Documentation
¶
Index ¶
- Constants
- Variables
- func TimeOutChecker(params TimeOutParams)
- type Clientdeprecated
- type Engine
- type EventHandler
- type EventType
- type Executor
- type ExecutorEngine
- type ExecutorPool
- type ExecutorV2
- type ExecutorV2Pool
- type Handler
- type InitPayload
- type InitialHttpRequestContext
- type Messagedeprecated
- type Protocol
- type TimeOutParams
- type TransportClient
- type UniversalProtocolHandler
- type UniversalProtocolHandlerOptions
- type WebsocketInitFunc
Constants ¶
const ( DefaultKeepAliveInterval = "15s" DefaultSubscriptionUpdateInterval = "1s" DefaultReadErrorTimeOut = "5s" )
const ( MessageTypeConnectionInit = "connection_init" MessageTypeConnectionAck = "connection_ack" MessageTypeConnectionError = "connection_error" MessageTypeConnectionTerminate = "connection_terminate" MessageTypeConnectionKeepAlive = "ka" MessageTypeStart = "start" MessageTypeStop = "stop" MessageTypeData = "data" MessageTypeError = "error" MessageTypeComplete = "complete" )
Variables ¶
var ErrCouldNotReadMessageFromClient = errors.New("could not read message from client")
var (
ErrSubscriberIDAlreadyExists = errors.New("subscriber id already exists")
)
var ErrTransportClientClosedConnection = errors.New("transport client has a closed connection")
ErrTransportClientClosedConnection is an error to indicate that the transport client is using closed connection.
Functions ¶
func TimeOutChecker ¶
func TimeOutChecker(params TimeOutParams)
TimeOutChecker is a function that can be used in a go routine to perform a time-out action after a specific duration or prevent the time-out action by canceling the time-out context before. Use TimeOutParams for configuration.
Types ¶
type Client
deprecated
type Client interface {
// ReadFromClient will invoke a read operation from the client connection.
ReadFromClient() (*Message, error)
// WriteToClient will invoke a write operation to the client connection.
WriteToClient(Message) error
// IsConnected will indicate if a connection is still established.
IsConnected() bool
// Disconnect will close the connection between server and client.
Disconnect() error
}
Client provides an interface which can be implemented by any possible subscription client like websockets, mqtt, etc.
Deprecated: Use TransportClient instead.
type Engine ¶
type Engine interface {
StartOperation(ctx context.Context, id string, payload []byte, eventHandler EventHandler) error
StopSubscription(id string, eventHandler EventHandler) error
TerminateAllSubscriptions(eventHandler EventHandler) error
}
Engine defines the function for a subscription engine.
type EventHandler ¶
EventHandler is an interface that handles subscription events.
type EventType ¶
type EventType int
EventType can be used to define subscription events decoupled from any protocols.
const ( EventTypeOnError EventType = iota EventTypeOnSubscriptionData EventTypeOnSubscriptionCompleted EventTypeOnNonSubscriptionExecutionResult EventTypeOnConnectionTerminatedByClient EventTypeOnConnectionTerminatedByServer EventTypeOnConnectionError EventTypeOnConnectionOpened EventTypeOnDuplicatedSubscriberID )
type Executor ¶
type Executor interface {
Execute(writer resolve.SubscriptionResponseWriter) error
OperationType() ast.OperationType
SetContext(context context.Context)
Reset()
}
Executor is an abstraction for executing a GraphQL engine
type ExecutorEngine ¶
type ExecutorEngine struct {
// contains filtered or unexported fields
}
ExecutorEngine is an implementation of Engine and works with subscription.Executor.
func (*ExecutorEngine) StartOperation ¶
func (e *ExecutorEngine) StartOperation(ctx context.Context, id string, payload []byte, eventHandler EventHandler) error
StartOperation will start any operation.
func (*ExecutorEngine) StopSubscription ¶
func (e *ExecutorEngine) StopSubscription(id string, eventHandler EventHandler) error
StopSubscription will stop an active subscription.
func (*ExecutorEngine) TerminateAllSubscriptions ¶
func (e *ExecutorEngine) TerminateAllSubscriptions(eventHandler EventHandler) error
TerminateAllSubscriptions will cancel all active subscriptions.
type ExecutorPool ¶
ExecutorPool is an abstraction for creating executors
type ExecutorV2 ¶
type ExecutorV2 struct {
// contains filtered or unexported fields
}
func (*ExecutorV2) Execute ¶
func (e *ExecutorV2) Execute(writer resolve.SubscriptionResponseWriter) error
func (*ExecutorV2) OperationType ¶
func (e *ExecutorV2) OperationType() ast.OperationType
func (*ExecutorV2) Reset ¶
func (e *ExecutorV2) Reset()
func (*ExecutorV2) SetContext ¶
func (e *ExecutorV2) SetContext(context context.Context)
type ExecutorV2Pool ¶
type ExecutorV2Pool struct {
// contains filtered or unexported fields
}
ExecutorV2Pool - provides reusable executors
func NewExecutorV2Pool ¶
func NewExecutorV2Pool(engine *engine.ExecutionEngine, connectionInitReqCtx context.Context) *ExecutorV2Pool
func (*ExecutorV2Pool) Put ¶
func (e *ExecutorV2Pool) Put(executor Executor) error
type Handler ¶
type Handler struct {
// contains filtered or unexported fields
}
Handler is the actual subscription handler which will keep track on how to handle messages coming from the client.
func NewHandler ¶
func NewHandler(logger abstractlogger.Logger, client Client, executorPool ExecutorPool) (*Handler, error)
NewHandler creates a new subscription handler.
func NewHandlerWithInitFunc ¶
func NewHandlerWithInitFunc( logger abstractlogger.Logger, client Client, executorPool ExecutorPool, initFunc WebsocketInitFunc, ) (*Handler, error)
func (*Handler) ActiveSubscriptions ¶
ActiveSubscriptions will return the actual number of active subscriptions for that client.
func (*Handler) ChangeKeepAliveInterval ¶
ChangeKeepAliveInterval can be used to change the keep alive interval.
func (*Handler) ChangeSubscriptionUpdateInterval ¶
ChangeSubscriptionUpdateInterval can be used to change the update interval.
type InitPayload ¶
type InitPayload json.RawMessage
InitPayload is a structure that is parsed from the websocket init message payload. Deprecated: Use websocket.InitPayload instead.
func (InitPayload) Authorization ¶
func (p InitPayload) Authorization() string
Authorization is a shorthand for getting the Authorization header from the payload.
func (InitPayload) GetString ¶
func (p InitPayload) GetString(key string) string
GetString safely gets a string value from the payload. It returns an empty string if the payload is nil or the value isn't set.
type InitialHttpRequestContext ¶
func NewInitialHttpRequestContext ¶
func NewInitialHttpRequestContext(r *http.Request) *InitialHttpRequestContext
type Message
deprecated
type Message struct {
Id string `json:"id"`
Type string `json:"type"`
Payload json.RawMessage `json:"payload"`
}
Message defines the actual subscription message which will be passed from client to server and vice versa.
Deprecated: Prefer using TransportClient that is based on byte slices instead of this Message struct.
type Protocol ¶
type Protocol interface {
Handle(ctx context.Context, engine Engine, message []byte) error
EventHandler() EventHandler
}
Protocol defines an interface for a subscription protocol decoupled from the underlying transport.
type TimeOutParams ¶
type TimeOutParams struct {
Name string
Logger abstractlogger.Logger
TimeOutContext context.Context
TimeOutAction func()
TimeOutDuration time.Duration
}
TimeOutParams is a struct to configure a TimeOutChecker.
type TransportClient ¶
type TransportClient interface {
// ReadBytesFromClient will invoke a read operation from the client connection and return a byte slice.
// This function should return ErrTransportClientClosedConnection when reading on a closed connection.
ReadBytesFromClient() ([]byte, error)
// WriteBytesToClient will invoke a write operation to the client connection using a byte slice.
// This function should return ErrTransportClientClosedConnection when writing on a closed connection.
WriteBytesToClient([]byte) error
// IsConnected will indicate if a connection is still established.
IsConnected() bool
// Disconnect will close the connection between server and client.
Disconnect() error
// DisconnectWithReason will close the connection but is also able to process a reason for closure.
DisconnectWithReason(reason interface{}) error
}
TransportClient provides an interface that can be implemented by any possible subscription client like websockets, mqtt, etc. It operates with raw byte slices.
type UniversalProtocolHandler ¶
type UniversalProtocolHandler struct {
// contains filtered or unexported fields
}
UniversalProtocolHandler can handle any protocol by using the Protocol interface.
func NewUniversalProtocolHandler ¶
func NewUniversalProtocolHandler(client TransportClient, protocol Protocol, executorPool ExecutorPool) (*UniversalProtocolHandler, error)
NewUniversalProtocolHandler creates a new UniversalProtocolHandler.
func NewUniversalProtocolHandlerWithOptions ¶
func NewUniversalProtocolHandlerWithOptions(client TransportClient, protocol Protocol, executorPool ExecutorPool, options UniversalProtocolHandlerOptions) (*UniversalProtocolHandler, error)
NewUniversalProtocolHandlerWithOptions creates a new UniversalProtocolHandler. It requires an option struct.
func (*UniversalProtocolHandler) Handle ¶
func (u *UniversalProtocolHandler) Handle(ctx context.Context)
Handle will handle the subscription logic and forward messages to the actual protocol handler.
type UniversalProtocolHandlerOptions ¶
type UniversalProtocolHandlerOptions struct {
Logger abstractlogger.Logger
CustomSubscriptionUpdateInterval time.Duration
CustomReadErrorTimeOut time.Duration
CustomEngine Engine
}
UniversalProtocolHandlerOptions is struct that defines options for the UniversalProtocolHandler.
type WebsocketInitFunc ¶
WebsocketInitFunc is called when the server receives connection init message from the client. This can be used to check initial payload to see whether to accept the websocket connection. Deprecated: Use websocket.InitFunc instead.
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