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
$ hg init repo
$ cd repo
$ echo a > a
$ hg commit -A -ma
adding a
$ echo b >> a
$ hg commit -mb
$ echo c >> a
$ hg commit -mc
$ hg up 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo d >> a
$ hg commit -md
created new head
$ hg up 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo e >> a
$ hg commit -me
created new head
$ hg up 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
Should fail because not at a head:
$ hg merge
abort: working directory not at a head revision
(use 'hg update' or merge with an explicit revision)
[255]
$ hg up
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
updated to "f25cbe84d8b3: e"
2 other heads for branch "default"
Should fail because > 2 heads:
$ HGMERGE=internal:other; export HGMERGE
$ hg merge
abort: branch 'default' has 3 heads - please merge with an explicit rev
(run 'hg heads .' to see heads, specify rev with -r)
[255]
Should succeed (we're specifying commands.merge.require-rev=True just to test
that it allows merge to succeed if we specify a revision):
$ hg merge 2 --config commands.merge.require-rev=True
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg id -Tjson
[
{
"bookmarks": [],
"branch": "default",
"dirty": "+",
"id": "f25cbe84d8b320e298e7703f18a25a3959518c23+2d95304fed5d89bc9d70b2a0d02f0d567469c3ab+",
"node": "ffffffffffffffffffffffffffffffffffffffff",
"parents": ["f25cbe84d8b320e298e7703f18a25a3959518c23", "2d95304fed5d89bc9d70b2a0d02f0d567469c3ab"],
"tags": ["tip"]
}
]
$ hg commit -mm1
Should fail because we didn't specify a revision (even though it would have
succeeded without this):
$ hg merge --config commands.merge.require-rev=True
abort: configuration requires specifying revision to merge with
[10]
Should succeed - 2 heads:
$ hg merge -P
changeset: 3:ea9ff125ff88
parent: 1:1846eede8b68
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: d
$ hg merge
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg commit -mm2
$ hg id -r 1 -Tjson
[
{
"bookmarks": [],
"branch": "default",
"id": "1846eede8b6886d8cc8a88c96a687b7fe8f3b9d1",
"node": "1846eede8b6886d8cc8a88c96a687b7fe8f3b9d1",
"tags": []
}
]
Should fail because we didn't specify a revision (even though it would have
failed without this due to being on tip, but this check comes first):
$ hg merge --config commands.merge.require-rev=True
abort: configuration requires specifying revision to merge with
[10]
Should fail because at tip:
$ hg merge
abort: nothing to merge
[255]
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
Should fail because there is only one head:
$ hg merge
abort: nothing to merge
(use 'hg update' instead)
[255]
$ hg up 3
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo f >> a
$ hg branch foobranch
marked working directory as branch foobranch
(branches are permanent and global, did you want a bookmark?)
$ hg commit -mf
Should fail because merge with other branch:
$ hg merge
abort: branch 'foobranch' has one head - please merge with an explicit rev
(run 'hg heads' to see all heads, specify rev with -r)
[255]
Test for issue2043: ensure that 'merge -P' shows ancestors of 6 that
are not ancestors of 7, regardless of where their common ancestors are.
Merge preview not affected by common ancestor:
$ hg up -q 7
$ hg merge -q -P 6
2:2d95304fed5d
4:f25cbe84d8b3
5:a431fabd6039
6:e88e33f3bf62
Test experimental destination revset
$ hg log -r '_destmerge()'
abort: branch 'foobranch' has one head - please merge with an explicit rev
(run 'hg heads' to see all heads, specify rev with -r)
[255]
(on a branch with a two heads)
$ hg up 5
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo f >> a
$ hg commit -mf
created new head
$ hg log -r '_destmerge()'
changeset: 6:e88e33f3bf62
parent: 5:a431fabd6039
parent: 3:ea9ff125ff88
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: m2
(from the other head)
$ hg log -r '_destmerge(e88e33f3bf62)'
changeset: 8:b613918999e2
tag: tip
parent: 5:a431fabd6039
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: f
(from unrelated branch)
$ hg log -r '_destmerge(foobranch)'
abort: branch 'foobranch' has one head - please merge with an explicit rev
(run 'hg heads' to see all heads, specify rev with -r)
[255]