revlog: break up compression of large deltas
Python's zlib apparently makes an internal copy of strings passed to
compress(). To avoid this, compress strings 1M at a time, then join
them at the end if the result would be smaller than the original.
For initial commits of large but compressible files, this cuts peak
memory usage nearly in half.
#!/bin/sh
echo "[extensions]" >> $HGRCPATH
echo "mq=" >> $HGRCPATH
cat >> readlink.py <<EOF
import errno, os, sys
for f in sys.argv[1:]:
try:
print f, '->', os.readlink(f)
except OSError, err:
if err.errno != errno.EINVAL: raise
print f, 'not a symlink'
EOF
hg init
hg qinit
hg qnew base.patch
echo a > a
echo b > b
hg add a b
hg qrefresh
python readlink.py a
hg qnew symlink.patch
rm a
ln -s b a
hg qrefresh --git
python readlink.py a
hg qpop
hg qpush
python readlink.py a