plugeth/les/utils/weighted_select_test.go
gary rong f78ffc0545
les: create utilities as common package (#20509)
* les: move execqueue into utilities package

execqueue is a util for executing queued functions
in a serial order which is used by both les server
and les client. Move it to common package.

* les: move randselect to utilities package

weighted_random_selector is a helpful tool for randomly select
items maintained in a set but based on the item weight.

It's used anywhere is LES package, mainly by les client but will
be used in les server with very high chance. So move it into a
common package as the second step for les separation.

* les: rename to utils
2020-03-31 17:17:24 +02:00

68 lines
1.6 KiB
Go

// 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 utils
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)
}