localrepo: delete obsolete comment about `prefix in repo` raising exception
We dropped support for `prefix in repo`, where `prefix` is a hex
prefix, in
8b86acc7aa64 (context: drop support for looking up context
by ambiguous changeid (API), 2018-04-28), after having deprecated it a
while before that. These days you get a `ProgrammingError` instead if
you pass in a short nodeid.
Differential Revision: https://phab.mercurial-scm.org/D9599
node: import symbols explicitly
There is no point in lazy importing mercurial.node, it is used all over
the place anyway. So consistently import the used symbols directly.
Fix one file using symbols indirectly via mercurial.revlog.
Differential Revision: https://phab.mercurial-scm.org/D9480
debugdiscovery: fix swapped heads and roots
Patch provided without comment…
Differential Revision: https://phab.mercurial-scm.org/D9566
debugdiscovery: display the number of roundtrip used
This is a good metric of the complexity of a discovery process.
Differential Revision: https://phab.mercurial-scm.org/D9565
copies: make calculating lazy for dir move detection's "addedfiles"
The information calculated here was only needed if (a) --debug was specified, or
(b) a directory move was plausibly detected. With tree manifests (especially in
my pathological repo and with our custom setup), pre-calculating the `u1` and
`u2` can be quite slow, and it's not even necessary in many cases. Let's delay
calculating it until we know it's actually necessary. This should have no
observable differences in output.
### Performance
I ran a rebase command in my pathological repo, rebasing two nodes across
several public phase commits, but where no directory copies exist in any of the
paths I'm tracking.
#### Before
```
Time (mean ± σ): 3.711 s ± 0.061 s [User: 0.3 ms, System: 1.5 ms]
Range (min … max): 3.640 s … 3.827 s 10 runs
```
#### After
```
Time (mean ± σ): 868.3 ms ± 10.1 ms [User: 0.5 ms, System: 1.2 ms]
Range (min … max): 856.6 ms … 883.6 ms 10 runs
```
Differential Revision: https://phab.mercurial-scm.org/D9567