// and the previous byte block for cross block matching.
type deflateFast struct {
	table [tableSize]tableEntry
	prev  []byte // Previous block, zero length if unknown.
	cur   int32  // Current match offset.
}

func newDeflateFast() *deflateFast {
	return &deflateFast{cur: maxStoreBlockSize, prev: make([]byte, 0, maxStoreBlockSize)}
}

// encode encodes a block given in src and appends tokens
// to dst and returns the result.

	case level == BestSpeed:
		d.compressionLevel = levels[level]
		d.window = make([]byte, maxStoreBlockSize)
		d.fill = (*compressor).fillStore
		d.step = (*compressor).encSpeed
		d.bestSpeed = newDeflateFast()
		d.tokens = make([]token, maxStoreBlockSize)
	case level == DefaultCompression:
		level = 6
		fallthrough
	case 2 <= level && level <= 9:
		d.compressionLevel = levels[level]
		d.initDeflate()

		}
	}
}

func TestBestSpeedShiftOffsets(t *testing.T) {
	// Test if shiftoffsets properly preserves matches and resets out-of-range matches
	// seen in https://github.com/golang/go/issues/4142
	enc := newDeflateFast()

	// testData may not generate internal matches.
	testData := make([]byte, 32)
	rng := rand.New(rand.NewSource(0))
	for i := range testData {
		testData[i] = byte(rng.Uint32())
	}