revset: add depth limit to descendants() (issue5374)
This is naive implementation using two-pass scanning. Tracking descendants
isn't an easy problem if both start and stop depths are specified. It's
impractical to remember all possible depths of each node while scanning from
roots to descendants because the number of depths explodes. Instead, we could
cache (min, max) depths as a good approximation and track ancestors back when
needed, but that's likely to have off-by-one bug.
Since this implementation appears not significantly slower, and is quite
straightforward, I think it's good enough for practical use cases. The time
and space complexity is O(n) ish.
revisions:
0) 1-pass scanning with (min, max)-depth cache (worst-case quadratic)
1) 2-pass scanning (this version)
repository:
mozilla-central
# descendants(0) (for reference)
*) 0.430353
# descendants(0, depth=1000)
0) 0.264889
1) 0.398289
# descendants(limit(tip:0, 1, offset=10000), depth=1000)
0) 0.025478
1) 0.029099
# descendants(0, depth=2000, startdepth=1000)
0) painfully slow (due to quadratic backtracking of ancestors)
1) 1.531138
#!/bin/bash -e
#
# Build a Mercurial RPM from the current repo
#
# Tested on
# - Fedora 20
# - CentOS 5
# - centOS 6
. $(dirname $0)/packagelib.sh
BUILD=1
RPMBUILDDIR="$PWD/rpmbuild"
while [ "$1" ]; do
case "$1" in
--prepare )
shift
BUILD=
;;
--withpython | --with-python)
shift
PYTHONVER=2.7.10
PYTHONMD5=d7547558fd673bd9d38e2108c6b42521
;;
--rpmbuilddir )
shift
RPMBUILDDIR="$1"
shift
;;
* )
echo "Invalid parameter $1!" 1>&2
exit 1
;;
esac
done
cd "`dirname $0`/.."
specfile=$PWD/contrib/mercurial.spec
if [ ! -f $specfile ]; then
echo "Cannot find $specfile!" 1>&2
exit 1
fi
if [ ! -d .hg ]; then
echo 'You are not inside a Mercurial repository!' 1>&2
exit 1
fi
gethgversion
# TODO: handle distance/node set, and type set
if [ -z "$type" ] ; then
release=1
else
release=0.9_$type
fi
if [ -n "$distance" ] ; then
release=$release+$distance_$node
fi
if [ "$PYTHONVER" ]; then
release=$release+$PYTHONVER
RPMPYTHONVER=$PYTHONVER
else
RPMPYTHONVER=%{nil}
fi
mkdir -p $RPMBUILDDIR/{SOURCES,BUILD,SRPMS,RPMS}
$HG archive -t tgz $RPMBUILDDIR/SOURCES/mercurial-$version-$release.tar.gz
if [ "$PYTHONVER" ]; then
(
mkdir -p build
cd build
PYTHON_SRCFILE=Python-$PYTHONVER.tgz
[ -f $PYTHON_SRCFILE ] || curl -Lo $PYTHON_SRCFILE http://www.python.org/ftp/python/$PYTHONVER/$PYTHON_SRCFILE
if [ "$PYTHONMD5" ]; then
echo "$PYTHONMD5 $PYTHON_SRCFILE" | md5sum -w -c
fi
ln -f $PYTHON_SRCFILE $RPMBUILDDIR/SOURCES/$PYTHON_SRCFILE
DOCUTILSVER=`sed -ne "s/^%global docutilsname docutils-//p" $specfile`
DOCUTILS_SRCFILE=docutils-$DOCUTILSVER.tar.gz
[ -f $DOCUTILS_SRCFILE ] || curl -Lo $DOCUTILS_SRCFILE http://downloads.sourceforge.net/project/docutils/docutils/$DOCUTILSVER/$DOCUTILS_SRCFILE
DOCUTILSMD5=`sed -ne "s/^%global docutilsmd5 //p" $specfile`
if [ "$DOCUTILSMD5" ]; then
echo "$DOCUTILSMD5 $DOCUTILS_SRCFILE" | md5sum -w -c
fi
ln -f $DOCUTILS_SRCFILE $RPMBUILDDIR/SOURCES/$DOCUTILS_SRCFILE
)
fi
mkdir -p $RPMBUILDDIR/SPECS
rpmspec=$RPMBUILDDIR/SPECS/mercurial.spec
sed -e "s,^Version:.*,Version: $version," \
-e "s,^Release:.*,Release: $release," \
$specfile > $rpmspec
echo >> $rpmspec
echo "%changelog" >> $rpmspec
if echo $version | grep '+' > /dev/null 2>&1; then
latesttag="`echo $version | sed -e 's/+.*//'`"
$HG log -r .:"$latesttag" -fM \
--template '{date|hgdate}\t{author}\t{desc|firstline}\n' | python -c '
import sys, time
def datestr(date, format):
return time.strftime(format, time.gmtime(float(date[0]) - date[1]))
changelog = []
for l in sys.stdin.readlines():
tok = l.split("\t")
hgdate = tuple(int(v) for v in tok[0].split())
changelog.append((datestr(hgdate, "%F"), tok[1], hgdate, tok[2]))
prevtitle = ""
for l in sorted(changelog, reverse=True):
title = "* %s %s" % (datestr(l[2], "%a %b %d %Y"), l[1])
if prevtitle != title:
prevtitle = title
print
print title
print "- %s" % l[3].strip()
' >> $rpmspec
else
$HG log \
--template '{date|hgdate}\t{author}\t{desc|firstline}\n' \
.hgtags | python -c '
import sys, time
def datestr(date, format):
return time.strftime(format, time.gmtime(float(date[0]) - date[1]))
for l in sys.stdin.readlines():
tok = l.split("\t")
hgdate = tuple(int(v) for v in tok[0].split())
print "* %s %s\n- %s" % (datestr(hgdate, "%a %b %d %Y"), tok[1], tok[2])
' >> $rpmspec
fi
sed -i \
-e "s/^%define withpython.*$/%define withpython $RPMPYTHONVER/" \
$rpmspec
if [ "$BUILD" ]; then
rpmbuild --define "_topdir $RPMBUILDDIR" -ba $rpmspec --clean
if [ $? = 0 ]; then
echo
echo "Built packages for $version-$release:"
find $RPMBUILDDIR/*RPMS/ -type f -newer $rpmspec
fi
else
echo "Prepared sources for $version-$release $rpmspec are in $RPMBUILDDIR/SOURCES/ - use like:"
echo "rpmbuild --define '_topdir $RPMBUILDDIR' -ba $rpmspec --clean"
fi