github.com/zhiqiangxu/go-ethereum@v1.9.16-0.20210824055606-be91cfdebc48/graphql/service.go (about) 1 // Copyright 2019 The go-ethereum Authors 2 // This file is part of the go-ethereum library. 3 // 4 // The go-ethereum library is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU Lesser General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // The go-ethereum library is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU Lesser General Public License for more details. 13 // 14 // You should have received a copy of the GNU Lesser General Public License 15 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. 16 17 package graphql 18 19 import ( 20 "fmt" 21 "net" 22 "net/http" 23 24 "github.com/graph-gophers/graphql-go" 25 "github.com/graph-gophers/graphql-go/relay" 26 "github.com/zhiqiangxu/go-ethereum/internal/ethapi" 27 "github.com/zhiqiangxu/go-ethereum/log" 28 "github.com/zhiqiangxu/go-ethereum/node" 29 "github.com/zhiqiangxu/go-ethereum/p2p" 30 "github.com/zhiqiangxu/go-ethereum/rpc" 31 ) 32 33 // Service encapsulates a GraphQL service. 34 type Service struct { 35 endpoint string // The host:port endpoint for this service. 36 cors []string // Allowed CORS domains 37 vhosts []string // Recognised vhosts 38 timeouts rpc.HTTPTimeouts // Timeout settings for HTTP requests. 39 backend ethapi.Backend // The backend that queries will operate on. 40 handler http.Handler // The `http.Handler` used to answer queries. 41 listener net.Listener // The listening socket. 42 } 43 44 // New constructs a new GraphQL service instance. 45 func New(backend ethapi.Backend, endpoint string, cors, vhosts []string, timeouts rpc.HTTPTimeouts) (*Service, error) { 46 return &Service{ 47 endpoint: endpoint, 48 cors: cors, 49 vhosts: vhosts, 50 timeouts: timeouts, 51 backend: backend, 52 }, nil 53 } 54 55 // Protocols returns the list of protocols exported by this service. 56 func (s *Service) Protocols() []p2p.Protocol { return nil } 57 58 // APIs returns the list of APIs exported by this service. 59 func (s *Service) APIs() []rpc.API { return nil } 60 61 // Start is called after all services have been constructed and the networking 62 // layer was also initialized to spawn any goroutines required by the service. 63 func (s *Service) Start(server *p2p.Server) error { 64 var err error 65 s.handler, err = newHandler(s.backend) 66 if err != nil { 67 return err 68 } 69 if s.listener, err = net.Listen("tcp", s.endpoint); err != nil { 70 return err 71 } 72 // create handler stack and wrap the graphql handler 73 handler := node.NewHTTPHandlerStack(s.handler, s.cors, s.vhosts) 74 // make sure timeout values are meaningful 75 node.CheckTimeouts(&s.timeouts) 76 // create http server 77 httpSrv := &http.Server{ 78 Handler: handler, 79 ReadTimeout: s.timeouts.ReadTimeout, 80 WriteTimeout: s.timeouts.WriteTimeout, 81 IdleTimeout: s.timeouts.IdleTimeout, 82 } 83 go httpSrv.Serve(s.listener) 84 log.Info("GraphQL endpoint opened", "url", fmt.Sprintf("http://%s", s.endpoint)) 85 return nil 86 } 87 88 // newHandler returns a new `http.Handler` that will answer GraphQL queries. 89 // It additionally exports an interactive query browser on the / endpoint. 90 func newHandler(backend ethapi.Backend) (http.Handler, error) { 91 q := Resolver{backend} 92 93 s, err := graphql.ParseSchema(schema, &q) 94 if err != nil { 95 return nil, err 96 } 97 h := &relay.Handler{Schema: s} 98 99 mux := http.NewServeMux() 100 mux.Handle("/", GraphiQL{}) 101 mux.Handle("/graphql", h) 102 mux.Handle("/graphql/", h) 103 return mux, nil 104 } 105 106 // Stop terminates all goroutines belonging to the service, blocking until they 107 // are all terminated. 108 func (s *Service) Stop() error { 109 if s.listener != nil { 110 s.listener.Close() 111 s.listener = nil 112 log.Info("GraphQL endpoint closed", "url", fmt.Sprintf("http://%s", s.endpoint)) 113 } 114 return nil 115 }