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