gitea/vendor/github.com/pierrec/lz4/v4/state.go

76 lines
1.6 KiB
Go
Raw Normal View History

package lz4
import (
"errors"
"fmt"
"io"
"github.com/pierrec/lz4/v4/internal/lz4errors"
)
//go:generate go run golang.org/x/tools/cmd/stringer -type=aState -output state_gen.go
const (
noState aState = iota // uninitialized reader
errorState // unrecoverable error encountered
newState // instantiated object
readState // reading data
writeState // writing data
closedState // all done
)
type (
aState uint8
_State struct {
states []aState
state aState
err error
}
)
func (s *_State) init(states []aState) {
s.states = states
s.state = states[0]
}
func (s *_State) reset() {
s.state = s.states[0]
s.err = nil
}
// next sets the state to the next one unless it is passed a non nil error.
// It returns whether or not it is in error.
func (s *_State) next(err error) bool {
if err != nil {
s.err = fmt.Errorf("%s: %w", s.state, err)
s.state = errorState
return true
}
s.state = s.states[s.state]
return false
}
// nextd is like next but for defers.
func (s *_State) nextd(errp *error) bool {
return errp != nil && s.next(*errp)
}
// check sets s in error if not already in error and if the error is not nil or io.EOF,
func (s *_State) check(errp *error) {
if s.state == errorState || errp == nil {
return
}
if err := *errp; err != nil {
s.err = fmt.Errorf("%w[%s]", err, s.state)
if !errors.Is(err, io.EOF) {
s.state = errorState
}
}
}
func (s *_State) fail() error {
s.state = errorState
s.err = fmt.Errorf("%w[%s]", lz4errors.ErrInternalUnhandledState, s.state)
return s.err
}