wireprotov2: define and implement "manifestdata" command

The added command can be used for obtaining manifest data.
Given a manifest path and set of manifest nodes, data about
manifests can be retrieved.

Unlike changeset data, we wish to emit deltas to describe
manifest revisions. So the command uses the relatively new
API for building delta requests and emitting them.

The code calls into deltaparent(), which I'm not very keen of.
There's still work to be done in delta generation land so
implementation details of storage (e.g. exactly one delta
is stored/available) don't creep into higher levels. But we
can worry about this later (there is already a TODO on
imanifestorage tracking this).

On the subject of parent deltas, the server assumes parent revisions
exist on the receiving end. This is obviously wrong for shallow
clone. I've added TODOs to add a mechanism to the command to
allow clients to specify desired behavior. This shouldn't be
too difficult to implement.

Another big change is that the client must explicitly request
manifest nodes to retrieve. This is a major departure from
"getbundle," where the server derives relevant manifests as it
iterates changesets and sends them automatically. As implemented,
the client must transmit each requested node to the server. At
20 bytes per node, we're looking at 2 MB per 100,000 nodes. Plus
wire encoding overhead. This isn't ideal for clients with limited
upload bandwidth. I plan to address this in the future by allowing
alternate mechanisms for defining the revisions to retrieve. One
idea is to define a range of changeset revisions whose manifest
revisions to retrieve (similar to how "changesetdata" works).
We almost certainly want an API to look up an individual manifest
by node. And that's where I've chosen to start with the implementation.
Again, a theme of this early exchangev2 work is I want to start by
building primitives for accessing raw repository data first and see
how far we can get with those before we need more complexity.

Differential Revision: https://phab.mercurial-scm.org/D4488

tests/test-wireproto-command-manifestdata.t

@@ -0,0 +1,507 b''
+  $ . $TESTDIR/wireprotohelpers.sh
+
+  $ hg init server
+  $ enablehttpv2 server
+  $ cd server
+  $ echo a0 > a
+  $ echo b0 > b
+  $ mkdir -p dir0/child0 dir0/child1 dir1
+  $ echo c0 > dir0/c
+  $ echo d0 > dir0/d
+  $ echo e0 > dir0/child0/e
+  $ echo f0 > dir0/child1/f
+  $ hg -q commit -A -m 'commit 0'
+
+  $ echo a1 > a
+  $ echo d1 > dir0/d
+  $ hg commit -m 'commit 1'
+  $ echo f0 > dir0/child1/f
+  $ hg commit -m 'commit 2'
+  nothing changed
+  [1]
+
+  $ hg -q up -r 0
+  $ echo a2 > a
+  $ hg commit -m 'commit 3'
+  created new head
+
+  $ hg log -G -T '{rev}:{node} {desc}\n'
+  @  2:c8757a2ffe552850d1e0dfe60d295ebf64c196d9 commit 3
+  |
+  | o  1:650165e803375748a94df471e5b58d85763e0b29 commit 1
+  |/
+  o  0:6d85ca1270b377d320098556ba5bfad34a9ee12d commit 0
+  
+
+  $ hg --debug debugindex -m
+     rev linkrev nodeid                                   p1                                       p2
+       0       0 1b175b595f022cfab5b809cc0ed551bd0b3ff5e4 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000
+       1       1 91e0bdbfb0dde0023fa063edc1445f207a22eac7 1b175b595f022cfab5b809cc0ed551bd0b3ff5e4 0000000000000000000000000000000000000000
+       2       2 46a6721b5edaf0ea04b79a5cb3218854a4d2aba0 1b175b595f022cfab5b809cc0ed551bd0b3ff5e4 0000000000000000000000000000000000000000
+
+  $ hg serve -p $HGPORT -d --pid-file hg.pid -E error.log
+  $ cat hg.pid > $DAEMON_PIDS
+
+Missing arguments is an error
+
+  $ sendhttpv2peer << EOF
+  > command manifestdata
+  > EOF
+  creating http peer for wire protocol version 2
+  sending manifestdata command
+  s>     POST /api/exp-http-v2-0001/ro/manifestdata HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-exp-framing-0005\r\n
+  s>     content-type: application/mercurial-exp-framing-0005\r\n
+  s>     content-length: 27\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s>     \x13\x00\x00\x01\x00\x01\x01\x11\xa1DnameLmanifestdata
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 OK\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-exp-framing-0005\r\n
+  s>     Transfer-Encoding: chunked\r\n
+  s>     \r\n
+  s>     45\r\n
+  s>     =\x00\x00\x01\x00\x02\x012
+  s>     \xa2Eerror\xa1GmessageX\x1enodes argument must be definedFstatusEerror
+  s>     \r\n
+  received frame(size=61; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=eos)
+  s>     0\r\n
+  s>     \r\n
+  abort: nodes argument must be defined!
+  [255]
+
+  $ sendhttpv2peer << EOF
+  > command manifestdata
+  >     nodes eval:[]
+  > EOF
+  creating http peer for wire protocol version 2
+  sending manifestdata command
+  s>     POST /api/exp-http-v2-0001/ro/manifestdata HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-exp-framing-0005\r\n
+  s>     content-type: application/mercurial-exp-framing-0005\r\n
+  s>     content-length: 40\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s>      \x00\x00\x01\x00\x01\x01\x11\xa2Dargs\xa1Enodes\x80DnameLmanifestdata
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 OK\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-exp-framing-0005\r\n
+  s>     Transfer-Encoding: chunked\r\n
+  s>     \r\n
+  s>     44\r\n
+  s>     <\x00\x00\x01\x00\x02\x012
+  s>     \xa2Eerror\xa1GmessageX\x1dtree argument must be definedFstatusEerror
+  s>     \r\n
+  received frame(size=60; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=eos)
+  s>     0\r\n
+  s>     \r\n
+  abort: tree argument must be defined!
+  [255]
+
+Unknown node is an error
+
+  $ sendhttpv2peer << EOF
+  > command manifestdata
+  >     nodes eval:[b'\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa']
+  >     tree eval:b''
+  > EOF
+  creating http peer for wire protocol version 2
+  sending manifestdata command
+  s>     POST /api/exp-http-v2-0001/ro/manifestdata HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-exp-framing-0005\r\n
+  s>     content-type: application/mercurial-exp-framing-0005\r\n
+  s>     content-length: 67\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s>     ;\x00\x00\x01\x00\x01\x01\x11\xa2Dargs\xa2Enodes\x81T\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaaDtree@DnameLmanifestdata
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 OK\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-exp-framing-0005\r\n
+  s>     Transfer-Encoding: chunked\r\n
+  s>     \r\n
+  s>     51\r\n
+  s>     I\x00\x00\x01\x00\x02\x012
+  s>     \xa2Eerror\xa2Dargs\x81T\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaaGmessagePunknown node: %sFstatusEerror
+  s>     \r\n
+  received frame(size=73; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=eos)
+  s>     0\r\n
+  s>     \r\n
+  abort: unknown node: \xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa! (esc)
+  [255]
+
+Fetching a single revision returns just metadata by default
+
+  $ sendhttpv2peer << EOF
+  > command manifestdata
+  >     nodes eval:[b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
+  >     tree eval:b''
+  > EOF
+  creating http peer for wire protocol version 2
+  sending manifestdata command
+  s>     POST /api/exp-http-v2-0001/ro/manifestdata HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-exp-framing-0005\r\n
+  s>     content-type: application/mercurial-exp-framing-0005\r\n
+  s>     content-length: 67\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s>     ;\x00\x00\x01\x00\x01\x01\x11\xa2Dargs\xa2Enodes\x81TF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0Dtree@DnameLmanifestdata
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 OK\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-exp-framing-0005\r\n
+  s>     Transfer-Encoding: chunked\r\n
+  s>     \r\n
+  s>     13\r\n
+  s>     \x0b\x00\x00\x01\x00\x02\x011
+  s>     \xa1FstatusBok
+  s>     \r\n
+  received frame(size=11; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=continuation)
+  s>     30\r\n
+  s>     (\x00\x00\x01\x00\x02\x001
+  s>     \xa1Jtotalitems\x01\xa1DnodeTF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0
+  s>     \r\n
+  received frame(size=40; request=1; stream=2; streamflags=; type=command-response; flags=continuation)
+  s>     8\r\n
+  s>     \x00\x00\x00\x01\x00\x02\x002
+  s>     \r\n
+  s>     0\r\n
+  s>     \r\n
+  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
+  response: gen[
+    {
+      b'totalitems': 1
+    },
+    {
+      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0'
+    }
+  ]
+
+Requesting parents works
+
+  $ sendhttpv2peer << EOF
+  > command manifestdata
+  >     nodes eval:[b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
+  >     tree eval:b''
+  >     fields eval:[b'parents']
+  > EOF
+  creating http peer for wire protocol version 2
+  sending manifestdata command
+  s>     POST /api/exp-http-v2-0001/ro/manifestdata HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-exp-framing-0005\r\n
+  s>     content-type: application/mercurial-exp-framing-0005\r\n
+  s>     content-length: 83\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s>     K\x00\x00\x01\x00\x01\x01\x11\xa2Dargs\xa3Ffields\x81GparentsEnodes\x81TF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0Dtree@DnameLmanifestdata
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 OK\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-exp-framing-0005\r\n
+  s>     Transfer-Encoding: chunked\r\n
+  s>     \r\n
+  s>     13\r\n
+  s>     \x0b\x00\x00\x01\x00\x02\x011
+  s>     \xa1FstatusBok
+  s>     \r\n
+  received frame(size=11; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=continuation)
+  s>     63\r\n
+  s>     [\x00\x00\x01\x00\x02\x001
+  s>     \xa1Jtotalitems\x01\xa2DnodeTF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0Gparents\x82T\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4T\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00
+  s>     \r\n
+  received frame(size=91; request=1; stream=2; streamflags=; type=command-response; flags=continuation)
+  s>     8\r\n
+  s>     \x00\x00\x00\x01\x00\x02\x002
+  s>     \r\n
+  s>     0\r\n
+  s>     \r\n
+  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
+  response: gen[
+    {
+      b'totalitems': 1
+    },
+    {
+      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0',
+      b'parents': [
+        b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+      ]
+    }
+  ]
+
+Requesting revision data works
+
+  $ sendhttpv2peer << EOF
+  > command manifestdata
+  >     nodes eval:[b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
+  >     tree eval:b''
+  >     fields eval:[b'revision']
+  > EOF
+  creating http peer for wire protocol version 2
+  sending manifestdata command
+  s>     POST /api/exp-http-v2-0001/ro/manifestdata HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-exp-framing-0005\r\n
+  s>     content-type: application/mercurial-exp-framing-0005\r\n
+  s>     content-length: 84\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s>     L\x00\x00\x01\x00\x01\x01\x11\xa2Dargs\xa3Ffields\x81HrevisionEnodes\x81TF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0Dtree@DnameLmanifestdata
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 OK\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-exp-framing-0005\r\n
+  s>     Transfer-Encoding: chunked\r\n
+  s>     \r\n
+  s>     13\r\n
+  s>     \x0b\x00\x00\x01\x00\x02\x011
+  s>     \xa1FstatusBok
+  s>     \r\n
+  received frame(size=11; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=continuation)
+  s>     98\r\n
+  s>     \x90\x00\x00\x01\x00\x02\x001
+  s>     \xa1Jtotalitems\x01\xa3MdeltabasenodeT\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4Ideltasize\x187DnodeTF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0X7\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n
+  s>     \r\n
+  received frame(size=144; request=1; stream=2; streamflags=; type=command-response; flags=continuation)
+  s>     8\r\n
+  s>     \x00\x00\x00\x01\x00\x02\x002
+  s>     \r\n
+  s>     0\r\n
+  s>     \r\n
+  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
+  response: gen[
+    {
+      b'totalitems': 1
+    },
+    {
+      b'deltabasenode': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
+      b'deltasize': 55,
+      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0'
+    },
+    b'\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n'
+  ]
+
+Requesting multiple revisions works
+
+  $ sendhttpv2peer << EOF
+  > command manifestdata
+  >     nodes eval:[b'\x1b\x17\x5b\x59\x5f\x02\x2c\xfa\xb5\xb8\x09\xcc\x0e\xd5\x51\xbd\x0b\x3f\xf5\xe4', b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
+  >     tree eval:b''
+  >     fields eval:[b'revision']
+  > EOF
+  creating http peer for wire protocol version 2
+  sending manifestdata command
+  s>     POST /api/exp-http-v2-0001/ro/manifestdata HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-exp-framing-0005\r\n
+  s>     content-type: application/mercurial-exp-framing-0005\r\n
+  s>     content-length: 105\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s>     a\x00\x00\x01\x00\x01\x01\x11\xa2Dargs\xa3Ffields\x81HrevisionEnodes\x82T\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4TF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0Dtree@DnameLmanifestdata
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 OK\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-exp-framing-0005\r\n
+  s>     Transfer-Encoding: chunked\r\n
+  s>     \r\n
+  s>     13\r\n
+  s>     \x0b\x00\x00\x01\x00\x02\x011
+  s>     \xa1FstatusBok
+  s>     \r\n
+  received frame(size=11; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=continuation)
+  s>     1ea\r\n
+  s>     \xe2\x01\x00\x01\x00\x02\x001
+  s>     \xa1Jtotalitems\x02\xa2DnodeT\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4Lrevisionsize\x19\x01$Y\x01$a\x002b4eb07319bfa077a40a2f04913659aef0da42da\n
+  s>     b\x00819e258d31a5e1606629f365bb902a1b21ee4216\n
+  s>     dir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\n
+  s>     dir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\n
+  s>     dir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\n
+  s>     dir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n
+  s>     \xa3MdeltabasenodeT\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4Ideltasize\x187DnodeTF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0X7\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n
+  s>     \r\n
+  received frame(size=482; request=1; stream=2; streamflags=; type=command-response; flags=continuation)
+  s>     8\r\n
+  s>     \x00\x00\x00\x01\x00\x02\x002
+  s>     \r\n
+  s>     0\r\n
+  s>     \r\n
+  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
+  response: gen[
+    {
+      b'totalitems': 2
+    },
+    {
+      b'node': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
+      b'revisionsize': 292
+    },
+    b'a\x002b4eb07319bfa077a40a2f04913659aef0da42da\nb\x00819e258d31a5e1606629f365bb902a1b21ee4216\ndir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\ndir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\ndir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\ndir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n',
+    {
+      b'deltabasenode': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
+      b'deltasize': 55,
+      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0'
+    },
+    b'\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n'
+  ]
+
+Revisions are sorted by DAG order, parents first
+
+  $ sendhttpv2peer << EOF
+  > command manifestdata
+  >     nodes eval:[b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0', b'\x1b\x17\x5b\x59\x5f\x02\x2c\xfa\xb5\xb8\x09\xcc\x0e\xd5\x51\xbd\x0b\x3f\xf5\xe4']
+  >     tree eval:b''
+  >     fields eval:[b'revision']
+  > EOF
+  creating http peer for wire protocol version 2
+  sending manifestdata command
+  s>     POST /api/exp-http-v2-0001/ro/manifestdata HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-exp-framing-0005\r\n
+  s>     content-type: application/mercurial-exp-framing-0005\r\n
+  s>     content-length: 105\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s>     a\x00\x00\x01\x00\x01\x01\x11\xa2Dargs\xa3Ffields\x81HrevisionEnodes\x82TF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0T\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4Dtree@DnameLmanifestdata
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 OK\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-exp-framing-0005\r\n
+  s>     Transfer-Encoding: chunked\r\n
+  s>     \r\n
+  s>     13\r\n
+  s>     \x0b\x00\x00\x01\x00\x02\x011
+  s>     \xa1FstatusBok
+  s>     \r\n
+  received frame(size=11; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=continuation)
+  s>     1ea\r\n
+  s>     \xe2\x01\x00\x01\x00\x02\x001
+  s>     \xa1Jtotalitems\x02\xa2DnodeT\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4Lrevisionsize\x19\x01$Y\x01$a\x002b4eb07319bfa077a40a2f04913659aef0da42da\n
+  s>     b\x00819e258d31a5e1606629f365bb902a1b21ee4216\n
+  s>     dir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\n
+  s>     dir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\n
+  s>     dir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\n
+  s>     dir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n
+  s>     \xa3MdeltabasenodeT\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4Ideltasize\x187DnodeTF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0X7\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n
+  s>     \r\n
+  received frame(size=482; request=1; stream=2; streamflags=; type=command-response; flags=continuation)
+  s>     8\r\n
+  s>     \x00\x00\x00\x01\x00\x02\x002
+  s>     \r\n
+  s>     0\r\n
+  s>     \r\n
+  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
+  response: gen[
+    {
+      b'totalitems': 2
+    },
+    {
+      b'node': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
+      b'revisionsize': 292
+    },
+    b'a\x002b4eb07319bfa077a40a2f04913659aef0da42da\nb\x00819e258d31a5e1606629f365bb902a1b21ee4216\ndir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\ndir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\ndir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\ndir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n',
+    {
+      b'deltabasenode': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
+      b'deltasize': 55,
+      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0'
+    },
+    b'\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n'
+  ]
+
+Requesting parents and revision data works
+
+  $ sendhttpv2peer << EOF
+  > command manifestdata
+  >     nodes eval:[b'\x1b\x17\x5b\x59\x5f\x02\x2c\xfa\xb5\xb8\x09\xcc\x0e\xd5\x51\xbd\x0b\x3f\xf5\xe4', b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
+  >     tree eval:b''
+  >     fields eval:[b'parents', b'revision']
+  > EOF
+  creating http peer for wire protocol version 2
+  sending manifestdata command
+  s>     POST /api/exp-http-v2-0001/ro/manifestdata HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-exp-framing-0005\r\n
+  s>     content-type: application/mercurial-exp-framing-0005\r\n
+  s>     content-length: 113\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s>     i\x00\x00\x01\x00\x01\x01\x11\xa2Dargs\xa3Ffields\x82GparentsHrevisionEnodes\x82T\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4TF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0Dtree@DnameLmanifestdata
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 OK\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-exp-framing-0005\r\n
+  s>     Transfer-Encoding: chunked\r\n
+  s>     \r\n
+  s>     13\r\n
+  s>     \x0b\x00\x00\x01\x00\x02\x011
+  s>     \xa1FstatusBok
+  s>     \r\n
+  received frame(size=11; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=continuation)
+  s>     250\r\n
+  s>     H\x02\x00\x01\x00\x02\x001
+  s>     \xa1Jtotalitems\x02\xa3DnodeT\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4Gparents\x82T\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00T\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00Lrevisionsize\x19\x01$Y\x01$a\x002b4eb07319bfa077a40a2f04913659aef0da42da\n
+  s>     b\x00819e258d31a5e1606629f365bb902a1b21ee4216\n
+  s>     dir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\n
+  s>     dir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\n
+  s>     dir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\n
+  s>     dir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n
+  s>     \xa4MdeltabasenodeT\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4Ideltasize\x187DnodeTF\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0Gparents\x82T\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4T\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00X7\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n
+  s>     \r\n
+  received frame(size=584; request=1; stream=2; streamflags=; type=command-response; flags=continuation)
+  s>     8\r\n
+  s>     \x00\x00\x00\x01\x00\x02\x002
+  s>     \r\n
+  s>     0\r\n
+  s>     \r\n
+  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
+  response: gen[
+    {
+      b'totalitems': 2
+    },
+    {
+      b'node': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
+      b'parents': [
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+      ],
+      b'revisionsize': 292
+    },
+    b'a\x002b4eb07319bfa077a40a2f04913659aef0da42da\nb\x00819e258d31a5e1606629f365bb902a1b21ee4216\ndir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\ndir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\ndir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\ndir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n',
+    {
+      b'deltabasenode': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
+      b'deltasize': 55,
+      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0',
+      b'parents': [
+        b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+      ]
+    },
+    b'\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n'
+  ]
+
+  $ cat error.log

mercurial/help/internals/wireprotocolv2.txt

@@ -258,6 +258,80 b' key'
 
 On success, returns a bytestring containing the resolved node.
 
+manifestdata
+------------
+
+Obtain various data related to manifests (which are lists of files in
+a revision).
+
+The command accepts the following arguments:
+
+fields
+   (set of bytestring) Which data associated with manifests to fetch.
+   The following values are recognized:
+
+   parents
+      Parent nodes for the manifest.
+
+   revision
+      The raw revision data for the manifest.
+
+nodes
+   (array of bytestring) Manifest nodes whose data to retrieve.
+
+tree
+   (bytestring) Path to manifest to retrieve. The empty bytestring represents
+   the root manifest. All other values represent directories/trees within
+   the repository.
+
+TODO allow specifying revisions via alternate means (such as from changeset
+revisions or ranges)
+TODO consider recursive expansion of manifests (with path filtering for
+narrow use cases)
+TODO more control over whether to emit fulltexts or deltas
+
+The response bytestream starts with a CBOR map describing the data that
+follows. It has the following bytestring keys:
+
+totalitems
+   (unsigned integer) Total number of manifest revisions whose data is
+   being returned.
+
+Following the header map is a series of 0 or more CBOR values. The first
+value is always a map describing a manifest revision. If this map has the
+``deltasize`` or ``revisionsize`` keys, a bytestring containing the delta
+or revision, respectively, will immediately follow the map. Otherwise
+the next value will be a map describing the next manifest revision.
+
+Each map has the following bytestring keys:
+
+node
+   (bytestring) The node of the manifest revision whose data is represented.
+
+deltabasenode
+   (bytestring) The node that the delta representation of this revision is
+   computed against. Only present if the ``revision`` field is requested and
+   a delta is being emitted.
+
+deltasize
+   (unsigned integer) The size of the delta data that follows this map.
+   Only present if the ``revision`` field is requested and a delta is
+   being emitted.
+
+parents
+   (array of bytestring) The nodes of the parents of this manifest revision.
+   Only present if the ``parents`` field is requested.
+
+revisionsize
+   (unsigned integer) The size of the fulltext revision data that follows
+   this map. Only present if the ``revision`` field is requested and a fulltext
+   revision is being emitted.
+
+When ``revision`` data is requested, the server chooses to emit either fulltext
+revision data or a delta. What the server decides can be inferred by looking
+for the presence of the ``deltasize`` or ``revisionsize`` keys in the map.
+Servers MUST NOT define both keys.
+
 pushkey
 -------
 

mercurial/wireprotov2server.py

@@ -11,8 +11,11 b' import contextlib'
 from .i18n import _
 from .node import (
     nullid,
+    nullrev,
 )
 from . import (
+    changegroup,
+    dagop,
     discovery,
     encoding,
     error,
@@ -411,6 +414,67 b' def _capabilitiesv2(repo, proto):'
 
     return proto.addcapabilities(repo, caps)
 
+def builddeltarequests(store, nodes):
+    """Build a series of revision delta requests against a backend store.
+
+    Returns a list of revision numbers in the order they should be sent
+    and a list of ``irevisiondeltarequest`` instances to be made against
+    the backend store.
+    """
+    # We sort and send nodes in DAG order because this is optimal for
+    # storage emission.
+    # TODO we may want a better storage API here - one where we can throw
+    # a list of nodes and delta preconditions over a figurative wall and
+    # have the storage backend figure it out for us.
+    revs = dagop.linearize({store.rev(n) for n in nodes}, store.parentrevs)
+
+    requests = []
+
+    for rev in revs:
+        node = store.node(rev)
+        parents = store.parents(node)
+        deltaparent = store.node(store.deltaparent(rev))
+
+        # There is a delta in storage. That means we can send the delta
+        # efficiently.
+        #
+        # But, the delta may be against a revision the receiver doesn't
+        # have (e.g. shallow clone or when the delta isn't against a parent
+        # revision). For now, we ignore the problem of shallow clone. As
+        # long as a delta exists against a parent, we send it.
+        # TODO allow arguments to control this behavior, as the receiver
+        # may not have the base revision in some scenarios.
+        if deltaparent != nullid and deltaparent in parents:
+            basenode = deltaparent
+
+        # Else there is no delta parent in storage or the delta that is
+        # # there isn't suitable. Let's use a delta against a parent
+        # revision, if possible.
+        #
+        # There is room to check if the delta parent is in the ancestry of
+        # this node. But there isn't an API on the manifest storage object
+        # for that. So ignore this case for now.
+
+        elif parents[0] != nullid:
+            basenode = parents[0]
+        elif parents[1] != nullid:
+            basenode = parents[1]
+
+        # No potential bases to delta against. Send a full revision.
+        else:
+            basenode = nullid
+
+        requests.append(changegroup.revisiondeltarequest(
+            node=node,
+            p1node=parents[0],
+            p2node=parents[1],
+            # Receiver deals with linknode resolution.
+            linknode=nullid,
+            basenode=basenode,
+        ))
+
+    return revs, requests
+
 def wireprotocommand(name, args=None, permission='push'):
     """Decorator to declare a wire protocol command.
 
@@ -630,6 +694,87 b' def lookupv2(repo, proto, key):'
 
     yield node
 
+@wireprotocommand('manifestdata',
+                  args={
+                      'nodes': [b'0123456...'],
+                      'fields': [b'parents', b'revision'],
+                      'tree': b'',
+                  },
+                  permission='pull')
+def manifestdata(repo, proto, nodes=None, fields=None, tree=None):
+    fields = fields or set()
+
+    if nodes is None:
+        raise error.WireprotoCommandError(
+            'nodes argument must be defined')
+
+    if tree is None:
+        raise error.WireprotoCommandError(
+            'tree argument must be defined')
+
+    store = repo.manifestlog.getstorage(tree)
+
+    # Validate the node is known and abort on unknown revisions.
+    for node in nodes:
+        try:
+            store.rev(node)
+        except error.LookupError:
+            raise error.WireprotoCommandError(
+                'unknown node: %s', (node,))
+
+    revs, requests = builddeltarequests(store, nodes)
+
+    yield {
+        b'totalitems': len(revs),
+    }
+
+    if b'revision' in fields:
+        deltas = store.emitrevisiondeltas(requests)
+    else:
+        deltas = None
+
+    for rev in revs:
+        node = store.node(rev)
+
+        if deltas is not None:
+            delta = next(deltas)
+        else:
+            delta = None
+
+        d = {
+            b'node': node,
+        }
+
+        if b'parents' in fields:
+            d[b'parents'] = store.parents(node)
+
+        if b'revision' in fields:
+            assert delta is not None
+            assert delta.flags == 0
+            assert d[b'node'] == delta.node
+
+            if delta.revision is not None:
+                revisiondata = delta.revision
+                d[b'revisionsize'] = len(revisiondata)
+            else:
+                d[b'deltabasenode'] = delta.basenode
+                revisiondata = delta.delta
+                d[b'deltasize'] = len(revisiondata)
+        else:
+            revisiondata = None
+
+        yield d
+
+        if revisiondata is not None:
+            yield revisiondata
+
+    if deltas is not None:
+        try:
+            next(deltas)
+            raise error.ProgrammingError('should not have more deltas')
+        except GeneratorExit:
+            pass
+
 @wireprotocommand('pushkey',
                   args={
                       'namespace': b'ns',

tests/test-http-protocol.t

@@ -313,7 +313,7 b' Client with HTTPv2 enabled automatically'
   s>     Content-Type: application/mercurial-cbor\r\n
   s>     Content-Length: *\r\n (glob)
   s>     \r\n
-  s>     \xa3GapibaseDapi/Dapis\xa1Pexp-http-v2-0001\xa4Hcommands\xa8Ibranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullMchangesetdata\xa2Dargs\xa3Ffields\xd9\x01\x02\x82GparentsHrevisionInoderange\x82\x81J0123456...\x81Iabcdef...Enodes\x81J0123456...Kpermissions\x81DpullEheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyInamespaceBnsCnewCnewColdColdKpermissions\x81DpushKcompression\x81\xa1DnameDzlibQframingmediatypes\x81X&application/mercurial-exp-framing-0005Nrawrepoformats\x82LgeneraldeltaHrevlogv1Nv1capabilitiesY\x01\xc5batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
+  s>     \xa3GapibaseDapi/Dapis\xa1Pexp-http-v2-0001\xa4Hcommands\xa9Ibranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullMchangesetdata\xa2Dargs\xa3Ffields\xd9\x01\x02\x82GparentsHrevisionInoderange\x82\x81J0123456...\x81Iabcdef...Enodes\x81J0123456...Kpermissions\x81DpullEheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullLmanifestdata\xa2Dargs\xa3Ffields\x82GparentsHrevisionEnodes\x81J0123456...Dtree@Kpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyInamespaceBnsCnewCnewColdColdKpermissions\x81DpushKcompression\x81\xa1DnameDzlibQframingmediatypes\x81X&application/mercurial-exp-framing-0005Nrawrepoformats\x82LgeneraldeltaHrevlogv1Nv1capabilitiesY\x01\xc5batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
   sending heads command
   s>     POST /api/exp-http-v2-0001/ro/heads HTTP/1.1\r\n
   s>     Accept-Encoding: identity\r\n

tests/test-wireproto-command-capabilities.t

@@ -212,7 +212,7 b' Request for HTTPv2 service returns infor'
   s>     Content-Type: application/mercurial-cbor\r\n
   s>     Content-Length: *\r\n (glob)
   s>     \r\n
-  s>     \xa3GapibaseDapi/Dapis\xa1Pexp-http-v2-0001\xa4Hcommands\xa8Ibranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullMchangesetdata\xa2Dargs\xa3Ffields\xd9\x01\x02\x82GparentsHrevisionInoderange\x82\x81J0123456...\x81Iabcdef...Enodes\x81J0123456...Kpermissions\x81DpullEheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyInamespaceBnsCnewCnewColdColdKpermissions\x81DpushKcompression\x81\xa1DnameDzlibQframingmediatypes\x81X&application/mercurial-exp-framing-0005Nrawrepoformats\x82LgeneraldeltaHrevlogv1Nv1capabilitiesY\x01\xc5batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
+  s>     \xa3GapibaseDapi/Dapis\xa1Pexp-http-v2-0001\xa4Hcommands\xa9Ibranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullMchangesetdata\xa2Dargs\xa3Ffields\xd9\x01\x02\x82GparentsHrevisionInoderange\x82\x81J0123456...\x81Iabcdef...Enodes\x81J0123456...Kpermissions\x81DpullEheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullLmanifestdata\xa2Dargs\xa3Ffields\x82GparentsHrevisionEnodes\x81J0123456...Dtree@Kpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyInamespaceBnsCnewCnewColdColdKpermissions\x81DpushKcompression\x81\xa1DnameDzlibQframingmediatypes\x81X&application/mercurial-exp-framing-0005Nrawrepoformats\x82LgeneraldeltaHrevlogv1Nv1capabilitiesY\x01\xc5batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
   cbor> {
     b'apibase': b'api/',
     b'apis': {
@@ -286,6 +286,21 b' Request for HTTPv2 service returns infor'
               b'pull'
             ]
           },
+          b'manifestdata': {
+            b'args': {
+              b'fields': [
+                b'parents',
+                b'revision'
+              ],
+              b'nodes': [
+                b'0123456...'
+              ],
+              b'tree': b''
+            },
+            b'permissions': [
+              b'pull'
+            ]
+          },
           b'pushkey': {
             b'args': {
               b'key': b'key',
@@ -337,7 +352,7 b' capabilities command returns expected in'
   s>     Content-Type: application/mercurial-cbor\r\n
   s>     Content-Length: *\r\n (glob)
   s>     \r\n
-  s>     \xa3GapibaseDapi/Dapis\xa1Pexp-http-v2-0001\xa4Hcommands\xa8Ibranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullMchangesetdata\xa2Dargs\xa3Ffields\xd9\x01\x02\x82GparentsHrevisionInoderange\x82\x81J0123456...\x81Iabcdef...Enodes\x81J0123456...Kpermissions\x81DpullEheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyInamespaceBnsCnewCnewColdColdKpermissions\x81DpushKcompression\x81\xa1DnameDzlibQframingmediatypes\x81X&application/mercurial-exp-framing-0005Nrawrepoformats\x82LgeneraldeltaHrevlogv1Nv1capabilitiesY\x01\xc5batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
+  s>     \xa3GapibaseDapi/Dapis\xa1Pexp-http-v2-0001\xa4Hcommands\xa9Ibranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullMchangesetdata\xa2Dargs\xa3Ffields\xd9\x01\x02\x82GparentsHrevisionInoderange\x82\x81J0123456...\x81Iabcdef...Enodes\x81J0123456...Kpermissions\x81DpullEheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullLmanifestdata\xa2Dargs\xa3Ffields\x82GparentsHrevisionEnodes\x81J0123456...Dtree@Kpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyInamespaceBnsCnewCnewColdColdKpermissions\x81DpushKcompression\x81\xa1DnameDzlibQframingmediatypes\x81X&application/mercurial-exp-framing-0005Nrawrepoformats\x82LgeneraldeltaHrevlogv1Nv1capabilitiesY\x01\xc5batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
   sending capabilities command
   s>     POST /api/exp-http-v2-0001/ro/capabilities HTTP/1.1\r\n
   s>     Accept-Encoding: identity\r\n
@@ -360,11 +375,11 b' capabilities command returns expected in'
   s>     \xa1FstatusBok
   s>     \r\n
   received frame(size=11; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=continuation)
-  s>     243\r\n
-  s>     ;\x02\x00\x01\x00\x02\x001
-  s>     \xa4Hcommands\xa8Ibranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullMchangesetdata\xa2Dargs\xa3Ffields\xd9\x01\x02\x82GparentsHrevisionInoderange\x82\x81J0123456...\x81Iabcdef...Enodes\x81J0123456...Kpermissions\x81DpullEheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyInamespaceBnsCnewCnewColdColdKpermissions\x81DpushKcompression\x81\xa1DnameDzlibQframingmediatypes\x81X&application/mercurial-exp-framing-0005Nrawrepoformats\x82LgeneraldeltaHrevlogv1
+  s>     29a\r\n
+  s>     \x92\x02\x00\x01\x00\x02\x001
+  s>     \xa4Hcommands\xa9Ibranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullMchangesetdata\xa2Dargs\xa3Ffields\xd9\x01\x02\x82GparentsHrevisionInoderange\x82\x81J0123456...\x81Iabcdef...Enodes\x81J0123456...Kpermissions\x81DpullEheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullLmanifestdata\xa2Dargs\xa3Ffields\x82GparentsHrevisionEnodes\x81J0123456...Dtree@Kpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyInamespaceBnsCnewCnewColdColdKpermissions\x81DpushKcompression\x81\xa1DnameDzlibQframingmediatypes\x81X&application/mercurial-exp-framing-0005Nrawrepoformats\x82LgeneraldeltaHrevlogv1
   s>     \r\n
-  received frame(size=571; request=1; stream=2; streamflags=; type=command-response; flags=continuation)
+  received frame(size=658; request=1; stream=2; streamflags=; type=command-response; flags=continuation)
   s>     8\r\n
   s>     \x00\x00\x00\x01\x00\x02\x002
   s>     \r\n
@@ -442,6 +457,21 b' capabilities command returns expected in'
             b'pull'
           ]
         },
+        b'manifestdata': {
+          b'args': {
+            b'fields': [
+              b'parents',
+              b'revision'
+            ],
+            b'nodes': [
+              b'0123456...'
+            ],
+            b'tree': b''
+          },
+          b'permissions': [
+            b'pull'
+          ]
+        },
         b'pushkey': {
           b'args': {
             b'key': b'key',