b'pull')
def capabilities(repo, proto):
    caps = _capabilities(repo, proto)
    return wireprototypes.bytesresponse(b' '.join(sorted(caps)))


@wireprotocommand(b'changegroup', b'roots', permission=b'pull')
def changegroup(repo, proto, roots):
    nodes = wireprototypes.decodelist(roots)
    outgoing = discovery.outgoing(
        repo, missingroots=nodes, ancestorsof=repo.heads()
    )
    cg = changegroupmod.makechangegroup(repo, outgoing, b'01', b'serve')
    gen = iter(lambda: cg.read(32768), b'')
    return wireprototypes.streamres(gen=gen)


@wireprotocommand(b'changegroupsubset', b'bases heads', permission=b'pull')
def changegroupsubset(repo, proto, bases, heads):
    bases = wireprototypes.decodelist(bases)
    heads = wireprototypes.decodelist(heads)
    outgoing = discovery.outgoing(repo, missingroots=bases, ancestorsof=heads)
    cg = changegroupmod.makechangegroup(repo, outgoing, b'01', b'serve')
    gen = iter(lambda: cg.read(32768), b'')
    return wireprototypes.streamres(gen=gen)


@wireprotocommand(b'debugwireargs', b'one two *', permission=b'pull')
def debugwireargs(repo, proto, one, two, others):
    # only accept optional args from the known set
    opts = options(b'debugwireargs', [b'three', b'four'], others)
    return wireprototypes.bytesresponse(
        repo.debugwireargs(one, two, **pycompat.strkwargs(opts))
    )


def find_pullbundle(repo, proto, opts, clheads, heads, common):
    """Return a file object for the first matching pullbundle.

    Pullbundles are specified in .hg/pullbundles.manifest similar to
    clonebundles.
    For each entry, the bundle specification is checked for compatibility:
    - Client features vs the BUNDLESPEC.
    - Revisions shared with the clients vs base revisions of the bundle.
      A bundle can be applied only if all its base revisions are known by
      the client.
    - At least one leaf of the bundle's DAG is missing on the client.
    - Every leaf of the bundle's DAG is part of node set the client wants.
      E.g. do not send a bundle of all changes if the client wants only
      one specific branch of many.
    """

    def decodehexstring(s):
        return {binascii.unhexlify(h) for h in s.split(b';')}

    manifest = repo.vfs.tryread(b'pullbundles.manifest')
    if not manifest:
        return None
    res = bundlecaches.parseclonebundlesmanifest(repo, manifest)
    res = bundlecaches.filterclonebundleentries(repo, res)
    if not res:
        return None
    cl = repo.unfiltered().changelog
    heads_anc = cl.ancestors([cl.rev(rev) for rev in heads], inclusive=True)
    common_anc = cl.ancestors([cl.rev(rev) for rev in common], inclusive=True)
    compformats = clientcompressionsupport(proto)
    for entry in res:
        comp = entry.get(b'COMPRESSION')
        altcomp = util.compengines._bundlenames.get(comp)
        if comp and comp not in compformats and altcomp not in compformats:
            continue
        # No test yet for VERSION, since V2 is supported by any client
        # that advertises partial pulls
        if b'heads' in entry:
            try:
                bundle_heads = decodehexstring(entry[b'heads'])
            except TypeError:
                # Bad heads entry
                continue
            if bundle_heads.issubset(common):
                continue  # Nothing new
            if all(cl.rev(rev) in common_anc for rev in bundle_heads):
                continue  # Still nothing new
            if any(
                cl.rev(rev) not in heads_anc and cl.rev(rev) not in common_anc
                for rev in bundle_heads
            ):
                continue
        if b'bases' in entry:
            try:
                bundle_bases = decodehexstring(entry[b'bases'])
            except TypeError:
                # Bad bases entry
                continue
            if not all(cl.rev(rev) in common_anc for rev in bundle_bases):
                continue
        path = entry[b'URL']
        repo.ui.debug(b'sending pullbundle "%s"\n' % path)
        try:
            return repo.vfs.open(path)
        except IOError:
            repo.ui.debug(b'pullbundle "%s" not accessible\n' % path)
            continue
    return None


@wireprotocommand(b'getbundle', b'*', permission=b'pull')
def getbundle(repo, proto, others):
    opts = options(
        b'getbundle', wireprototypes.GETBUNDLE_ARGUMENTS.keys(), others
    )
    for k, v in pycompat.iteritems(opts):
        keytype = wireprototypes.GETBUNDLE_ARGUMENTS[k]
        if keytype == b'nodes':
            opts[k] = wireprototypes.decodelist(v)
        elif keytype == b'csv':
            opts[k] = list(v.split(b','))
        elif keytype == b'scsv':
            opts[k] = set(v.split(b','))
        elif keytype == b'boolean':
            # Client should serialize False as '0', which is a non-empty string
            # so it evaluates as a True bool.
            if v == b'0':
                opts[k] = False
            else:
                opts[k] = bool(v)
        elif keytype != b'plain':
            raise KeyError(b'unknown getbundle option type %s' % keytype)

    if not bundle1allowed(repo, b'pull'):
        if not exchange.bundle2requested(opts.get(b'bundlecaps')):
            if proto.name == b'http-v1':
                return wireprototypes.ooberror(bundle2required)
            raise error.Abort(bundle2requiredmain, hint=bundle2requiredhint)

    try:
        clheads = set(repo.changelog.heads())
        heads = set(opts.get(b'heads', set()))
        common = set(opts.get(b'common', set()))
        common.discard(nullid)
        if (
            repo.ui.configbool(b'server', b'pullbundle')
            and b'partial-pull' in proto.getprotocaps()
        ):
            # Check if a pre-built bundle covers this request.
            bundle = find_pullbundle(repo, proto, opts, clheads, heads, common)
            if bundle:
                return wireprototypes.streamres(
                    gen=util.filechunkiter(bundle), prefer_uncompressed=True
                )

        if repo.ui.configbool(b'server', b'disablefullbundle'):
            # Check to see if this is a full clone.
            changegroup = opts.get(b'cg', True)
            if changegroup and not common and clheads == heads:
                raise error.Abort(
                    _(b'server has pull-based clones disabled'),
                    hint=_(b'remove --pull if specified or upgrade Mercurial'),
                )

        info, chunks = exchange.getbundlechunks(
            repo, b'serve', **pycompat.strkwargs(opts)
        )
        prefercompressed = info.get(b'prefercompressed', True)
    except error.Abort as exc:
        # cleanly forward Abort error to the client
        if not exchange.bundle2requested(opts.get(b'bundlecaps')):
            if proto.name == b'http-v1':
                return wireprototypes.ooberror(exc.message + b'\n')
            raise  # cannot do better for bundle1 + ssh
        # bundle2 request expect a bundle2 reply
        bundler = bundle2.bundle20(repo.ui)
        manargs = [(b'message', exc.message)]
        advargs = []
        if exc.hint is not None:
            advargs.append((b'hint', exc.hint))
        bundler.addpart(bundle2.bundlepart(b'error:abort', manargs, advargs))
        chunks = bundler.getchunks()
        prefercompressed = False

    return wireprototypes.streamres(
        gen=chunks, prefer_uncompressed=not prefercompressed
    )


@wireprotocommand(b'heads', permission=b'pull')
def heads(repo, proto):
    h = repo.heads()
    return wireprototypes.bytesresponse(wireprototypes.encodelist(h) + b'\n')


@wireprotocommand(b'hello', permission=b'pull')
def hello(repo, proto):
    """Called as part of SSH handshake to obtain server info.

    Returns a list of lines describing interesting things about the
    server, in an RFC822-like format.

    Currently, the only one defined is ``capabilities``, which consists of a
    line of space separated tokens describing server abilities:

        capabilities: <token0> <token1> <token2>
    """
    caps = capabilities(repo, proto).data
    return wireprototypes.bytesresponse(b'capabilities: %s\n' % caps)


@wireprotocommand(b'listkeys', b'namespace', permission=b'pull')
def listkeys(repo, proto, namespace):
    d = sorted(repo.listkeys(encoding.tolocal(namespace)).items())
    return wireprototypes.bytesresponse(pushkeymod.encodekeys(d))


@wireprotocommand(b'lookup', b'key', permission=b'pull')
def lookup(repo, proto, key):
    try:
        k = encoding.tolocal(key)
        n = repo.lookup(k)
        r = hex(n)
        success = 1
    except Exception as inst:
        r = stringutil.forcebytestr(inst)
        success = 0
    return wireprototypes.bytesresponse(b'%d %s\n' % (success, r))


@wireprotocommand(b'known', b'nodes *', permission=b'pull')
def known(repo, proto, nodes, others):
    v = b''.join(
        b and b'1' or b'0' for b in repo.known(wireprototypes.decodelist(nodes))
    )
    return wireprototypes.bytesresponse(v)


@wireprotocommand(b'protocaps', b'caps', permission=b'pull')
def protocaps(repo, proto, caps):
    if proto.name == wireprototypes.SSHV1:
        proto._protocaps = set(caps.split(b' '))
    return wireprototypes.bytesresponse(b'OK')


@wireprotocommand(b'pushkey', b'namespace key old new', permission=b'push')
def pushkey(repo, proto, namespace, key, old, new):
    # compatibility with pre-1.8 clients which were accidentally
    # sending raw binary nodes rather than utf-8-encoded hex
    if len(new) == 20 and stringutil.escapestr(new) != new:
        # looks like it could be a binary node
        try:
            new.decode('utf-8')
            new = encoding.tolocal(new)  # but cleanly decodes as UTF-8
        except UnicodeDecodeError:
            pass  # binary, leave unmodified
    else:
        new = encoding.tolocal(new)  # normal path

    with proto.mayberedirectstdio() as output:
        r = (
            repo.pushkey(
                encoding.tolocal(namespace),
                encoding.tolocal(key),
                encoding.tolocal(old),
                new,
            )
            or False
        )

    output = output.getvalue() if output else b''
    return wireprototypes.bytesresponse(b'%d\n%s' % (int(r), output))


@wireprotocommand(b'stream_out', permission=b'pull')
def stream(repo, proto):
    '''If the server supports streaming clone, it advertises the "stream"
    capability with a value representing the version and flags of the repo
    it is serving. Client checks to see if it understands the format.
    '''
    return wireprototypes.streamreslegacy(streamclone.generatev1wireproto(repo))


@wireprotocommand(b'unbundle', b'heads', permission=b'push')
def unbundle(repo, proto, heads):
    their_heads = wireprototypes.decodelist(heads)

    with proto.mayberedirectstdio() as output:
        try:
            exchange.check_heads(repo, their_heads, b'preparing changes')
            cleanup = lambda: None
            try:
                payload = proto.getpayload()
                if repo.ui.configbool(b'server', b'streamunbundle'):

                    def cleanup():
                        # Ensure that the full payload is consumed, so
                        # that the connection doesn't contain trailing garbage.
                        for p in payload:
                            pass

                    fp = util.chunkbuffer(payload)
                else:
                    # write bundle data to temporary file as it can be big
                    fp, tempname = None, None

                    def cleanup():
                        if fp:
                            fp.close()
                        if tempname:
                            os.unlink(tempname)

                    fd, tempname = pycompat.mkstemp(prefix=b'hg-unbundle-')
                    repo.ui.debug(
                        b'redirecting incoming bundle to %s\n' % tempname
                    )
                    fp = os.fdopen(fd, pycompat.sysstr(b'wb+'))
                    for p in payload:
                        fp.write(p)
                    fp.seek(0)

                gen = exchange.readbundle(repo.ui, fp, None)
                if isinstance(
                    gen, changegroupmod.cg1unpacker
                ) and not bundle1allowed(repo, b'push'):
                    if proto.name == b'http-v1':
                        # need to special case http because stderr do not get to
                        # the http client on failed push so we need to abuse
                        # some other error type to make sure the message get to
                        # the user.
                        return wireprototypes.ooberror(bundle2required)
                    raise error.Abort(
                        bundle2requiredmain, hint=bundle2requiredhint
                    )

                r = exchange.unbundle(
                    repo, gen, their_heads, b'serve', proto.client()
                )
                if util.safehasattr(r, b'addpart'):
                    # The return looks streamable, we are in the bundle2 case
                    # and should return a stream.
                    return wireprototypes.streamreslegacy(gen=r.getchunks())
                return wireprototypes.pushres(
                    r, output.getvalue() if output else b''
                )

            finally:
                cleanup()

        except (error.BundleValueError, error.Abort, error.PushRaced) as exc:
            # handle non-bundle2 case first
            if not getattr(exc, 'duringunbundle2', False):
                try:
                    raise
                except error.Abort as exc:
                    # The old code we moved used procutil.stderr directly.
                    # We did not change it to minimise code change.
                    # This need to be moved to something proper.
                    # Feel free to do it.
                    procutil.stderr.write(exc.format())
                    procutil.stderr.flush()
                    return wireprototypes.pushres(
                        0, output.getvalue() if output else b''
                    )
                except error.PushRaced:
                    return wireprototypes.pusherr(
                        pycompat.bytestr(exc),
                        output.getvalue() if output else b'',
                    )

            bundler = bundle2.bundle20(repo.ui)
            for out in getattr(exc, '_bundle2salvagedoutput', ()):
                bundler.addpart(out)
            try:
                try:
                    raise
                except error.PushkeyFailed as exc:
                    # check client caps
                    remotecaps = getattr(exc, '_replycaps', None)
                    if (
                        remotecaps is not None
                        and b'pushkey' not in remotecaps.get(b'error', ())
                    ):
                        # no support remote side, fallback to Abort handler.
                        raise
                    part = bundler.newpart(b'error:pushkey')
                    part.addparam(b'in-reply-to', exc.partid)
                    if exc.namespace is not None:
                        part.addparam(
                            b'namespace', exc.namespace, mandatory=False
                        )
                    if exc.key is not None:
                        part.addparam(b'key', exc.key, mandatory=False)
                    if exc.new is not None:
                        part.addparam(b'new', exc.new, mandatory=False)
                    if exc.old is not None:
                        part.addparam(b'old', exc.old, mandatory=False)
                    if exc.ret is not None:
                        part.addparam(b'ret', exc.ret, mandatory=False)
            except error.BundleValueError as exc:
                errpart = bundler.newpart(b'error:unsupportedcontent')
                if exc.parttype is not None:
                    errpart.addparam(b'parttype', exc.parttype)
                if exc.params:
                    errpart.addparam(b'params', b'\0'.join(exc.params))
            except error.Abort as exc:
                manargs = [(b'message', exc.message)]
                advargs = []
                if exc.hint is not None:
                    advargs.append((b'hint', exc.hint))
                bundler.addpart(
                    bundle2.bundlepart(b'error:abort', manargs, advargs)
                )
            except error.PushRaced as exc:
                bundler.newpart(
                    b'error:pushraced',
                    [(b'message', stringutil.forcebytestr(exc))],
                )
            return wireprototypes.streamreslegacy(gen=bundler.getchunks())