Merge remote-tracking branch 'origin/master' into topic/seth/sumstats-updates

scripts/base/frameworks/sumstats/plugins/__load__.bro

@@ -5,5 +5,6 @@
 @load ./sample
 @load ./std-dev
 @load ./sum
+@load ./topk
 @load ./unique
-@load ./variance
+@load ./variance

scripts/base/frameworks/sumstats/plugins/topk.bro

@@ -0,0 +1,50 @@
+@load base/frameworks/sumstats
+
+module SumStats;
+
+export {
+	redef record Reducer += {
+		## number of elements to keep in the top-k list
+		topk_size: count &default=500;
+	};
+
+	redef enum Calculation += {
+		TOPK
+	};
+
+	redef record ResultVal += {
+		topk: opaque of topk &optional;
+	};
+
+}
+
+hook init_resultval_hook(r: Reducer, rv: ResultVal)
+	{
+	if ( TOPK in r$apply && ! rv?$topk )
+		rv$topk = topk_init(r$topk_size);
+	}
+
+hook observe_hook(r: Reducer, val: double, obs: Observation, rv: ResultVal)
+	{
+	if ( TOPK in r$apply )
+		topk_add(rv$topk, obs);
+	}
+
+hook compose_resultvals_hook(result: ResultVal, rv1: ResultVal, rv2: ResultVal)
+	{
+	if ( rv1?$topk )
+		{
+		result$topk = topk_init(topk_size(rv1$topk));
+
+		topk_merge(result$topk, rv1$topk);
+
+		if ( rv2?$topk )
+			topk_merge(result$topk, rv2$topk);
+		}
+
+	else if ( rv2?$topk )
+		{
+		result$topk = topk_init(topk_size(rv2$topk));
+		topk_merge(result$topk, rv2$topk);
+		}
+	}