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 "imerge=" >> $HGRCPATH
HGMERGE=true
export HGMERGE
hg init base
cd base
echo foo > foo
echo bar > bar
hg ci -Am0 -d '0 0'
hg mv foo foo2
echo foo >> foo2
hg ci -m1 -d '1 0'
hg up -C 0
echo bar >> foo
echo bar >> bar
hg ci -m2 -d '2 0'
echo % start imerge
hg imerge
cat foo2
cat bar
echo % status -v
hg -v imerge st
echo % next
hg imerge next
echo % merge next
hg --traceback imerge
echo % unresolve
hg imerge unres foo
echo % merge foo
hg imerge merge foo
echo % save
echo foo > foo2
hg imerge save ../savedmerge
echo % load
hg up -C 0
hg imerge --traceback load ../savedmerge
cat foo2
hg ci -m'merged' -d '3 0'
hg tip -v
echo % nothing to merge -- tip
hg imerge
hg up 0
echo % nothing to merge
hg imerge
exit 0