1/* 2 * Copyright 2019 gRPC authors. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package edsbalancer 18 19import ( 20 "google.golang.org/grpc/internal/wrr" 21 xdsclient "google.golang.org/grpc/xds/internal/client" 22) 23 24var newRandomWRR = wrr.NewRandom 25 26type dropper struct { 27 c xdsclient.OverloadDropConfig 28 w wrr.WRR 29} 30 31func newDropper(c xdsclient.OverloadDropConfig) *dropper { 32 w := newRandomWRR() 33 w.Add(true, int64(c.Numerator)) 34 w.Add(false, int64(c.Denominator-c.Numerator)) 35 36 return &dropper{ 37 c: c, 38 w: w, 39 } 40} 41 42func (d *dropper) drop() (ret bool) { 43 return d.w.Next().(bool) 44} 45