exchangev2: start to implement pull with wire protocol v2 Wire protocol version 2 will take a substantially different approach to exchange than version 1 (at least as far as pulling is concerned). This commit establishes a new exchangev2 module for holding code related to exchange using wire protocol v2. I could have added things to the existing exchange module. But it is already quite big. And doing things inline isn't in question because the existing code is already littered with conditional code for various states of support for the existing wire protocol as it evolved over 10+ years. A new module gives us a chance to make a clean break. This approach does mean we'll end up writing some duplicate code. And there's a significant chance we'll miss functionality as code is ported. The plan is to eventually add #testcase's to existing tests so the new wire protocol is tested side-by-side with the existing one. This will hopefully tease out any features that weren't ported properly. But before we get there, we need to build up support for the new exchange methods. Our journey towards implementing a new exchange begins with pulling. And pulling begins with discovery. The discovery code added to exchangev2 is heavily drawn from the following functions: * exchange._pulldiscoverychangegroup * discovery.findcommonincoming For now, we build on top of existing discovery mechanisms. The new wire protocol should be capable of doing things more efficiently. But I'd rather defer on this problem. To foster the transition, we invent a fake capability on the HTTPv2 peer and have the main pull code in exchange.py call into exchangev2 when the new wire protocol is being used. Differential Revision: https://phab.mercurial-scm.org/D4480

     1

HTTPV2=exp-http-v2-0001

     2

MEDIATYPE=application/mercurial-exp-framing-0005

     3

     4

sendhttpraw() {

     5

  hg --verbose debugwireproto --peer raw http://$LOCALIP:$HGPORT/

     6

}

     7

     8

sendhttpv2peer() {

     9

  hg --verbose debugwireproto --nologhandshake --peer http2 http://$LOCALIP:$HGPORT/

    10

}

    11

    12

sendhttpv2peerhandshake() {

    13

  hg --verbose debugwireproto --peer http2 http://$LOCALIP:$HGPORT/

    14

}

    15

    16

cat > dummycommands.py << EOF

    17

from mercurial import (

    18

    wireprototypes,

    19

    wireprotov1server,

    20

    wireprotov2server,

    21

)

    22

    23

@wireprotov1server.wireprotocommand(b'customreadonly', permission=b'pull')

    24

def customreadonlyv1(repo, proto):

    25

    return wireprototypes.bytesresponse(b'customreadonly bytes response')

    26

    27

@wireprotov2server.wireprotocommand(b'customreadonly', permission=b'pull')

    28

def customreadonlyv2(repo, proto):

    29

    yield b'customreadonly bytes response'

    30

    31

@wireprotov1server.wireprotocommand(b'customreadwrite', permission=b'push')

    32

def customreadwrite(repo, proto):

    33

    return wireprototypes.bytesresponse(b'customreadwrite bytes response')

    34

    35

@wireprotov2server.wireprotocommand(b'customreadwrite', permission=b'push')

    36

def customreadwritev2(repo, proto):

    37

    yield b'customreadwrite bytes response'

    38

EOF

    39

    40

cat >> $HGRCPATH << EOF

    41

[extensions]

    42

drawdag = $TESTDIR/drawdag.py

    43

EOF

    44

    45

enabledummycommands() {

    46

  cat >> $HGRCPATH << EOF

    47

[extensions]

    48

dummycommands = $TESTTMP/dummycommands.py

    49

EOF

    50

}

    51

    52

enablehttpv2() {

    53

  cat >> $1/.hg/hgrc << EOF

    54

[experimental]

    55

web.apiserver = true

    56

web.api.http-v2 = true

    57

EOF

    58

}

    59

    60

enablehttpv2client() {

    61

  cat >> $HGRCPATH << EOF

    62

[experimental]

    63

httppeer.advertise-v2 = true

    64

EOF

    65

}