reftable/record: reuse message when decoding log records
Same as the preceding commit we can allocate log messages as needed when
decoding log records, thus further reducing the number of allocations.
Before:
HEAP SUMMARY:
in use at exit: 13,473 bytes in 122 blocks
total heap usage: 3,068,488 allocs, 3,068,366 frees, 307,122,961 bytes allocated
After:
HEAP SUMMARY:
in use at exit: 13,473 bytes in 122 blocks
total heap usage: 2,068,487 allocs, 2,068,365 frees, 305,122,946 bytes allocated
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>