github.com/aigarnetwork/aigar@v0.0.0-20191115204914-d59a6eb70f8e/graphql/service.go (about)

     1  //  Copyright 2018 The go-ethereum Authors
     2  //  Copyright 2019 The go-aigar Authors
     3  //  This file is part of the go-aigar library.
     4  //
     5  //  The go-aigar library is free software: you can redistribute it and/or modify
     6  //  it under the terms of the GNU Lesser General Public License as published by
     7  //  the Free Software Foundation, either version 3 of the License, or
     8  //  (at your option) any later version.
     9  //
    10  //  The go-aigar library is distributed in the hope that it will be useful,
    11  //  but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    13  //  GNU Lesser General Public License for more details.
    14  //
    15  //  You should have received a copy of the GNU Lesser General Public License
    16  //  along with the go-aigar library. If not, see <http://www.gnu.org/licenses/>.
    17  
    18  package graphql
    19  
    20  import (
    21  	"fmt"
    22  	"net"
    23  	"net/http"
    24  
    25  	"github.com/AigarNetwork/aigar/internal/ethapi"
    26  	"github.com/AigarNetwork/aigar/log"
    27  	"github.com/AigarNetwork/aigar/p2p"
    28  	"github.com/AigarNetwork/aigar/rpc"
    29  	"github.com/graph-gophers/graphql-go"
    30  	"github.com/graph-gophers/graphql-go/relay"
    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 onn.
    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  	go rpc.NewHTTPServer(s.cors, s.vhosts, s.timeouts, s.handler).Serve(s.listener)
    73  	log.Info("GraphQL endpoint opened", "url", fmt.Sprintf("http://%s", s.endpoint))
    74  	return nil
    75  }
    76  
    77  // newHandler returns a new `http.Handler` that will answer GraphQL queries.
    78  // It additionally exports an interactive query browser on the / endpoint.
    79  func newHandler(backend ethapi.Backend) (http.Handler, error) {
    80  	q := Resolver{backend}
    81  
    82  	s, err := graphql.ParseSchema(schema, &q)
    83  	if err != nil {
    84  		return nil, err
    85  	}
    86  	h := &relay.Handler{Schema: s}
    87  
    88  	mux := http.NewServeMux()
    89  	mux.Handle("/", GraphiQL{})
    90  	mux.Handle("/graphql", h)
    91  	mux.Handle("/graphql/", h)
    92  	return mux, nil
    93  }
    94  
    95  // Stop terminates all goroutines belonging to the service, blocking until they
    96  // are all terminated.
    97  func (s *Service) Stop() error {
    98  	if s.listener != nil {
    99  		s.listener.Close()
   100  		s.listener = nil
   101  		log.Info("GraphQL endpoint closed", "url", fmt.Sprintf("http://%s", s.endpoint))
   102  	}
   103  	return nil
   104  }