Mercurial > hg-stable
view tests/test-export.t @ 26379:39d643252b9f
revlog: use existing file handle when reading during _addrevision
_addrevision() may need to read from revlogs as part of computing
deltas. Previously, we would flush existing file handles and open
a new, short-lived file handle to perform the reading.
If we have an existing file handle, it seems logical to reuse it
for reading instead of opening a new file handle. This patch
makes that the new behavior.
After this patch, revlog files are only reopened when adding
revisions if the revlog is switched from inline to non-inline.
On Linux when unbundling a bundle of the mozilla-central repo, this
patch has the following impact on system call counts:
Call Before After Delta
write 827,639 673,390 -154,249
open 700,103 684,089 -16,014
read 74,489 74,489 0
fstat 493,924 461,896 -32,028
close 249,131 233,117 -16,014
stat 242,001 242,001 0
lstat 18,676 18,676 0
lseek 20,268 20,268 0
ioctl 14,652 13,173 -1,479
TOTAL 3,180,758 2,930,679 -250,079
It's worth noting that many of the open() calls fail due to missing
files. That's why there are many more open() calls than close().
Despite the significant system call reduction, this change does not
seem to have a significant performance impact on Linux.
On Windows 10 (not a VM, on a SSD), this patch appears to reduce
unbundle time for mozilla-central from ~960s to ~920s. This isn't
as significant as I was hoping. But a decrease it is nonetheless.
Still, Windows unbundle performance is still >2x slower than Linux.
Despite the lack of significant gains, fewer system calls is fewer
system calls. If nothing else, this will narrow the focus of potential
areas to optimize in the future.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 27 Sep 2015 16:08:18 -0700 |
parents | e955549cd045 |
children | 9d04b4da6773 |
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$ hg init repo $ cd repo $ touch foo $ hg add foo $ for i in 0 1 2 3 4 5 6 7 8 9 10 11; do > echo "foo-$i" >> foo > hg ci -m "foo-$i" > done $ for out in "%nof%N" "%%%H" "%b-%R" "%h" "%r" "%m"; do > echo > echo "# foo-$out.patch" > hg export -v -o "foo-$out.patch" 2:tip > done # foo-%nof%N.patch exporting patches: foo-01of10.patch foo-02of10.patch foo-03of10.patch foo-04of10.patch foo-05of10.patch foo-06of10.patch foo-07of10.patch foo-08of10.patch foo-09of10.patch foo-10of10.patch # foo-%%%H.patch exporting patches: foo-%617188a1c80f869a7b66c85134da88a6fb145f67.patch foo-%dd41a5ff707a5225204105611ba49cc5c229d55f.patch foo-%f95a5410f8664b6e1490a4af654e4b7d41a7b321.patch foo-%4346bcfde53b4d9042489078bcfa9c3e28201db2.patch foo-%afda8c3a009cc99449a05ad8aa4655648c4ecd34.patch foo-%35284ce2b6b99c9d2ac66268fe99e68e1974e1aa.patch foo-%9688c41894e6931305fa7165a37f6568050b4e9b.patch foo-%747d3c68f8ec44bb35816bfcd59aeb50b9654c2f.patch foo-%5f17a83f5fbd9414006a5e563eab4c8a00729efd.patch foo-%f3acbafac161ec68f1598af38f794f28847ca5d3.patch # foo-%b-%R.patch exporting patches: foo-repo-2.patch foo-repo-3.patch foo-repo-4.patch foo-repo-5.patch foo-repo-6.patch foo-repo-7.patch foo-repo-8.patch foo-repo-9.patch foo-repo-10.patch foo-repo-11.patch # foo-%h.patch exporting patches: foo-617188a1c80f.patch foo-dd41a5ff707a.patch foo-f95a5410f866.patch foo-4346bcfde53b.patch foo-afda8c3a009c.patch foo-35284ce2b6b9.patch foo-9688c41894e6.patch foo-747d3c68f8ec.patch foo-5f17a83f5fbd.patch foo-f3acbafac161.patch # foo-%r.patch exporting patches: foo-02.patch foo-03.patch foo-04.patch foo-05.patch foo-06.patch foo-07.patch foo-08.patch foo-09.patch foo-10.patch foo-11.patch # foo-%m.patch exporting patches: foo-foo_2.patch foo-foo_3.patch foo-foo_4.patch foo-foo_5.patch foo-foo_6.patch foo-foo_7.patch foo-foo_8.patch foo-foo_9.patch foo-foo_10.patch foo-foo_11.patch Doing it again clobbers the files rather than appending: $ hg export -v -o "foo-%m.patch" 2:3 exporting patches: foo-foo_2.patch foo-foo_3.patch $ grep HG foo-foo_2.patch | wc -l \s*1 (re) $ grep HG foo-foo_3.patch | wc -l \s*1 (re) Exporting 4 changesets to a file: $ hg export -o export_internal 1 2 3 4 $ grep HG export_internal | wc -l \s*4 (re) Doing it again clobbers the file rather than appending: $ hg export -o export_internal 1 2 3 4 $ grep HG export_internal | wc -l \s*4 (re) Exporting 4 changesets to stdout: $ hg export 1 2 3 4 | grep HG | wc -l \s*4 (re) Exporting revision -2 to a file: $ hg export -- -2 # HG changeset patch # User test # Date 0 0 # Thu Jan 01 00:00:00 1970 +0000 # Node ID 5f17a83f5fbd9414006a5e563eab4c8a00729efd # Parent 747d3c68f8ec44bb35816bfcd59aeb50b9654c2f foo-10 diff -r 747d3c68f8ec -r 5f17a83f5fbd foo --- a/foo Thu Jan 01 00:00:00 1970 +0000 +++ b/foo Thu Jan 01 00:00:00 1970 +0000 @@ -8,3 +8,4 @@ foo-7 foo-8 foo-9 +foo-10 Checking if only alphanumeric characters are used in the file name (%m option): $ echo "line" >> foo $ hg commit -m " !\"#$%&(,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_\`abcdefghijklmnopqrstuvwxyz{|}~" $ hg export -v -o %m.patch tip exporting patch: ____________0123456789_______ABCDEFGHIJKLMNOPQRSTUVWXYZ______abcdefghijklmnopqrstuvwxyz____.patch Catch exporting unknown revisions (especially empty revsets, see issue3353) $ hg export # HG changeset patch # User test # Date 0 0 # Thu Jan 01 00:00:00 1970 +0000 # Node ID 197ecd81a57f760b54f34a58817ad5b04991fa47 # Parent f3acbafac161ec68f1598af38f794f28847ca5d3 !"#$%&(,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~ diff -r f3acbafac161 -r 197ecd81a57f foo --- a/foo Thu Jan 01 00:00:00 1970 +0000 +++ b/foo Thu Jan 01 00:00:00 1970 +0000 @@ -10,3 +10,4 @@ foo-9 foo-10 foo-11 +line $ hg export "" hg: parse error: empty query [255] $ hg export 999 abort: unknown revision '999'! [255] $ hg export "not all()" abort: export requires at least one changeset [255] Check for color output $ cat <<EOF >> $HGRCPATH > [color] > mode = ansi > [extensions] > color = > EOF $ hg export --color always --nodates tip # HG changeset patch # User test # Date 0 0 # Thu Jan 01 00:00:00 1970 +0000 # Node ID * (glob) # Parent * (glob) !"#$%&(,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~ \x1b[0;1mdiff -r f3acbafac161 -r 197ecd81a57f foo\x1b[0m (esc) \x1b[0;31;1m--- a/foo\x1b[0m (esc) \x1b[0;32;1m+++ b/foo\x1b[0m (esc) \x1b[0;35m@@ -10,3 +10,4 @@\x1b[0m (esc) foo-9 foo-10 foo-11 \x1b[0;32m+line\x1b[0m (esc) $ cd ..