1 /* 2 Copyright 2016 Google LLC 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 17 package testutil 18 19 import ( 20 "fmt" 21 "log" 22 "net" 23 "regexp" 24 "strconv" 25 26 "google.golang.org/grpc" 27 "google.golang.org/grpc/codes" 28 "google.golang.org/grpc/status" 29 ) 30 31 // A Server is an in-process gRPC server, listening on a system-chosen port on 32 // the local loopback interface. Servers are for testing only and are not 33 // intended to be used in production code. 34 // 35 // To create a server, make a new Server, register your handlers, then call 36 // Start: 37 // 38 // srv, err := NewServer() 39 // ... 40 // mypb.RegisterMyServiceServer(srv.Gsrv, &myHandler) 41 // .... 42 // srv.Start() 43 // 44 // Clients should connect to the server with no security: 45 // 46 // conn, err := grpc.Dial(srv.Addr, grpc.WithInsecure()) 47 // ... 48 type Server struct { 49 Addr string 50 Port int 51 l net.Listener 52 Gsrv *grpc.Server 53 } 54 55 // NewServer creates a new Server. The Server will be listening for gRPC connections 56 // at the address named by the Addr field, without TLS. 57 func NewServer(opts ...grpc.ServerOption) (*Server, error) { 58 return NewServerWithPort(0, opts...) 59 } 60 61 // NewServerWithPort creates a new Server at a specific port. The Server will be listening 62 // for gRPC connections at the address named by the Addr field, without TLS. 63 func NewServerWithPort(port int, opts ...grpc.ServerOption) (*Server, error) { 64 l, err := net.Listen("tcp", fmt.Sprintf("localhost:%d", port)) 65 if err != nil { 66 return nil, err 67 } 68 s := &Server{ 69 Addr: l.Addr().String(), 70 Port: parsePort(l.Addr().String()), 71 l: l, 72 Gsrv: grpc.NewServer(opts...), 73 } 74 return s, nil 75 } 76 77 // Start causes the server to start accepting incoming connections. 78 // Call Start after registering handlers. 79 func (s *Server) Start() { 80 go func() { 81 if err := s.Gsrv.Serve(s.l); err != nil { 82 log.Printf("testutil.Server.Start: %v", err) 83 } 84 }() 85 } 86 87 // Close shuts down the server. 88 func (s *Server) Close() { 89 s.Gsrv.Stop() 90 s.l.Close() 91 } 92 93 // PageBounds converts an incoming page size and token from an RPC request into 94 // slice bounds and the outgoing next-page token. 95 // 96 // PageBounds assumes that the complete, unpaginated list of items exists as a 97 // single slice. In addition to the page size and token, PageBounds needs the 98 // length of that slice. 99 // 100 // PageBounds's first two return values should be used to construct a sub-slice of 101 // the complete, unpaginated slice. E.g. if the complete slice is s, then 102 // s[from:to] is the desired page. Its third return value should be set as the 103 // NextPageToken field of the RPC response. 104 func PageBounds(pageSize int, pageToken string, length int) (from, to int, nextPageToken string, err error) { 105 from, to = 0, length 106 if pageToken != "" { 107 from, err = strconv.Atoi(pageToken) 108 if err != nil { 109 return 0, 0, "", status.Errorf(codes.InvalidArgument, "bad page token: %v", err) 110 } 111 if from >= length { 112 return length, length, "", nil 113 } 114 } 115 if pageSize > 0 && from+pageSize < length { 116 to = from + pageSize 117 nextPageToken = strconv.Itoa(to) 118 } 119 return from, to, nextPageToken, nil 120 } 121 122 var portParser = regexp.MustCompile(`:[0-9]+`) 123 124 func parsePort(addr string) int { 125 res := portParser.FindAllString(addr, -1) 126 if len(res) == 0 { 127 panic(fmt.Errorf("parsePort: found no numbers in %s", addr)) 128 } 129 stringPort := res[0][1:] // strip the : 130 p, err := strconv.ParseInt(stringPort, 10, 32) 131 if err != nil { 132 panic(err) 133 } 134 return int(p) 135 } 136