wireprotov2: define and implement "changesetdata" command
This commit introduces the "changesetdata" wire protocol command.
The role of the command is to expose data associated with changelog
revisions, including the raw revision data itself.
This command is the first piece of a new clone/pull strategy that
is built on top of domain-specific commands for data retrieval.
Instead of a monolithic "getbundle" command that transfers all of the
things, we'll be introducing commands for fetching specific pieces
of data.
Since the changeset is the fundamental unit from which we derive
pointers to other data (manifests, file nodes, etc), it makes sense
to start reimplementing pull with this data.
The command accepts as arguments a set of root and head revisions
defining the changesets that should be fetched as well as an explicit
list of nodes. By default, the command returns only the node values:
the client must explicitly request additional fields be added to the
response. Current supported fields are the list of parent nodes and
the revision fulltext.
My plan is to eventually add support for transferring other data
associated with changesets, including phases, bookmarks, obsolescence
markers, etc. Since the response format is CBOR, we'll be able to add
this data into the response object relatively easily (it should be
as simple as adding a key in a map).
The documentation captures a number of TODO items. Some of these may
require BC breaking changes. That's fine: wire protocol v2 is still
highly experimental.
Differential Revision: https://phab.mercurial-scm.org/D4481
#require no-chg
$ . $TESTDIR/wireprotohelpers.sh
$ hg init server
zstd isn't present in plain builds. Make tests easier by removing
zstd from the equation.
$ cat >> server/.hg/hgrc << EOF
> [server]
> compressionengines = zlib
> EOF
$ hg -R server serve -p $HGPORT -d --pid-file hg.pid -E error.log
$ cat hg.pid > $DAEMON_PIDS
A normal capabilities request is serviced for version 1
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 Script output follows\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-0.1\r\n
s> Content-Length: *\r\n (glob)
s> \r\n
s> batch 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
A proper request without the API server enabled returns the legacy response
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: foo
> x-hgproto-1: cbor
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgproto-1: cbor\r\n
s> x-hgupgrade-1: foo\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 Script output follows\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-0.1\r\n
s> Content-Length: *\r\n (glob)
s> \r\n
s> batch 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
Restart with just API server enabled. This enables serving the new format.
$ killdaemons.py
$ cat error.log
$ cat >> server/.hg/hgrc << EOF
> [experimental]
> web.apiserver = true
> EOF
$ hg -R server serve -p $HGPORT -d --pid-file hg.pid -E error.log
$ cat hg.pid > $DAEMON_PIDS
X-HgUpgrade-<N> without CBOR advertisement uses legacy response
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: foo bar
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgupgrade-1: foo bar\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 Script output follows\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-0.1\r\n
s> Content-Length: *\r\n (glob)
s> \r\n
s> batch 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
X-HgUpgrade-<N> without known serialization in X-HgProto-<N> uses legacy response
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: foo bar
> x-hgproto-1: some value
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgproto-1: some value\r\n
s> x-hgupgrade-1: foo bar\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
s> makefile('rb', None)
s> HTTP/1.1 200 Script output follows\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
s> Content-Type: application/mercurial-0.1\r\n
s> Content-Length: *\r\n (glob)
s> \r\n
s> batch 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
X-HgUpgrade-<N> + X-HgProto-<N> headers trigger new response format
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: foo bar
> x-hgproto-1: cbor
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgproto-1: cbor\r\n
s> x-hgupgrade-1: foo bar\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
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-cbor\r\n
s> Content-Length: *\r\n (glob)
s> \r\n
s> \xa3GapibaseDapi/Dapis\xa0Nv1capabilitiesY\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': {},
b'v1capabilities': b'batch 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'
}
Restart server to enable HTTPv2
$ killdaemons.py
$ enablehttpv2 server
$ hg -R server serve -p $HGPORT -d --pid-file hg.pid -E error.log
$ cat hg.pid > $DAEMON_PIDS
Only requested API services are returned
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: foo bar
> x-hgproto-1: cbor
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgproto-1: cbor\r\n
s> x-hgupgrade-1: foo bar\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
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-cbor\r\n
s> Content-Length: *\r\n (glob)
s> \r\n
s> \xa3GapibaseDapi/Dapis\xa0Nv1capabilitiesY\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': {},
b'v1capabilities': b'batch 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'
}
Request for HTTPv2 service returns information about it
$ sendhttpraw << EOF
> httprequest GET ?cmd=capabilities
> user-agent: test
> x-hgupgrade-1: exp-http-v2-0001 foo bar
> x-hgproto-1: cbor
> EOF
using raw connection to peer
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> user-agent: test\r\n
s> x-hgproto-1: cbor\r\n
s> x-hgupgrade-1: exp-http-v2-0001 foo bar\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> \r\n
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-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
cbor> {
b'apibase': b'api/',
b'apis': {
b'exp-http-v2-0001': {
b'commands': {
b'branchmap': {
b'args': {},
b'permissions': [
b'pull'
]
},
b'capabilities': {
b'args': {},
b'permissions': [
b'pull'
]
},
b'changesetdata': {
b'args': {
b'fields': set([
b'parents',
b'revision'
]),
b'noderange': [
[
b'0123456...'
],
[
b'abcdef...'
]
],
b'nodes': [
b'0123456...'
]
},
b'permissions': [
b'pull'
]
},
b'heads': {
b'args': {
b'publiconly': False
},
b'permissions': [
b'pull'
]
},
b'known': {
b'args': {
b'nodes': [
b'deadbeef'
]
},
b'permissions': [
b'pull'
]
},
b'listkeys': {
b'args': {
b'namespace': b'ns'
},
b'permissions': [
b'pull'
]
},
b'lookup': {
b'args': {
b'key': b'foo'
},
b'permissions': [
b'pull'
]
},
b'pushkey': {
b'args': {
b'key': b'key',
b'namespace': b'ns',
b'new': b'new',
b'old': b'old'
},
b'permissions': [
b'push'
]
}
},
b'compression': [
{
b'name': b'zlib'
}
],
b'framingmediatypes': [
b'application/mercurial-exp-framing-0005'
],
b'rawrepoformats': [
b'generaldelta',
b'revlogv1'
]
}
},
b'v1capabilities': b'batch 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'
}
capabilities command returns expected info
$ sendhttpv2peerhandshake << EOF
> command capabilities
> EOF
creating http peer for wire protocol version 2
s> GET /?cmd=capabilities HTTP/1.1\r\n
s> Accept-Encoding: identity\r\n
s> vary: X-HgProto-1,X-HgUpgrade-1\r\n
s> x-hgproto-1: cbor\r\n
s> x-hgupgrade-1: exp-http-v2-0001\r\n
s> accept: application/mercurial-0.1\r\n
s> host: $LOCALIP:$HGPORT\r\n (glob)
s> user-agent: Mercurial debugwireproto\r\n
s> \r\n
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-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
sending capabilities command
s> POST /api/exp-http-v2-0001/ro/capabilities 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\xa1DnameLcapabilities
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> 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> \r\n
received frame(size=571; 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'commands': {
b'branchmap': {
b'args': {},
b'permissions': [
b'pull'
]
},
b'capabilities': {
b'args': {},
b'permissions': [
b'pull'
]
},
b'changesetdata': {
b'args': {
b'fields': set([
b'parents',
b'revision'
]),
b'noderange': [
[
b'0123456...'
],
[
b'abcdef...'
]
],
b'nodes': [
b'0123456...'
]
},
b'permissions': [
b'pull'
]
},
b'heads': {
b'args': {
b'publiconly': False
},
b'permissions': [
b'pull'
]
},
b'known': {
b'args': {
b'nodes': [
b'deadbeef'
]
},
b'permissions': [
b'pull'
]
},
b'listkeys': {
b'args': {
b'namespace': b'ns'
},
b'permissions': [
b'pull'
]
},
b'lookup': {
b'args': {
b'key': b'foo'
},
b'permissions': [
b'pull'
]
},
b'pushkey': {
b'args': {
b'key': b'key',
b'namespace': b'ns',
b'new': b'new',
b'old': b'old'
},
b'permissions': [
b'push'
]
}
},
b'compression': [
{
b'name': b'zlib'
}
],
b'framingmediatypes': [
b'application/mercurial-exp-framing-0005'
],
b'rawrepoformats': [
b'generaldelta',
b'revlogv1'
]
}
]
$ cat error.log