| /* |
| * |
| * Copyright 2020 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| package xdsrouting |
| |
| import ( |
| "google.golang.org/grpc/balancer" |
| "google.golang.org/grpc/codes" |
| "google.golang.org/grpc/status" |
| ) |
| |
| // pickerGroup contains a list of route matchers and their corresponding |
| // pickers. For each pick, the first matched picker is used. If the picker isn't |
| // ready, the pick will be queued. |
| type pickerGroup struct { |
| routes []route |
| pickers map[string]balancer.Picker |
| } |
| |
| func newPickerGroup(routes []route, idToPickerState map[string]*subBalancerState) *pickerGroup { |
| pickers := make(map[string]balancer.Picker) |
| for id, st := range idToPickerState { |
| pickers[id] = st.state.Picker |
| } |
| return &pickerGroup{ |
| routes: routes, |
| pickers: pickers, |
| } |
| } |
| |
| var errNoMatchedRouteFound = status.Errorf(codes.Unavailable, "no matched route was found") |
| |
| func (pg *pickerGroup) Pick(info balancer.PickInfo) (balancer.PickResult, error) { |
| for _, rt := range pg.routes { |
| if rt.m.match(info) { |
| // action from route is the ID for the sub-balancer to use. |
| p, ok := pg.pickers[rt.action] |
| if !ok { |
| return balancer.PickResult{}, balancer.ErrNoSubConnAvailable |
| } |
| return p.Pick(info) |
| } |
| } |
| return balancer.PickResult{}, errNoMatchedRouteFound |
| } |