bdiff: use Python memory allocator in fixws
Python has its own memory allocation APIs. For allocations
<= 512 bytes, it allocates memory from arenas. This means that
average small allocations don't call the system allocator, which
makes them faster. Also, arena allocations cut down on memory
fragmentation, which can matter for performance in long-running
processes.
Another advantage of using the Python memory allocator is that
allocations are tracked by Python. This is a bigger deal in
Python 3, as modern versions of Python have some decent built-in
tools for examining memory usage, leaks, etc.
This patch converts a trivial malloc() + free() in the bdiff code
to use the Python allocator APIs. Since the object being
operated on is a line, chances are it will use an arena. So,
this could have a net positive impact on performance (although
I didn't measure it).
$ cat > adddrop.py <<EOF
> from mercurial import cmdutil
> cmdtable = {}
> command = cmdutil.command(cmdtable)
> @command('debugadddrop',
> [('', 'drop', False, 'drop file from dirstate', 'FILE'),
> ('', 'normal-lookup', False, 'add file to dirstate', 'FILE')],
> 'hg debugadddrop')
> def debugadddrop(ui, repo, *pats, **opts):
> '''Add or drop unnamed arguments to or from the dirstate'''
> drop = opts.get('drop')
> nl = opts.get('normal_lookup')
> if nl and drop:
> raise error.Abort('drop and normal-lookup are mutually exclusive')
> wlock = repo.wlock()
> try:
> for file in pats:
> if opts.get('normal_lookup'):
> repo.dirstate.normallookup(file)
> else:
> repo.dirstate.drop(file)
>
> repo.dirstate.write(repo.currenttransaction())
> finally:
> wlock.release()
> EOF
$ echo "[extensions]" >> $HGRCPATH
$ echo "debugadddrop=`pwd`/adddrop.py" >> $HGRCPATH
basic test for hg debugrebuildstate
$ hg init repo
$ cd repo
$ touch foo bar
$ hg ci -Am 'add foo bar'
adding bar
adding foo
$ touch baz
$ hg add baz
$ hg rm bar
$ hg debugrebuildstate
state dump after
$ hg debugstate --nodates | sort
n 0 -1 unset bar
n 0 -1 unset foo
$ hg debugadddrop --normal-lookup file1 file2
$ hg debugadddrop --drop bar
$ hg debugadddrop --drop
$ hg debugstate --nodates
n 0 -1 unset file1
n 0 -1 unset file2
n 0 -1 unset foo
$ hg debugrebuildstate
status
$ hg st -A
! bar
? baz
C foo
Test debugdirstate --minimal where a file is not in parent manifest
but in the dirstate
$ touch foo bar qux
$ hg add qux
$ hg remove bar
$ hg status -A
A qux
R bar
? baz
C foo
$ hg debugadddrop --normal-lookup baz
$ hg debugdirstate --nodates
r 0 0 * bar (glob)
n 0 -1 * baz (glob)
n 644 0 * foo (glob)
a 0 -1 * qux (glob)
$ hg debugrebuilddirstate --minimal
$ hg debugdirstate --nodates
r 0 0 * bar (glob)
n 644 0 * foo (glob)
a 0 -1 * qux (glob)
$ hg status -A
A qux
R bar
? baz
C foo
Test debugdirstate --minimal where file is in the parent manifest but not the
dirstate
$ hg manifest
bar
foo
$ hg status -A
A qux
R bar
? baz
C foo
$ hg debugdirstate --nodates
r 0 0 * bar (glob)
n 644 0 * foo (glob)
a 0 -1 * qux (glob)
$ hg debugadddrop --drop foo
$ hg debugdirstate --nodates
r 0 0 * bar (glob)
a 0 -1 * qux (glob)
$ hg debugrebuilddirstate --minimal
$ hg debugdirstate --nodates
r 0 0 * bar (glob)
n 0 -1 * foo (glob)
a 0 -1 * qux (glob)
$ hg status -A
A qux
R bar
? baz
C foo