gorealis-v2/errors.go

/**
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package realis

// Using a pattern described by Dave Cheney to differentiate errors
// https://dave.cheney.net/2016/04/27/dont-just-check-errors-handle-them-gracefully
type timeout interface {
	Timeout() bool
}

func IsTimeout(err error) bool {
	temp, ok := err.(timeout)
	return ok && temp.Timeout()
}

type TimeoutErr struct {
	error
	timeout bool
}

func (t *TimeoutErr) Timeout() bool {
	return t.timeout
}

func NewTimeoutError(err error) *TimeoutErr {
	return &TimeoutErr{error: err, timeout: true}
}

type temporary interface {
	Temporary() bool
}

func IsTemporary(err error) bool {
	temp, ok := err.(temporary)
	return ok && temp.Temporary()
}

type TemporaryErr struct {
	error
	temporary bool
}

func (t *TemporaryErr) Temporary() bool {
	return t.temporary
}

// Retrying after receiving this error is advised
func NewTemporaryError(err error) *TemporaryErr {
	return &TemporaryErr{error: err, temporary: true}
}

// Nothing can be done about this error
func NewPermamentError(err error) TemporaryErr {
	return TemporaryErr{error: err, temporary: false}
}