revset: optimize "draft() & ::x" pattern
The `draft() & ::x` type query could be common for selecting one or more
draft feature branches being worked on.
Before this patch, `::x` may travel through the changelog DAG for a long
distance until it gets a smaller revision number than `min(draft())`. It
could be very slow on long changelog with distant (in terms of revision
numbers) drafts.
This patch adds a fast path for this situation, and will stop traveling the
changelog DAG once `::x` hits a non-draft revision.
The fast path also works for `secret()` and `not public()`.
To measure the performance difference, I used drawdag to create a repo that
emulates distant drafts:
DRAFT4
|
DRAFT3 # draft
/
PUBLIC9999 # public
|
PUBLIC9998
|
. DRAFT2
. |
. DRAFT1 # draft
| /
PUBLIC0001 # public
And measured the performance using the repo:
(BEFORE)
$ hg perfrevset 'draft() & ::(DRAFT2+DRAFT4)'
! wall 0.017132 comb 0.010000 user 0.010000 sys 0.000000 (best of 156)
$ hg perfrevset 'draft() & ::(all())'
! wall 0.024221 comb 0.030000 user 0.030000 sys 0.000000 (best of 113)
(AFTER)
$ hg perfrevset 'draft() & ::(DRAFT2+DRAFT4)'
! wall 0.000243 comb 0.000000 user 0.000000 sys 0.000000 (best of 9303)
$ hg perfrevset 'draft() & ::(all())'
! wall 0.004319 comb 0.000000 user 0.000000 sys 0.000000 (best of 655)
Differential Revision: https://phab.mercurial-scm.org/D441
#!/usr/bin/env python
"""
Tests the behavior of filelog w.r.t. data starting with '\1\n'
"""
from __future__ import absolute_import, print_function
from mercurial.node import (
hex,
nullid,
)
from mercurial import (
hg,
ui as uimod,
)
myui = uimod.ui.load()
repo = hg.repository(myui, path='.', create=True)
fl = repo.file('foobar')
def addrev(text, renamed=False):
if renamed:
# data doesn't matter. Just make sure filelog.renamed() returns True
meta = {'copyrev': hex(nullid), 'copy': 'bar'}
else:
meta = {}
lock = t = None
try:
lock = repo.lock()
t = repo.transaction('commit')
node = fl.add(text, meta, t, 0, nullid, nullid)
return node
finally:
if t:
t.close()
if lock:
lock.release()
def error(text):
print('ERROR: ' + text)
textwith = '\1\nfoo'
without = 'foo'
node = addrev(textwith)
if not textwith == fl.read(node):
error('filelog.read for data starting with \\1\\n')
if fl.cmp(node, textwith) or not fl.cmp(node, without):
error('filelog.cmp for data starting with \\1\\n')
if fl.size(0) != len(textwith):
error('FIXME: This is a known failure of filelog.size for data starting '
'with \\1\\n')
node = addrev(textwith, renamed=True)
if not textwith == fl.read(node):
error('filelog.read for a renaming + data starting with \\1\\n')
if fl.cmp(node, textwith) or not fl.cmp(node, without):
error('filelog.cmp for a renaming + data starting with \\1\\n')
if fl.size(1) != len(textwith):
error('filelog.size for a renaming + data starting with \\1\\n')
print('OK.')