rust-nodemap: accounting for dead blocks
By the very append-only nature of the `NodeTree`, inserting
new blocks has the effect of making some of the older ones
useless as they become unreachable.
Therefore some automatic housekeeping will need to be provided.
This is standard procedure in the word of databases, under names
such as "repack" or "vacuum".
The new `masked_readonly_blocks()` will provide callers with
useful information to decide if the nodetree is ripe for
repacking, but all the `NodeTree` can provide is how many
blocks have been masked in the currently mutable part. Analysing
the readonly part would be way too long to do it for each
transaction and defeat the whole purpose of nodemap persistence.
Serializing callers (from the Python layer) will get this figure
before each extraction and maintain an aggregate counter of
unreachable blocks separately.
Note: at this point, the most efficient repacking is just to restart
afresh with a full rescan.
Differential Revision: https://phab.mercurial-scm.org/D8097
test --time
$ hg --time help -q help 2>&1 | grep time > /dev/null
$ hg init a
$ cd a
Function to check that statprof ran
$ statprofran () {
> egrep 'Sample count:|No samples recorded' > /dev/null
> }
test --profile
$ hg st --profile 2>&1 | statprofran
Abreviated version
$ hg st --prof 2>&1 | statprofran
In alias
$ hg --config "alias.profst=status --profile" profst 2>&1 | statprofran
#if lsprof
$ prof='hg --config profiling.type=ls --profile'
$ $prof st 2>../out
$ grep CallCount ../out > /dev/null || cat ../out
$ $prof --config profiling.output=../out st
$ grep CallCount ../out > /dev/null || cat ../out
$ $prof --config profiling.output=blackbox --config extensions.blackbox= st
$ grep CallCount .hg/blackbox.log > /dev/null || cat .hg/blackbox.log
$ $prof --config profiling.format=text st 2>../out
$ grep CallCount ../out > /dev/null || cat ../out
$ echo "[profiling]" >> $HGRCPATH
$ echo "format=kcachegrind" >> $HGRCPATH
$ $prof st 2>../out
$ grep 'events: Ticks' ../out > /dev/null || cat ../out
$ $prof --config profiling.output=../out st
$ grep 'events: Ticks' ../out > /dev/null || cat ../out
#endif
#if lsprof serve
Profiling of HTTP requests works
$ $prof --config profiling.format=text --config profiling.output=../profile.log serve -d -p $HGPORT --pid-file ../hg.pid -A ../access.log
$ cat ../hg.pid >> $DAEMON_PIDS
$ hg -q clone -U http://localhost:$HGPORT ../clone
A single profile is logged because file logging doesn't append
$ grep CallCount ../profile.log | wc -l
\s*1 (re)
#endif
Install an extension that can sleep and guarantee a profiler has time to run
$ cat >> sleepext.py << EOF
> import time
> from mercurial import registrar
> cmdtable = {}
> command = registrar.command(cmdtable)
> @command(b'sleep', [], b'hg sleep')
> def sleep(ui, *args, **kwargs):
> time.sleep(0.1)
> EOF
$ cat >> $HGRCPATH << EOF
> [extensions]
> sleep = `pwd`/sleepext.py
> EOF
statistical profiler works
$ hg --profile sleep 2>../out
$ cat ../out | statprofran
Various statprof formatters work
$ hg --profile --config profiling.statformat=byline sleep 2>../out || cat ../out
$ head -n 3 ../out
% cumulative self
time seconds seconds name
* sleepext.py:*:sleep (glob)
$ cat ../out | statprofran
$ hg --profile --config profiling.statformat=bymethod sleep 2>../out || cat ../out
$ head -n 1 ../out
% cumulative self
$ cat ../out | statprofran
$ hg --profile --config profiling.statformat=hotpath sleep 2>../out || cat ../out
$ cat ../out | statprofran
$ hg --profile --config profiling.statformat=json sleep 2>../out || cat ../out
$ cat ../out
\[\[-?\d+.* (re)
statprof can be used as a standalone module
$ "$PYTHON" -m mercurial.statprof hotpath
must specify --file to load
[1]
$ cd ..
#if no-chg
profiler extension could be loaded before other extensions
$ cat > fooprof.py <<EOF
> from __future__ import absolute_import
> import contextlib
> import sys
> @contextlib.contextmanager
> def profile(ui, fp):
> print('fooprof: start profile')
> sys.stdout.flush()
> yield
> print('fooprof: end profile')
> sys.stdout.flush()
> def extsetup(ui):
> ui.write(b'fooprof: loaded\n')
> EOF
$ cat > otherextension.py <<EOF
> from __future__ import absolute_import
> def extsetup(ui):
> ui.write(b'otherextension: loaded\n')
> EOF
$ hg init b
$ cd b
$ cat >> .hg/hgrc <<EOF
> [extensions]
> other = $TESTTMP/otherextension.py
> fooprof = $TESTTMP/fooprof.py
> EOF
$ hg root
otherextension: loaded
fooprof: loaded
$TESTTMP/b
$ HGPROF=fooprof hg root --profile
fooprof: loaded
fooprof: start profile
otherextension: loaded
$TESTTMP/b
fooprof: end profile
$ HGPROF=other hg root --profile 2>&1 | head -n 2
otherextension: loaded
unrecognized profiler 'other' - ignored
$ HGPROF=unknown hg root --profile 2>&1 | head -n 1
unrecognized profiler 'unknown' - ignored
$ cd ..
#endif