commit dc20764a37894e042fc3f8be9c5e413fe2521873
from: Stefan Sperling <stsp@stsp.name>
date: Fri Oct 15 09:30:29 2021 UTC

limit delta chain length in newly created pack files to 32 deltas

Our former limit was 128 which is fairly high. Git uses 50 by default.
A smaller limit results in slightly larger pack files but makes both
packing and unpacking faster.

commit - 94dac27cd14d635dc83d202ffa7ed21dad0de278
commit + dc20764a37894e042fc3f8be9c5e413fe2521873
blob - 953b2e8620ccc19d5c6e3c05fe05180156f20819
blob + 6bcae584755aeb68d508d3c15e9ab65336ee79a7
--- lib/pack_create.c
+++ lib/pack_create.c
@@ -221,7 +221,7 @@ pick_deltas(struct got_pack_meta **meta, int nmeta, in
 			}
 			base = meta[j];
 			/* long chains make unpacking slow, avoid such bases */
-			if (base->nchain >= 128 ||
+			if (base->nchain >= 32 ||
 			    base->obj_type != m->obj_type)
 				continue;