Mercurial > hg
view tests/test-permissions.t @ 27475:a2e2a8fa5fd1
revlog: avoid string slice when decompressing u* chunks
Revlog chunks can be stored uncompressed. If the first byte of the
raw data is \0, we store the data as is. Else we prefix it with 'u'.
Before, we performed a string slice to strip out the 'u' prefix.
With this patch, we use a buffer to avoid an extra memory copy and
associated garbage collection overhead.
I was unable to verify any performance impact of this patch. For both
mozilla-central and the hg repos, the number of manifest revisions
with 'u' prefixes is very small - under 1%. So this change likely
isn't called enough to have an impact on manifest reading. However,
the reasoning behind this change is solid, so it should be safe.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 20 Dec 2015 16:00:27 -0800 |
parents | 8fb6844a4ff1 |
children | 435f63d12475 |
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#require unix-permissions no-root $ hg init t $ cd t $ echo foo > a $ hg add a $ hg commit -m "1" $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 1 changesets, 1 total revisions $ chmod -r .hg/store/data/a.i $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files abort: Permission denied: $TESTTMP/t/.hg/store/data/a.i [255] $ chmod +r .hg/store/data/a.i $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 1 changesets, 1 total revisions $ chmod -w .hg/store/data/a.i $ echo barber > a $ hg commit -m "2" trouble committing a! abort: Permission denied: $TESTTMP/t/.hg/store/data/a.i [255] $ chmod -w . $ hg diff --nodates diff -r 2a18120dc1c9 a --- a/a +++ b/a @@ -1,1 +1,1 @@ -foo +barber $ chmod +w . $ chmod +w .hg/store/data/a.i $ mkdir dir $ touch dir/a $ hg status M a ? dir/a $ chmod -rx dir $ hg status dir: Permission denied M a Reenable perm to allow deletion: $ chmod +rx dir $ cd ..