Mercurial > hg
view tests/test-patch-offset.t @ 24735:07200e3332a1
tags: extract .hgtags filenodes cache to a standalone file
Resolution of .hgtags filenodes values has historically been a
performance pain point for large repositories, where reading individual
manifests can take over 100ms. Multiplied by hundreds or even thousands
of heads and resolving .hgtags filenodes becomes a performance issue.
This patch establishes a standalone cache file holding the .hgtags
filenodes for each changeset. After this patch, the .hgtags filenode
for any particular changeset should only have to be computed once
during the lifetime of the repository.
The introduced hgtagsfnodes1 cache file is modeled after the rev branch
cache: the cache is effectively an array of entries consisting of a
changeset fragment and the filenode for a revision. The file grows in
proportion to the length of the repository (24 bytes per changeset) and
is truncated when the repository is stripped. The file is not written
unless tag info is requested and tags have changed since last time.
This patch partially addresses issue4550. Future patches will split the
"tags" cache file into per-filter files and will refactor the cache
format to not capture the .hgtags fnodes, as these are now stored in
the hgtagsfnodes1 cache. This patch is capable of standing alone. We
should not have to wait on the tags cache filter split and format
refactor for this patch to land.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 15 Apr 2015 17:42:38 -0400 |
parents | a387b0390082 |
children | 75be14993fda |
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$ cat > writepatterns.py <<EOF > import sys > > path = sys.argv[1] > patterns = sys.argv[2:] > > fp = file(path, 'wb') > for pattern in patterns: > count = int(pattern[0:-1]) > char = pattern[-1] + '\n' > fp.write(char*count) > fp.close() > EOF prepare repo $ hg init a $ cd a These initial lines of Xs were not in the original file used to generate the patch. So all the patch hunks need to be applied to a constant offset within this file. If the offset isn't tracked then the hunks can be applied to the wrong lines of this file. $ python ../writepatterns.py a 34X 10A 1B 10A 1C 10A 1B 10A 1D 10A 1B 10A 1E 10A 1B 10A $ hg commit -Am adda adding a This is a cleaner patch generated via diff In this case it reproduces the problem when the output of hg export does not import patch $ hg import -v -m 'b' -d '2 0' - <<EOF > --- a/a 2009-12-08 19:26:17.000000000 -0800 > +++ b/a 2009-12-08 19:26:17.000000000 -0800 > @@ -9,7 +9,7 @@ > A > A > B > -A > +a > A > A > A > @@ -53,7 +53,7 @@ > A > A > B > -A > +a > A > A > A > @@ -75,7 +75,7 @@ > A > A > B > -A > +a > A > A > A > EOF applying patch from stdin patching file a Hunk #1 succeeded at 43 (offset 34 lines). Hunk #2 succeeded at 87 (offset 34 lines). Hunk #3 succeeded at 109 (offset 34 lines). committing files: a committing manifest committing changelog created 189885cecb41 compare imported changes against reference file $ python ../writepatterns.py aref 34X 10A 1B 1a 9A 1C 10A 1B 10A 1D 10A 1B 1a 9A 1E 10A 1B 1a 9A $ diff aref a $ cd ..