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 "extdiff=" >> $HGRCPATH
hg init a
cd a
echo a > a
echo b > b
hg add
# should diff cloned directories
hg extdiff -o -r $opt
echo "[extdiff]" >> $HGRCPATH
echo "cmd.falabala=echo" >> $HGRCPATH
echo "opts.falabala=diffing" >> $HGRCPATH
hg falabala
hg help falabala
hg ci -d '0 0' -mtest1
echo b >> a
hg ci -d '1 0' -mtest2
# should diff cloned files directly
hg falabala -r 0:1
# test diff during merge
hg update 0
echo c >> c
hg add c
hg ci -m "new branch" -d '1 0'
hg update -C 1
hg merge tip
# should diff cloned file against wc file
hg falabala > out || echo "diff-like tools yield a non-zero exit code"
# cleanup the output since the wc is a tmp directory
sed 's:\(.* \).*\(\/test-extdiff\):\1[tmp]\2:' out