phases: rework the logic of _pushdiscoveryphase to bound complexity
This rework the various graph traversal in _pushdiscoveryphase to keep the
complexity in check.
This is done though a couple of things:
- first, limiting the space we have to explore, for example, if we are not in
publishing push, we don't need to consider remote draft roots that are also
draft locally, as there is nothing to be moved there.
- avoid unbounded descendant computation, and use the faster "rev between"
computation.
This provide a massive boost to performance when exchanging with repository with
a massive amount of draft, like mozilla-try:
### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
# benchmark.name = hg.command.push
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.explicit-rev = all-out-heads
# benchmark.variants.issue6528 = disabled
# benchmark.variants.protocol = ssh
# benchmark.variants.reuse-external-delta-parent = default
## benchmark.variants.revs = any-1-extra-rev
before: 20.346590 seconds
after: 11.232059 seconds (-38.15%, -7.48 seconds)
## benchmark.variants.revs = any-100-extra-rev
before: 24.752051 seconds
after: 15.367412 seconds (-37.91%, -9.38 seconds)
After this changes, the push operation is still quite too slow. Some of this
can be attributed to general phases slowness (reading all the roots from disk
for example) and other know slowness (not using persistent-nodemap, branchmap,
tags, etc. We are also working on them, but with this series, phase discovery
during push no longer showing up in profile and this is a pretty nice and bit
low-hanging fruit out of the way.
### (same case as the above)
# benchmark.variants.revs = any-1-extra-rev
pre-%ln-change: 44.235070
this-changeset: 11.232059 seconds (-74.61%, -33.00 seconds)
# benchmark.variants.revs = any-100-extra-rev
pre-%ln-change: 49.234697
this-changeset: 15.367412 seconds (-68.79%, -33.87 seconds)
Note that with this change, the `hg push` performance is now much closer to the
`hg pull` performance, even it still lagging behind a bit. (and the overall
performance are still too slow).
### data-env-vars.name = mozilla-try-2023-03-22-ds2-pnm
# benchmark.variants.explicit-rev = all-out-heads
# benchmark.variants.issue6528 = disabled
# benchmark.variants.protocol = ssh
# benchmark.variants.pulled-delta-reuse-policy = default
# bin-env-vars.hg.flavor = rust
## benchmark.variants.revs = any-1-extra-rev
hg.command.pull: 6.517450
hg.command.push: 11.219888
## benchmark.variants.revs = any-100-extra-rev
hg.command.pull: 10.160991
hg.command.push: 14.251107
### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.explicit-rev = all-out-heads
# benchmark.variants.issue6528 = disabled
# benchmark.variants.protocol = ssh
# benchmark.variants.pulled-delta-reuse-policy = default
## bin-env-vars.hg.flavor = default
## benchmark.variants.revs = any-1-extra-rev
hg.command.pull: 8.577772
hg.command.push: 11.232059
## bin-env-vars.hg.flavor = default
## benchmark.variants.revs = any-100-extra-rev
hg.command.pull: 13.152976
hg.command.push: 15.367412
## bin-env-vars.hg.flavor = rust
## benchmark.variants.revs = any-1-extra-rev
hg.command.pull: 8.731982
hg.command.push: 11.178751
## bin-env-vars.hg.flavor = rust
## benchmark.variants.revs = any-100-extra-rev
hg.command.pull: 13.184236
hg.command.push: 15.620843
$ cat <<EOF >> $HGRCPATH
> [extensions]
> notify =
> hooklib =
>
> [phases]
> publish = False
>
> [notify]
> sources = pull
> diffstat = False
> messageidseed = example
> domain = example.com
>
> [reposubs]
> * = baz
> EOF
$ hg init a
$ hg --cwd a debugbuilddag .
$ hg init b
$ cat <<EOF >> b/.hg/hgrc
> [hooks]
> incoming.notify = python:hgext.notify.hook
> txnclose-phase.changeset_published = python:hgext.hooklib.changeset_published.hook
> EOF
$ hg --cwd b pull ../a | "$PYTHON" $TESTDIR/unwrap-message-id.py
pulling from ../a
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files
new changesets 1ea73414a91b (1 drafts)
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Date: * (glob)
Subject: changeset in * (glob)
From: debugbuilddag@example.com
X-Hg-Notification: changeset 1ea73414a91b
Message-Id: <hg.81c297828fd2d5afaadf2775a6a71b74143b6451dfaac09fac939e9107a50d01@example.com>
To: baz@example.com
changeset 1ea73414a91b in $TESTTMP/b
details: $TESTTMP/b?cmd=changeset;node=1ea73414a91b
description:
r0
(run 'hg update' to get a working copy)
$ hg --cwd a phase --public 0
$ hg --cwd b pull ../a | "$PYTHON" $TESTDIR/unwrap-message-id.py
pulling from ../a
searching for changes
no changes found
1 local changesets published
Subject: changeset published
In-reply-to: <hg.81c297828fd2d5afaadf2775a6a71b74143b6451dfaac09fac939e9107a50d01@example.com>
Message-Id: <hg.2ec19bbddee5b542442bf5e1aed97bf706afff6aa765629883fbd1f4edd6fcb0@example.com>
Date: * (glob)
From: test@example.com
To: baz@example.com
This changeset has been published.
$ hg --cwd b phase --force --draft 0
$ cat <<EOF >> b/.hg/hgrc
> [notify_published]
> messageidseed = example2
> domain = alt.example.com
> template = Subject: changeset published
> From: hg@example.com\n
> This draft changeset has been published.\n
> EOF
$ hg --cwd b pull ../a | "$PYTHON" $TESTDIR/unwrap-message-id.py
pulling from ../a
searching for changes
no changes found
1 local changesets published
Subject: changeset published
From: hg@example.com
In-reply-to: <hg.e3381dc41c051215e50b1c166a72949d0fff99609eb373420bcb763af80ef230@alt.example.com>
Message-Id: <hg.c927f3d324e645a4245bfed20b0efb5b9582999d6be9bef45a37e7ec21208b24@alt.example.com>
Date: * (glob)
To: baz@example.com
This draft changeset has been published.