dirstate: when calling rebuild(), avoid some N^2 codepaths
I had a user repo with 200k files in it. Calling `hg debugrebuilddirstate` took
tens of minutes (I didn't wait for it). In that situation,
changedfiles==allfiles, and both are lists. This meant that we had to run an
average of 100k comparisons, for each of 200k files, just to check whether a
file needed to have normallookup called (it always did), or drop.
While it's probably not a huge issue, in my very awkward synthetic benchmark I
wrote (not using a benchmark library or anything), I was seeing some slowdowns
for small-changedfiles and very-large-allfiles invocations, with an inflection
somewhere around 10 items in changedfiles (regardless of the size of allfiles);
above 10 items in changedfiles, the new code appears to always be faster. For
the case of 50k files in changedfiles and the same items in allfiles, I'm seeing
differences of 15s of just running comparisons vs. 0.003793s. I haven't bothered
to run a comparison of 200k items in changedfiles and allfiles. :)
Differential Revision: https://phab.mercurial-scm.org/D7665
Test the 'check-commit' script
==============================
A fine patch:
$ cat > patch-with-long-header.diff << EOF
> # HG changeset patch
> # User timeless <timeless@mozdev.org>
> # Date 1448911706 0
> # Mon Nov 30 19:28:26 2015 +0000
> # Node ID c41cb6d2b7dbd62b1033727f8606b8c09fc4aa88
> # Parent 42aa0e570eaa364a622bc4443b0bcb79b1100a58
> # ClownJoke This is a veryly long header that should not be warned about because its not the description
> bundle2: use Oxford comma (issue123) (BC)
>
> diff --git a/hgext/transplant.py b/hgext/transplant.py
> --- a/hgext/transplant.py
> +++ b/hgext/transplant.py
> @@ -599,7 +599,7 @@
> return
> if not (opts.get('source') or revs or
> opts.get('merge') or opts.get('branch')):
> - raise error.Abort(_('no source URL, branch revision or revision '
> + raise error.Abort(_('no source URL, branch revision, or revision '
> 'list provided'))
> if opts.get('all'):
>
> + def blahblah(x):
> + pass
> EOF
$ cat patch-with-long-header.diff | $TESTDIR/../contrib/check-commit
This would normally be against the rules, but it's okay because that's
what tagging and signing looks like:
$ cat > creates-a-tag.diff << EOF
> # HG changeset patch
> # User Augie Fackler <raf@durin42.com>
> # Date 1484787778 18000
> # Wed Jan 18 20:02:58 2017 -0500
> # Branch stable
> # Node ID c177635e4acf52923bc3aa9f72a5b1ad1197b173
> # Parent a1dd2c0c479e0550040542e392e87bc91262517e
> Added tag 4.1-rc for changeset a1dd2c0c479e
>
> diff --git a/.hgtags b/.hgtags
> --- a/.hgtags
> +++ b/.hgtags
> @@ -150,3 +150,4 @@ 438173c415874f6ac653efc1099dec9c9150e90f
> eab27446995210c334c3d06f1a659e3b9b5da769 4.0
> b3b1ae98f6a0e14c1e1ba806a6c18e193b6dae5c 4.0.1
> e69874dc1f4e142746ff3df91e678a09c6fc208c 4.0.2
> +a1dd2c0c479e0550040542e392e87bc91262517e 4.1-rc
> EOF
$ $TESTDIR/../contrib/check-commit < creates-a-tag.diff
A patch with lots of errors:
$ cat > patch-with-long-header.diff << EOF
> # HG changeset patch
> # User timeless
> # Date 1448911706 0
> # Mon Nov 30 19:28:26 2015 +0000
> # Node ID c41cb6d2b7dbd62b1033727f8606b8c09fc4aa88
> # Parent 42aa0e570eaa364a622bc4443b0bcb79b1100a58
> # ClownJoke This is a veryly long header that should not be warned about because its not the description
> transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
>
> diff --git a/hgext/transplant.py b/hgext/transplant.py
> --- a/hgext/transplant.py
> +++ b/hgext/transplant.py
> @@ -599,7 +599,7 @@
> return
> if not (opts.get('source') or revs or
> opts.get('merge') or opts.get('branch')):
> - raise error.Abort(_('no source URL, branch revision or revision '
> + raise error.Abort(_('no source URL, branch revision, or revision '
> 'list provided'))
> if opts.get('all'):
> EOF
$ cat patch-with-long-header.diff | $TESTDIR/../contrib/check-commit
1: username is not an email address
# User timeless
7: summary keyword should be most user-relevant one-word command or topic
transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
7: (BC) needs to be uppercase
transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
7: use (issueDDDD) instead of bug
transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
7: no space allowed between issue and number
transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
7: summary line too long (limit is 78)
transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
[1]
A patch with other errors:
$ cat > patch-with-long-header.diff << EOF
> # HG changeset patch
> # User timeless
> # Date 1448911706 0
> # Mon Nov 30 19:28:26 2015 +0000
> # Node ID c41cb6d2b7dbd62b1033727f8606b8c09fc4aa88
> # Parent 42aa0e570eaa364a622bc4443b0bcb79b1100a58
> # ClownJoke This is a veryly long header that should not be warned about because its not the description
> This has no topic and ends with a period.
>
> diff --git a/hgext/transplant.py b/hgext/transplant.py
> --- a/hgext/transplant.py
> +++ b/hgext/transplant.py
> @@ -599,7 +599,7 @@
> if opts.get('all'):
>
>
> +
> + some = otherjunk
> +
> +
> + def blah_blah(x):
> + pass
> +
>
> EOF
$ cat patch-with-long-header.diff | $TESTDIR/../contrib/check-commit
1: username is not an email address
# User timeless
7: don't capitalize summary lines
This has no topic and ends with a period.
7: summary line doesn't start with 'topic: '
This has no topic and ends with a period.
7: don't add trailing period on summary line
This has no topic and ends with a period.
[1]