les: implement light server pool

les/randselect_test.go

@@ -0,0 +1,67 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package les
+
+import (
+	"math/rand"
+	"testing"
+)
+
+type testWrsItem struct {
+	idx  int
+	widx *int
+}
+
+func (t *testWrsItem) Weight() int64 {
+	w := *t.widx
+	if w == -1 || w == t.idx {
+		return int64(t.idx + 1)
+	}
+	return 0
+}
+
+func TestWeightedRandomSelect(t *testing.T) {
+	testFn := func(cnt int) {
+		s := newWeightedRandomSelect()
+		w := -1
+		list := make([]testWrsItem, cnt)
+		for i, _ := range list {
+			list[i] = testWrsItem{idx: i, widx: &w}
+			s.update(&list[i])
+		}
+		w = rand.Intn(cnt)
+		c := s.choose()
+		if c == nil {
+			t.Errorf("expected item, got nil")
+		} else {
+			if c.(*testWrsItem).idx != w {
+				t.Errorf("expected another item")
+			}
+		}
+		w = -2
+		if s.choose() != nil {
+			t.Errorf("expected nil, got item")
+		}
+	}
+	testFn(1)
+	testFn(10)
+	testFn(100)
+	testFn(1000)
+	testFn(10000)
+	testFn(100000)
+	testFn(1000000)
+}