1package moxio

2

3import (

4 "github.com/mjl-/flate"

5)

6

7// FlateWriter wraps a flate.Writer and ensures no Write/Flush/Close calls are made

8// again on the underlying flate writer when a panic came out of the flate writer

9// (e.g. raised by the destination writer of the flate writer). After a panic

10// "through" a flate.Writer, its state is inconsistent and further calls could

11// panic with out of bounds slice accesses.

12type FlateWriter struct {

13 w *flate.Writer

14 panic any

15}

16

17func NewFlateWriter(w *flate.Writer) *FlateWriter {

18 return &FlateWriter{w, nil}

19}

20

21func (w *FlateWriter) checkBroken() func() {

22 if w.panic != nil {

23 panic(w.panic)

24 }

25 return func() {

26 x := recover()

27 if x == nil {

28 return

29 }

30 w.panic = x

31 panic(x)

32 }

33}

34

35func (w *FlateWriter) Write(data []byte) (int, error) {

36 defer w.checkBroken()()

37 return w.w.Write(data)

38}

39

40func (w *FlateWriter) Flush() error {

41 defer w.checkBroken()()

42 return w.w.Flush()

43}

44

45func (w *FlateWriter) Close() error {

46 defer w.checkBroken()()

47 return w.w.Close()

48}

49