update docs

1 files changed, 8 insertions, 1 deletions

diff --git a/skate/zipkey/batch_test.go b/skate/zipkey/batch_test.go
index 38a1307..6156fbf 100644
--- a/skate/zipkey/batch_test.go
+++ b/skate/zipkey/batch_test.go
@@ -40,11 +40,15 @@ func TestBatcherLarge(t *testing.T) {
 		N          = 1000000
 		numWorkers = 24
 		size       = 7000
+
 		// We share a single writer across threads, so we need to guard each
 		// write. TODO: measure performance impact.
 		mu  sync.Mutex
 		buf bytes.Buffer
-		f   = func(g *Group) error {
+
+		// The reducer is a simple function that will write "1" into the
+		// buffer, if the groups are equal, "0" otherwise.
+		f = func(g *Group) error {
 			var v string
 			if reflect.DeepEqual(g.G0, g.G1) {
 				v = "1"
@@ -62,6 +66,7 @@ func TestBatcherLarge(t *testing.T) {
 	)
 	b.Size = size
 	b.NumWorkers = numWorkers
+
 	for i := 0; i < N; i++ {
 		var u, v string
 		if i%2 == 0 {
@@ -87,3 +92,5 @@ func TestBatcherLarge(t *testing.T) {
 		t.Fatalf("got %v, want %v (count0=%v, buf=%s)", count1, N/2, count0, buf.String())
 	}
 }
+
+// TODO: BenchmarkBatcher with different worker counts.