• Sina Mahmoodi's avatar
    graphql, node, rpc: improve HTTP write timeout handling (#25457) · f20eba42
    Sina Mahmoodi authored
    Here we add special handling for sending an error response when the write timeout of the
    HTTP server is just about to expire. This is surprisingly difficult to get right, since is
    must be ensured that all output is fully flushed in time, which needs support from
    multiple levels of the RPC handler stack:
    
    The timeout response can't use chunked transfer-encoding because there is no way to write
    the final terminating chunk. net/http writes it when the topmost handler returns, but the
    timeout will already be over by the time that happens. We decided to disable chunked
    encoding by setting content-length explicitly.
    
    Gzip compression must also be disabled for timeout responses because we don't know the
    true content-length before compressing all output, i.e. compression would reintroduce
    chunked transfer-encoding.
    Unverified
    f20eba42
errors.go 3.73 KB
// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package rpc

import "fmt"

// HTTPError is returned by client operations when the HTTP status code of the
// response is not a 2xx status.
type HTTPError struct {
	StatusCode int
	Status     string
	Body       []byte
}

func (err HTTPError) Error() string {
	if len(err.Body) == 0 {
		return err.Status
	}
	return fmt.Sprintf("%v: %s", err.Status, err.Body)
}

// Error wraps RPC errors, which contain an error code in addition to the message.
type Error interface {
	Error() string  // returns the message
	ErrorCode() int // returns the code
}

// A DataError contains some data in addition to the error message.
type DataError interface {
	Error() string          // returns the message
	ErrorData() interface{} // returns the error data
}

// Error types defined below are the built-in JSON-RPC errors.

var (
	_ Error = new(methodNotFoundError)
	_ Error = new(subscriptionNotFoundError)
	_ Error = new(parseError)
	_ Error = new(invalidRequestError)
	_ Error = new(invalidMessageError)
	_ Error = new(invalidParamsError)
	_ Error = new(internalServerError)
)

const (
	errcodeDefault                  = -32000
	errcodeNotificationsUnsupported = -32001
	errcodeTimeout                  = -32002
	errcodePanic                    = -32603
	errcodeMarshalError             = -32603
)

const (
	errMsgTimeout = "request timed out"
)

type methodNotFoundError struct{ method string }

func (e *methodNotFoundError) ErrorCode() int { return -32601 }

func (e *methodNotFoundError) Error() string {
	return fmt.Sprintf("the method %s does not exist/is not available", e.method)
}

type subscriptionNotFoundError struct{ namespace, subscription string }

func (e *subscriptionNotFoundError) ErrorCode() int { return -32601 }

func (e *subscriptionNotFoundError) Error() string {
	return fmt.Sprintf("no %q subscription in %s namespace", e.subscription, e.namespace)
}

// Invalid JSON was received by the server.
type parseError struct{ message string }

func (e *parseError) ErrorCode() int { return -32700 }

func (e *parseError) Error() string { return e.message }

// received message isn't a valid request
type invalidRequestError struct{ message string }

func (e *invalidRequestError) ErrorCode() int { return -32600 }

func (e *invalidRequestError) Error() string { return e.message }

// received message is invalid
type invalidMessageError struct{ message string }

func (e *invalidMessageError) ErrorCode() int { return -32700 }

func (e *invalidMessageError) Error() string { return e.message }

// unable to decode supplied params, or an invalid number of parameters
type invalidParamsError struct{ message string }

func (e *invalidParamsError) ErrorCode() int { return -32602 }

func (e *invalidParamsError) Error() string { return e.message }

// internalServerError is used for server errors during request processing.
type internalServerError struct {
	code    int
	message string
}

func (e *internalServerError) ErrorCode() int { return e.code }

func (e *internalServerError) Error() string { return e.message }