handler

Documentation

Overview

The handler package allows managing Kappa handlers, an abstraction on top of serverless handlers.

Index

• func EncodeCoordCallResult(res CCResT) ([]byte, error)
• type AppEvT
• type CCResT
• type CoordCall
  • func (v CoordCall) MarshalEasyJSON(w *jwriter.Writer)
  • func (v CoordCall) MarshalJSON() ([]byte, error)
  • func (v *CoordCall) UnmarshalEasyJSON(l *jlexer.Lexer)
  • func (v *CoordCall) UnmarshalJSON(data []byte) error
• type CrashedError
  • func (e *CrashedError) Error() string
• type EnvT
• type Handler
  • func Create(platform string, conf io.Reader, name string, deployedFiles []string, ...) (Handler, error)
• type InvokeRet
• type InvokeTarget
• type PidT
• type Request
  • func ParseRequest(b []byte) (*Request, error)
  • func (v Request) MarshalEasyJSON(w *jwriter.Writer)
  • func (v Request) MarshalJSON() ([]byte, error)
  • func (v *Request) UnmarshalEasyJSON(l *jlexer.Lexer)
  • func (v *Request) UnmarshalJSON(data []byte) error
• type SeqnoT
• type TimeoutError
  • func (*TimeoutError) Error() string

Functions

func EncodeCoordCallResult

func EncodeCoordCallResult(res CCResT) ([]byte, error)

Types

type AppEvT

type AppEvT interface{} // Type of application events.

type CCResT

type CCResT interface{} // Return type of coordinator calls.

TODO(zhangwen): using interface{} liberally is worrisome.

type CoordCall

type CoordCall struct {
	Seqno  SeqnoT              `json:"seqno"`
	Op     string              `json:"op"`
	Params easyjson.RawMessage `json:"params"`
}

CoordCall is the format of a single coordinator call inside a request to the coordinator.

func (CoordCall) MarshalEasyJSON

func (v CoordCall) MarshalEasyJSON(w *jwriter.Writer)

MarshalEasyJSON supports easyjson.Marshaler interface

func (CoordCall) MarshalJSON

func (v CoordCall) MarshalJSON() ([]byte, error)

MarshalJSON supports json.Marshaler interface

func (*CoordCall) UnmarshalEasyJSON

func (v *CoordCall) UnmarshalEasyJSON(l *jlexer.Lexer)

UnmarshalEasyJSON supports easyjson.Unmarshaler interface

func (*CoordCall) UnmarshalJSON

func (v *CoordCall) UnmarshalJSON(data []byte) error

UnmarshalJSON supports json.Unmarshaler interface

type CrashedError

type CrashedError struct {
	ErrorMessage string
}

CrashedError is returned when a handler has crashed (e.g., due to an uncaught exception).

func (*CrashedError) Error

func (e *CrashedError) Error() string

type EnvT

type EnvT map[string]string

type Handler

type Handler interface {
	// Returns a channel to read the invocation result from; the channel is closed after the result is written to it.
	InvokeAsync(pid PidT, seqno SeqnoT, chkID string, ccRes CCResT, appEv AppEvT, target InvokeTarget) <-chan InvokeRet

	// Finalize cleans up allocated resources.  Any error encountered during cleanup is logged but ignored.
	Finalize()
}

func Create

func Create(platform string, conf io.Reader, name string, deployedFiles []string, timeoutSecs int,
	env EnvT, logWriter io.Writer) (Handler, error)

type InvokeRet

type InvokeRet struct {
	Req *Request
	Err error
}

type InvokeTarget

type InvokeTarget int

const (
	OnCoordinator InvokeTarget = iota
	OnLambda
)

type PidT

type PidT int // Overflow is unlikely.

type Request

type Request struct {
	Pid     PidT        `json:"pid"`
	Seqno   SeqnoT      `json:"seqno"`
	ChkID   string      `json:"chk_id"`
	Calls   []CoordCall `json:"calls"`
	Blocked bool        `json:"blocked"`
	Err     *string     `json:"err"`
}

Request is the format of a handler's request to the coordinator.

func ParseRequest

func ParseRequest(b []byte) (*Request, error)

func (Request) MarshalEasyJSON

func (v Request) MarshalEasyJSON(w *jwriter.Writer)

MarshalEasyJSON supports easyjson.Marshaler interface

func (Request) MarshalJSON

func (v Request) MarshalJSON() ([]byte, error)

MarshalJSON supports json.Marshaler interface

func (*Request) UnmarshalEasyJSON

func (v *Request) UnmarshalEasyJSON(l *jlexer.Lexer)

UnmarshalEasyJSON supports easyjson.Unmarshaler interface

func (*Request) UnmarshalJSON

func (v *Request) UnmarshalJSON(data []byte) error

UnmarshalJSON supports json.Unmarshaler interface

type SeqnoT

type SeqnoT int

type TimeoutError

type TimeoutError struct{}

TimeoutError is returned when a handler has been killed by timeout.

func (*TimeoutError) Error

func (*TimeoutError) Error() string