github.com/99designs/gqlgen@v0.17.45/graphql/handler/transport/websocket_graphql_transport_ws.go (about)

     1  package transport
     2  
     3  import (
     4  	"encoding/json"
     5  	"fmt"
     6  
     7  	"github.com/gorilla/websocket"
     8  )
     9  
    10  // https://github.com/apollographql/subscriptions-transport-ws/blob/master/PROTOCOL.md
    11  const (
    12  	graphqltransportwsSubprotocol = "graphql-transport-ws"
    13  
    14  	graphqltransportwsConnectionInitMsg = graphqltransportwsMessageType("connection_init")
    15  	graphqltransportwsConnectionAckMsg  = graphqltransportwsMessageType("connection_ack")
    16  	graphqltransportwsSubscribeMsg      = graphqltransportwsMessageType("subscribe")
    17  	graphqltransportwsNextMsg           = graphqltransportwsMessageType("next")
    18  	graphqltransportwsErrorMsg          = graphqltransportwsMessageType("error")
    19  	graphqltransportwsCompleteMsg       = graphqltransportwsMessageType("complete")
    20  	graphqltransportwsPingMsg           = graphqltransportwsMessageType("ping")
    21  	graphqltransportwsPongMsg           = graphqltransportwsMessageType("pong")
    22  )
    23  
    24  var allGraphqltransportwsMessageTypes = []graphqltransportwsMessageType{
    25  	graphqltransportwsConnectionInitMsg,
    26  	graphqltransportwsConnectionAckMsg,
    27  	graphqltransportwsSubscribeMsg,
    28  	graphqltransportwsNextMsg,
    29  	graphqltransportwsErrorMsg,
    30  	graphqltransportwsCompleteMsg,
    31  	graphqltransportwsPingMsg,
    32  	graphqltransportwsPongMsg,
    33  }
    34  
    35  type (
    36  	graphqltransportwsMessageExchanger struct {
    37  		c *websocket.Conn
    38  	}
    39  
    40  	graphqltransportwsMessage struct {
    41  		Payload json.RawMessage               `json:"payload,omitempty"`
    42  		ID      string                        `json:"id,omitempty"`
    43  		Type    graphqltransportwsMessageType `json:"type"`
    44  		noOp    bool
    45  	}
    46  
    47  	graphqltransportwsMessageType string
    48  )
    49  
    50  func (me graphqltransportwsMessageExchanger) NextMessage() (message, error) {
    51  	_, r, err := me.c.NextReader()
    52  	if err != nil {
    53  		return message{}, handleNextReaderError(err)
    54  	}
    55  
    56  	var graphqltransportwsMessage graphqltransportwsMessage
    57  	if err := jsonDecode(r, &graphqltransportwsMessage); err != nil {
    58  		return message{}, errInvalidMsg
    59  	}
    60  
    61  	return graphqltransportwsMessage.toMessage()
    62  }
    63  
    64  func (me graphqltransportwsMessageExchanger) Send(m *message) error {
    65  	msg := &graphqltransportwsMessage{}
    66  	if err := msg.fromMessage(m); err != nil {
    67  		return err
    68  	}
    69  
    70  	if msg.noOp {
    71  		return nil
    72  	}
    73  
    74  	return me.c.WriteJSON(msg)
    75  }
    76  
    77  func (t *graphqltransportwsMessageType) UnmarshalText(text []byte) (err error) {
    78  	var found bool
    79  	for _, candidate := range allGraphqltransportwsMessageTypes {
    80  		if string(candidate) == string(text) {
    81  			*t = candidate
    82  			found = true
    83  			break
    84  		}
    85  	}
    86  
    87  	if !found {
    88  		err = fmt.Errorf("invalid message type %s", string(text))
    89  	}
    90  
    91  	return err
    92  }
    93  
    94  func (t graphqltransportwsMessageType) MarshalText() ([]byte, error) {
    95  	return []byte(string(t)), nil
    96  }
    97  
    98  func (m graphqltransportwsMessage) toMessage() (message, error) {
    99  	var t messageType
   100  	var err error
   101  	switch m.Type {
   102  	default:
   103  		err = fmt.Errorf("invalid client->server message type %s", m.Type)
   104  	case graphqltransportwsConnectionInitMsg:
   105  		t = initMessageType
   106  	case graphqltransportwsSubscribeMsg:
   107  		t = startMessageType
   108  	case graphqltransportwsCompleteMsg:
   109  		t = stopMessageType
   110  	case graphqltransportwsPingMsg:
   111  		t = pingMessageType
   112  	case graphqltransportwsPongMsg:
   113  		t = pongMessageType
   114  	}
   115  
   116  	return message{
   117  		payload: m.Payload,
   118  		id:      m.ID,
   119  		t:       t,
   120  	}, err
   121  }
   122  
   123  func (m *graphqltransportwsMessage) fromMessage(msg *message) (err error) {
   124  	m.ID = msg.id
   125  	m.Payload = msg.payload
   126  
   127  	switch msg.t {
   128  	default:
   129  		err = fmt.Errorf("invalid server->client message type %s", msg.t)
   130  	case connectionAckMessageType:
   131  		m.Type = graphqltransportwsConnectionAckMsg
   132  	case keepAliveMessageType:
   133  		m.noOp = true
   134  	case connectionErrorMessageType:
   135  		m.noOp = true
   136  	case dataMessageType:
   137  		m.Type = graphqltransportwsNextMsg
   138  	case completeMessageType:
   139  		m.Type = graphqltransportwsCompleteMsg
   140  	case errorMessageType:
   141  		m.Type = graphqltransportwsErrorMsg
   142  	case pingMessageType:
   143  		m.Type = graphqltransportwsPingMsg
   144  	case pongMessageType:
   145  		m.Type = graphqltransportwsPongMsg
   146  	}
   147  
   148  	return err
   149  }