redis/error.go

123 lines
2.2 KiB
Go

package redis
import (
"context"
"io"
"net"
"strings"
"github.com/go-redis/redis/v8/internal/pool"
"github.com/go-redis/redis/v8/internal/proto"
)
var ErrClosed = pool.ErrClosed
type Error interface {
error
// RedisError is a no-op function but
// serves to distinguish types that are Redis
// errors from ordinary errors: a type is a
// Redis error if it has a RedisError method.
RedisError()
}
var _ Error = proto.RedisError("")
func shouldRetry(err error, retryTimeout bool) bool {
switch err {
case io.EOF, io.ErrUnexpectedEOF:
return true
case nil, context.Canceled, context.DeadlineExceeded:
return false
}
if v, ok := err.(timeoutError); ok {
if v.Timeout() {
return retryTimeout
}
return true
}
s := err.Error()
if s == "ERR max number of clients reached" {
return true
}
if strings.HasPrefix(s, "LOADING ") {
return true
}
if strings.HasPrefix(s, "READONLY ") {
return true
}
if strings.HasPrefix(s, "CLUSTERDOWN ") {
return true
}
if strings.HasPrefix(s, "TRYAGAIN ") {
return true
}
return false
}
func isRedisError(err error) bool {
_, ok := err.(proto.RedisError)
return ok
}
func isBadConn(err error, allowTimeout bool) bool {
if err == nil {
return false
}
if isRedisError(err) {
// Close connections in read only state in case domain addr is used
// and domain resolves to a different Redis Server. See #790.
return isReadOnlyError(err)
}
if allowTimeout {
if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
return !netErr.Temporary()
}
}
return true
}
func isMovedError(err error) (moved bool, ask bool, addr string) {
if !isRedisError(err) {
return
}
s := err.Error()
switch {
case strings.HasPrefix(s, "MOVED "):
moved = true
case strings.HasPrefix(s, "ASK "):
ask = true
default:
return
}
ind := strings.LastIndex(s, " ")
if ind == -1 {
return false, false, ""
}
addr = s[ind+1:]
return
}
func isLoadingError(err error) bool {
return strings.HasPrefix(err.Error(), "LOADING ")
}
func isReadOnlyError(err error) bool {
return strings.HasPrefix(err.Error(), "READONLY ")
}
//------------------------------------------------------------------------------
type timeoutError interface {
Timeout() bool
}