jsonrpc2

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Published: Jun 24, 2020 License: Apache-2.0 Imports: 14 Imported by: 0

Documentation

Overview

Package jsonrpc2 is a minimal implementation of the JSON RPC 2 spec. https://www.jsonrpc.org/specification It is intended to be compatible with other implementations at the wire level.

Index

Constants

View Source
const (
	// Send indicates the message is outgoing.
	Send = Direction(true)
	// Receive indicates the message is incoming.
	Receive = Direction(false)
)
View Source
const (
	// CodeUnknownError should be used for all non coded errors.
	CodeUnknownError = -32001
	// CodeParseError is used when invalid JSON was received by the server.
	CodeParseError = -32700
	//CodeInvalidRequest is used when the JSON sent is not a valid Request object.
	CodeInvalidRequest = -32600
	// CodeMethodNotFound should be returned by the handler when the method does
	// not exist / is not available.
	CodeMethodNotFound = -32601
	// CodeInvalidParams should be returned by the handler when method
	// parameter(s) were invalid.
	CodeInvalidParams = -32602
	// CodeInternalError is not currently returned but defined for completeness.
	CodeInternalError = -32603

	//CodeServerOverloaded is returned when a message was refused due to a
	//server being temporarily unable to accept any new messages.
	CodeServerOverloaded = -32000
)

Variables

View Source
var ErrDisconnected = errors.New("disconnected")

ErrDisconnected signals that the stream or connection exited normally.

View Source
var ErrIdleTimeout = errors.New("timed out waiting for new connections")

ErrIdleTimeout is returned when serving timed out waiting for new connections.

Functions

func ListenAndServe

func ListenAndServe(ctx context.Context, network, addr string, server StreamServer, idleTimeout time.Duration) error

ListenAndServe starts an jsonrpc2 server on the given address. If idleTimeout is non-zero, ListenAndServe exits after there are no clients for this duration, otherwise it exits only on error.

func Serve

func Serve(ctx context.Context, ln net.Listener, server StreamServer, idleTimeout time.Duration) error

Serve accepts incoming connections from the network, and handles them using the provided server. If idleTimeout is non-zero, ListenAndServe exits after there are no clients for this duration, otherwise it exits only on error.

Types

type Conn

type Conn struct {
	// contains filtered or unexported fields
}

Conn is a JSON RPC 2 client server connection. Conn is bidirectional; it does not have a designated server or client end.

func NewConn

func NewConn(s Stream) *Conn

NewConn creates a new connection object around the supplied stream. You must call Run for the connection to be active.

func (*Conn) AddHandler

func (c *Conn) AddHandler(handler Handler)

AddHandler adds a new handler to the set the connection will invoke. Handlers are invoked in the reverse order of how they were added, this allows the most recent addition to be the first one to attempt to handle a message.

func (*Conn) Call

func (c *Conn) Call(ctx context.Context, method string, params, result interface{}) (err error)

Call sends a request over the connection and then waits for a response. If the response is not an error, it will be decoded into result. result must be of a type you an pass to json.Unmarshal.

func (*Conn) Cancel

func (c *Conn) Cancel(id ID)

Cancel cancels a pending Call on the server side. The call is identified by its id. JSON RPC 2 does not specify a cancel message, so cancellation support is not directly wired in. This method allows a higher level protocol to choose how to propagate the cancel.

func (*Conn) Notify

func (c *Conn) Notify(ctx context.Context, method string, params interface{}) (err error)

Notify is called to send a notification request over the connection. It will return as soon as the notification has been sent, as no response is possible.

func (*Conn) Run

func (c *Conn) Run(runCtx context.Context) error

Run blocks until the connection is terminated, and returns any error that caused the termination. It must be called exactly once for each Conn. It returns only when the reader is closed or there is an error in the stream.

type Direction

type Direction bool

Direction is used to indicate to a logger whether the logged message was being sent or received.

func (Direction) String

func (d Direction) String() string

type EmptyHandler

type EmptyHandler struct{}

func (EmptyHandler) Cancel

func (EmptyHandler) Cancel(ctx context.Context, conn *Conn, id ID, cancelled bool) bool

func (EmptyHandler) Deliver

func (EmptyHandler) Deliver(ctx context.Context, r *Request, delivered bool) bool

func (EmptyHandler) Done

func (EmptyHandler) Done(ctx context.Context, err error)

func (EmptyHandler) Error

func (EmptyHandler) Error(ctx context.Context, err error)

func (EmptyHandler) Read

func (EmptyHandler) Read(ctx context.Context, bytes int64) context.Context

func (EmptyHandler) Request

func (EmptyHandler) Request(ctx context.Context, conn *Conn, direction Direction, r *WireRequest) context.Context

func (EmptyHandler) Response

func (EmptyHandler) Response(ctx context.Context, conn *Conn, direction Direction, r *WireResponse) context.Context

func (EmptyHandler) Wrote

func (EmptyHandler) Wrote(ctx context.Context, bytes int64) context.Context

type Error

type Error struct {
	// Code is an error code indicating the type of failure.
	Code int64 `json:"code"`
	// Message is a short description of the error.
	Message string `json:"message"`
	// Data is optional structured data containing additional information about the error.
	Data *json.RawMessage `json:"data"`
}

Error represents a structured error in a Response.

func NewErrorf

func NewErrorf(code int64, format string, args ...interface{}) *Error

NewErrorf builds a Error struct for the supplied message and code. If args is not empty, message and args will be passed to Sprintf.

func (*Error) Error

func (err *Error) Error() string

type Handler

type Handler interface {
	// Deliver is invoked to handle incoming requests.
	// If the request returns false from IsNotify then the Handler must eventually
	// call Reply on the Conn with the supplied request.
	// Handlers are called synchronously, they should pass the work off to a go
	// routine if they are going to take a long time.
	// If Deliver returns true all subsequent handlers will be invoked with
	// delivered set to true, and should not attempt to deliver the message.
	Deliver(ctx context.Context, r *Request, delivered bool) bool

	// Cancel is invoked for cancelled outgoing requests.
	// It is okay to use the connection to send notifications, but the context will
	// be in the cancelled state, so you must do it with the background context
	// instead.
	// If Cancel returns true all subsequent handlers will be invoked with
	// cancelled set to true, and should not attempt to cancel the message.
	Cancel(ctx context.Context, conn *Conn, id ID, cancelled bool) bool

	// Request is called near the start of processing any request.
	Request(ctx context.Context, conn *Conn, direction Direction, r *WireRequest) context.Context
	// Response is called near the start of processing any response.
	Response(ctx context.Context, conn *Conn, direction Direction, r *WireResponse) context.Context
	// Done is called when any request is fully processed.
	// For calls, this means the response has also been processed, for notifies
	// this is as soon as the message has been written to the stream.
	// If err is set, it implies the request failed.
	Done(ctx context.Context, err error)
	// Read is called with a count each time some data is read from the stream.
	// The read calls are delayed until after the data has been interpreted so
	// that it can be attributed to a request/response.
	Read(ctx context.Context, bytes int64) context.Context
	// Wrote is called each time some data is written to the stream.
	Wrote(ctx context.Context, bytes int64) context.Context
	// Error is called with errors that cannot be delivered through the normal
	// mechanisms, for instance a failure to process a notify cannot be delivered
	// back to the other party.
	Error(ctx context.Context, err error)
}

Handler is the interface used to hook into the message handling of an rpc connection.

type ID

type ID struct {
	Name   string
	Number int64
}

ID is a Request identifier. Only one of either the Name or Number members will be set, using the number form if the Name is the empty string.

func (*ID) MarshalJSON

func (id *ID) MarshalJSON() ([]byte, error)

func (*ID) String

func (id *ID) String() string

String returns a string representation of the ID. The representation is non ambiguous, string forms are quoted, number forms are preceded by a #

func (*ID) UnmarshalJSON

func (id *ID) UnmarshalJSON(data []byte) error

type Request

type Request struct {

	// The Wire values of the request.
	WireRequest
	// contains filtered or unexported fields
}

Request is sent to a server to represent a Call or Notify operaton.

func (*Request) Conn

func (r *Request) Conn() *Conn

Conn returns the connection that created this request.

func (*Request) IsNotify

func (r *Request) IsNotify() bool

IsNotify returns true if this request is a notification.

func (*Request) Parallel

func (r *Request) Parallel()

Parallel indicates that the system is now allowed to process other requests in parallel with this one. It is safe to call any number of times, but must only be called from the request handling go routine. It is implied by both reply and by the handler returning.

func (*Request) Reply

func (r *Request) Reply(ctx context.Context, result interface{}, err error) error

Reply sends a reply to the given request. It is an error to call this if request was not a call. You must call this exactly once for any given request. It should only be called from the handler go routine. If err is set then result will be ignored. If the request has not yet dropped into parallel mode it will be before this function returns.

type ServerFunc

type ServerFunc func(context.Context, Stream) error

The ServerFunc type is an adapter that implements the StreamServer interface using an ordinary function.

func (ServerFunc) ServeStream

func (f ServerFunc) ServeStream(ctx context.Context, s Stream) error

ServeStream calls f(ctx, s).

type Stream

type Stream interface {
	// Read gets the next message from the stream.
	// It is never called concurrently.
	Read(context.Context) ([]byte, int64, error)
	// Write sends a message to the stream.
	// It must be safe for concurrent use.
	Write(context.Context, []byte) (int64, error)
}

Stream abstracts the transport mechanics from the JSON RPC protocol. A Conn reads and writes messages using the stream it was provided on construction, and assumes that each call to Read or Write fully transfers a single message, or returns an error.

func NewHeaderStream

func NewHeaderStream(in io.Reader, out io.Writer) Stream

NewHeaderStream returns a Stream built on top of an io.Reader and io.Writer The messages are sent with HTTP content length and MIME type headers. This is the format used by LSP and others.

func NewStream

func NewStream(in io.Reader, out io.Writer) Stream

NewStream returns a Stream built on top of an io.Reader and io.Writer The messages are sent with no wrapping, and rely on json decode consistency to determine message boundaries.

type StreamServer

type StreamServer interface {
	ServeStream(context.Context, Stream) error
}

A StreamServer is used to serve incoming jsonrpc2 clients communicating over a newly created stream.

func HandlerServer

func HandlerServer(h Handler) StreamServer

HandlerServer returns a StreamServer that handles incoming streams using the provided handler.

type VersionTag

type VersionTag struct{}

VersionTag is a special 0 sized struct that encodes as the jsonrpc version tag. It will fail during decode if it is not the correct version tag in the stream.

func (VersionTag) MarshalJSON

func (VersionTag) MarshalJSON() ([]byte, error)

func (VersionTag) UnmarshalJSON

func (VersionTag) UnmarshalJSON(data []byte) error

type WireRequest

type WireRequest struct {
	// VersionTag is always encoded as the string "2.0"
	VersionTag VersionTag `json:"jsonrpc"`
	// Method is a string containing the method name to invoke.
	Method string `json:"method"`
	// Params is either a struct or an array with the parameters of the method.
	Params *json.RawMessage `json:"params,omitempty"`
	// The id of this request, used to tie the Response back to the request.
	// Will be either a string or a number. If not set, the Request is a notify,
	// and no response is possible.
	ID *ID `json:"id,omitempty"`
}

WireRequest is sent to a server to represent a Call or Notify operaton.

type WireResponse

type WireResponse struct {
	// VersionTag is always encoded as the string "2.0"
	VersionTag VersionTag `json:"jsonrpc"`
	// Result is the response value, and is required on success.
	Result *json.RawMessage `json:"result,omitempty"`
	// Error is a structured error response if the call fails.
	Error *Error `json:"error,omitempty"`
	// ID must be set and is the identifier of the Request this is a response to.
	ID *ID `json:"id,omitempty"`
}

WireResponse is a reply to a Request. It will always have the ID field set to tie it back to a request, and will have either the Result or Error fields set depending on whether it is a success or failure response.

Directories

Path Synopsis
Package servertest provides utilities for running tests against a remote LSP server.
Package servertest provides utilities for running tests against a remote LSP server.

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