Mercurial > hg-stable
view tests/test-histedit-no-change.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 | 6084926366b9 |
children | 890273343170 |
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test for old histedit issue #6: editing a changeset without any actual change would corrupt the repository $ . "$TESTDIR/histedit-helpers.sh" $ cat >> $HGRCPATH <<EOF > [extensions] > histedit= > EOF $ initrepo () > { > dir="$1" > comment="$2" > if [ -n "${comment}" ]; then > echo % ${comment} > echo % ${comment} | sed 's:.:-:g' > fi > hg init ${dir} > cd ${dir} > for x in a b c d e f ; do > echo $x > $x > hg add $x > hg ci -m $x > done > cd .. > } $ geneditor () > { > # generate an editor script for selecting changesets to be edited > choice=$1 # changesets that should be edited (using sed line ranges) > cat <<EOF | sed 's:^....::' > # editing the rules, replacing 'pick' with 'edit' for the chosen lines > sed '${choice}s:^pick:edit:' "\$1" > "\${1}.tmp" > mv "\${1}.tmp" "\$1" > # displaying the resulting rules, minus comments and empty lines > sed '/^#/d;/^$/d;s:^:| :' "\$1" >&2 > EOF > } $ startediting () > { > # begin an editing session > choice="$1" # changesets that should be edited > number="$2" # number of changesets considered (from tip) > comment="$3" > geneditor "${choice}" > edit.sh > echo % start editing the history ${comment} > HGEDITOR="sh ./edit.sh" hg histedit -- -${number} 2>&1 | fixbundle > } $ continueediting () > { > # continue an edit already in progress > editor="$1" # message editor when finalizing editing > comment="$2" > echo % finalize changeset editing ${comment} > HGEDITOR=${editor} hg histedit --continue 2>&1 | fixbundle > } $ graphlog () > { > comment="${1:-log}" > echo % "${comment}" > hg log -G --template '{rev} {node} \"{desc|firstline}\"\n' > } $ initrepo r1 "test editing with no change" % test editing with no change ----------------------------- $ cd r1 $ graphlog "log before editing" % log before editing @ 5 652413bf663ef2a641cab26574e46d5f5a64a55a "f" | o 4 e860deea161a2f77de56603b340ebbb4536308ae "e" | o 3 055a42cdd88768532f9cf79daa407fc8d138de9b "d" | o 2 177f92b773850b59254aa5e923436f921b55483b "c" | o 1 d2ae7f538514cd87c17547b0de4cea71fe1af9fb "b" | o 0 cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b "a" $ startediting 2 3 "(not changing anything)" # edit the 2nd of 3 changesets % start editing the history (not changing anything) | pick 055a42cdd887 3 d | edit e860deea161a 4 e | pick 652413bf663e 5 f 0 files updated, 0 files merged, 2 files removed, 0 files unresolved Make changes as needed, you may commit or record as needed now. When you are finished, run hg histedit --continue to resume. $ continueediting true "(leaving commit message unaltered)" % finalize changeset editing (leaving commit message unaltered) 0 files updated, 0 files merged, 0 files removed, 0 files unresolved 0 files updated, 0 files merged, 0 files removed, 0 files unresolved check state of working copy $ hg id 794fe033d0a0 tip $ graphlog "log after history editing" % log after history editing @ 5 794fe033d0a030f8df77c5de945fca35c9181c30 "f" | o 4 04d2fab980779f332dec458cc944f28de8b43435 "e" | o 3 055a42cdd88768532f9cf79daa407fc8d138de9b "d" | o 2 177f92b773850b59254aa5e923436f921b55483b "c" | o 1 d2ae7f538514cd87c17547b0de4cea71fe1af9fb "b" | o 0 cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b "a" $ cd .. $ initrepo r2 "test editing with no change, then abort" % test editing with no change, then abort ----------------------------------------- $ cd r2 $ graphlog "log before editing" % log before editing @ 5 652413bf663ef2a641cab26574e46d5f5a64a55a "f" | o 4 e860deea161a2f77de56603b340ebbb4536308ae "e" | o 3 055a42cdd88768532f9cf79daa407fc8d138de9b "d" | o 2 177f92b773850b59254aa5e923436f921b55483b "c" | o 1 d2ae7f538514cd87c17547b0de4cea71fe1af9fb "b" | o 0 cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b "a" $ startediting 1,2 3 "(not changing anything)" # edit the 1st two of 3 changesets % start editing the history (not changing anything) | edit 055a42cdd887 3 d | edit e860deea161a 4 e | pick 652413bf663e 5 f 0 files updated, 0 files merged, 3 files removed, 0 files unresolved Make changes as needed, you may commit or record as needed now. When you are finished, run hg histedit --continue to resume. $ continueediting true "(leaving commit message unaltered)" % finalize changeset editing (leaving commit message unaltered) 0 files updated, 0 files merged, 0 files removed, 0 files unresolved Make changes as needed, you may commit or record as needed now. When you are finished, run hg histedit --continue to resume. $ graphlog "log after first edit" % log after first edit @ 6 e5ae3ca2f1ffdbd89ec41ebc273a231f7c3022f2 "d" | | o 5 652413bf663ef2a641cab26574e46d5f5a64a55a "f" | | | o 4 e860deea161a2f77de56603b340ebbb4536308ae "e" | | | o 3 055a42cdd88768532f9cf79daa407fc8d138de9b "d" |/ o 2 177f92b773850b59254aa5e923436f921b55483b "c" | o 1 d2ae7f538514cd87c17547b0de4cea71fe1af9fb "b" | o 0 cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b "a" abort editing session, after first forcibly updating away $ hg up 0 abort: histedit in progress (use 'hg histedit --continue' or 'hg histedit --abort') [255] $ mv .hg/histedit-state .hg/histedit-state-ignore $ hg up 0 0 files updated, 0 files merged, 3 files removed, 0 files unresolved $ mv .hg/histedit-state-ignore .hg/histedit-state $ hg sum parent: 0:cb9a9f314b8b a branch: default commit: 1 added, 1 unknown (new branch head) update: 6 new changesets (update) phases: 7 draft hist: 2 remaining (histedit --continue) $ hg histedit --abort 2>&1 | fixbundle [1] modified files should survive the abort when we've moved away already $ hg st A e ? edit.sh $ graphlog "log after abort" % log after abort o 5 652413bf663ef2a641cab26574e46d5f5a64a55a "f" | o 4 e860deea161a2f77de56603b340ebbb4536308ae "e" | o 3 055a42cdd88768532f9cf79daa407fc8d138de9b "d" | o 2 177f92b773850b59254aa5e923436f921b55483b "c" | o 1 d2ae7f538514cd87c17547b0de4cea71fe1af9fb "b" | @ 0 cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b "a" $ cd ..