diff --git a/vendor/github.com/klauspost/compress/huff0/decompress.go b/vendor/github.com/klauspost/compress/huff0/decompress.go
new file mode 100644
index 0000000..41703bb
--- /dev/null
+++ b/vendor/github.com/klauspost/compress/huff0/decompress.go
@@ -0,0 +1,1164 @@
+package huff0
+
+import (
+	"errors"
+	"fmt"
+	"io"
+
+	"github.com/klauspost/compress/fse"
+)
+
+type dTable struct {
+	single []dEntrySingle
+	double []dEntryDouble
+}
+
+// single-symbols decoding
+type dEntrySingle struct {
+	entry uint16
+}
+
+// double-symbols decoding
+type dEntryDouble struct {
+	seq   uint16
+	nBits uint8
+	len   uint8
+}
+
+// Uses special code for all tables that are < 8 bits.
+const use8BitTables = true
+
+// ReadTable will read a table from the input.
+// The size of the input may be larger than the table definition.
+// Any content remaining after the table definition will be returned.
+// If no Scratch is provided a new one is allocated.
+// The returned Scratch can be used for encoding or decoding input using this table.
+func ReadTable(in []byte, s *Scratch) (s2 *Scratch, remain []byte, err error) {
+	s, err = s.prepare(in)
+	if err != nil {
+		return s, nil, err
+	}
+	if len(in) <= 1 {
+		return s, nil, errors.New("input too small for table")
+	}
+	iSize := in[0]
+	in = in[1:]
+	if iSize >= 128 {
+		// Uncompressed
+		oSize := iSize - 127
+		iSize = (oSize + 1) / 2
+		if int(iSize) > len(in) {
+			return s, nil, errors.New("input too small for table")
+		}
+		for n := uint8(0); n < oSize; n += 2 {
+			v := in[n/2]
+			s.huffWeight[n] = v >> 4
+			s.huffWeight[n+1] = v & 15
+		}
+		s.symbolLen = uint16(oSize)
+		in = in[iSize:]
+	} else {
+		if len(in) < int(iSize) {
+			return s, nil, fmt.Errorf("input too small for table, want %d bytes, have %d", iSize, len(in))
+		}
+		// FSE compressed weights
+		s.fse.DecompressLimit = 255
+		hw := s.huffWeight[:]
+		s.fse.Out = hw
+		b, err := fse.Decompress(in[:iSize], s.fse)
+		s.fse.Out = nil
+		if err != nil {
+			return s, nil, err
+		}
+		if len(b) > 255 {
+			return s, nil, errors.New("corrupt input: output table too large")
+		}
+		s.symbolLen = uint16(len(b))
+		in = in[iSize:]
+	}
+
+	// collect weight stats
+	var rankStats [16]uint32
+	weightTotal := uint32(0)
+	for _, v := range s.huffWeight[:s.symbolLen] {
+		if v > tableLogMax {
+			return s, nil, errors.New("corrupt input: weight too large")
+		}
+		v2 := v & 15
+		rankStats[v2]++
+		// (1 << (v2-1)) is slower since the compiler cannot prove that v2 isn't 0.
+		weightTotal += (1 << v2) >> 1
+	}
+	if weightTotal == 0 {
+		return s, nil, errors.New("corrupt input: weights zero")
+	}
+
+	// get last non-null symbol weight (implied, total must be 2^n)
+	{
+		tableLog := highBit32(weightTotal) + 1
+		if tableLog > tableLogMax {
+			return s, nil, errors.New("corrupt input: tableLog too big")
+		}
+		s.actualTableLog = uint8(tableLog)
+		// determine last weight
+		{
+			total := uint32(1) << tableLog
+			rest := total - weightTotal
+			verif := uint32(1) << highBit32(rest)
+			lastWeight := highBit32(rest) + 1
+			if verif != rest {
+				// last value must be a clean power of 2
+				return s, nil, errors.New("corrupt input: last value not power of two")
+			}
+			s.huffWeight[s.symbolLen] = uint8(lastWeight)
+			s.symbolLen++
+			rankStats[lastWeight]++
+		}
+	}
+
+	if (rankStats[1] < 2) || (rankStats[1]&1 != 0) {
+		// by construction : at least 2 elts of rank 1, must be even
+		return s, nil, errors.New("corrupt input: min elt size, even check failed ")
+	}
+
+	// TODO: Choose between single/double symbol decoding
+
+	// Calculate starting value for each rank
+	{
+		var nextRankStart uint32
+		for n := uint8(1); n < s.actualTableLog+1; n++ {
+			current := nextRankStart
+			nextRankStart += rankStats[n] << (n - 1)
+			rankStats[n] = current
+		}
+	}
+
+	// fill DTable (always full size)
+	tSize := 1 << tableLogMax
+	if len(s.dt.single) != tSize {
+		s.dt.single = make([]dEntrySingle, tSize)
+	}
+	cTable := s.prevTable
+	if cap(cTable) < maxSymbolValue+1 {
+		cTable = make([]cTableEntry, 0, maxSymbolValue+1)
+	}
+	cTable = cTable[:maxSymbolValue+1]
+	s.prevTable = cTable[:s.symbolLen]
+	s.prevTableLog = s.actualTableLog
+
+	for n, w := range s.huffWeight[:s.symbolLen] {
+		if w == 0 {
+			cTable[n] = cTableEntry{
+				val:   0,
+				nBits: 0,
+			}
+			continue
+		}
+		length := (uint32(1) << w) >> 1
+		d := dEntrySingle{
+			entry: uint16(s.actualTableLog+1-w) | (uint16(n) << 8),
+		}
+
+		rank := &rankStats[w]
+		cTable[n] = cTableEntry{
+			val:   uint16(*rank >> (w - 1)),
+			nBits: uint8(d.entry),
+		}
+
+		single := s.dt.single[*rank : *rank+length]
+		for i := range single {
+			single[i] = d
+		}
+		*rank += length
+	}
+
+	return s, in, nil
+}
+
+// Decompress1X will decompress a 1X encoded stream.
+// The length of the supplied input must match the end of a block exactly.
+// Before this is called, the table must be initialized with ReadTable unless
+// the encoder re-used the table.
+// deprecated: Use the stateless Decoder() to get a concurrent version.
+func (s *Scratch) Decompress1X(in []byte) (out []byte, err error) {
+	if cap(s.Out) < s.MaxDecodedSize {
+		s.Out = make([]byte, s.MaxDecodedSize)
+	}
+	s.Out = s.Out[:0:s.MaxDecodedSize]
+	s.Out, err = s.Decoder().Decompress1X(s.Out, in)
+	return s.Out, err
+}
+
+// Decompress4X will decompress a 4X encoded stream.
+// Before this is called, the table must be initialized with ReadTable unless
+// the encoder re-used the table.
+// The length of the supplied input must match the end of a block exactly.
+// The destination size of the uncompressed data must be known and provided.
+// deprecated: Use the stateless Decoder() to get a concurrent version.
+func (s *Scratch) Decompress4X(in []byte, dstSize int) (out []byte, err error) {
+	if dstSize > s.MaxDecodedSize {
+		return nil, ErrMaxDecodedSizeExceeded
+	}
+	if cap(s.Out) < dstSize {
+		s.Out = make([]byte, s.MaxDecodedSize)
+	}
+	s.Out = s.Out[:0:dstSize]
+	s.Out, err = s.Decoder().Decompress4X(s.Out, in)
+	return s.Out, err
+}
+
+// Decoder will return a stateless decoder that can be used by multiple
+// decompressors concurrently.
+// Before this is called, the table must be initialized with ReadTable.
+// The Decoder is still linked to the scratch buffer so that cannot be reused.
+// However, it is safe to discard the scratch.
+func (s *Scratch) Decoder() *Decoder {
+	return &Decoder{
+		dt:             s.dt,
+		actualTableLog: s.actualTableLog,
+	}
+}
+
+// Decoder provides stateless decoding.
+type Decoder struct {
+	dt             dTable
+	actualTableLog uint8
+}
+
+// Decompress1X will decompress a 1X encoded stream.
+// The cap of the output buffer will be the maximum decompressed size.
+// The length of the supplied input must match the end of a block exactly.
+func (d *Decoder) Decompress1X(dst, src []byte) ([]byte, error) {
+	if len(d.dt.single) == 0 {
+		return nil, errors.New("no table loaded")
+	}
+	if use8BitTables && d.actualTableLog <= 8 {
+		return d.decompress1X8Bit(dst, src)
+	}
+	var br bitReaderShifted
+	err := br.init(src)
+	if err != nil {
+		return dst, err
+	}
+	maxDecodedSize := cap(dst)
+	dst = dst[:0]
+
+	// Avoid bounds check by always having full sized table.
+	const tlSize = 1 << tableLogMax
+	const tlMask = tlSize - 1
+	dt := d.dt.single[:tlSize]
+
+	// Use temp table to avoid bound checks/append penalty.
+	var buf [256]byte
+	var off uint8
+
+	for br.off >= 8 {
+		br.fillFast()
+		v := dt[br.peekBitsFast(d.actualTableLog)&tlMask]
+		br.advance(uint8(v.entry))
+		buf[off+0] = uint8(v.entry >> 8)
+
+		v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
+		br.advance(uint8(v.entry))
+		buf[off+1] = uint8(v.entry >> 8)
+
+		// Refill
+		br.fillFast()
+
+		v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
+		br.advance(uint8(v.entry))
+		buf[off+2] = uint8(v.entry >> 8)
+
+		v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
+		br.advance(uint8(v.entry))
+		buf[off+3] = uint8(v.entry >> 8)
+
+		off += 4
+		if off == 0 {
+			if len(dst)+256 > maxDecodedSize {
+				br.close()
+				return nil, ErrMaxDecodedSizeExceeded
+			}
+			dst = append(dst, buf[:]...)
+		}
+	}
+
+	if len(dst)+int(off) > maxDecodedSize {
+		br.close()
+		return nil, ErrMaxDecodedSizeExceeded
+	}
+	dst = append(dst, buf[:off]...)
+
+	// br < 8, so uint8 is fine
+	bitsLeft := uint8(br.off)*8 + 64 - br.bitsRead
+	for bitsLeft > 0 {
+		br.fill()
+		if false && br.bitsRead >= 32 {
+			if br.off >= 4 {
+				v := br.in[br.off-4:]
+				v = v[:4]
+				low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
+				br.value = (br.value << 32) | uint64(low)
+				br.bitsRead -= 32
+				br.off -= 4
+			} else {
+				for br.off > 0 {
+					br.value = (br.value << 8) | uint64(br.in[br.off-1])
+					br.bitsRead -= 8
+					br.off--
+				}
+			}
+		}
+		if len(dst) >= maxDecodedSize {
+			br.close()
+			return nil, ErrMaxDecodedSizeExceeded
+		}
+		v := d.dt.single[br.peekBitsFast(d.actualTableLog)&tlMask]
+		nBits := uint8(v.entry)
+		br.advance(nBits)
+		bitsLeft -= nBits
+		dst = append(dst, uint8(v.entry>>8))
+	}
+	return dst, br.close()
+}
+
+// decompress1X8Bit will decompress a 1X encoded stream with tablelog <= 8.
+// The cap of the output buffer will be the maximum decompressed size.
+// The length of the supplied input must match the end of a block exactly.
+func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
+	if d.actualTableLog == 8 {
+		return d.decompress1X8BitExactly(dst, src)
+	}
+	var br bitReaderBytes
+	err := br.init(src)
+	if err != nil {
+		return dst, err
+	}
+	maxDecodedSize := cap(dst)
+	dst = dst[:0]
+
+	// Avoid bounds check by always having full sized table.
+	dt := d.dt.single[:256]
+
+	// Use temp table to avoid bound checks/append penalty.
+	var buf [256]byte
+	var off uint8
+
+	shift := (8 - d.actualTableLog) & 7
+
+	//fmt.Printf("mask: %b, tl:%d\n", mask, d.actualTableLog)
+	for br.off >= 4 {
+		br.fillFast()
+		v := dt[br.peekByteFast()>>shift]
+		br.advance(uint8(v.entry))
+		buf[off+0] = uint8(v.entry >> 8)
+
+		v = dt[br.peekByteFast()>>shift]
+		br.advance(uint8(v.entry))
+		buf[off+1] = uint8(v.entry >> 8)
+
+		v = dt[br.peekByteFast()>>shift]
+		br.advance(uint8(v.entry))
+		buf[off+2] = uint8(v.entry >> 8)
+
+		v = dt[br.peekByteFast()>>shift]
+		br.advance(uint8(v.entry))
+		buf[off+3] = uint8(v.entry >> 8)
+
+		off += 4
+		if off == 0 {
+			if len(dst)+256 > maxDecodedSize {
+				br.close()
+				return nil, ErrMaxDecodedSizeExceeded
+			}
+			dst = append(dst, buf[:]...)
+		}
+	}
+
+	if len(dst)+int(off) > maxDecodedSize {
+		br.close()
+		return nil, ErrMaxDecodedSizeExceeded
+	}
+	dst = append(dst, buf[:off]...)
+
+	// br < 4, so uint8 is fine
+	bitsLeft := int8(uint8(br.off)*8 + (64 - br.bitsRead))
+	for bitsLeft > 0 {
+		if br.bitsRead >= 64-8 {
+			for br.off > 0 {
+				br.value |= uint64(br.in[br.off-1]) << (br.bitsRead - 8)
+				br.bitsRead -= 8
+				br.off--
+			}
+		}
+		if len(dst) >= maxDecodedSize {
+			br.close()
+			return nil, ErrMaxDecodedSizeExceeded
+		}
+		v := dt[br.peekByteFast()>>shift]
+		nBits := uint8(v.entry)
+		br.advance(nBits)
+		bitsLeft -= int8(nBits)
+		dst = append(dst, uint8(v.entry>>8))
+	}
+	return dst, br.close()
+}
+
+// decompress1X8Bit will decompress a 1X encoded stream with tablelog <= 8.
+// The cap of the output buffer will be the maximum decompressed size.
+// The length of the supplied input must match the end of a block exactly.
+func (d *Decoder) decompress1X8BitExactly(dst, src []byte) ([]byte, error) {
+	var br bitReaderBytes
+	err := br.init(src)
+	if err != nil {
+		return dst, err
+	}
+	maxDecodedSize := cap(dst)
+	dst = dst[:0]
+
+	// Avoid bounds check by always having full sized table.
+	dt := d.dt.single[:256]
+
+	// Use temp table to avoid bound checks/append penalty.
+	var buf [256]byte
+	var off uint8
+
+	const shift = 0
+
+	//fmt.Printf("mask: %b, tl:%d\n", mask, d.actualTableLog)
+	for br.off >= 4 {
+		br.fillFast()
+		v := dt[br.peekByteFast()>>shift]
+		br.advance(uint8(v.entry))
+		buf[off+0] = uint8(v.entry >> 8)
+
+		v = dt[br.peekByteFast()>>shift]
+		br.advance(uint8(v.entry))
+		buf[off+1] = uint8(v.entry >> 8)
+
+		v = dt[br.peekByteFast()>>shift]
+		br.advance(uint8(v.entry))
+		buf[off+2] = uint8(v.entry >> 8)
+
+		v = dt[br.peekByteFast()>>shift]
+		br.advance(uint8(v.entry))
+		buf[off+3] = uint8(v.entry >> 8)
+
+		off += 4
+		if off == 0 {
+			if len(dst)+256 > maxDecodedSize {
+				br.close()
+				return nil, ErrMaxDecodedSizeExceeded
+			}
+			dst = append(dst, buf[:]...)
+		}
+	}
+
+	if len(dst)+int(off) > maxDecodedSize {
+		br.close()
+		return nil, ErrMaxDecodedSizeExceeded
+	}
+	dst = append(dst, buf[:off]...)
+
+	// br < 4, so uint8 is fine
+	bitsLeft := int8(uint8(br.off)*8 + (64 - br.bitsRead))
+	for bitsLeft > 0 {
+		if br.bitsRead >= 64-8 {
+			for br.off > 0 {
+				br.value |= uint64(br.in[br.off-1]) << (br.bitsRead - 8)
+				br.bitsRead -= 8
+				br.off--
+			}
+		}
+		if len(dst) >= maxDecodedSize {
+			br.close()
+			return nil, ErrMaxDecodedSizeExceeded
+		}
+		v := dt[br.peekByteFast()>>shift]
+		nBits := uint8(v.entry)
+		br.advance(nBits)
+		bitsLeft -= int8(nBits)
+		dst = append(dst, uint8(v.entry>>8))
+	}
+	return dst, br.close()
+}
+
+// Decompress4X will decompress a 4X encoded stream.
+// The length of the supplied input must match the end of a block exactly.
+// The *capacity* of the dst slice must match the destination size of
+// the uncompressed data exactly.
+func (d *Decoder) Decompress4X(dst, src []byte) ([]byte, error) {
+	if len(d.dt.single) == 0 {
+		return nil, errors.New("no table loaded")
+	}
+	if len(src) < 6+(4*1) {
+		return nil, errors.New("input too small")
+	}
+	if use8BitTables && d.actualTableLog <= 8 {
+		return d.decompress4X8bit(dst, src)
+	}
+
+	var br [4]bitReaderShifted
+	start := 6
+	for i := 0; i < 3; i++ {
+		length := int(src[i*2]) | (int(src[i*2+1]) << 8)
+		if start+length >= len(src) {
+			return nil, errors.New("truncated input (or invalid offset)")
+		}
+		err := br[i].init(src[start : start+length])
+		if err != nil {
+			return nil, err
+		}
+		start += length
+	}
+	err := br[3].init(src[start:])
+	if err != nil {
+		return nil, err
+	}
+
+	// destination, offset to match first output
+	dstSize := cap(dst)
+	dst = dst[:dstSize]
+	out := dst
+	dstEvery := (dstSize + 3) / 4
+
+	const tlSize = 1 << tableLogMax
+	const tlMask = tlSize - 1
+	single := d.dt.single[:tlSize]
+
+	// Use temp table to avoid bound checks/append penalty.
+	var buf [256]byte
+	var off uint8
+	var decoded int
+
+	// Decode 2 values from each decoder/loop.
+	const bufoff = 256 / 4
+	for {
+		if br[0].off < 4 || br[1].off < 4 || br[2].off < 4 || br[3].off < 4 {
+			break
+		}
+
+		{
+			const stream = 0
+			const stream2 = 1
+			br[stream].fillFast()
+			br[stream2].fillFast()
+
+			val := br[stream].peekBitsFast(d.actualTableLog)
+			v := single[val&tlMask]
+			br[stream].advance(uint8(v.entry))
+			buf[off+bufoff*stream] = uint8(v.entry >> 8)
+
+			val2 := br[stream2].peekBitsFast(d.actualTableLog)
+			v2 := single[val2&tlMask]
+			br[stream2].advance(uint8(v2.entry))
+			buf[off+bufoff*stream2] = uint8(v2.entry >> 8)
+
+			val = br[stream].peekBitsFast(d.actualTableLog)
+			v = single[val&tlMask]
+			br[stream].advance(uint8(v.entry))
+			buf[off+bufoff*stream+1] = uint8(v.entry >> 8)
+
+			val2 = br[stream2].peekBitsFast(d.actualTableLog)
+			v2 = single[val2&tlMask]
+			br[stream2].advance(uint8(v2.entry))
+			buf[off+bufoff*stream2+1] = uint8(v2.entry >> 8)
+		}
+
+		{
+			const stream = 2
+			const stream2 = 3
+			br[stream].fillFast()
+			br[stream2].fillFast()
+
+			val := br[stream].peekBitsFast(d.actualTableLog)
+			v := single[val&tlMask]
+			br[stream].advance(uint8(v.entry))
+			buf[off+bufoff*stream] = uint8(v.entry >> 8)
+
+			val2 := br[stream2].peekBitsFast(d.actualTableLog)
+			v2 := single[val2&tlMask]
+			br[stream2].advance(uint8(v2.entry))
+			buf[off+bufoff*stream2] = uint8(v2.entry >> 8)
+
+			val = br[stream].peekBitsFast(d.actualTableLog)
+			v = single[val&tlMask]
+			br[stream].advance(uint8(v.entry))
+			buf[off+bufoff*stream+1] = uint8(v.entry >> 8)
+
+			val2 = br[stream2].peekBitsFast(d.actualTableLog)
+			v2 = single[val2&tlMask]
+			br[stream2].advance(uint8(v2.entry))
+			buf[off+bufoff*stream2+1] = uint8(v2.entry >> 8)
+		}
+
+		off += 2
+
+		if off == bufoff {
+			if bufoff > dstEvery {
+				return nil, errors.New("corruption detected: stream overrun 1")
+			}
+			copy(out, buf[:bufoff])
+			copy(out[dstEvery:], buf[bufoff:bufoff*2])
+			copy(out[dstEvery*2:], buf[bufoff*2:bufoff*3])
+			copy(out[dstEvery*3:], buf[bufoff*3:bufoff*4])
+			off = 0
+			out = out[bufoff:]
+			decoded += 256
+			// There must at least be 3 buffers left.
+			if len(out) < dstEvery*3 {
+				return nil, errors.New("corruption detected: stream overrun 2")
+			}
+		}
+	}
+	if off > 0 {
+		ioff := int(off)
+		if len(out) < dstEvery*3+ioff {
+			return nil, errors.New("corruption detected: stream overrun 3")
+		}
+		copy(out, buf[:off])
+		copy(out[dstEvery:dstEvery+ioff], buf[bufoff:bufoff*2])
+		copy(out[dstEvery*2:dstEvery*2+ioff], buf[bufoff*2:bufoff*3])
+		copy(out[dstEvery*3:dstEvery*3+ioff], buf[bufoff*3:bufoff*4])
+		decoded += int(off) * 4
+		out = out[off:]
+	}
+
+	// Decode remaining.
+	for i := range br {
+		offset := dstEvery * i
+		br := &br[i]
+		bitsLeft := br.off*8 + uint(64-br.bitsRead)
+		for bitsLeft > 0 {
+			br.fill()
+			if false && br.bitsRead >= 32 {
+				if br.off >= 4 {
+					v := br.in[br.off-4:]
+					v = v[:4]
+					low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
+					br.value = (br.value << 32) | uint64(low)
+					br.bitsRead -= 32
+					br.off -= 4
+				} else {
+					for br.off > 0 {
+						br.value = (br.value << 8) | uint64(br.in[br.off-1])
+						br.bitsRead -= 8
+						br.off--
+					}
+				}
+			}
+			// end inline...
+			if offset >= len(out) {
+				return nil, errors.New("corruption detected: stream overrun 4")
+			}
+
+			// Read value and increment offset.
+			val := br.peekBitsFast(d.actualTableLog)
+			v := single[val&tlMask].entry
+			nBits := uint8(v)
+			br.advance(nBits)
+			bitsLeft -= uint(nBits)
+			out[offset] = uint8(v >> 8)
+			offset++
+		}
+		decoded += offset - dstEvery*i
+		err = br.close()
+		if err != nil {
+			return nil, err
+		}
+	}
+	if dstSize != decoded {
+		return nil, errors.New("corruption detected: short output block")
+	}
+	return dst, nil
+}
+
+// Decompress4X will decompress a 4X encoded stream.
+// The length of the supplied input must match the end of a block exactly.
+// The *capacity* of the dst slice must match the destination size of
+// the uncompressed data exactly.
+func (d *Decoder) decompress4X8bit(dst, src []byte) ([]byte, error) {
+	if d.actualTableLog == 8 {
+		return d.decompress4X8bitExactly(dst, src)
+	}
+
+	var br [4]bitReaderBytes
+	start := 6
+	for i := 0; i < 3; i++ {
+		length := int(src[i*2]) | (int(src[i*2+1]) << 8)
+		if start+length >= len(src) {
+			return nil, errors.New("truncated input (or invalid offset)")
+		}
+		err := br[i].init(src[start : start+length])
+		if err != nil {
+			return nil, err
+		}
+		start += length
+	}
+	err := br[3].init(src[start:])
+	if err != nil {
+		return nil, err
+	}
+
+	// destination, offset to match first output
+	dstSize := cap(dst)
+	dst = dst[:dstSize]
+	out := dst
+	dstEvery := (dstSize + 3) / 4
+
+	shift := (8 - d.actualTableLog) & 7
+
+	const tlSize = 1 << 8
+	const tlMask = tlSize - 1
+	single := d.dt.single[:tlSize]
+
+	// Use temp table to avoid bound checks/append penalty.
+	var buf [256]byte
+	var off uint8
+	var decoded int
+
+	// Decode 4 values from each decoder/loop.
+	const bufoff = 256 / 4
+	for {
+		if br[0].off < 4 || br[1].off < 4 || br[2].off < 4 || br[3].off < 4 {
+			break
+		}
+
+		{
+			// Interleave 2 decodes.
+			const stream = 0
+			const stream2 = 1
+			br[stream].fillFast()
+			br[stream2].fillFast()
+
+			v := single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 := single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+1] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+1] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+2] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+2] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+3] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+3] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+		}
+
+		{
+			const stream = 2
+			const stream2 = 3
+			br[stream].fillFast()
+			br[stream2].fillFast()
+
+			v := single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 := single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+1] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+1] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+2] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+2] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+3] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+3] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+		}
+
+		off += 4
+
+		if off == bufoff {
+			if bufoff > dstEvery {
+				return nil, errors.New("corruption detected: stream overrun 1")
+			}
+			copy(out, buf[:bufoff])
+			copy(out[dstEvery:], buf[bufoff:bufoff*2])
+			copy(out[dstEvery*2:], buf[bufoff*2:bufoff*3])
+			copy(out[dstEvery*3:], buf[bufoff*3:bufoff*4])
+			off = 0
+			out = out[bufoff:]
+			decoded += 256
+			// There must at least be 3 buffers left.
+			if len(out) < dstEvery*3 {
+				return nil, errors.New("corruption detected: stream overrun 2")
+			}
+		}
+	}
+	if off > 0 {
+		ioff := int(off)
+		if len(out) < dstEvery*3+ioff {
+			return nil, errors.New("corruption detected: stream overrun 3")
+		}
+		copy(out, buf[:off])
+		copy(out[dstEvery:dstEvery+ioff], buf[bufoff:bufoff*2])
+		copy(out[dstEvery*2:dstEvery*2+ioff], buf[bufoff*2:bufoff*3])
+		copy(out[dstEvery*3:dstEvery*3+ioff], buf[bufoff*3:bufoff*4])
+		decoded += int(off) * 4
+		out = out[off:]
+	}
+
+	// Decode remaining.
+	for i := range br {
+		offset := dstEvery * i
+		br := &br[i]
+		bitsLeft := int(br.off*8) + int(64-br.bitsRead)
+		for bitsLeft > 0 {
+			if br.finished() {
+				return nil, io.ErrUnexpectedEOF
+			}
+			if br.bitsRead >= 56 {
+				if br.off >= 4 {
+					v := br.in[br.off-4:]
+					v = v[:4]
+					low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
+					br.value |= uint64(low) << (br.bitsRead - 32)
+					br.bitsRead -= 32
+					br.off -= 4
+				} else {
+					for br.off > 0 {
+						br.value |= uint64(br.in[br.off-1]) << (br.bitsRead - 8)
+						br.bitsRead -= 8
+						br.off--
+					}
+				}
+			}
+			// end inline...
+			if offset >= len(out) {
+				return nil, errors.New("corruption detected: stream overrun 4")
+			}
+
+			// Read value and increment offset.
+			v := single[br.peekByteFast()>>shift].entry
+			nBits := uint8(v)
+			br.advance(nBits)
+			bitsLeft -= int(nBits)
+			out[offset] = uint8(v >> 8)
+			offset++
+		}
+		decoded += offset - dstEvery*i
+		err = br.close()
+		if err != nil {
+			return nil, err
+		}
+	}
+	if dstSize != decoded {
+		return nil, errors.New("corruption detected: short output block")
+	}
+	return dst, nil
+}
+
+// Decompress4X will decompress a 4X encoded stream.
+// The length of the supplied input must match the end of a block exactly.
+// The *capacity* of the dst slice must match the destination size of
+// the uncompressed data exactly.
+func (d *Decoder) decompress4X8bitExactly(dst, src []byte) ([]byte, error) {
+	var br [4]bitReaderBytes
+	start := 6
+	for i := 0; i < 3; i++ {
+		length := int(src[i*2]) | (int(src[i*2+1]) << 8)
+		if start+length >= len(src) {
+			return nil, errors.New("truncated input (or invalid offset)")
+		}
+		err := br[i].init(src[start : start+length])
+		if err != nil {
+			return nil, err
+		}
+		start += length
+	}
+	err := br[3].init(src[start:])
+	if err != nil {
+		return nil, err
+	}
+
+	// destination, offset to match first output
+	dstSize := cap(dst)
+	dst = dst[:dstSize]
+	out := dst
+	dstEvery := (dstSize + 3) / 4
+
+	const shift = 0
+	const tlSize = 1 << 8
+	const tlMask = tlSize - 1
+	single := d.dt.single[:tlSize]
+
+	// Use temp table to avoid bound checks/append penalty.
+	var buf [256]byte
+	var off uint8
+	var decoded int
+
+	// Decode 4 values from each decoder/loop.
+	const bufoff = 256 / 4
+	for {
+		if br[0].off < 4 || br[1].off < 4 || br[2].off < 4 || br[3].off < 4 {
+			break
+		}
+
+		{
+			// Interleave 2 decodes.
+			const stream = 0
+			const stream2 = 1
+			br[stream].fillFast()
+			br[stream2].fillFast()
+
+			v := single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 := single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+1] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+1] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+2] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+2] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+3] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+3] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+		}
+
+		{
+			const stream = 2
+			const stream2 = 3
+			br[stream].fillFast()
+			br[stream2].fillFast()
+
+			v := single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 := single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+1] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+1] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+2] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+2] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+
+			v = single[br[stream].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream+3] = uint8(v >> 8)
+			br[stream].advance(uint8(v))
+
+			v2 = single[br[stream2].peekByteFast()>>shift].entry
+			buf[off+bufoff*stream2+3] = uint8(v2 >> 8)
+			br[stream2].advance(uint8(v2))
+		}
+
+		off += 4
+
+		if off == bufoff {
+			if bufoff > dstEvery {
+				return nil, errors.New("corruption detected: stream overrun 1")
+			}
+			copy(out, buf[:bufoff])
+			copy(out[dstEvery:], buf[bufoff:bufoff*2])
+			copy(out[dstEvery*2:], buf[bufoff*2:bufoff*3])
+			copy(out[dstEvery*3:], buf[bufoff*3:bufoff*4])
+			off = 0
+			out = out[bufoff:]
+			decoded += 256
+			// There must at least be 3 buffers left.
+			if len(out) < dstEvery*3 {
+				return nil, errors.New("corruption detected: stream overrun 2")
+			}
+		}
+	}
+	if off > 0 {
+		ioff := int(off)
+		if len(out) < dstEvery*3+ioff {
+			return nil, errors.New("corruption detected: stream overrun 3")
+		}
+		copy(out, buf[:off])
+		copy(out[dstEvery:dstEvery+ioff], buf[bufoff:bufoff*2])
+		copy(out[dstEvery*2:dstEvery*2+ioff], buf[bufoff*2:bufoff*3])
+		copy(out[dstEvery*3:dstEvery*3+ioff], buf[bufoff*3:bufoff*4])
+		decoded += int(off) * 4
+		out = out[off:]
+	}
+
+	// Decode remaining.
+	for i := range br {
+		offset := dstEvery * i
+		br := &br[i]
+		bitsLeft := int(br.off*8) + int(64-br.bitsRead)
+		for bitsLeft > 0 {
+			if br.finished() {
+				return nil, io.ErrUnexpectedEOF
+			}
+			if br.bitsRead >= 56 {
+				if br.off >= 4 {
+					v := br.in[br.off-4:]
+					v = v[:4]
+					low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
+					br.value |= uint64(low) << (br.bitsRead - 32)
+					br.bitsRead -= 32
+					br.off -= 4
+				} else {
+					for br.off > 0 {
+						br.value |= uint64(br.in[br.off-1]) << (br.bitsRead - 8)
+						br.bitsRead -= 8
+						br.off--
+					}
+				}
+			}
+			// end inline...
+			if offset >= len(out) {
+				return nil, errors.New("corruption detected: stream overrun 4")
+			}
+
+			// Read value and increment offset.
+			v := single[br.peekByteFast()>>shift].entry
+			nBits := uint8(v)
+			br.advance(nBits)
+			bitsLeft -= int(nBits)
+			out[offset] = uint8(v >> 8)
+			offset++
+		}
+		decoded += offset - dstEvery*i
+		err = br.close()
+		if err != nil {
+			return nil, err
+		}
+	}
+	if dstSize != decoded {
+		return nil, errors.New("corruption detected: short output block")
+	}
+	return dst, nil
+}
+
+// matches will compare a decoding table to a coding table.
+// Errors are written to the writer.
+// Nothing will be written if table is ok.
+func (s *Scratch) matches(ct cTable, w io.Writer) {
+	if s == nil || len(s.dt.single) == 0 {
+		return
+	}
+	dt := s.dt.single[:1<<s.actualTableLog]
+	tablelog := s.actualTableLog
+	ok := 0
+	broken := 0
+	for sym, enc := range ct {
+		errs := 0
+		broken++
+		if enc.nBits == 0 {
+			for _, dec := range dt {
+				if uint8(dec.entry>>8) == byte(sym) {
+					fmt.Fprintf(w, "symbol %x has decoder, but no encoder\n", sym)
+					errs++
+					break
+				}
+			}
+			if errs == 0 {
+				broken--
+			}
+			continue
+		}
+		// Unused bits in input
+		ub := tablelog - enc.nBits
+		top := enc.val << ub
+		// decoder looks at top bits.
+		dec := dt[top]
+		if uint8(dec.entry) != enc.nBits {
+			fmt.Fprintf(w, "symbol 0x%x bit size mismatch (enc: %d, dec:%d).\n", sym, enc.nBits, uint8(dec.entry))
+			errs++
+		}
+		if uint8(dec.entry>>8) != uint8(sym) {
+			fmt.Fprintf(w, "symbol 0x%x decoder output mismatch (enc: %d, dec:%d).\n", sym, sym, uint8(dec.entry>>8))
+			errs++
+		}
+		if errs > 0 {
+			fmt.Fprintf(w, "%d errros in base, stopping\n", errs)
+			continue
+		}
+		// Ensure that all combinations are covered.
+		for i := uint16(0); i < (1 << ub); i++ {
+			vval := top | i
+			dec := dt[vval]
+			if uint8(dec.entry) != enc.nBits {
+				fmt.Fprintf(w, "symbol 0x%x bit size mismatch (enc: %d, dec:%d).\n", vval, enc.nBits, uint8(dec.entry))
+				errs++
+			}
+			if uint8(dec.entry>>8) != uint8(sym) {
+				fmt.Fprintf(w, "symbol 0x%x decoder output mismatch (enc: %d, dec:%d).\n", vval, sym, uint8(dec.entry>>8))
+				errs++
+			}
+			if errs > 20 {
+				fmt.Fprintf(w, "%d errros, stopping\n", errs)
+				break
+			}
+		}
+		if errs == 0 {
+			ok++
+			broken--
+		}
+	}
+	if broken > 0 {
+		fmt.Fprintf(w, "%d broken, %d ok\n", broken, ok)
+	}
+}