osbase/logtree: use constant for defaultDNQuota

Change-Id: I74273a63b837b92f7147b2f694fd5324da34fbd4
Reviewed-on: https://review.monogon.dev/c/monogon/+/4451
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
Tested-by: Jenkins CI
diff --git a/osbase/logtree/journal_entry.go b/osbase/logtree/journal_entry.go
index 1f10c0f..c553ac8 100644
--- a/osbase/logtree/journal_entry.go
+++ b/osbase/logtree/journal_entry.go
@@ -45,6 +45,9 @@
 	seqLocal uint64
 }
 
+// defaultDNQuota defines how many messages should be stored per DN.
+const defaultDNQuota = 8192
+
 // external returns a LogEntry object for this entry, ie. the public version of
 // this object, without fields relating to the parent journal, linked lists,
 // sequences, etc. These objects are visible to library consumers.
@@ -119,7 +122,7 @@
 
 	// Create quota if necessary.
 	if _, ok := j.quota[e.origin]; !ok {
-		j.quota[e.origin] = &quota{origin: e.origin, max: 8192}
+		j.quota[e.origin] = &quota{origin: e.origin, max: defaultDNQuota}
 	}
 
 	// Insert at head in local linked list, calculate seqLocal, set pointers.