github.com/99designs/gqlgen@v0.17.45/graphql/handler/transport/websocket_graphqlws.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/enisdenjo/graphql-ws/blob/master/PROTOCOL.md
    11  const (
    12  	graphqlwsSubprotocol = "graphql-ws"
    13  
    14  	graphqlwsConnectionInitMsg      = graphqlwsMessageType("connection_init")
    15  	graphqlwsConnectionTerminateMsg = graphqlwsMessageType("connection_terminate")
    16  	graphqlwsStartMsg               = graphqlwsMessageType("start")
    17  	graphqlwsStopMsg                = graphqlwsMessageType("stop")
    18  	graphqlwsConnectionAckMsg       = graphqlwsMessageType("connection_ack")
    19  	graphqlwsConnectionErrorMsg     = graphqlwsMessageType("connection_error")
    20  	graphqlwsDataMsg                = graphqlwsMessageType("data")
    21  	graphqlwsErrorMsg               = graphqlwsMessageType("error")
    22  	graphqlwsCompleteMsg            = graphqlwsMessageType("complete")
    23  	graphqlwsConnectionKeepAliveMsg = graphqlwsMessageType("ka")
    24  )
    25  
    26  var allGraphqlwsMessageTypes = []graphqlwsMessageType{
    27  	graphqlwsConnectionInitMsg,
    28  	graphqlwsConnectionTerminateMsg,
    29  	graphqlwsStartMsg,
    30  	graphqlwsStopMsg,
    31  	graphqlwsConnectionAckMsg,
    32  	graphqlwsConnectionErrorMsg,
    33  	graphqlwsDataMsg,
    34  	graphqlwsErrorMsg,
    35  	graphqlwsCompleteMsg,
    36  	graphqlwsConnectionKeepAliveMsg,
    37  }
    38  
    39  type (
    40  	graphqlwsMessageExchanger struct {
    41  		c *websocket.Conn
    42  	}
    43  
    44  	graphqlwsMessage struct {
    45  		Payload json.RawMessage      `json:"payload,omitempty"`
    46  		ID      string               `json:"id,omitempty"`
    47  		Type    graphqlwsMessageType `json:"type"`
    48  		noOp    bool
    49  	}
    50  
    51  	graphqlwsMessageType string
    52  )
    53  
    54  func (me graphqlwsMessageExchanger) NextMessage() (message, error) {
    55  	_, r, err := me.c.NextReader()
    56  	if err != nil {
    57  		return message{}, handleNextReaderError(err)
    58  	}
    59  
    60  	var graphqlwsMessage graphqlwsMessage
    61  	if err := jsonDecode(r, &graphqlwsMessage); err != nil {
    62  		return message{}, errInvalidMsg
    63  	}
    64  
    65  	return graphqlwsMessage.toMessage()
    66  }
    67  
    68  func (me graphqlwsMessageExchanger) Send(m *message) error {
    69  	msg := &graphqlwsMessage{}
    70  	if err := msg.fromMessage(m); err != nil {
    71  		return err
    72  	}
    73  
    74  	if msg.noOp {
    75  		return nil
    76  	}
    77  
    78  	return me.c.WriteJSON(msg)
    79  }
    80  
    81  func (t *graphqlwsMessageType) UnmarshalText(text []byte) (err error) {
    82  	var found bool
    83  	for _, candidate := range allGraphqlwsMessageTypes {
    84  		if string(candidate) == string(text) {
    85  			*t = candidate
    86  			found = true
    87  			break
    88  		}
    89  	}
    90  
    91  	if !found {
    92  		err = fmt.Errorf("invalid message type %s", string(text))
    93  	}
    94  
    95  	return err
    96  }
    97  
    98  func (t graphqlwsMessageType) MarshalText() ([]byte, error) {
    99  	return []byte(string(t)), nil
   100  }
   101  
   102  func (m graphqlwsMessage) toMessage() (message, error) {
   103  	var t messageType
   104  	var err error
   105  	switch m.Type {
   106  	default:
   107  		err = fmt.Errorf("invalid client->server message type %s", m.Type)
   108  	case graphqlwsConnectionInitMsg:
   109  		t = initMessageType
   110  	case graphqlwsConnectionTerminateMsg:
   111  		t = connectionCloseMessageType
   112  	case graphqlwsStartMsg:
   113  		t = startMessageType
   114  	case graphqlwsStopMsg:
   115  		t = stopMessageType
   116  	case graphqlwsConnectionAckMsg:
   117  		t = connectionAckMessageType
   118  	case graphqlwsConnectionErrorMsg:
   119  		t = connectionErrorMessageType
   120  	case graphqlwsDataMsg:
   121  		t = dataMessageType
   122  	case graphqlwsErrorMsg:
   123  		t = errorMessageType
   124  	case graphqlwsCompleteMsg:
   125  		t = completeMessageType
   126  	case graphqlwsConnectionKeepAliveMsg:
   127  		t = keepAliveMessageType
   128  	}
   129  
   130  	return message{
   131  		payload: m.Payload,
   132  		id:      m.ID,
   133  		t:       t,
   134  	}, err
   135  }
   136  
   137  func (m *graphqlwsMessage) fromMessage(msg *message) (err error) {
   138  	m.ID = msg.id
   139  	m.Payload = msg.payload
   140  
   141  	switch msg.t {
   142  	default:
   143  		err = fmt.Errorf("invalid server->client message type %s", msg.t)
   144  	case initMessageType:
   145  		m.Type = graphqlwsConnectionInitMsg
   146  	case connectionAckMessageType:
   147  		m.Type = graphqlwsConnectionAckMsg
   148  	case keepAliveMessageType:
   149  		m.Type = graphqlwsConnectionKeepAliveMsg
   150  	case connectionErrorMessageType:
   151  		m.Type = graphqlwsConnectionErrorMsg
   152  	case connectionCloseMessageType:
   153  		m.Type = graphqlwsConnectionTerminateMsg
   154  	case startMessageType:
   155  		m.Type = graphqlwsStartMsg
   156  	case stopMessageType:
   157  		m.Type = graphqlwsStopMsg
   158  	case dataMessageType:
   159  		m.Type = graphqlwsDataMsg
   160  	case completeMessageType:
   161  		m.Type = graphqlwsCompleteMsg
   162  	case errorMessageType:
   163  		m.Type = graphqlwsErrorMsg
   164  	case pingMessageType:
   165  		m.noOp = true
   166  	case pongMessageType:
   167  		m.noOp = true
   168  	}
   169  
   170  	return err
   171  }