revlog: remove unnecessary cache validation in _chunks
Previously, we likely called _chunkraw() multiple times in order to
ensure it didn't change out from under us. I'm pretty certain this code
had its origins in the days where we attempted to have thread safety of
localrepository and thus revlog instances.
revlog instances are already not thread safe for writing. And, as of
Mercurial 3.6, hgweb uses a separate localrepository instance per
request, so there should only be a single thread reading a revlog at
a time. We more or less decided that attempting to make classes like
revlog thread safe is a lost cause.
So, this patch removes thread safety from _chunks. As a result, we make
one less call into _chunkraw() when the initial read isn't serviced
by the cache. This translates to savings of 4 function calls overall
and possibly prevents the creation of an additional buffer view into the
cache. I doubt this translates into any real world performance wins
because decompression will almost certainly dwarf time spent in
_chunks(). But it does make the code simpler, so it is an improvement.
#!/bin/sh -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
$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