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.

adding foo
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
adding foo
   rev    offset  length   base linkrev nodeid       p1           p2
     0         0       0      0       0 b80de5d13875 000000000000 000000000000
     1         0      24      0       1 0376abec49b8 000000000000 000000000000