Re: [PATCH] index-pack: eliminate unlimited recursion in get_delta_base()
From: Shawn Pearce <hidden>
Date: 2016-06-15 22:52:35
2011/12/7 Nguyễn Thái Ngọc Duy [off-list ref]:
Revert the order of delta applying so that by the time a delta is applied, its base is either non-delta or already inflated. get_delta_base() is still recursive, but because base's data is always ready, the inner get_delta_base() call never has any chance to call itself again.
...
quoted hunk ↗ jump to hunk
@@ -508,10 +508,25 @@ static void *get_base_data(struct base_data *c){ if (!c->data) { struct object_entry *obj = c->obj; + struct base_data **delta = NULL; + int delta_nr = 0, delta_alloc = 0; - if (is_delta_type(obj->type)) { - void *base = get_base_data(c->base); - void *raw = get_data_from_pack(obj);
I think you missed the critical recursion. The real work is the recursion within find_unresolved_deltas(). This little helper get_base_data() shouldn't be tripping over these cases unless we have run out of delta_base_cache_limit and released objects near the base end of the delta chain, in which case this will restore them. Maybe this is useful on its own, but in my opinion its not an interesting patch to consider without first fixing find_unresolved_deltas's recursion.