Function fuzzFseEncoder

zstd/blockenc.go:443–477

fuzzFseEncoder can be used to fuzz the FSE encoder.

(data []byte)

// fuzzFseEncoder can be used to fuzz the FSE encoder.
func fuzzFseEncoder(data []byte) int {
	if len(data) > maxSequences || len(data) < 2 {
		return 0
	}
	enc := fseEncoder{}
	hist := enc.Histogram()
	maxSym := uint8(0)
	for i, v := range data {
		v = v & 63
		data[i] = v
		hist[v]++
		if v > maxSym {
			maxSym = v
		}
	}
	if maxSym == 0 {
		// All 0
		return 0
	}
	cnt := int(slices.Max(hist[:maxSym]))
	if cnt == len(data) {
		// RLE
		return 0
	}
	enc.HistogramFinished(maxSym, cnt)
	err := enc.normalizeCount(len(data))
	if err != nil {
		return 0
	}
	_, err = enc.writeCount(nil)
	if err != nil {
		panic(err)
	}
	return 1
}

// encode will encode the block and append the output in b.output.
// Previous offset codes must be pushed if more blocks are expected.