Macaron 1.5 (#12596)

* update macaron to v1.5 of fork

* update macaron to v1.5 of fork

* test gzip PR

* add push method impl to context_tests

* use proper gzip commit

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

32 files changed, 2464 insertions, 575 deletions

diff --git a/vendor/github.com/klauspost/compress/flate/deflate.go b/vendor/github.com/klauspost/compress/flate/deflate.go
index 2b101d26b2..25dbe3e15f 100644
--- a/vendor/github.com/klauspost/compress/flate/deflate.go
+++ b/vendor/github.com/klauspost/compress/flate/deflate.go
@@ -80,9 +80,7 @@ type advancedState struct {
 	// deflate state
 	length         int
 	offset         int
-	hash           uint32
 	maxInsertIndex int
-	ii             uint16 // position of last match, intended to overflow to reset.
 
 	// Input hash chains
 	// hashHead[hashValue] contains the largest inputIndex with the specified hash value
@@ -97,6 +95,9 @@ type advancedState struct {
 	// input window: unprocessed data is window[index:windowEnd]
 	index     int
 	hashMatch [maxMatchLength + minMatchLength]uint32
+
+	hash uint32
+	ii   uint16 // position of last match, intended to overflow to reset.
 }
 
 type compressor struct {
@@ -107,18 +108,19 @@ type compressor struct {
 	// compression algorithm
 	fill func(*compressor, []byte) int // copy data to window
 	step func(*compressor)             // process window
-	sync bool                          // requesting flush
 
-	window        []byte
-	windowEnd     int
-	blockStart    int  // window index where current tokens start
-	byteAvailable bool // if true, still need to process window[index-1].
-	err           error
+	window     []byte
+	windowEnd  int
+	blockStart int // window index where current tokens start
+	err        error
 
 	// queued output tokens
 	tokens tokens
 	fast   fastEnc
 	state  *advancedState
+
+	sync          bool // requesting flush
+	byteAvailable bool // if true, still need to process window[index-1].
 }
 
 func (d *compressor) fillDeflate(b []byte) int {
diff --git a/vendor/github.com/klauspost/compress/flate/inflate.go b/vendor/github.com/klauspost/compress/flate/inflate.go
index 7f175a4ec2..3e4259f157 100644
--- a/vendor/github.com/klauspost/compress/flate/inflate.go
+++ b/vendor/github.com/klauspost/compress/flate/inflate.go
@@ -295,10 +295,6 @@ type decompressor struct {
 	r       Reader
 	roffset int64
 
-	// Input bits, in top of b.
-	b  uint32
-	nb uint
-
 	// Huffman decoders for literal/length, distance.
 	h1, h2 huffmanDecoder
 
@@ -309,19 +305,24 @@ type decompressor struct {
 	// Output history, buffer.
 	dict dictDecoder
 
-	// Temporary buffer (avoids repeated allocation).
-	buf [4]byte
-
 	// Next step in the decompression,
 	// and decompression state.
 	step      func(*decompressor)
 	stepState int
-	final     bool
 	err       error
 	toRead    []byte
 	hl, hd    *huffmanDecoder
 	copyLen   int
 	copyDist  int
+
+	// Temporary buffer (avoids repeated allocation).
+	buf [4]byte
+
+	// Input bits, in top of b.
+	b uint32
+
+	nb    uint
+	final bool
 }
 
 func (f *decompressor) nextBlock() {
diff --git a/vendor/github.com/klauspost/compress/fse/bitreader.go b/vendor/github.com/klauspost/compress/fse/bitreader.go
index b9db204f59..f65eb3909c 100644
--- a/vendor/github.com/klauspost/compress/fse/bitreader.go
+++ b/vendor/github.com/klauspost/compress/fse/bitreader.go
@@ -6,6 +6,7 @@
 package fse
 
 import (
+	"encoding/binary"
 	"errors"
 	"io"
 )
@@ -34,8 +35,12 @@ func (b *bitReader) init(in []byte) error {
 	}
 	b.bitsRead = 64
 	b.value = 0
-	b.fill()
-	b.fill()
+	if len(in) >= 8 {
+		b.fillFastStart()
+	} else {
+		b.fill()
+		b.fill()
+	}
 	b.bitsRead += 8 - uint8(highBits(uint32(v)))
 	return nil
 }
@@ -63,8 +68,9 @@ func (b *bitReader) fillFast() {
 	if b.bitsRead < 32 {
 		return
 	}
-	// Do single re-slice to avoid bounds checks.
-	v := b.in[b.off-4 : b.off]
+	// 2 bounds checks.
+	v := b.in[b.off-4:]
+	v = v[:4]
 	low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
 	b.value = (b.value << 32) | uint64(low)
 	b.bitsRead -= 32
@@ -77,7 +83,8 @@ func (b *bitReader) fill() {
 		return
 	}
 	if b.off > 4 {
-		v := b.in[b.off-4 : b.off]
+		v := b.in[b.off-4:]
+		v = v[:4]
 		low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
 		b.value = (b.value << 32) | uint64(low)
 		b.bitsRead -= 32
@@ -91,9 +98,17 @@ func (b *bitReader) fill() {
 	}
 }
 
+// fillFastStart() assumes the bitreader is empty and there is at least 8 bytes to read.
+func (b *bitReader) fillFastStart() {
+	// Do single re-slice to avoid bounds checks.
+	b.value = binary.LittleEndian.Uint64(b.in[b.off-8:])
+	b.bitsRead = 0
+	b.off -= 8
+}
+
 // finished returns true if all bits have been read from the bit stream.
 func (b *bitReader) finished() bool {
-	return b.off == 0 && b.bitsRead >= 64
+	return b.bitsRead >= 64 && b.off == 0
 }
 
 // close the bitstream and returns an error if out-of-buffer reads occurred.
diff --git a/vendor/github.com/klauspost/compress/fse/bytereader.go b/vendor/github.com/klauspost/compress/fse/bytereader.go
index f228a46cdf..abade2d605 100644
--- a/vendor/github.com/klauspost/compress/fse/bytereader.go
+++ b/vendor/github.com/klauspost/compress/fse/bytereader.go
@@ -25,19 +25,10 @@ func (b *byteReader) advance(n uint) {
 	b.off += int(n)
 }
 
-// Int32 returns a little endian int32 starting at current offset.
-func (b byteReader) Int32() int32 {
-	b2 := b.b[b.off : b.off+4 : b.off+4]
-	v3 := int32(b2[3])
-	v2 := int32(b2[2])
-	v1 := int32(b2[1])
-	v0 := int32(b2[0])
-	return v0 | (v1 << 8) | (v2 << 16) | (v3 << 24)
-}
-
 // Uint32 returns a little endian uint32 starting at current offset.
 func (b byteReader) Uint32() uint32 {
-	b2 := b.b[b.off : b.off+4 : b.off+4]
+	b2 := b.b[b.off:]
+	b2 = b2[:4]
 	v3 := uint32(b2[3])
 	v2 := uint32(b2[2])
 	v1 := uint32(b2[1])
diff --git a/vendor/github.com/klauspost/compress/fse/fse.go b/vendor/github.com/klauspost/compress/fse/fse.go
index 075357b5b1..535cbadfde 100644
--- a/vendor/github.com/klauspost/compress/fse/fse.go
+++ b/vendor/github.com/klauspost/compress/fse/fse.go
@@ -44,18 +44,14 @@ var (
 // Scratch provides temporary storage for compression and decompression.
 type Scratch struct {
 	// Private
-	count          [maxSymbolValue + 1]uint32
-	norm           [maxSymbolValue + 1]int16
-	symbolLen      uint16 // Length of active part of the symbol table.
-	actualTableLog uint8  // Selected tablelog.
-	br             byteReader
-	bits           bitReader
-	bw             bitWriter
-	ct             cTable      // Compression tables.
-	decTable       []decSymbol // Decompression table.
-	zeroBits       bool        // no bits has prob > 50%.
-	clearCount     bool        // clear count
-	maxCount       int         // count of the most probable symbol
+	count    [maxSymbolValue + 1]uint32
+	norm     [maxSymbolValue + 1]int16
+	br       byteReader
+	bits     bitReader
+	bw       bitWriter
+	ct       cTable      // Compression tables.
+	decTable []decSymbol // Decompression table.
+	maxCount int         // count of the most probable symbol
 
 	// Per block parameters.
 	// These can be used to override compression parameters of the block.
@@ -68,17 +64,22 @@ type Scratch struct {
 	// and allocation will be avoided.
 	Out []byte
 
-	// MaxSymbolValue will override the maximum symbol value of the next block.
-	MaxSymbolValue uint8
-
-	// TableLog will attempt to override the tablelog for the next block.
-	TableLog uint8
-
 	// DecompressLimit limits the maximum decoded size acceptable.
 	// If > 0 decompression will stop when approximately this many bytes
 	// has been decoded.
 	// If 0, maximum size will be 2GB.
 	DecompressLimit int
+
+	symbolLen      uint16 // Length of active part of the symbol table.
+	actualTableLog uint8  // Selected tablelog.
+	zeroBits       bool   // no bits has prob > 50%.
+	clearCount     bool   // clear count
+
+	// MaxSymbolValue will override the maximum symbol value of the next block.
+	MaxSymbolValue uint8
+
+	// TableLog will attempt to override the tablelog for the next block.
+	TableLog uint8
 }
 
 // Histogram allows to populate the histogram and skip that step in the compression,
diff --git a/vendor/github.com/klauspost/compress/gzip/gzip.go b/vendor/github.com/klauspost/compress/gzip/gzip.go
index 6794cf48f4..26203851bd 100644
--- a/vendor/github.com/klauspost/compress/gzip/gzip.go
+++ b/vendor/github.com/klauspost/compress/gzip/gzip.go
@@ -37,13 +37,13 @@ type Writer struct {
 	Header      // written at first call to Write, Flush, or Close
 	w           io.Writer
 	level       int
-	wroteHeader bool
+	err         error
 	compressor  *flate.Writer
 	digest      uint32 // CRC-32, IEEE polynomial (section 8)
 	size        uint32 // Uncompressed size (section 2.3.1)
+	wroteHeader bool
 	closed      bool
 	buf         [10]byte
-	err         error
 }
 
 // NewWriter returns a new Writer.
diff --git a/vendor/github.com/klauspost/compress/huff0/README.md b/vendor/github.com/klauspost/compress/huff0/README.md
index 0a8448ce9f..e12da4db2f 100644
--- a/vendor/github.com/klauspost/compress/huff0/README.md
+++ b/vendor/github.com/klauspost/compress/huff0/README.md
@@ -12,8 +12,6 @@ but it can be used as a secondary step to compressors (like Snappy) that does no
 

 * [Godoc documentation](https://godoc.org/github.com/klauspost/compress/huff0)

 

-THIS PACKAGE IS NOT CONSIDERED STABLE AND API OR ENCODING MAY CHANGE IN THE FUTURE.

-

 ## News

 

  * Mar 2018: First implementation released. Consider this beta software for now.

@@ -75,6 +73,8 @@ which can be given to the decompressor.
 Decompressing is done by calling the [`Decompress1X`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch.Decompress1X) 

 or [`Decompress4X`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch.Decompress4X) function.

 

+For concurrently decompressing content with a fixed table a stateless [`Decoder`](https://godoc.org/github.com/klauspost/compress/huff0#Decoder) can be requested which will remain correct as long as the scratch is unchanged. The capacity of the provided slice indicates the expected output size.

+

 You must provide the output from the compression stage, at exactly the size you got back. If you receive an error back

 your input was likely corrupted. 

 

@@ -84,4 +84,4 @@ There are no integrity checks, so relying on errors from the decompressor does n
 # Contributing

 

 Contributions are always welcome. Be aware that adding public functions will require good justification and breaking 

-changes will likely not be accepted. If in doubt open an issue before writing the PR.
\ No newline at end of file
+changes will likely not be accepted. If in doubt open an issue before writing the PR.

diff --git a/vendor/github.com/klauspost/compress/huff0/bitreader.go b/vendor/github.com/klauspost/compress/huff0/bitreader.go
index 7d0903c701..a4979e8868 100644
--- a/vendor/github.com/klauspost/compress/huff0/bitreader.go
+++ b/vendor/github.com/klauspost/compress/huff0/bitreader.go
@@ -6,6 +6,7 @@
 package huff0
 
 import (
+	"encoding/binary"
 	"errors"
 	"io"
 )
@@ -34,29 +35,16 @@ func (b *bitReader) init(in []byte) error {
 	}
 	b.bitsRead = 64
 	b.value = 0
-	b.fill()
-	b.fill()
+	if len(in) >= 8 {
+		b.fillFastStart()
+	} else {
+		b.fill()
+		b.fill()
+	}
 	b.bitsRead += 8 - uint8(highBit32(uint32(v)))
 	return nil
 }
 
-// getBits will return n bits. n can be 0.
-func (b *bitReader) getBits(n uint8) uint16 {
-	if n == 0 || b.bitsRead >= 64 {
-		return 0
-	}
-	return b.getBitsFast(n)
-}
-
-// getBitsFast requires that at least one bit is requested every time.
-// There are no checks if the buffer is filled.
-func (b *bitReader) getBitsFast(n uint8) uint16 {
-	const regMask = 64 - 1
-	v := uint16((b.value << (b.bitsRead & regMask)) >> ((regMask + 1 - n) & regMask))
-	b.bitsRead += n
-	return v
-}
-
 // peekBitsFast requires that at least one bit is requested every time.
 // There are no checks if the buffer is filled.
 func (b *bitReader) peekBitsFast(n uint8) uint16 {
@@ -71,21 +59,36 @@ func (b *bitReader) fillFast() {
 	if b.bitsRead < 32 {
 		return
 	}
-	// Do single re-slice to avoid bounds checks.
+
+	// 2 bounds checks.
 	v := b.in[b.off-4 : b.off]
+	v = v[:4]
 	low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
 	b.value = (b.value << 32) | uint64(low)
 	b.bitsRead -= 32
 	b.off -= 4
 }
 
+func (b *bitReader) advance(n uint8) {
+	b.bitsRead += n
+}
+
+// fillFastStart() assumes the bitreader is empty and there is at least 8 bytes to read.
+func (b *bitReader) fillFastStart() {
+	// Do single re-slice to avoid bounds checks.
+	b.value = binary.LittleEndian.Uint64(b.in[b.off-8:])
+	b.bitsRead = 0
+	b.off -= 8
+}
+
 // fill() will make sure at least 32 bits are available.
 func (b *bitReader) fill() {
 	if b.bitsRead < 32 {
 		return
 	}
 	if b.off > 4 {
-		v := b.in[b.off-4 : b.off]
+		v := b.in[b.off-4:]
+		v = v[:4]
 		low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
 		b.value = (b.value << 32) | uint64(low)
 		b.bitsRead -= 32
@@ -113,3 +116,214 @@ func (b *bitReader) close() error {
 	}
 	return nil
 }
+
+// bitReader reads a bitstream in reverse.
+// The last set bit indicates the start of the stream and is used
+// for aligning the input.
+type bitReaderBytes struct {
+	in       []byte
+	off      uint // next byte to read is at in[off - 1]
+	value    uint64
+	bitsRead uint8
+}
+
+// init initializes and resets the bit reader.
+func (b *bitReaderBytes) init(in []byte) error {
+	if len(in) < 1 {
+		return errors.New("corrupt stream: too short")
+	}
+	b.in = in
+	b.off = uint(len(in))
+	// The highest bit of the last byte indicates where to start
+	v := in[len(in)-1]
+	if v == 0 {
+		return errors.New("corrupt stream, did not find end of stream")
+	}
+	b.bitsRead = 64
+	b.value = 0
+	if len(in) >= 8 {
+		b.fillFastStart()
+	} else {
+		b.fill()
+		b.fill()
+	}
+	b.advance(8 - uint8(highBit32(uint32(v))))
+	return nil
+}
+
+// peekBitsFast requires that at least one bit is requested every time.
+// There are no checks if the buffer is filled.
+func (b *bitReaderBytes) peekByteFast() uint8 {
+	got := uint8(b.value >> 56)
+	return got
+}
+
+func (b *bitReaderBytes) advance(n uint8) {
+	b.bitsRead += n
+	b.value <<= n & 63
+}
+
+// fillFast() will make sure at least 32 bits are available.
+// There must be at least 4 bytes available.
+func (b *bitReaderBytes) fillFast() {
+	if b.bitsRead < 32 {
+		return
+	}
+
+	// 2 bounds checks.
+	v := b.in[b.off-4 : b.off]
+	v = v[:4]
+	low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
+	b.value |= uint64(low) << (b.bitsRead - 32)
+	b.bitsRead -= 32
+	b.off -= 4
+}
+
+// fillFastStart() assumes the bitReaderBytes is empty and there is at least 8 bytes to read.
+func (b *bitReaderBytes) fillFastStart() {
+	// Do single re-slice to avoid bounds checks.
+	b.value = binary.LittleEndian.Uint64(b.in[b.off-8:])
+	b.bitsRead = 0
+	b.off -= 8
+}
+
+// fill() will make sure at least 32 bits are available.
+func (b *bitReaderBytes) fill() {
+	if b.bitsRead < 32 {
+		return
+	}
+	if b.off > 4 {
+		v := b.in[b.off-4:]
+		v = v[:4]
+		low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
+		b.value |= uint64(low) << (b.bitsRead - 32)
+		b.bitsRead -= 32
+		b.off -= 4
+		return
+	}
+	for b.off > 0 {
+		b.value |= uint64(b.in[b.off-1]) << (b.bitsRead - 8)
+		b.bitsRead -= 8
+		b.off--
+	}
+}
+
+// finished returns true if all bits have been read from the bit stream.
+func (b *bitReaderBytes) finished() bool {
+	return b.off == 0 && b.bitsRead >= 64
+}
+
+// close the bitstream and returns an error if out-of-buffer reads occurred.
+func (b *bitReaderBytes) close() error {
+	// Release reference.
+	b.in = nil
+	if b.bitsRead > 64 {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+
+// bitReaderShifted reads a bitstream in reverse.
+// The last set bit indicates the start of the stream and is used
+// for aligning the input.
+type bitReaderShifted struct {
+	in       []byte
+	off      uint // next byte to read is at in[off - 1]
+	value    uint64
+	bitsRead uint8
+}
+
+// init initializes and resets the bit reader.
+func (b *bitReaderShifted) init(in []byte) error {
+	if len(in) < 1 {
+		return errors.New("corrupt stream: too short")
+	}
+	b.in = in
+	b.off = uint(len(in))
+	// The highest bit of the last byte indicates where to start
+	v := in[len(in)-1]
+	if v == 0 {
+		return errors.New("corrupt stream, did not find end of stream")
+	}
+	b.bitsRead = 64
+	b.value = 0
+	if len(in) >= 8 {
+		b.fillFastStart()
+	} else {
+		b.fill()
+		b.fill()
+	}
+	b.advance(8 - uint8(highBit32(uint32(v))))
+	return nil
+}
+
+// peekBitsFast requires that at least one bit is requested every time.
+// There are no checks if the buffer is filled.
+func (b *bitReaderShifted) peekBitsFast(n uint8) uint16 {
+	return uint16(b.value >> ((64 - n) & 63))
+}
+
+func (b *bitReaderShifted) advance(n uint8) {
+	b.bitsRead += n
+	b.value <<= n & 63
+}
+
+// fillFast() will make sure at least 32 bits are available.
+// There must be at least 4 bytes available.
+func (b *bitReaderShifted) fillFast() {
+	if b.bitsRead < 32 {
+		return
+	}
+
+	// 2 bounds checks.
+	v := b.in[b.off-4 : b.off]
+	v = v[:4]
+	low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
+	b.value |= uint64(low) << ((b.bitsRead - 32) & 63)
+	b.bitsRead -= 32
+	b.off -= 4
+}
+
+// fillFastStart() assumes the bitReaderShifted is empty and there is at least 8 bytes to read.
+func (b *bitReaderShifted) fillFastStart() {
+	// Do single re-slice to avoid bounds checks.
+	b.value = binary.LittleEndian.Uint64(b.in[b.off-8:])
+	b.bitsRead = 0
+	b.off -= 8
+}
+
+// fill() will make sure at least 32 bits are available.
+func (b *bitReaderShifted) fill() {
+	if b.bitsRead < 32 {
+		return
+	}
+	if b.off > 4 {
+		v := b.in[b.off-4:]
+		v = v[:4]
+		low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
+		b.value |= uint64(low) << ((b.bitsRead - 32) & 63)
+		b.bitsRead -= 32
+		b.off -= 4
+		return
+	}
+	for b.off > 0 {
+		b.value |= uint64(b.in[b.off-1]) << ((b.bitsRead - 8) & 63)
+		b.bitsRead -= 8
+		b.off--
+	}
+}
+
+// finished returns true if all bits have been read from the bit stream.
+func (b *bitReaderShifted) finished() bool {
+	return b.off == 0 && b.bitsRead >= 64
+}
+
+// close the bitstream and returns an error if out-of-buffer reads occurred.
+func (b *bitReaderShifted) close() error {
+	// Release reference.
+	b.in = nil
+	if b.bitsRead > 64 {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
diff --git a/vendor/github.com/klauspost/compress/huff0/bitwriter.go b/vendor/github.com/klauspost/compress/huff0/bitwriter.go
index bda4021efd..6bce4e87d4 100644
--- a/vendor/github.com/klauspost/compress/huff0/bitwriter.go
+++ b/vendor/github.com/klauspost/compress/huff0/bitwriter.go
@@ -43,6 +43,11 @@ func (b *bitWriter) addBits16Clean(value uint16, bits uint8) {
 func (b *bitWriter) encSymbol(ct cTable, symbol byte) {
 	enc := ct[symbol]
 	b.bitContainer |= uint64(enc.val) << (b.nBits & 63)
+	if false {
+		if enc.nBits == 0 {
+			panic("nbits 0")
+		}
+	}
 	b.nBits += enc.nBits
 }
 
@@ -54,6 +59,14 @@ func (b *bitWriter) encTwoSymbols(ct cTable, av, bv byte) {
 	sh := b.nBits & 63
 	combined := uint64(encA.val) | (uint64(encB.val) << (encA.nBits & 63))
 	b.bitContainer |= combined << sh
+	if false {
+		if encA.nBits == 0 {
+			panic("nbitsA 0")
+		}
+		if encB.nBits == 0 {
+			panic("nbitsB 0")
+		}
+	}
 	b.nBits += encA.nBits + encB.nBits
 }
 
diff --git a/vendor/github.com/klauspost/compress/huff0/compress.go b/vendor/github.com/klauspost/compress/huff0/compress.go
index 0843cb014f..f9ed5f8306 100644
--- a/vendor/github.com/klauspost/compress/huff0/compress.go
+++ b/vendor/github.com/klauspost/compress/huff0/compress.go
@@ -77,8 +77,11 @@ func compress(in []byte, s *Scratch, compressor func(src []byte) ([]byte, error)
 		// Each symbol present maximum once or too well distributed.
 		return nil, false, ErrIncompressible
 	}
-
-	if s.Reuse == ReusePolicyPrefer && canReuse {
+	if s.Reuse == ReusePolicyMust && !canReuse {
+		// We must reuse, but we can't.
+		return nil, false, ErrIncompressible
+	}
+	if (s.Reuse == ReusePolicyPrefer || s.Reuse == ReusePolicyMust) && canReuse {
 		keepTable := s.cTable
 		keepTL := s.actualTableLog
 		s.cTable = s.prevTable
@@ -90,6 +93,9 @@ func compress(in []byte, s *Scratch, compressor func(src []byte) ([]byte, error)
 			s.OutData = s.Out
 			return s.Out, true, nil
 		}
+		if s.Reuse == ReusePolicyMust {
+			return nil, false, ErrIncompressible
+		}
 		// Do not attempt to re-use later.
 		s.prevTable = s.prevTable[:0]
 	}
diff --git a/vendor/github.com/klauspost/compress/huff0/decompress.go b/vendor/github.com/klauspost/compress/huff0/decompress.go
index 97ae66a4ac..41703bba4d 100644
--- a/vendor/github.com/klauspost/compress/huff0/decompress.go
+++ b/vendor/github.com/klauspost/compress/huff0/decompress.go
@@ -25,11 +25,14 @@ type dEntryDouble struct {
 	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 decoding input using this table.
+// 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 {
@@ -55,8 +58,8 @@ func ReadTable(in []byte, s *Scratch) (s2 *Scratch, remain []byte, err error) {
 		s.symbolLen = uint16(oSize)
 		in = in[iSize:]
 	} else {
-		if len(in) <= int(iSize) {
-			return s, nil, errors.New("input too small for table")
+		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
@@ -83,6 +86,7 @@ func ReadTable(in []byte, s *Scratch) (s2 *Scratch, remain []byte, err error) {
 		}
 		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 {
@@ -134,20 +138,40 @@ func ReadTable(in []byte, s *Scratch) (s2 *Scratch, remain []byte, err error) {
 	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),
 		}
-		single := s.dt.single[rankStats[w] : rankStats[w]+length]
+
+		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
 		}
-		rankStats[w] += length
+		*rank += length
 	}
+
 	return s, in, nil
 }
 
@@ -155,237 +179,905 @@ func ReadTable(in []byte, s *Scratch) (s2 *Scratch, remain []byte, err error) {
 // 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 len(s.dt.single) == 0 {
-		return nil, errors.New("no table loaded")
+	if cap(s.Out) < s.MaxDecodedSize {
+		s.Out = make([]byte, s.MaxDecodedSize)
 	}
-	var br bitReader
-	err = br.init(in)
-	if err != nil {
-		return nil, err
+	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,
 	}
-	s.Out = s.Out[:0]
+}
 
-	decode := func() byte {
-		val := br.peekBitsFast(s.actualTableLog) /* note : actualTableLog >= 1 */
-		v := s.dt.single[val]
-		br.bitsRead += uint8(v.entry)
-		return uint8(v.entry >> 8)
+// 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")
 	}
-	hasDec := func(v dEntrySingle) byte {
-		br.bitsRead += uint8(v.entry)
-		return uint8(v.entry >> 8)
+	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 := s.dt.single[:tlSize]
+	dt := d.dt.single[:tlSize]
 
 	// Use temp table to avoid bound checks/append penalty.
-	var tmp = s.huffWeight[:256]
+	var buf [256]byte
 	var off uint8
 
 	for br.off >= 8 {
 		br.fillFast()
-		tmp[off+0] = hasDec(dt[br.peekBitsFast(s.actualTableLog)&tlMask])
-		tmp[off+1] = hasDec(dt[br.peekBitsFast(s.actualTableLog)&tlMask])
+		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()
-		tmp[off+2] = hasDec(dt[br.peekBitsFast(s.actualTableLog)&tlMask])
-		tmp[off+3] = hasDec(dt[br.peekBitsFast(s.actualTableLog)&tlMask])
+
+		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(s.Out)+256 > s.MaxDecodedSize {
+			if len(dst)+256 > maxDecodedSize {
 				br.close()
 				return nil, ErrMaxDecodedSizeExceeded
 			}
-			s.Out = append(s.Out, tmp...)
+			dst = append(dst, buf[:]...)
 		}
 	}
 
-	if len(s.Out)+int(off) > s.MaxDecodedSize {
+	if len(dst)+int(off) > maxDecodedSize {
 		br.close()
 		return nil, ErrMaxDecodedSizeExceeded
 	}
-	s.Out = append(s.Out, tmp[:off]...)
+	dst = append(dst, buf[:off]...)
 
-	for !br.finished() {
+	// br < 8, so uint8 is fine
+	bitsLeft := uint8(br.off)*8 + 64 - br.bitsRead
+	for bitsLeft > 0 {
 		br.fill()
-		if len(s.Out) >= s.MaxDecodedSize {
+		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
 		}
-		s.Out = append(s.Out, decode())
+		v := dt[br.peekByteFast()>>shift]
+		nBits := uint8(v.entry)
+		br.advance(nBits)
+		bitsLeft -= int8(nBits)
+		dst = append(dst, uint8(v.entry>>8))
 	}
-	return s.Out, br.close()
+	return dst, br.close()
 }
 
 // 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.
-func (s *Scratch) Decompress4X(in []byte, dstSize int) (out []byte, err error) {
-	if len(s.dt.single) == 0 {
+// 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(in) < 6+(4*1) {
+	if len(src) < 6+(4*1) {
 		return nil, errors.New("input too small")
 	}
-	if dstSize > s.MaxDecodedSize {
-		return nil, ErrMaxDecodedSizeExceeded
+	if use8BitTables && d.actualTableLog <= 8 {
+		return d.decompress4X8bit(dst, src)
 	}
-	// TODO: We do not detect when we overrun a buffer, except if the last one does.
 
-	var br [4]bitReader
+	var br [4]bitReaderShifted
 	start := 6
 	for i := 0; i < 3; i++ {
-		length := int(in[i*2]) | (int(in[i*2+1]) << 8)
-		if start+length >= len(in) {
+		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(in[start : start+length])
+		err := br[i].init(src[start : start+length])
 		if err != nil {
 			return nil, err
 		}
 		start += length
 	}
-	err = br[3].init(in[start:])
+	err := br[3].init(src[start:])
 	if err != nil {
 		return nil, err
 	}
 
-	// Prepare output
-	if cap(s.Out) < dstSize {
-		s.Out = make([]byte, 0, dstSize)
-	}
-	s.Out = s.Out[:dstSize]
 	// destination, offset to match first output
-	dstOut := s.Out
+	dstSize := cap(dst)
+	dst = dst[:dstSize]
+	out := dst
 	dstEvery := (dstSize + 3) / 4
 
 	const tlSize = 1 << tableLogMax
 	const tlMask = tlSize - 1
-	single := s.dt.single[:tlSize]
-
-	decode := func(br *bitReader) byte {
-		val := br.peekBitsFast(s.actualTableLog) /* note : actualTableLog >= 1 */
-		v := single[val&tlMask]
-		br.bitsRead += uint8(v.entry)
-		return uint8(v.entry >> 8)
-	}
+	single := d.dt.single[:tlSize]
 
 	// Use temp table to avoid bound checks/append penalty.
-	var tmp = s.huffWeight[:256]
+	var buf [256]byte
 	var off uint8
 	var decoded int
 
 	// Decode 2 values from each decoder/loop.
 	const bufoff = 256 / 4
-bigloop:
 	for {
-		for i := range br {
-			br := &br[i]
-			if br.off < 4 {
-				break bigloop
-			}
-			br.fillFast()
+		if br[0].off < 4 || br[1].off < 4 || br[2].off < 4 || br[3].off < 4 {
+			break
 		}
 
 		{
 			const stream = 0
-			val := br[stream].peekBitsFast(s.actualTableLog)
+			const stream2 = 1
+			br[stream].fillFast()
+			br[stream2].fillFast()
+
+			val := br[stream].peekBitsFast(d.actualTableLog)
 			v := single[val&tlMask]
-			br[stream].bitsRead += uint8(v.entry)
+			br[stream].advance(uint8(v.entry))
+			buf[off+bufoff*stream] = uint8(v.entry >> 8)
 
-			val2 := br[stream].peekBitsFast(s.actualTableLog)
+			val2 := br[stream2].peekBitsFast(d.actualTableLog)
 			v2 := single[val2&tlMask]
-			tmp[off+bufoff*stream+1] = uint8(v2.entry >> 8)
-			tmp[off+bufoff*stream] = uint8(v.entry >> 8)
-			br[stream].bitsRead += uint8(v2.entry)
+			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 = 1
-			val := br[stream].peekBitsFast(s.actualTableLog)
+			const stream = 2
+			const stream2 = 3
+			br[stream].fillFast()
+			br[stream2].fillFast()
+
+			val := br[stream].peekBitsFast(d.actualTableLog)
 			v := single[val&tlMask]
-			br[stream].bitsRead += uint8(v.entry)
+			br[stream].advance(uint8(v.entry))
+			buf[off+bufoff*stream] = uint8(v.entry >> 8)
 
-			val2 := br[stream].peekBitsFast(s.actualTableLog)
+			val2 := br[stream2].peekBitsFast(d.actualTableLog)
 			v2 := single[val2&tlMask]
-			tmp[off+bufoff*stream+1] = uint8(v2.entry >> 8)
-			tmp[off+bufoff*stream] = uint8(v.entry >> 8)
-			br[stream].bitsRead += uint8(v2.entry)
+			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
-			val := br[stream].peekBitsFast(s.actualTableLog)
-			v := single[val&tlMask]
-			br[stream].bitsRead += uint8(v.entry)
+			const stream2 = 3
+			br[stream].fillFast()
+			br[stream2].fillFast()
 
-			val2 := br[stream].peekBitsFast(s.actualTableLog)
-			v2 := single[val2&tlMask]
-			tmp[off+bufoff*stream+1] = uint8(v2.entry >> 8)
-			tmp[off+bufoff*stream] = uint8(v.entry >> 8)
-			br[stream].bitsRead += uint8(v2.entry)
+			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
 		}
 
 		{
-			const stream = 3
-			val := br[stream].peekBitsFast(s.actualTableLog)
-			v := single[val&tlMask]
-			br[stream].bitsRead += uint8(v.entry)
+			// Interleave 2 decodes.
+			const stream = 0
+			const stream2 = 1
+			br[stream].fillFast()
+			br[stream2].fillFast()
 
-			val2 := br[stream].peekBitsFast(s.actualTableLog)
-			v2 := single[val2&tlMask]
-			tmp[off+bufoff*stream+1] = uint8(v2.entry >> 8)
-			tmp[off+bufoff*stream] = uint8(v.entry >> 8)
-			br[stream].bitsRead += uint8(v2.entry)
+			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 += 2
+		{
+			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(dstOut, tmp[:bufoff])
-			copy(dstOut[dstEvery:], tmp[bufoff:bufoff*2])
-			copy(dstOut[dstEvery*2:], tmp[bufoff*2:bufoff*3])
-			copy(dstOut[dstEvery*3:], tmp[bufoff*3:bufoff*4])
+			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
-			dstOut = dstOut[bufoff:]
+			out = out[bufoff:]
 			decoded += 256
 			// There must at least be 3 buffers left.
-			if len(dstOut) < dstEvery*3 {
+			if len(out) < dstEvery*3 {
 				return nil, errors.New("corruption detected: stream overrun 2")
 			}
 		}
 	}
 	if off > 0 {
 		ioff := int(off)
-		if len(dstOut) < dstEvery*3+ioff {
+		if len(out) < dstEvery*3+ioff {
 			return nil, errors.New("corruption detected: stream overrun 3")
 		}
-		copy(dstOut, tmp[:off])
-		copy(dstOut[dstEvery:dstEvery+ioff], tmp[bufoff:bufoff*2])
-		copy(dstOut[dstEvery*2:dstEvery*2+ioff], tmp[bufoff*2:bufoff*3])
-		copy(dstOut[dstEvery*3:dstEvery*3+ioff], tmp[bufoff*3:bufoff*4])
+		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
-		dstOut = dstOut[off:]
+		out = out[off:]
 	}
 
 	// Decode remaining.
 	for i := range br {
 		offset := dstEvery * i
 		br := &br[i]
-		for !br.finished() {
-			br.fill()
-			if offset >= len(dstOut) {
+		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")
 			}
-			dstOut[offset] = decode(br)
+
+			// 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
@@ -397,7 +1089,7 @@ bigloop:
 	if dstSize != decoded {
 		return nil, errors.New("corruption detected: short output block")
 	}
-	return s.Out, nil
+	return dst, nil
 }
 
 // matches will compare a decoding table to a coding table.
diff --git a/vendor/github.com/klauspost/compress/huff0/huff0.go b/vendor/github.com/klauspost/compress/huff0/huff0.go
index 53249df056..5dd66854b0 100644
--- a/vendor/github.com/klauspost/compress/huff0/huff0.go
+++ b/vendor/github.com/klauspost/compress/huff0/huff0.go
@@ -55,6 +55,9 @@ const (
 	// ReusePolicyNone will disable re-use of tables.
 	// This is slightly faster than ReusePolicyAllow but may produce larger output.
 	ReusePolicyNone
+
+	// ReusePolicyMust must allow reuse and produce smaller output.
+	ReusePolicyMust
 )
 
 type Scratch struct {
@@ -79,6 +82,13 @@ type Scratch struct {
 	// Slice of the returned data.
 	OutData []byte
 
+	// MaxDecodedSize will set the maximum allowed output size.
+	// This value will automatically be set to BlockSizeMax if not set.
+	// Decoders will return ErrMaxDecodedSizeExceeded is this limit is exceeded.
+	MaxDecodedSize int
+
+	br byteReader
+
 	// MaxSymbolValue will override the maximum symbol value of the next block.
 	MaxSymbolValue uint8
 
@@ -95,12 +105,6 @@ type Scratch struct {
 	// If WantLogLess == 0 any improvement will do.
 	WantLogLess uint8
 
-	// MaxDecodedSize will set the maximum allowed output size.
-	// This value will automatically be set to BlockSizeMax if not set.
-	// Decoders will return ErrMaxDecodedSizeExceeded is this limit is exceeded.
-	MaxDecodedSize int
-
-	br             byteReader
 	symbolLen      uint16 // Length of active part of the symbol table.
 	maxCount       int    // count of the most probable symbol
 	clearCount     bool   // clear count
diff --git a/vendor/github.com/klauspost/compress/zstd/README.md b/vendor/github.com/klauspost/compress/zstd/README.md
index bc977a3023..ac3640dc90 100644
--- a/vendor/github.com/klauspost/compress/zstd/README.md
+++ b/vendor/github.com/klauspost/compress/zstd/README.md
@@ -5,11 +5,9 @@ It offers a very wide range of compression / speed trade-off, while being backed
 A high performance compression algorithm is implemented. For now focused on speed. 
 
 This package provides [compression](#Compressor) to and [decompression](#Decompressor) of Zstandard content. 
-Note that custom dictionaries are not supported yet, so if your code relies on that, 
-you cannot use the package as-is.
+Note that custom dictionaries are only supported for decompression.
 
 This package is pure Go and without use of "unsafe". 
-If a significant speedup can be achieved using "unsafe", it may be added as an option later.
 
 The `zstd` package is provided as open source software using a Go standard license.
 
@@ -142,80 +140,96 @@ Using the Encoder for both a stream and individual blocks concurrently is safe.
 I have collected some speed examples to compare speed and compression against other compressors.
 
 * `file` is the input file.
-* `out` is the compressor used. `zskp` is this package. `gzstd` is gzip standard library. `zstd` is the Datadog cgo library.
+* `out` is the compressor used. `zskp` is this package. `zstd` is the Datadog cgo library. `gzstd/gzkp` is gzip standard and this library.
 * `level` is the compression level used. For `zskp` level 1 is "fastest", level 2 is "default".
 * `insize`/`outsize` is the input/output size.
 * `millis` is the number of milliseconds used for compression.
 * `mb/s` is megabytes (2^20 bytes) per second.
 
 ```
-The test data for the Large Text Compression Benchmark is the first
-10^9 bytes of the English Wikipedia dump on Mar. 3, 2006.
-http://mattmahoney.net/dc/textdata.html
-
-file    out     level   insize  outsize     millis  mb/s
-enwik9  zskp    1   1000000000  343833033   5840    163.30
-enwik9  zskp    2   1000000000  317822183   8449    112.87
-enwik9  gzstd   1   1000000000  382578136   13627   69.98
-enwik9  gzstd   3   1000000000  349139651   22344   42.68
-enwik9  zstd    1   1000000000  357416379   4838    197.12
-enwik9  zstd    3   1000000000  313734522   7556    126.21
+Silesia Corpus:
+http://sun.aei.polsl.pl/~sdeor/corpus/silesia.zip
 
-GOB stream of binary data. Highly compressible.
-https://files.klauspost.com/compress/gob-stream.7z
+This package:
+file    out     level   insize      outsize     millis  mb/s
+silesia.tar zskp    1   211947520   73101992    643     313.87
+silesia.tar zskp    2   211947520   67504318    969     208.38
+silesia.tar zskp    3   211947520   65177448    1899    106.44
 
-file        out level   insize      outsize     millis  mb/s
-gob-stream  zskp    1   1911399616  234981983   5100    357.42
-gob-stream  zskp    2   1911399616  208674003   6698    272.15
-gob-stream  gzstd   1   1911399616  357382641   14727   123.78
-gob-stream  gzstd   3   1911399616  327835097   17005   107.19
-gob-stream  zstd    1   1911399616  250787165   4075    447.22
-gob-stream  zstd    3   1911399616  208191888   5511    330.77
-
-Highly compressible JSON file. Similar to logs in a lot of ways.
-https://files.klauspost.com/compress/adresser.001.gz
-
-file            out level   insize      outsize     millis  mb/s
-adresser.001    zskp    1   1073741824  18510122    1477    692.83
-adresser.001    zskp    2   1073741824  19831697    1705    600.59
-adresser.001    gzstd   1   1073741824  47755503    3079    332.47
-adresser.001    gzstd   3   1073741824  40052381    3051    335.63
-adresser.001    zstd    1   1073741824  16135896    994     1030.18
-adresser.001    zstd    3   1073741824  17794465    905     1131.49
+cgo zstd:
+silesia.tar zstd    1   211947520   73605392    543     371.56
+silesia.tar zstd    3   211947520   66793289    864     233.68
+silesia.tar zstd    6   211947520   62916450    1913    105.66
 
-VM Image, Linux mint with a few installed applications:
-https://files.klauspost.com/compress/rawstudio-mint14.7z
+gzip, stdlib/this package:
+silesia.tar gzstd   1   211947520   80007735    1654    122.21
+silesia.tar gzkp    1   211947520   80369488    1168    173.06
 
-file    out level   insize  outsize millis  mb/s
-rawstudio-mint14.tar    zskp    1   8558382592  3648168838  33398   244.38
-rawstudio-mint14.tar    zskp    2   8558382592  3376721436  50962   160.16
-rawstudio-mint14.tar    gzstd   1   8558382592  3926257486  84712   96.35
-rawstudio-mint14.tar    gzstd   3   8558382592  3740711978  176344  46.28
-rawstudio-mint14.tar    zstd    1   8558382592  3607859742  27903   292.51
-rawstudio-mint14.tar    zstd    3   8558382592  3341710879  46700   174.77
+GOB stream of binary data. Highly compressible.
+https://files.klauspost.com/compress/gob-stream.7z
 
+file        out     level   insize  outsize     millis  mb/s
+gob-stream  zskp    1   1911399616  235022249   3088    590.30
+gob-stream  zskp    2   1911399616  205669791   3786    481.34
+gob-stream  zskp    3   1911399616  185792019   9324    195.48
+gob-stream  zstd    1   1911399616  249810424   2637    691.26
+gob-stream  zstd    3   1911399616  208192146   3490    522.31
+gob-stream  zstd    6   1911399616  193632038   6687    272.56
+gob-stream  gzstd   1   1911399616  357382641   10251   177.82
+gob-stream  gzkp    1   1911399616  362156523   5695    320.08
 
-The test data is designed to test archivers in realistic backup scenarios.
-http://mattmahoney.net/dc/10gb.html
+The test data for the Large Text Compression Benchmark is the first
+10^9 bytes of the English Wikipedia dump on Mar. 3, 2006.
+http://mattmahoney.net/dc/textdata.html
 
-file    out level   insize  outsize millis  mb/s
-10gb.tar    zskp    1   10065157632 4883149814  45715   209.97
-10gb.tar    zskp    2   10065157632 4638110010  60970   157.44
-10gb.tar    gzstd   1   10065157632 5198296126  97769   98.18
-10gb.tar    gzstd   3   10065157632 4932665487  313427  30.63
-10gb.tar    zstd    1   10065157632 4940796535  40391   237.65
-10gb.tar    zstd    3   10065157632 4638618579  52911   181.42
+file    out level   insize      outsize     millis  mb/s
+enwik9  zskp    1   1000000000  343848582   3609    264.18
+enwik9  zskp    2   1000000000  317276632   5746    165.97
+enwik9  zskp    3   1000000000  294540704   11725   81.34
+enwik9  zstd    1   1000000000  358072021   3110    306.65
+enwik9  zstd    3   1000000000  313734672   4784    199.35
+enwik9  zstd    6   1000000000  295138875   10290   92.68
+enwik9  gzstd   1   1000000000  382578136   9604    99.30
+enwik9  gzkp    1   1000000000  383825945   6544    145.73
+
+Highly compressible JSON file.
+https://files.klauspost.com/compress/github-june-2days-2019.json.zst
+
+file                        out level   insize      outsize     millis  mb/s
+github-june-2days-2019.json zskp    1   6273951764  699045015   10620   563.40
+github-june-2days-2019.json zskp    2   6273951764  617881763   11687   511.96
+github-june-2days-2019.json zskp    3   6273951764  537511906   29252   204.54
+github-june-2days-2019.json zstd    1   6273951764  766284037   8450    708.00
+github-june-2days-2019.json zstd    3   6273951764  661889476   10927   547.57
+github-june-2days-2019.json zstd    6   6273951764  642756859   22996   260.18
+github-june-2days-2019.json gzstd   1   6273951764  1164400847  29948   199.79
+github-june-2days-2019.json gzkp    1   6273951764  1128755542  19236   311.03
 
-Silesia Corpus:
-http://sun.aei.polsl.pl/~sdeor/corpus/silesia.zip
+VM Image, Linux mint with a few installed applications:
+https://files.klauspost.com/compress/rawstudio-mint14.7z
 
-file    out level   insize  outsize millis  mb/s
-silesia.tar zskp    1   211947520   73025800    1108    182.26
-silesia.tar zskp    2   211947520   67674684    1599    126.41
-silesia.tar gzstd   1   211947520   80007735    2515    80.37
-silesia.tar gzstd   3   211947520   73133380    4259    47.45
-silesia.tar zstd    1   211947520   73513991    933     216.64
-silesia.tar zstd    3   211947520   66793301    1377    146.79
+file                    out level   insize      outsize     millis  mb/s
+rawstudio-mint14.tar    zskp    1   8558382592  3667489370  20210   403.84
+rawstudio-mint14.tar    zskp    2   8558382592  3364592300  31873   256.07
+rawstudio-mint14.tar    zskp    3   8558382592  3224594213  71751   113.75
+rawstudio-mint14.tar    zstd    1   8558382592  3609250104  17136   476.27
+rawstudio-mint14.tar    zstd    3   8558382592  3341679997  29262   278.92
+rawstudio-mint14.tar    zstd    6   8558382592  3235846406  77904   104.77
+rawstudio-mint14.tar    gzstd   1   8558382592  3926257486  57722   141.40
+rawstudio-mint14.tar    gzkp    1   8558382592  3970463184  41749   195.49
+
+CSV data:
+https://files.klauspost.com/compress/nyc-taxi-data-10M.csv.zst
+
+file                    out level   insize      outsize     millis  mb/s
+nyc-taxi-data-10M.csv   zskp    1   3325605752  641339945   8925    355.35
+nyc-taxi-data-10M.csv   zskp    2   3325605752  591748091   11268   281.44
+nyc-taxi-data-10M.csv   zskp    3   3325605752  538490114   19880   159.53
+nyc-taxi-data-10M.csv   zstd    1   3325605752  687399637   8233    385.18
+nyc-taxi-data-10M.csv   zstd    3   3325605752  598514411   10065   315.07
+nyc-taxi-data-10M.csv   zstd    6   3325605752  570522953   20038   158.27
+nyc-taxi-data-10M.csv   gzstd   1   3325605752  928656485   23876   132.83
+nyc-taxi-data-10M.csv   gzkp    1   3325605752  924718719   16388   193.53
 ```
 
 ### Converters
@@ -309,6 +323,20 @@ The decoder can be used for *concurrent* decompression of multiple buffers.
 It will only allow a certain number of concurrent operations to run. 
 To tweak that yourself use the `WithDecoderConcurrency(n)` option when creating the decoder.   
 
+### Dictionaries
+
+Data compressed with [dictionaries](https://github.com/facebook/zstd#the-case-for-small-data-compression) can be decompressed.
+
+Dictionaries are added individually to Decoders.
+Dictionaries are generated by the `zstd --train` command and contains an initial state for the decoder.
+To add a dictionary use the `WithDecoderDicts(dicts ...[]byte)` option with the dictionary data.
+Several dictionaries can be added at once.
+
+The dictionary will be used automatically for the data that specifies them.
+A re-used Decoder will still contain the dictionaries registered.
+
+When registering multiple dictionaries with the same ID, the last one will be used.
+
 ### Allocation-less operation
 
 The decoder has been designed to operate without allocations after a warmup. 
@@ -350,36 +378,42 @@ These are some examples of performance compared to [datadog cgo library](https:/
 The first two are streaming decodes and the last are smaller inputs. 
  
 ```
-BenchmarkDecoderSilesia-8             20       642550210 ns/op   329.85 MB/s      3101 B/op        8 allocs/op
-BenchmarkDecoderSilesiaCgo-8         100       384930000 ns/op   550.61 MB/s    451878 B/op     9713 allocs/op
-
-BenchmarkDecoderEnwik9-2              10        3146000080 ns/op         317.86 MB/s        2649 B/op          9 allocs/op
-BenchmarkDecoderEnwik9Cgo-2           20        1905900000 ns/op         524.69 MB/s     1125120 B/op      45785 allocs/op
-
-BenchmarkDecoder_DecodeAll/z000000.zst-8               200     7049994 ns/op   138.26 MB/s        40 B/op        2 allocs/op
-BenchmarkDecoder_DecodeAll/z000001.zst-8            100000       19560 ns/op    97.49 MB/s        40 B/op        2 allocs/op
-BenchmarkDecoder_DecodeAll/z000002.zst-8              5000      297599 ns/op   236.99 MB/s        40 B/op        2 allocs/op
-BenchmarkDecoder_DecodeAll/z000003.zst-8              2000      725502 ns/op   141.17 MB/s        40 B/op        2 allocs/op
-BenchmarkDecoder_DecodeAll/z000004.zst-8            200000        9314 ns/op    54.54 MB/s        40 B/op        2 allocs/op
-BenchmarkDecoder_DecodeAll/z000005.zst-8             10000      137500 ns/op   104.72 MB/s        40 B/op        2 allocs/op
-BenchmarkDecoder_DecodeAll/z000006.zst-8               500     2316009 ns/op   206.06 MB/s        40 B/op        2 allocs/op
-BenchmarkDecoder_DecodeAll/z000007.zst-8             20000       64499 ns/op   344.90 MB/s        40 B/op        2 allocs/op
-BenchmarkDecoder_DecodeAll/z000008.zst-8             50000       24900 ns/op   219.56 MB/s        40 B/op        2 allocs/op
-BenchmarkDecoder_DecodeAll/z000009.zst-8              1000     2348999 ns/op   154.01 MB/s        40 B/op        2 allocs/op
-
-BenchmarkDecoder_DecodeAllCgo/z000000.zst-8            500     4268005 ns/op   228.38 MB/s   1228849 B/op        3 allocs/op
-BenchmarkDecoder_DecodeAllCgo/z000001.zst-8         100000       15250 ns/op   125.05 MB/s      2096 B/op        3 allocs/op
-BenchmarkDecoder_DecodeAllCgo/z000002.zst-8          10000      147399 ns/op   478.49 MB/s     73776 B/op        3 allocs/op
-BenchmarkDecoder_DecodeAllCgo/z000003.zst-8           5000      320798 ns/op   319.27 MB/s    139312 B/op        3 allocs/op
-BenchmarkDecoder_DecodeAllCgo/z000004.zst-8         200000       10004 ns/op    50.77 MB/s       560 B/op        3 allocs/op
-BenchmarkDecoder_DecodeAllCgo/z000005.zst-8          20000       73599 ns/op   195.64 MB/s     19120 B/op        3 allocs/op
-BenchmarkDecoder_DecodeAllCgo/z000006.zst-8           1000     1119003 ns/op   426.48 MB/s    557104 B/op        3 allocs/op
-BenchmarkDecoder_DecodeAllCgo/z000007.zst-8          20000      103450 ns/op   215.04 MB/s     71296 B/op        9 allocs/op
-BenchmarkDecoder_DecodeAllCgo/z000008.zst-8         100000       20130 ns/op   271.58 MB/s      6192 B/op        3 allocs/op
-BenchmarkDecoder_DecodeAllCgo/z000009.zst-8           2000     1123500 ns/op   322.00 MB/s    368688 B/op        3 allocs/op
+BenchmarkDecoderSilesia-8                          3     385000067 ns/op     550.51 MB/s        5498 B/op          8 allocs/op
+BenchmarkDecoderSilesiaCgo-8                       6     197666567 ns/op    1072.25 MB/s      270672 B/op          8 allocs/op
+
+BenchmarkDecoderEnwik9-8                           1    2027001600 ns/op     493.34 MB/s       10496 B/op         18 allocs/op
+BenchmarkDecoderEnwik9Cgo-8                        2     979499200 ns/op    1020.93 MB/s      270672 B/op          8 allocs/op
+
+Concurrent performance:
+
+BenchmarkDecoder_DecodeAllParallel/kppkn.gtb.zst-16                28915         42469 ns/op    4340.07 MB/s         114 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallel/geo.protodata.zst-16           116505          9965 ns/op    11900.16 MB/s         16 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallel/plrabn12.txt.zst-16              8952        134272 ns/op    3588.70 MB/s         915 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallel/lcet10.txt.zst-16               11820        102538 ns/op    4161.90 MB/s         594 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallel/asyoulik.txt.zst-16             34782         34184 ns/op    3661.88 MB/s          60 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallel/alice29.txt.zst-16              27712         43447 ns/op    3500.58 MB/s          99 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallel/html_x_4.zst-16                 62826         18750 ns/op    21845.10 MB/s        104 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallel/paper-100k.pdf.zst-16          631545          1794 ns/op    57078.74 MB/s          2 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallel/fireworks.jpeg.zst-16         1690140           712 ns/op    172938.13 MB/s         1 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallel/urls.10K.zst-16                 10432        113593 ns/op    6180.73 MB/s        1143 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallel/html.zst-16                    113206         10671 ns/op    9596.27 MB/s          15 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallel/comp-data.bin.zst-16          1530615           779 ns/op    5229.49 MB/s           0 B/op          0 allocs/op
+
+BenchmarkDecoder_DecodeAllParallelCgo/kppkn.gtb.zst-16             65217         16192 ns/op    11383.34 MB/s         46 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallelCgo/geo.protodata.zst-16        292671          4039 ns/op    29363.19 MB/s          6 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallelCgo/plrabn12.txt.zst-16          26314         46021 ns/op    10470.43 MB/s        293 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallelCgo/lcet10.txt.zst-16            33897         34900 ns/op    12227.96 MB/s        205 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallelCgo/asyoulik.txt.zst-16         104348         11433 ns/op    10949.01 MB/s         20 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallelCgo/alice29.txt.zst-16           75949         15510 ns/op    9805.60 MB/s          32 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallelCgo/html_x_4.zst-16             173910          6756 ns/op    60624.29 MB/s         37 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallelCgo/paper-100k.pdf.zst-16       923076          1339 ns/op    76474.87 MB/s          1 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallelCgo/fireworks.jpeg.zst-16       922920          1351 ns/op    91102.57 MB/s          2 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallelCgo/urls.10K.zst-16              27649         43618 ns/op    16096.19 MB/s        407 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallelCgo/html.zst-16                 279073          4160 ns/op    24614.18 MB/s          6 B/op          0 allocs/op
+BenchmarkDecoder_DecodeAllParallelCgo/comp-data.bin.zst-16        749938          1579 ns/op    2581.71 MB/s           0 B/op          0 allocs/op
 ```
 
-This reflects the performance around May 2019, but this may be out of date.
+This reflects the performance around May 2020, but this may be out of date.
 
 # Contributions
 
diff --git a/vendor/github.com/klauspost/compress/zstd/bitreader.go b/vendor/github.com/klauspost/compress/zstd/bitreader.go
index 15d79d439f..8544585371 100644
--- a/vendor/github.com/klauspost/compress/zstd/bitreader.go
+++ b/vendor/github.com/klauspost/compress/zstd/bitreader.go
@@ -5,6 +5,7 @@
 package zstd
 
 import (
+	"encoding/binary"
 	"errors"
 	"io"
 	"math/bits"
@@ -34,8 +35,12 @@ func (b *bitReader) init(in []byte) error {
 	}
 	b.bitsRead = 64
 	b.value = 0
-	b.fill()
-	b.fill()
+	if len(in) >= 8 {
+		b.fillFastStart()
+	} else {
+		b.fill()
+		b.fill()
+	}
 	b.bitsRead += 8 - uint8(highBits(uint32(v)))
 	return nil
 }
@@ -63,21 +68,31 @@ func (b *bitReader) fillFast() {
 	if b.bitsRead < 32 {
 		return
 	}
-	// Do single re-slice to avoid bounds checks.
-	v := b.in[b.off-4 : b.off]
+	// 2 bounds checks.
+	v := b.in[b.off-4:]
+	v = v[:4]
 	low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
 	b.value = (b.value << 32) | uint64(low)
 	b.bitsRead -= 32
 	b.off -= 4
 }
 
+// fillFastStart() assumes the bitreader is empty and there is at least 8 bytes to read.
+func (b *bitReader) fillFastStart() {
+	// Do single re-slice to avoid bounds checks.
+	b.value = binary.LittleEndian.Uint64(b.in[b.off-8:])
+	b.bitsRead = 0
+	b.off -= 8
+}
+
 // fill() will make sure at least 32 bits are available.
 func (b *bitReader) fill() {
 	if b.bitsRead < 32 {
 		return
 	}
 	if b.off >= 4 {
-		v := b.in[b.off-4 : b.off]
+		v := b.in[b.off-4:]
+		v = v[:4]
 		low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
 		b.value = (b.value << 32) | uint64(low)
 		b.bitsRead -= 32
diff --git a/vendor/github.com/klauspost/compress/zstd/blockdec.go b/vendor/github.com/klauspost/compress/zstd/blockdec.go
index ed670bcc7a..c8ec6e3312 100644
--- a/vendor/github.com/klauspost/compress/zstd/blockdec.go
+++ b/vendor/github.com/klauspost/compress/zstd/blockdec.go
@@ -75,21 +75,29 @@ type blockDec struct {
 
 	// Window size of the block.
 	WindowSize uint64
-	Type       blockType
-	RLESize    uint32
 
-	// Is this the last block of a frame?
-	Last bool
-
-	// Use less memory
-	lowMem      bool
 	history     chan *history
 	input       chan struct{}
 	result      chan decodeOutput
 	sequenceBuf []seq
-	tmp         [4]byte
 	err         error
 	decWG       sync.WaitGroup
+
+	// Frame to use for singlethreaded decoding.
+	// Should not be used by the decoder itself since parent may be another frame.
+	localFrame *frameDec
+
+	// Block is RLE, this is the size.
+	RLESize uint32
+	tmp     [4]byte
+
+	Type blockType
+
+	// Is this the last block of a frame?
+	Last bool
+
+	// Use less memory
+	lowMem bool
 }
 
 func (b *blockDec) String() string {
@@ -127,25 +135,37 @@ func (b *blockDec) reset(br byteBuffer, windowSize uint64) error {
 	b.Type = blockType((bh >> 1) & 3)
 	// find size.
 	cSize := int(bh >> 3)
+	maxSize := maxBlockSize
 	switch b.Type {
 	case blockTypeReserved:
 		return ErrReservedBlockType
 	case blockTypeRLE:
 		b.RLESize = uint32(cSize)
+		if b.lowMem {
+			maxSize = cSize
+		}
 		cSize = 1
 	case blockTypeCompressed:
 		if debug {
 			println("Data size on stream:", cSize)
 		}
 		b.RLESize = 0
+		maxSize = maxCompressedBlockSize
+		if windowSize < maxCompressedBlockSize && b.lowMem {
+			maxSize = int(windowSize)
+		}
 		if cSize > maxCompressedBlockSize || uint64(cSize) > b.WindowSize {
 			if debug {
 				printf("compressed block too big: csize:%d block: %+v\n", uint64(cSize), b)
 			}
 			return ErrCompressedSizeTooBig
 		}
-	default:
+	case blockTypeRaw:
 		b.RLESize = 0
+		// We do not need a destination for raw blocks.
+		maxSize = -1
+	default:
+		panic("Invalid block type")
 	}
 
 	// Read block data.
@@ -156,8 +176,8 @@ func (b *blockDec) reset(br byteBuffer, windowSize uint64) error {
 			b.dataStorage = make([]byte, 0, maxBlockSize)
 		}
 	}
-	if cap(b.dst) <= maxBlockSize {
-		b.dst = make([]byte, 0, maxBlockSize+1)
+	if cap(b.dst) <= maxSize {
+		b.dst = make([]byte, 0, maxSize+1)
 	}
 	var err error
 	b.data, err = br.readBig(cSize, b.dataStorage)
@@ -445,26 +465,22 @@ func (b *blockDec) decodeCompressed(hist *history) error {
 		if huff == nil {
 			huff = &huff0.Scratch{}
 		}
-		huff.Out = b.literalBuf[:0]
 		huff, literals, err = huff0.ReadTable(literals, huff)
 		if err != nil {
 			println("reading huffman table:", err)
 			return err
 		}
 		// Use our out buffer.
-		huff.Out = b.literalBuf[:0]
-		huff.MaxDecodedSize = litRegenSize
 		if fourStreams {
-			literals, err = huff.Decompress4X(literals, litRegenSize)
+			literals, err = huff.Decoder().Decompress4X(b.literalBuf[:0:litRegenSize], literals)
 		} else {
-			literals, err = huff.Decompress1X(literals)
+			literals, err = huff.Decoder().Decompress1X(b.literalBuf[:0:litRegenSize], literals)
 		}
 		if err != nil {
 			println("decoding compressed literals:", err)
 			return err
 		}
 		// Make sure we don't leak our literals buffer
-		huff.Out = nil
 		if len(literals) != litRegenSize {
 			return fmt.Errorf("literal output size mismatch want %d, got %d", litRegenSize, len(literals))
 		}
@@ -615,15 +631,12 @@ func (b *blockDec) decodeCompressed(hist *history) error {
 		var err error
 		// Use our out buffer.
 		huff = hist.huffTree
-		huff.Out = b.literalBuf[:0]
-		huff.MaxDecodedSize = litRegenSize
 		if fourStreams {
-			literals, err = huff.Decompress4X(literals, litRegenSize)
+			literals, err = huff.Decoder().Decompress4X(b.literalBuf[:0:litRegenSize], literals)
 		} else {
-			literals, err = huff.Decompress1X(literals)
+			literals, err = huff.Decoder().Decompress1X(b.literalBuf[:0:litRegenSize], literals)
 		}
 		// Make sure we don't leak our literals buffer
-		huff.Out = nil
 		if err != nil {
 			println("decompressing literals:", err)
 			return err
@@ -633,12 +646,13 @@ func (b *blockDec) decodeCompressed(hist *history) error {
 		}
 	} else {
 		if hist.huffTree != nil && huff != nil {
-			huffDecoderPool.Put(hist.huffTree)
+			if hist.dict == nil || hist.dict.litDec != hist.huffTree {
+				huffDecoderPool.Put(hist.huffTree)
+			}
 			hist.huffTree = nil
 		}
 	}
 	if huff != nil {
-		huff.Out = nil
 		hist.huffTree = huff
 	}
 	if debug {
@@ -671,12 +685,21 @@ func (b *blockDec) decodeCompressed(hist *history) error {
 	//   If only recent offsets were not transferred, this would be an obvious win.
 	// 	 Also, if first 3 sequences don't reference recent offsets, all sequences can be decoded.
 
+	hbytes := hist.b
+	if len(hbytes) > hist.windowSize {
+		hbytes = hbytes[len(hbytes)-hist.windowSize:]
+		// We do not need history any more.
+		if hist.dict != nil {
+			hist.dict.content = nil
+		}
+	}
+
 	if err := seqs.initialize(br, hist, literals, b.dst); err != nil {
 		println("initializing sequences:", err)
 		return err
 	}
 
-	err = seqs.decode(nSeqs, br, hist.b)
+	err = seqs.decode(nSeqs, br, hbytes)
 	if err != nil {
 		return err
 	}
diff --git a/vendor/github.com/klauspost/compress/zstd/blockenc.go b/vendor/github.com/klauspost/compress/zstd/blockenc.go
index 4f0eba22f0..be718afd43 100644
--- a/vendor/github.com/klauspost/compress/zstd/blockenc.go
+++ b/vendor/github.com/klauspost/compress/zstd/blockenc.go
@@ -295,7 +295,7 @@ func (b *blockEnc) encodeRaw(a []byte) {
 	b.output = bh.appendTo(b.output[:0])
 	b.output = append(b.output, a...)
 	if debug {
-		println("Adding RAW block, length", len(a))
+		println("Adding RAW block, length", len(a), "last:", b.last)
 	}
 }
 
@@ -308,7 +308,7 @@ func (b *blockEnc) encodeRawTo(dst, src []byte) []byte {
 	dst = bh.appendTo(dst)
 	dst = append(dst, src...)
 	if debug {
-		println("Adding RAW block, length", len(src))
+		println("Adding RAW block, length", len(src), "last:", b.last)
 	}
 	return dst
 }
@@ -322,7 +322,7 @@ func (b *blockEnc) encodeLits(raw bool) error {
 	// Don't compress extremely small blocks
 	if len(b.literals) < 32 || raw {
 		if debug {
-			println("Adding RAW block, length", len(b.literals))
+			println("Adding RAW block, length", len(b.literals), "last:", b.last)
 		}
 		bh.setType(blockTypeRaw)
 		b.output = bh.appendTo(b.output)
@@ -349,7 +349,7 @@ func (b *blockEnc) encodeLits(raw bool) error {
 	switch err {
 	case huff0.ErrIncompressible:
 		if debug {
-			println("Adding RAW block, length", len(b.literals))
+			println("Adding RAW block, length", len(b.literals), "last:", b.last)
 		}
 		bh.setType(blockTypeRaw)
 		b.output = bh.appendTo(b.output)
@@ -444,9 +444,9 @@ func fuzzFseEncoder(data []byte) int {
 }
 
 // encode will encode the block and append the output in b.output.
-func (b *blockEnc) encode(raw bool) error {
+func (b *blockEnc) encode(raw, rawAllLits bool) error {
 	if len(b.sequences) == 0 {
-		return b.encodeLits(raw)
+		return b.encodeLits(rawAllLits)
 	}
 	// We want some difference
 	if len(b.literals) > (b.size - (b.size >> 5)) {
diff --git a/vendor/github.com/klauspost/compress/zstd/bytereader.go b/vendor/github.com/klauspost/compress/zstd/bytereader.go
index dc4378b640..2c4fca17fa 100644
--- a/vendor/github.com/klauspost/compress/zstd/bytereader.go
+++ b/vendor/github.com/klauspost/compress/zstd/bytereader.go
@@ -31,7 +31,8 @@ func (b *byteReader) overread() bool {
 
 // Int32 returns a little endian int32 starting at current offset.
 func (b byteReader) Int32() int32 {
-	b2 := b.b[b.off : b.off+4 : b.off+4]
+	b2 := b.b[b.off:]
+	b2 = b2[:4]
 	v3 := int32(b2[3])
 	v2 := int32(b2[2])
 	v1 := int32(b2[1])
@@ -55,7 +56,20 @@ func (b byteReader) Uint32() uint32 {
 		}
 		return v
 	}
-	b2 := b.b[b.off : b.off+4 : b.off+4]
+	b2 := b.b[b.off:]
+	b2 = b2[:4]
+	v3 := uint32(b2[3])
+	v2 := uint32(b2[2])
+	v1 := uint32(b2[1])
+	v0 := uint32(b2[0])
+	return v0 | (v1 << 8) | (v2 << 16) | (v3 << 24)
+}
+
+// Uint32NC returns a little endian uint32 starting at current offset.
+// The caller must be sure if there are at least 4 bytes left.
+func (b byteReader) Uint32NC() uint32 {
+	b2 := b.b[b.off:]
+	b2 = b2[:4]
 	v3 := uint32(b2[3])
 	v2 := uint32(b2[2])
 	v1 := uint32(b2[1])
diff --git a/vendor/github.com/klauspost/compress/zstd/decoder.go b/vendor/github.com/klauspost/compress/zstd/decoder.go
index 73ac3c630e..66b51bf2d3 100644
--- a/vendor/github.com/klauspost/compress/zstd/decoder.go
+++ b/vendor/github.com/klauspost/compress/zstd/decoder.go
@@ -23,17 +23,15 @@ type Decoder struct {
 	// Unreferenced decoders, ready for use.
 	decoders chan *blockDec
 
-	// Unreferenced decoders, ready for use.
-	frames chan *frameDec
-
 	// Streams ready to be decoded.
 	stream chan decodeStream
 
 	// Current read position used for Reader functionality.
 	current decoderState
 
-	// Custom dictionaries
-	dicts map[uint32]struct{}
+	// Custom dictionaries.
+	// Always uses copies.
+	dicts map[uint32]dict
 
 	// streamWg is the waitgroup for all streams
 	streamWg sync.WaitGroup
@@ -66,7 +64,7 @@ var (
 // A Decoder can be used in two modes:
 //
 // 1) As a stream, or
-// 2) For stateless decoding using DecodeAll or DecodeBuffer.
+// 2) For stateless decoding using DecodeAll.
 //
 // Only a single stream can be decoded concurrently, but the same decoder
 // can run multiple concurrent stateless decodes. It is even possible to
@@ -87,12 +85,19 @@ func NewReader(r io.Reader, opts ...DOption) (*Decoder, error) {
 	d.current.output = make(chan decodeOutput, d.o.concurrent)
 	d.current.flushed = true
 
+	// Transfer option dicts.
+	d.dicts = make(map[uint32]dict, len(d.o.dicts))
+	for _, dc := range d.o.dicts {
+		d.dicts[dc.id] = dc
+	}
+	d.o.dicts = nil
+
 	// Create decoders
 	d.decoders = make(chan *blockDec, d.o.concurrent)
-	d.frames = make(chan *frameDec, d.o.concurrent)
 	for i := 0; i < d.o.concurrent; i++ {
-		d.frames <- newFrameDec(d.o)
-		d.decoders <- newBlockDec(d.o.lowMem)
+		dec := newBlockDec(d.o.lowMem)
+		dec.localFrame = newFrameDec(d.o)
+		d.decoders <- dec
 	}
 
 	if r == nil {
@@ -169,7 +174,12 @@ func (d *Decoder) Reset(r io.Reader) error {
 			println("*bytes.Buffer detected, doing sync decode, len:", bb.Len())
 		}
 		b := bb.Bytes()
-		dst, err := d.DecodeAll(b, nil)
+		var dst []byte
+		if cap(d.current.b) > 0 {
+			dst = d.current.b
+		}
+
+		dst, err := d.DecodeAll(b, dst[:0])
 		if err == nil {
 			err = io.EOF
 		}
@@ -277,23 +287,31 @@ func (d *Decoder) DecodeAll(input, dst []byte) ([]byte, error) {
 	}
 
 	// Grab a block decoder and frame decoder.
-	block, frame := <-d.decoders, <-d.frames
+	block := <-d.decoders
+	frame := block.localFrame
 	defer func() {
 		if debug {
 			printf("re-adding decoder: %p", block)
 		}
-		d.decoders <- block
 		frame.rawInput = nil
 		frame.bBuf = nil
-		d.frames <- frame
+		d.decoders <- block
 	}()
 	frame.bBuf = input
 
 	for {
+		frame.history.reset()
 		err := frame.reset(&frame.bBuf)
 		if err == io.EOF {
 			return dst, nil
 		}
+		if frame.DictionaryID != nil {
+			dict, ok := d.dicts[*frame.DictionaryID]
+			if !ok {
+				return nil, ErrUnknownDictionary
+			}
+			frame.history.setDict(&dict)
+		}
 		if err != nil {
 			return dst, err
 		}
@@ -456,10 +474,19 @@ func (d *Decoder) startStreamDecoder(inStream chan decodeStream) {
 		br := readerWrapper{r: stream.r}
 	decodeStream:
 		for {
+			frame.history.reset()
 			err := frame.reset(&br)
 			if debug && err != nil {
 				println("Frame decoder returned", err)
 			}
+			if err == nil && frame.DictionaryID != nil {
+				dict, ok := d.dicts[*frame.DictionaryID]
+				if !ok {
+					err = ErrUnknownDictionary
+				} else {
+					frame.history.setDict(&dict)
+				}
+			}
 			if err != nil {
 				stream.output <- decodeOutput{
 					err: err,
diff --git a/vendor/github.com/klauspost/compress/zstd/decoder_options.go b/vendor/github.com/klauspost/compress/zstd/decoder_options.go
index 2ac9cd2dd3..284d384492 100644
--- a/vendor/github.com/klauspost/compress/zstd/decoder_options.go
+++ b/vendor/github.com/klauspost/compress/zstd/decoder_options.go
@@ -18,6 +18,7 @@ type decoderOptions struct {
 	lowMem         bool
 	concurrent     int
 	maxDecodedSize uint64
+	dicts          []dict
 }
 
 func (o *decoderOptions) setDefault() {
@@ -66,3 +67,18 @@ func WithDecoderMaxMemory(n uint64) DOption {
 		return nil
 	}
 }
+
+// WithDecoderDicts allows to register one or more dictionaries for the decoder.
+// If several dictionaries with the same ID is provided the last one will be used.
+func WithDecoderDicts(dicts ...[]byte) DOption {
+	return func(o *decoderOptions) error {
+		for _, b := range dicts {
+			d, err := loadDict(b)
+			if err != nil {
+				return err
+			}
+			o.dicts = append(o.dicts, *d)
+		}
+		return nil
+	}
+}
diff --git a/vendor/github.com/klauspost/compress/zstd/dict.go b/vendor/github.com/klauspost/compress/zstd/dict.go
new file mode 100644
index 0000000000..8eb6f6ba33
--- /dev/null
+++ b/vendor/github.com/klauspost/compress/zstd/dict.go
@@ -0,0 +1,104 @@
+package zstd
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+
+	"github.com/klauspost/compress/huff0"
+)
+
+type dict struct {
+	id uint32
+
+	litDec              *huff0.Scratch
+	llDec, ofDec, mlDec sequenceDec
+	offsets             [3]int
+	content             []byte
+}
+
+var dictMagic = [4]byte{0x37, 0xa4, 0x30, 0xec}
+
+// Load a dictionary as described in
+// https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#dictionary-format
+func loadDict(b []byte) (*dict, error) {
+	// Check static field size.
+	if len(b) <= 8+(3*4) {
+		return nil, io.ErrUnexpectedEOF
+	}
+	d := dict{
+		llDec: sequenceDec{fse: &fseDecoder{}},
+		ofDec: sequenceDec{fse: &fseDecoder{}},
+		mlDec: sequenceDec{fse: &fseDecoder{}},
+	}
+	if !bytes.Equal(b[:4], dictMagic[:]) {
+		return nil, ErrMagicMismatch
+	}
+	d.id = binary.LittleEndian.Uint32(b[4:8])
+	if d.id == 0 {
+		return nil, errors.New("dictionaries cannot have ID 0")
+	}
+
+	// Read literal table
+	var err error
+	d.litDec, b, err = huff0.ReadTable(b[8:], nil)
+	if err != nil {
+		return nil, err
+	}
+
+	br := byteReader{
+		b:   b,
+		off: 0,
+	}
+	readDec := func(i tableIndex, dec *fseDecoder) error {
+		if err := dec.readNCount(&br, uint16(maxTableSymbol[i])); err != nil {
+			return err
+		}
+		if br.overread() {
+			return io.ErrUnexpectedEOF
+		}
+		err = dec.transform(symbolTableX[i])
+		if err != nil {
+			println("Transform table error:", err)
+			return err
+		}
+		if debug {
+			println("Read table ok", "symbolLen:", dec.symbolLen)
+		}
+		// Set decoders as predefined so they aren't reused.
+		dec.preDefined = true
+		return nil
+	}
+
+	if err := readDec(tableOffsets, d.ofDec.fse); err != nil {
+		return nil, err
+	}
+	if err := readDec(tableMatchLengths, d.mlDec.fse); err != nil {
+		return nil, err
+	}
+	if err := readDec(tableLiteralLengths, d.llDec.fse); err != nil {
+		return nil, err
+	}
+	if br.remain() < 12 {
+		return nil, io.ErrUnexpectedEOF
+	}
+
+	d.offsets[0] = int(br.Uint32())
+	br.advance(4)
+	d.offsets[1] = int(br.Uint32())
+	br.advance(4)
+	d.offsets[2] = int(br.Uint32())
+	br.advance(4)
+	if d.offsets[0] <= 0 || d.offsets[1] <= 0 || d.offsets[2] <= 0 {
+		return nil, errors.New("invalid offset in dictionary")
+	}
+	d.content = make([]byte, br.remain())
+	copy(d.content, br.unread())
+	if d.offsets[0] > len(d.content) || d.offsets[1] > len(d.content) || d.offsets[2] > len(d.content) {
+		return nil, fmt.Errorf("initial offset bigger than dictionary content size %d, offsets: %v", len(d.content), d.offsets)
+	}
+
+	return &d, nil
+}
diff --git a/vendor/github.com/klauspost/compress/zstd/enc_better.go b/vendor/github.com/klauspost/compress/zstd/enc_better.go
new file mode 100644
index 0000000000..c120d90548
--- /dev/null
+++ b/vendor/github.com/klauspost/compress/zstd/enc_better.go
@@ -0,0 +1,518 @@
+// Copyright 2019+ Klaus Post. All rights reserved.
+// License information can be found in the LICENSE file.
+// Based on work by Yann Collet, released under BSD License.
+
+package zstd
+
+import "fmt"
+
+const (
+	betterLongTableBits = 19                       // Bits used in the long match table
+	betterLongTableSize = 1 << betterLongTableBits // Size of the table
+
+	// Note: Increasing the short table bits or making the hash shorter
+	// can actually lead to compression degradation since it will 'steal' more from the
+	// long match table and match offsets are quite big.
+	// This greatly depends on the type of input.
+	betterShortTableBits = 13                        // Bits used in the short match table
+	betterShortTableSize = 1 << betterShortTableBits // Size of the table
+)
+
+type prevEntry struct {
+	offset int32
+	prev   int32
+}
+
+// betterFastEncoder uses 2 tables, one for short matches (5 bytes) and one for long matches.
+// The long match table contains the previous entry with the same hash,
+// effectively making it a "chain" of length 2.
+// When we find a long match we choose between the two values and select the longest.
+// When we find a short match, after checking the long, we check if we can find a long at n+1
+// and that it is longer (lazy matching).
+type betterFastEncoder struct {
+	fastBase
+	table     [betterShortTableSize]tableEntry
+	longTable [betterLongTableSize]prevEntry
+}
+
+// Encode improves compression...
+func (e *betterFastEncoder) Encode(blk *blockEnc, src []byte) {
+	const (
+		// Input margin is the number of bytes we read (8)
+		// and the maximum we will read ahead (2)
+		inputMargin            = 8 + 2
+		minNonLiteralBlockSize = 16
+	)
+
+	// Protect against e.cur wraparound.
+	for e.cur >= bufferReset {
+		if len(e.hist) == 0 {
+			for i := range e.table[:] {
+				e.table[i] = tableEntry{}
+			}
+			for i := range e.longTable[:] {
+				e.longTable[i] = prevEntry{}
+			}
+			e.cur = e.maxMatchOff
+			break
+		}
+		// Shift down everything in the table that isn't already too far away.
+		minOff := e.cur + int32(len(e.hist)) - e.maxMatchOff
+		for i := range e.table[:] {
+			v := e.table[i].offset
+			if v < minOff {
+				v = 0
+			} else {
+				v = v - e.cur + e.maxMatchOff
+			}
+			e.table[i].offset = v
+		}
+		for i := range e.longTable[:] {
+			v := e.longTable[i].offset
+			v2 := e.longTable[i].prev
+			if v < minOff {
+				v = 0
+				v2 = 0
+			} else {
+				v = v - e.cur + e.maxMatchOff
+				if v2 < minOff {
+					v2 = 0
+				} else {
+					v2 = v2 - e.cur + e.maxMatchOff
+				}
+			}
+			e.longTable[i] = prevEntry{
+				offset: v,
+				prev:   v2,
+			}
+		}
+		e.cur = e.maxMatchOff
+		break
+	}
+
+	s := e.addBlock(src)
+	blk.size = len(src)
+	if len(src) < minNonLiteralBlockSize {
+		blk.extraLits = len(src)
+		blk.literals = blk.literals[:len(src)]
+		copy(blk.literals, src)
+		return
+	}
+
+	// Override src
+	src = e.hist
+	sLimit := int32(len(src)) - inputMargin
+	// stepSize is the number of bytes to skip on every main loop iteration.
+	// It should be >= 1.
+	const stepSize = 1
+
+	const kSearchStrength = 9
+
+	// nextEmit is where in src the next emitLiteral should start from.
+	nextEmit := s
+	cv := load6432(src, s)
+
+	// Relative offsets
+	offset1 := int32(blk.recentOffsets[0])
+	offset2 := int32(blk.recentOffsets[1])
+
+	addLiterals := func(s *seq, until int32) {
+		if until == nextEmit {
+			return
+		}
+		blk.literals = append(blk.literals, src[nextEmit:until]...)
+		s.litLen = uint32(until - nextEmit)
+	}
+	if debug {
+		println("recent offsets:", blk.recentOffsets)
+	}
+
+encodeLoop:
+	for {
+		var t int32
+		// We allow the encoder to optionally turn off repeat offsets across blocks
+		canRepeat := len(blk.sequences) > 2
+		var matched int32
+
+		for {
+			if debugAsserts && canRepeat && offset1 == 0 {
+				panic("offset0 was 0")
+			}
+
+			nextHashS := hash5(cv, betterShortTableBits)
+			nextHashL := hash8(cv, betterLongTableBits)
+			candidateL := e.longTable[nextHashL]
+			candidateS := e.table[nextHashS]
+
+			const repOff = 1
+			repIndex := s - offset1 + repOff
+			off := s + e.cur
+			e.longTable[nextHashL] = prevEntry{offset: off, prev: candidateL.offset}
+			e.table[nextHashS] = tableEntry{offset: off, val: uint32(cv)}
+
+			if canRepeat {
+				if repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>(repOff*8)) {
+					// Consider history as well.
+					var seq seq
+					lenght := 4 + e.matchlen(s+4+repOff, repIndex+4, src)
+
+					seq.matchLen = uint32(lenght - zstdMinMatch)
+
+					// We might be able to match backwards.
+					// Extend as long as we can.
+					start := s + repOff
+					// We end the search early, so we don't risk 0 literals
+					// and have to do special offset treatment.
+					startLimit := nextEmit + 1
+
+					tMin := s - e.maxMatchOff
+					if tMin < 0 {
+						tMin = 0
+					}
+					for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 {
+						repIndex--
+						start--
+						seq.matchLen++
+					}
+					addLiterals(&seq, start)
+
+					// rep 0
+					seq.offset = 1
+					if debugSequences {
+						println("repeat sequence", seq, "next s:", s)
+					}
+					blk.sequences = append(blk.sequences, seq)
+
+					// Index match start+1 (long) -> s - 1
+					index0 := s + repOff
+					s += lenght + repOff
+
+					nextEmit = s
+					if s >= sLimit {
+						if debug {
+							println("repeat ended", s, lenght)
+
+						}
+						break encodeLoop
+					}
+					// Index skipped...
+					for index0 < s-1 {
+						cv0 := load6432(src, index0)
+						cv1 := cv0 >> 8
+						h0 := hash8(cv0, betterLongTableBits)
+						off := index0 + e.cur
+						e.longTable[h0] = prevEntry{offset: off, prev: e.longTable[h0].offset}
+						e.table[hash5(cv1, betterShortTableBits)] = tableEntry{offset: off + 1, val: uint32(cv1)}
+						index0 += 2
+					}
+					cv = load6432(src, s)
+					continue
+				}
+				const repOff2 = 1
+
+				// We deviate from the reference encoder and also check offset 2.
+				// Still slower and not much better, so disabled.
+				// repIndex = s - offset2 + repOff2
+				if false && repIndex >= 0 && load6432(src, repIndex) == load6432(src, s+repOff) {
+					// Consider history as well.
+					var seq seq
+					lenght := 8 + e.matchlen(s+8+repOff2, repIndex+8, src)
+
+					seq.matchLen = uint32(lenght - zstdMinMatch)
+
+					// We might be able to match backwards.
+					// Extend as long as we can.
+					start := s + repOff2
+					// We end the search early, so we don't risk 0 literals
+					// and have to do special offset treatment.
+					startLimit := nextEmit + 1
+
+					tMin := s - e.maxMatchOff
+					if tMin < 0 {
+						tMin = 0
+					}
+					for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 {
+						repIndex--
+						start--
+						seq.matchLen++
+					}
+					addLiterals(&seq, start)
+
+					// rep 2
+					seq.offset = 2
+					if debugSequences {
+						println("repeat sequence 2", seq, "next s:", s)
+					}
+					blk.sequences = append(blk.sequences, seq)
+
+					index0 := s + repOff2
+					s += lenght + repOff2
+					nextEmit = s
+					if s >= sLimit {
+						if debug {
+							println("repeat ended", s, lenght)
+
+						}
+						break encodeLoop
+					}
+
+					// Index skipped...
+					for index0 < s-1 {
+						cv0 := load6432(src, index0)
+						cv1 := cv0 >> 8
+						h0 := hash8(cv0, betterLongTableBits)
+						off := index0 + e.cur
+						e.longTable[h0] = prevEntry{offset: off, prev: e.longTable[h0].offset}
+						e.table[hash5(cv1, betterShortTableBits)] = tableEntry{offset: off + 1, val: uint32(cv1)}
+						index0 += 2
+					}
+					cv = load6432(src, s)
+					// Swap offsets
+					offset1, offset2 = offset2, offset1
+					continue
+				}
+			}
+			// Find the offsets of our two matches.
+			coffsetL := candidateL.offset - e.cur
+			coffsetLP := candidateL.prev - e.cur
+
+			// Check if we have a long match.
+			if s-coffsetL < e.maxMatchOff && cv == load6432(src, coffsetL) {
+				// Found a long match, at least 8 bytes.
+				matched = e.matchlen(s+8, coffsetL+8, src) + 8
+				t = coffsetL
+				if debugAsserts && s <= t {
+					panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
+				}
+				if debugAsserts && s-t > e.maxMatchOff {
+					panic("s - t >e.maxMatchOff")
+				}
+				if debugMatches {
+					println("long match")
+				}
+
+				if s-coffsetLP < e.maxMatchOff && cv == load6432(src, coffsetLP) {
+					// Found a long match, at least 8 bytes.
+					prevMatch := e.matchlen(s+8, coffsetLP+8, src) + 8
+					if prevMatch > matched {
+						matched = prevMatch
+						t = coffsetLP
+					}
+					if debugAsserts && s <= t {
+						panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
+					}
+					if debugAsserts && s-t > e.maxMatchOff {
+						panic("s - t >e.maxMatchOff")
+					}
+					if debugMatches {
+						println("long match")
+					}
+				}
+				break
+			}
+
+			// Check if we have a long match on prev.
+			if s-coffsetLP < e.maxMatchOff && cv == load6432(src, coffsetLP) {
+				// Found a long match, at least 8 bytes.
+				matched = e.matchlen(s+8, coffsetLP+8, src) + 8
+				t = coffsetLP
+				if debugAsserts && s <= t {
+					panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
+				}
+				if debugAsserts && s-t > e.maxMatchOff {
+					panic("s - t >e.maxMatchOff")
+				}
+				if debugMatches {
+					println("long match")
+				}
+				break
+			}
+
+			coffsetS := candidateS.offset - e.cur
+
+			// Check if we have a short match.
+			if s-coffsetS < e.maxMatchOff && uint32(cv) == candidateS.val {
+				// found a regular match
+				matched = e.matchlen(s+4, coffsetS+4, src) + 4
+
+				// See if we can find a long match at s+1
+				const checkAt = 1
+				cv := load6432(src, s+checkAt)
+				nextHashL = hash8(cv, betterLongTableBits)
+				candidateL = e.longTable[nextHashL]
+				coffsetL = candidateL.offset - e.cur
+
+				// We can store it, since we have at least a 4 byte match.
+				e.longTable[nextHashL] = prevEntry{offset: s + checkAt + e.cur, prev: candidateL.offset}
+				if s-coffsetL < e.maxMatchOff && cv == load6432(src, coffsetL) {
+					// Found a long match, at least 8 bytes.
+					matchedNext := e.matchlen(s+8+checkAt, coffsetL+8, src) + 8
+					if matchedNext > matched {
+						t = coffsetL
+						s += checkAt
+						matched = matchedNext
+						if debugMatches {
+							println("long match (after short)")
+						}
+						break
+					}
+				}
+
+				// Check prev long...
+				coffsetL = candidateL.prev - e.cur
+				if s-coffsetL < e.maxMatchOff && cv == load6432(src, coffsetL) {
+					// Found a long match, at least 8 bytes.
+					matchedNext := e.matchlen(s+8+checkAt, coffsetL+8, src) + 8
+					if matchedNext > matched {
+						t = coffsetL
+						s += checkAt
+						matched = matchedNext
+						if debugMatches {
+							println("prev long match (after short)")
+						}
+						break
+					}
+				}
+				t = coffsetS
+				if debugAsserts && s <= t {
+					panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
+				}
+				if debugAsserts && s-t > e.maxMatchOff {
+					panic("s - t >e.maxMatchOff")
+				}
+				if debugAsserts && t < 0 {
+					panic("t<0")
+				}
+				if debugMatches {
+					println("short match")
+				}
+				break
+			}
+
+			// No match found, move forward in input.
+			s += stepSize + ((s - nextEmit) >> (kSearchStrength - 1))
+			if s >= sLimit {
+				break encodeLoop
+			}
+			cv = load6432(src, s)
+		}
+
+		// A 4-byte match has been found. Update recent offsets.
+		// We'll later see if more than 4 bytes.
+		offset2 = offset1
+		offset1 = s - t
+
+		if debugAsserts && s <= t {
+			panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
+		}
+
+		if debugAsserts && canRepeat && int(offset1) > len(src) {
+			panic("invalid offset")
+		}
+
+		// Extend the n-byte match as long as possible.
+		l := matched
+
+		// Extend backwards
+		tMin := s - e.maxMatchOff
+		if tMin < 0 {
+			tMin = 0
+		}
+		for t > tMin && s > nextEmit && src[t-1] == src[s-1] && l < maxMatchLength {
+			s--
+			t--
+			l++
+		}
+
+		// Write our sequence
+		var seq seq
+		seq.litLen = uint32(s - nextEmit)
+		seq.matchLen = uint32(l - zstdMinMatch)
+		if seq.litLen > 0 {
+			blk.literals = append(blk.literals, src[nextEmit:s]...)
+		}
+		seq.offset = uint32(s-t) + 3
+		s += l
+		if debugSequences {
+			println("sequence", seq, "next s:", s)
+		}
+		blk.sequences = append(blk.sequences, seq)
+		nextEmit = s
+		if s >= sLimit {
+			break encodeLoop
+		}
+
+		// Index match start+1 (long) -> s - 1
+		index0 := s - l + 1
+		for index0 < s-1 {
+			cv0 := load6432(src, index0)
+			cv1 := cv0 >> 8
+			h0 := hash8(cv0, betterLongTableBits)
+			off := index0 + e.cur
+			e.longTable[h0] = prevEntry{offset: off, prev: e.longTable[h0].offset}
+			e.table[hash5(cv1, betterShortTableBits)] = tableEntry{offset: off + 1, val: uint32(cv1)}
+			index0 += 2
+		}
+
+		cv = load6432(src, s)
+		if !canRepeat {
+			continue
+		}
+
+		// Check offset 2
+		for {
+			o2 := s - offset2
+			if load3232(src, o2) != uint32(cv) {
+				// Do regular search
+				break
+			}
+
+			// Store this, since we have it.
+			nextHashS := hash5(cv, betterShortTableBits)
+			nextHashL := hash8(cv, betterLongTableBits)
+
+			// We have at least 4 byte match.
+			// No need to check backwards. We come straight from a match
+			l := 4 + e.matchlen(s+4, o2+4, src)
+
+			e.longTable[nextHashL] = prevEntry{offset: s + e.cur, prev: e.longTable[nextHashL].offset}
+			e.table[nextHashS] = tableEntry{offset: s + e.cur, val: uint32(cv)}
+			seq.matchLen = uint32(l) - zstdMinMatch
+			seq.litLen = 0
+
+			// Since litlen is always 0, this is offset 1.
+			seq.offset = 1
+			s += l
+			nextEmit = s
+			if debugSequences {
+				println("sequence", seq, "next s:", s)
+			}
+			blk.sequences = append(blk.sequences, seq)
+
+			// Swap offset 1 and 2.
+			offset1, offset2 = offset2, offset1
+			if s >= sLimit {
+				// Finished
+				break encodeLoop
+			}
+			cv = load6432(src, s)
+		}
+	}
+
+	if int(nextEmit) < len(src) {
+		blk.literals = append(blk.literals, src[nextEmit:]...)
+		blk.extraLits = len(src) - int(nextEmit)
+	}
+	blk.recentOffsets[0] = uint32(offset1)
+	blk.recentOffsets[1] = uint32(offset2)
+	if debug {
+		println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits)
+	}
+}
+
+// EncodeNoHist will encode a block with no history and no following blocks.
+// Most notable difference is that src will not be copied for history and
+// we do not need to check for max match length.
+func (e *betterFastEncoder) EncodeNoHist(blk *blockEnc, src []byte) {
+	e.Encode(blk, src)
+}
diff --git a/vendor/github.com/klauspost/compress/zstd/enc_dfast.go b/vendor/github.com/klauspost/compress/zstd/enc_dfast.go
index 0ffea76554..50276bcde7 100644
--- a/vendor/github.com/klauspost/compress/zstd/enc_dfast.go
+++ b/vendor/github.com/klauspost/compress/zstd/enc_dfast.go
@@ -80,10 +80,7 @@ func (e *doubleFastEncoder) Encode(blk *blockEnc, src []byte) {
 	sLimit := int32(len(src)) - inputMargin
 	// stepSize is the number of bytes to skip on every main loop iteration.
 	// It should be >= 1.
-	stepSize := int32(e.o.targetLength)
-	if stepSize == 0 {
-		stepSize++
-	}
+	const stepSize = 1
 
 	const kSearchStrength = 8
 
@@ -172,55 +169,6 @@ encodeLoop:
 					cv = load6432(src, s)
 					continue
 				}
-				const repOff2 = 1
-				// We deviate from the reference encoder and also check offset 2.
-				// Slower and not consistently better, so disabled.
-				// repIndex = s - offset2 + repOff2
-				if false && repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>(repOff2*8)) {
-					// Consider history as well.
-					var seq seq
-					lenght := 4 + e.matchlen(s+4+repOff2, repIndex+4, src)
-
-					seq.matchLen = uint32(lenght - zstdMinMatch)
-
-					// We might be able to match backwards.
-					// Extend as long as we can.
-					start := s + repOff2
-					// We end the search early, so we don't risk 0 literals
-					// and have to do special offset treatment.
-					startLimit := nextEmit + 1
-
-					tMin := s - e.maxMatchOff
-					if tMin < 0 {
-						tMin = 0
-					}
-					for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 {
-						repIndex--
-						start--
-						seq.matchLen++
-					}
-					addLiterals(&seq, start)
-
-					// rep 2
-					seq.offset = 2
-					if debugSequences {
-						println("repeat sequence 2", seq, "next s:", s)
-					}
-					blk.sequences = append(blk.sequences, seq)
-					s += lenght + repOff2
-					nextEmit = s
-					if s >= sLimit {
-						if debug {
-							println("repeat ended", s, lenght)
-
-						}
-						break encodeLoop
-					}
-					cv = load6432(src, s)
-					// Swap offsets
-					offset1, offset2 = offset2, offset1
-					continue
-				}
 			}
 			// Find the offsets of our two matches.
 			coffsetL := s - (candidateL.offset - e.cur)
@@ -372,7 +320,7 @@ encodeLoop:
 			}
 
 			// Store this, since we have it.
-			nextHashS := hash5(cv1>>8, dFastShortTableBits)
+			nextHashS := hash5(cv, dFastShortTableBits)
 			nextHashL := hash8(cv, dFastLongTableBits)
 
 			// We have at least 4 byte match.
@@ -450,10 +398,7 @@ func (e *doubleFastEncoder) EncodeNoHist(blk *blockEnc, src []byte) {
 	sLimit := int32(len(src)) - inputMargin
 	// stepSize is the number of bytes to skip on every main loop iteration.
 	// It should be >= 1.
-	stepSize := int32(e.o.targetLength)
-	if stepSize == 0 {
-		stepSize++
-	}
+	const stepSize = 1
 
 	const kSearchStrength = 8
 
@@ -726,4 +671,8 @@ encodeLoop:
 		println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits)
 	}
 
+	// We do not store history, so we must offset e.cur to avoid false matches for next user.
+	if e.cur < bufferReset {
+		e.cur += int32(len(src))
+	}
 }
diff --git a/vendor/github.com/klauspost/compress/zstd/enc_fast.go b/vendor/github.com/klauspost/compress/zstd/enc_fast.go
index 28134b1589..4104b456ce 100644
--- a/vendor/github.com/klauspost/compress/zstd/enc_fast.go
+++ b/vendor/github.com/klauspost/compress/zstd/enc_fast.go
@@ -6,6 +6,7 @@ package zstd
 
 import (
 	"fmt"
+	"math"
 	"math/bits"
 
 	"github.com/klauspost/compress/zstd/internal/xxhash"
@@ -23,26 +24,29 @@ type tableEntry struct {
 	offset int32
 }
 
-type fastEncoder struct {
-	o encParams
+type fastBase struct {
 	// cur is the offset at the start of hist
 	cur int32
 	// maximum offset. Should be at least 2x block size.
 	maxMatchOff int32
 	hist        []byte
 	crc         *xxhash.Digest
-	table       [tableSize]tableEntry
 	tmp         [8]byte
 	blk         *blockEnc
 }
 
+type fastEncoder struct {
+	fastBase
+	table [tableSize]tableEntry
+}
+
 // CRC returns the underlying CRC writer.
-func (e *fastEncoder) CRC() *xxhash.Digest {
+func (e *fastBase) CRC() *xxhash.Digest {
 	return e.crc
 }
 
 // AppendCRC will append the CRC to the destination slice and return it.
-func (e *fastEncoder) AppendCRC(dst []byte) []byte {
+func (e *fastBase) AppendCRC(dst []byte) []byte {
 	crc := e.crc.Sum(e.tmp[:0])
 	dst = append(dst, crc[7], crc[6], crc[5], crc[4])
 	return dst
@@ -50,7 +54,7 @@ func (e *fastEncoder) AppendCRC(dst []byte) []byte {
 
 // WindowSize returns the window size of the encoder,
 // or a window size small enough to contain the input size, if > 0.
-func (e *fastEncoder) WindowSize(size int) int32 {
+func (e *fastBase) WindowSize(size int) int32 {
 	if size > 0 && size < int(e.maxMatchOff) {
 		b := int32(1) << uint(bits.Len(uint(size)))
 		// Keep minimum window.
@@ -63,7 +67,7 @@ func (e *fastEncoder) WindowSize(size int) int32 {
 }
 
 // Block returns the current block.
-func (e *fastEncoder) Block() *blockEnc {
+func (e *fastBase) Block() *blockEnc {
 	return e.blk
 }
 
@@ -112,11 +116,7 @@ func (e *fastEncoder) Encode(blk *blockEnc, src []byte) {
 	sLimit := int32(len(src)) - inputMargin
 	// stepSize is the number of bytes to skip on every main loop iteration.
 	// It should be >= 2.
-	stepSize := int32(e.o.targetLength)
-	if stepSize == 0 {
-		stepSize++
-	}
-	stepSize++
+	const stepSize = 2
 
 	// TEMPLATE
 	const hashLog = tableBits
@@ -169,9 +169,22 @@ encodeLoop:
 			if canRepeat && repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>16) {
 				// Consider history as well.
 				var seq seq
-				lenght := 4 + e.matchlen(s+6, repIndex+4, src)
+				var length int32
+				// length = 4 + e.matchlen(s+6, repIndex+4, src)
+				{
+					a := src[s+6:]
+					b := src[repIndex+4:]
+					endI := len(a) & (math.MaxInt32 - 7)
+					length = int32(endI) + 4
+					for i := 0; i < endI; i += 8 {
+						if diff := load64(a, i) ^ load64(b, i); diff != 0 {
+							length = int32(i+bits.TrailingZeros64(diff)>>3) + 4
+							break
+						}
+					}
+				}
 
-				seq.matchLen = uint32(lenght - zstdMinMatch)
+				seq.matchLen = uint32(length - zstdMinMatch)
 
 				// We might be able to match backwards.
 				// Extend as long as we can.
@@ -197,11 +210,11 @@ encodeLoop:
 					println("repeat sequence", seq, "next s:", s)
 				}
 				blk.sequences = append(blk.sequences, seq)
-				s += lenght + 2
+				s += length + 2
 				nextEmit = s
 				if s >= sLimit {
 					if debug {
-						println("repeat ended", s, lenght)
+						println("repeat ended", s, length)
 
 					}
 					break encodeLoop
@@ -257,7 +270,20 @@ encodeLoop:
 		}
 
 		// Extend the 4-byte match as long as possible.
-		l := e.matchlen(s+4, t+4, src) + 4
+		//l := e.matchlen(s+4, t+4, src) + 4
+		var l int32
+		{
+			a := src[s+4:]
+			b := src[t+4:]
+			endI := len(a) & (math.MaxInt32 - 7)
+			l = int32(endI) + 4
+			for i := 0; i < endI; i += 8 {
+				if diff := load64(a, i) ^ load64(b, i); diff != 0 {
+					l = int32(i+bits.TrailingZeros64(diff)>>3) + 4
+					break
+				}
+			}
+		}
 
 		// Extend backwards
 		tMin := s - e.maxMatchOff
@@ -294,7 +320,20 @@ encodeLoop:
 		if o2 := s - offset2; canRepeat && load3232(src, o2) == uint32(cv) {
 			// We have at least 4 byte match.
 			// No need to check backwards. We come straight from a match
-			l := 4 + e.matchlen(s+4, o2+4, src)
+			//l := 4 + e.matchlen(s+4, o2+4, src)
+			var l int32
+			{
+				a := src[s+4:]
+				b := src[o2+4:]
+				endI := len(a) & (math.MaxInt32 - 7)
+				l = int32(endI) + 4
+				for i := 0; i < endI; i += 8 {
+					if diff := load64(a, i) ^ load64(b, i); diff != 0 {
+						l = int32(i+bits.TrailingZeros64(diff)>>3) + 4
+						break
+					}
+				}
+			}
 
 			// Store this, since we have it.
 			nextHash := hash6(cv, hashLog)
@@ -344,6 +383,7 @@ func (e *fastEncoder) EncodeNoHist(blk *blockEnc, src []byte) {
 			panic("src too big")
 		}
 	}
+
 	// Protect against e.cur wraparound.
 	if e.cur >= bufferReset {
 		for i := range e.table[:] {
@@ -412,10 +452,23 @@ encodeLoop:
 			if len(blk.sequences) > 2 && load3232(src, repIndex) == uint32(cv>>16) {
 				// Consider history as well.
 				var seq seq
-				// lenght := 4 + e.matchlen(s+6, repIndex+4, src)
-				lenght := 4 + int32(matchLen(src[s+6:], src[repIndex+4:]))
+				// length := 4 + e.matchlen(s+6, repIndex+4, src)
+				// length := 4 + int32(matchLen(src[s+6:], src[repIndex+4:]))
+				var length int32
+				{
+					a := src[s+6:]
+					b := src[repIndex+4:]
+					endI := len(a) & (math.MaxInt32 - 7)
+					length = int32(endI) + 4
+					for i := 0; i < endI; i += 8 {
+						if diff := load64(a, i) ^ load64(b, i); diff != 0 {
+							length = int32(i+bits.TrailingZeros64(diff)>>3) + 4
+							break
+						}
+					}
+				}
 
-				seq.matchLen = uint32(lenght - zstdMinMatch)
+				seq.matchLen = uint32(length - zstdMinMatch)
 
 				// We might be able to match backwards.
 				// Extend as long as we can.
@@ -441,11 +494,11 @@ encodeLoop:
 					println("repeat sequence", seq, "next s:", s)
 				}
 				blk.sequences = append(blk.sequences, seq)
-				s += lenght + 2
+				s += length + 2
 				nextEmit = s
 				if s >= sLimit {
 					if debug {
-						println("repeat ended", s, lenght)
+						println("repeat ended", s, length)
 
 					}
 					break encodeLoop
@@ -464,6 +517,9 @@ encodeLoop:
 				if debugAsserts && s-t > e.maxMatchOff {
 					panic("s - t >e.maxMatchOff")
 				}
+				if debugAsserts && t < 0 {
+					panic(fmt.Sprintf("t (%d) < 0, candidate.offset: %d, e.cur: %d, coffset0: %d, e.maxMatchOff: %d", t, candidate.offset, e.cur, coffset0, e.maxMatchOff))
+				}
 				break
 			}
 
@@ -496,9 +552,25 @@ encodeLoop:
 			panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
 		}
 
+		if debugAsserts && t < 0 {
+			panic(fmt.Sprintf("t (%d) < 0 ", t))
+		}
 		// Extend the 4-byte match as long as possible.
 		//l := e.matchlenNoHist(s+4, t+4, src) + 4
-		l := int32(matchLen(src[s+4:], src[t+4:])) + 4
+		// l := int32(matchLen(src[s+4:], src[t+4:])) + 4
+		var l int32
+		{
+			a := src[s+4:]
+			b := src[t+4:]
+			endI := len(a) & (math.MaxInt32 - 7)
+			l = int32(endI) + 4
+			for i := 0; i < endI; i += 8 {
+				if diff := load64(a, i) ^ load64(b, i); diff != 0 {
+					l = int32(i+bits.TrailingZeros64(diff)>>3) + 4
+					break
+				}
+			}
+		}
 
 		// Extend backwards
 		tMin := s - e.maxMatchOff
@@ -536,7 +608,20 @@ encodeLoop:
 			// We have at least 4 byte match.
 			// No need to check backwards. We come straight from a match
 			//l := 4 + e.matchlenNoHist(s+4, o2+4, src)
-			l := 4 + int32(matchLen(src[s+4:], src[o2+4:]))
+			// l := 4 + int32(matchLen(src[s+4:], src[o2+4:]))
+			var l int32
+			{
+				a := src[s+4:]
+				b := src[o2+4:]
+				endI := len(a) & (math.MaxInt32 - 7)
+				l = int32(endI) + 4
+				for i := 0; i < endI; i += 8 {
+					if diff := load64(a, i) ^ load64(b, i); diff != 0 {
+						l = int32(i+bits.TrailingZeros64(diff)>>3) + 4
+						break
+					}
+				}
+			}
 
 			// Store this, since we have it.
 			nextHash := hash6(cv, hashLog)
@@ -569,9 +654,13 @@ encodeLoop:
 	if debug {
 		println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits)
 	}
+	// We do not store history, so we must offset e.cur to avoid false matches for next user.
+	if e.cur < bufferReset {
+		e.cur += int32(len(src))
+	}
 }
 
-func (e *fastEncoder) addBlock(src []byte) int32 {
+func (e *fastBase) addBlock(src []byte) int32 {
 	if debugAsserts && e.cur > bufferReset {
 		panic(fmt.Sprintf("ecur (%d) > buffer reset (%d)", e.cur, bufferReset))
 	}
@@ -602,17 +691,17 @@ func (e *fastEncoder) addBlock(src []byte) int32 {
 
 // useBlock will replace the block with the provided one,
 // but transfer recent offsets from the previous.
-func (e *fastEncoder) UseBlock(enc *blockEnc) {
+func (e *fastBase) UseBlock(enc *blockEnc) {
 	enc.reset(e.blk)
 	e.blk = enc
 }
 
-func (e *fastEncoder) matchlenNoHist(s, t int32, src []byte) int32 {
+func (e *fastBase) matchlenNoHist(s, t int32, src []byte) int32 {
 	// Extend the match to be as long as possible.
 	return int32(matchLen(src[s:], src[t:]))
 }
 
-func (e *fastEncoder) matchlen(s, t int32, src []byte) int32 {
+func (e *fastBase) matchlen(s, t int32, src []byte) int32 {
 	if debugAsserts {
 		if s < 0 {
 			err := fmt.Sprintf("s (%d) < 0", s)
@@ -626,18 +715,17 @@ func (e *fastEncoder) matchlen(s, t int32, src []byte) int32 {
 			err := fmt.Sprintf("s (%d) - t (%d) > maxMatchOff (%d)", s, t, e.maxMatchOff)
 			panic(err)
 		}
-	}
-	s1 := int(s) + maxMatchLength - 4
-	if s1 > len(src) {
-		s1 = len(src)
+		if len(src)-int(s) > maxCompressedBlockSize {
+			panic(fmt.Sprintf("len(src)-s (%d) > maxCompressedBlockSize (%d)", len(src)-int(s), maxCompressedBlockSize))
+		}
 	}
 
 	// Extend the match to be as long as possible.
-	return int32(matchLen(src[s:s1], src[t:]))
+	return int32(matchLen(src[s:], src[t:]))
 }
 
 // Reset the encoding table.
-func (e *fastEncoder) Reset() {
+func (e *fastBase) Reset(singleBlock bool) {
 	if e.blk == nil {
 		e.blk = &blockEnc{}
 		e.blk.init()
@@ -650,7 +738,7 @@ func (e *fastEncoder) Reset() {
 	} else {
 		e.crc.Reset()
 	}
-	if cap(e.hist) < int(e.maxMatchOff*2) {
+	if !singleBlock && cap(e.hist) < int(e.maxMatchOff*2) {
 		l := e.maxMatchOff * 2
 		// Make it at least 1MB.
 		if l < 1<<20 {
diff --git a/vendor/github.com/klauspost/compress/zstd/enc_params.go b/vendor/github.com/klauspost/compress/zstd/enc_params.go
index b6779ecb6d..d874116f71 100644
--- a/vendor/github.com/klauspost/compress/zstd/enc_params.go
+++ b/vendor/github.com/klauspost/compress/zstd/enc_params.go
@@ -4,6 +4,8 @@
 
 package zstd
 
+/*
+// encParams are not really used, just here for reference.
 type encParams struct {
 	// largest match distance : larger == more compression, more memory needed during decompression
 	windowLog uint8
@@ -152,3 +154,4 @@ var defEncParams = [4][]encParams{
 		{14, 15, 15, 10, 3, 999, strategyBtultra2}, // level 22.
 	},
 }
+*/
diff --git a/vendor/github.com/klauspost/compress/zstd/encoder.go b/vendor/github.com/klauspost/compress/zstd/encoder.go
index 4032fb9fc8..95ebc3d84e 100644
--- a/vendor/github.com/klauspost/compress/zstd/encoder.go
+++ b/vendor/github.com/klauspost/compress/zstd/encoder.go
@@ -35,21 +35,22 @@ type encoder interface {
 	AppendCRC([]byte) []byte
 	WindowSize(size int) int32
 	UseBlock(*blockEnc)
-	Reset()
+	Reset(singleBlock bool)
 }
 
 type encoderState struct {
-	w             io.Writer
-	filling       []byte
-	current       []byte
-	previous      []byte
-	encoder       encoder
-	writing       *blockEnc
-	err           error
-	writeErr      error
-	nWritten      int64
-	headerWritten bool
-	eofWritten    bool
+	w                io.Writer
+	filling          []byte
+	current          []byte
+	previous         []byte
+	encoder          encoder
+	writing          *blockEnc
+	err              error
+	writeErr         error
+	nWritten         int64
+	headerWritten    bool
+	eofWritten       bool
+	fullFrameWritten bool
 
 	// This waitgroup indicates an encode is running.
 	wg sync.WaitGroup
@@ -71,27 +72,26 @@ func NewWriter(w io.Writer, opts ...EOption) (*Encoder, error) {
 	}
 	if w != nil {
 		e.Reset(w)
-	} else {
-		e.init.Do(func() {
-			e.initialize()
-		})
 	}
 	return &e, nil
 }
 
 func (e *Encoder) initialize() {
+	if e.o.concurrent == 0 {
+		e.o.setDefault()
+	}
 	e.encoders = make(chan encoder, e.o.concurrent)
 	for i := 0; i < e.o.concurrent; i++ {
-		e.encoders <- e.o.encoder()
+		enc := e.o.encoder()
+		// If not single block, history will be allocated on first use.
+		enc.Reset(true)
+		e.encoders <- enc
 	}
 }
 
 // Reset will re-initialize the writer and new writes will encode to the supplied writer
 // as a new, independent stream.
 func (e *Encoder) Reset(w io.Writer) {
-	e.init.Do(func() {
-		e.initialize()
-	})
 	s := &e.state
 	s.wg.Wait()
 	s.wWg.Wait()
@@ -115,9 +115,10 @@ func (e *Encoder) Reset(w io.Writer) {
 	s.filling = s.filling[:0]
 	s.current = s.current[:0]
 	s.previous = s.previous[:0]
-	s.encoder.Reset()
+	s.encoder.Reset(false)
 	s.headerWritten = false
 	s.eofWritten = false
+	s.fullFrameWritten = false
 	s.w = w
 	s.err = nil
 	s.nWritten = 0
@@ -176,6 +177,23 @@ func (e *Encoder) nextBlock(final bool) error {
 		return fmt.Errorf("block > maxStoreBlockSize")
 	}
 	if !s.headerWritten {
+		// If we have a single block encode, do a sync compression.
+		if final && len(s.filling) > 0 {
+			s.current = e.EncodeAll(s.filling, s.current[:0])
+			var n2 int
+			n2, s.err = s.w.Write(s.current)
+			if s.err != nil {
+				return s.err
+			}
+			s.nWritten += int64(n2)
+			s.current = s.current[:0]
+			s.filling = s.filling[:0]
+			s.headerWritten = true
+			s.fullFrameWritten = true
+			s.eofWritten = true
+			return nil
+		}
+
 		var tmp [maxHeaderSize]byte
 		fh := frameHeader{
 			ContentSize:   0,
@@ -263,7 +281,7 @@ func (e *Encoder) nextBlock(final bool) error {
 			// If we got the exact same number of literals as input,
 			// assume the literals cannot be compressed.
 			if len(src) != len(blk.literals) || len(src) != e.o.blockSize {
-				err = blk.encode(e.o.noEntropy)
+				err = blk.encode(e.o.noEntropy, !e.o.allLitEntropy)
 			}
 			switch err {
 			case errIncompressible:
@@ -298,7 +316,9 @@ func (e *Encoder) ReadFrom(r io.Reader) (n int64, err error) {
 	src := e.state.filling
 	for {
 		n2, err := r.Read(src)
-		_, _ = e.state.encoder.CRC().Write(src[:n2])
+		if e.o.crc {
+			_, _ = e.state.encoder.CRC().Write(src[:n2])
+		}
 		// src is now the unfilled part...
 		src = src[n2:]
 		n += int64(n2)
@@ -363,6 +383,9 @@ func (e *Encoder) Close() error {
 	if err != nil {
 		return err
 	}
+	if e.state.fullFrameWritten {
+		return s.err
+	}
 	s.wg.Wait()
 	s.wWg.Wait()
 
@@ -422,18 +445,14 @@ func (e *Encoder) EncodeAll(src, dst []byte) []byte {
 		}
 		return dst
 	}
-	e.init.Do(func() {
-		e.o.setDefault()
-		e.initialize()
-	})
+	e.init.Do(e.initialize)
 	enc := <-e.encoders
 	defer func() {
 		// Release encoder reference to last block.
-		enc.Reset()
+		// If a non-single block is needed the encoder will reset again.
+		enc.Reset(true)
 		e.encoders <- enc
 	}()
-	enc.Reset()
-	blk := enc.Block()
 	// Use single segments when above minimum window and below 1MB.
 	single := len(src) < 1<<20 && len(src) > MinWindowSize
 	if e.o.single != nil {
@@ -456,12 +475,13 @@ func (e *Encoder) EncodeAll(src, dst []byte) []byte {
 		panic(err)
 	}
 
-	if len(src) <= e.o.blockSize && len(src) <= maxBlockSize {
+	// If we can do everything in one block, prefer that.
+	if len(src) <= maxCompressedBlockSize {
 		// Slightly faster with no history and everything in one block.
 		if e.o.crc {
 			_, _ = enc.CRC().Write(src)
 		}
-		blk.reset(nil)
+		blk := enc.Block()
 		blk.last = true
 		enc.EncodeNoHist(blk, src)
 
@@ -472,7 +492,7 @@ func (e *Encoder) EncodeAll(src, dst []byte) []byte {
 		if len(blk.literals) != len(src) || len(src) != e.o.blockSize {
 			// Output directly to dst
 			blk.output = dst
-			err = blk.encode(e.o.noEntropy)
+			err = blk.encode(e.o.noEntropy, !e.o.allLitEntropy)
 		}
 
 		switch err {
@@ -488,6 +508,8 @@ func (e *Encoder) EncodeAll(src, dst []byte) []byte {
 		}
 		blk.output = oldout
 	} else {
+		enc.Reset(false)
+		blk := enc.Block()
 		for len(src) > 0 {
 			todo := src
 			if len(todo) > e.o.blockSize {
@@ -507,7 +529,7 @@ func (e *Encoder) EncodeAll(src, dst []byte) []byte {
 			// If we got the exact same number of literals as input,
 			// assume the literals cannot be compressed.
 			if len(blk.literals) != len(todo) || len(todo) != e.o.blockSize {
-				err = blk.encode(e.o.noEntropy)
+				err = blk.encode(e.o.noEntropy, !e.o.allLitEntropy)
 			}
 
 			switch err {
diff --git a/vendor/github.com/klauspost/compress/zstd/encoder_options.go b/vendor/github.com/klauspost/compress/zstd/encoder_options.go
index 40eb457331..dfac14ddde 100644
--- a/vendor/github.com/klauspost/compress/zstd/encoder_options.go
+++ b/vendor/github.com/klauspost/compress/zstd/encoder_options.go
@@ -12,15 +12,18 @@ type EOption func(*encoderOptions) error
 
 // options retains accumulated state of multiple options.
 type encoderOptions struct {
-	concurrent int
-	crc        bool
-	single     *bool
-	pad        int
-	blockSize  int
-	windowSize int
-	level      EncoderLevel
-	fullZero   bool
-	noEntropy  bool
+	concurrent      int
+	level           EncoderLevel
+	single          *bool
+	pad             int
+	blockSize       int
+	windowSize      int
+	crc             bool
+	fullZero        bool
+	noEntropy       bool
+	allLitEntropy   bool
+	customWindow    bool
+	customALEntropy bool
 }
 
 func (o *encoderOptions) setDefault() {
@@ -30,7 +33,7 @@ func (o *encoderOptions) setDefault() {
 		crc:        true,
 		single:     nil,
 		blockSize:  1 << 16,
-		windowSize: 1 << 22,
+		windowSize: 8 << 20,
 		level:      SpeedDefault,
 	}
 }
@@ -39,9 +42,11 @@ func (o *encoderOptions) setDefault() {
 func (o encoderOptions) encoder() encoder {
 	switch o.level {
 	case SpeedDefault:
-		return &doubleFastEncoder{fastEncoder: fastEncoder{maxMatchOff: int32(o.windowSize)}}
+		return &doubleFastEncoder{fastEncoder: fastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize)}}}
+	case SpeedBetterCompression:
+		return &betterFastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize)}}
 	case SpeedFastest:
-		return &fastEncoder{maxMatchOff: int32(o.windowSize)}
+		return &fastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize)}}
 	}
 	panic("unknown compression level")
 }
@@ -67,7 +72,7 @@ func WithEncoderConcurrency(n int) EOption {
 }
 
 // WithWindowSize will set the maximum allowed back-reference distance.
-// The value must be a power of two between WindowSizeMin and WindowSizeMax.
+// The value must be a power of two between MinWindowSize and MaxWindowSize.
 // A larger value will enable better compression but allocate more memory and,
 // for above-default values, take considerably longer.
 // The default value is determined by the compression level.
@@ -83,6 +88,7 @@ func WithWindowSize(n int) EOption {
 		}
 
 		o.windowSize = n
+		o.customWindow = true
 		if o.blockSize > o.windowSize {
 			o.blockSize = o.windowSize
 		}
@@ -130,18 +136,18 @@ const (
 	// This is roughly equivalent to the default Zstandard mode (level 3).
 	SpeedDefault
 
+	// SpeedBetterCompression will yield better compression than the default.
+	// Currently it is about zstd level 7-8 with ~ 2x-3x the default CPU usage.
+	// By using this, notice that CPU usage may go up in the future.
+	SpeedBetterCompression
+
 	// speedLast should be kept as the last actual compression option.
 	// The is not for external usage, but is used to keep track of the valid options.
 	speedLast
 
-	// SpeedBetterCompression will (in the future) yield better compression than the default,
-	// but at approximately 4x the CPU usage of the default.
-	// For now this is not implemented.
-	SpeedBetterCompression = SpeedDefault
-
 	// SpeedBestCompression will choose the best available compression option.
 	// For now this is not implemented.
-	SpeedBestCompression = SpeedDefault
+	SpeedBestCompression = SpeedBetterCompression
 )
 
 // EncoderLevelFromString will convert a string representation of an encoding level back
@@ -163,8 +169,10 @@ func EncoderLevelFromZstd(level int) EncoderLevel {
 	switch {
 	case level < 3:
 		return SpeedFastest
-	case level >= 3:
+	case level >= 3 && level < 6:
 		return SpeedDefault
+	case level > 5:
+		return SpeedBetterCompression
 	}
 	return SpeedDefault
 }
@@ -176,6 +184,8 @@ func (e EncoderLevel) String() string {
 		return "fastest"
 	case SpeedDefault:
 		return "default"
+	case SpeedBetterCompression:
+		return "better"
 	default:
 		return "invalid"
 	}
@@ -189,6 +199,20 @@ func WithEncoderLevel(l EncoderLevel) EOption {
 			return fmt.Errorf("unknown encoder level")
 		}
 		o.level = l
+		if !o.customWindow {
+			switch o.level {
+			case SpeedFastest:
+				o.windowSize = 4 << 20
+			case SpeedDefault:
+				o.windowSize = 8 << 20
+			case SpeedBetterCompression:
+				o.windowSize = 16 << 20
+			}
+		}
+		if !o.customALEntropy {
+			o.allLitEntropy = l > SpeedFastest
+		}
+
 		return nil
 	}
 }
@@ -203,6 +227,18 @@ func WithZeroFrames(b bool) EOption {
 	}
 }
 
+// WithAllLitEntropyCompression will apply entropy compression if no matches are found.
+// Disabling this will skip incompressible data faster, but in cases with no matches but
+// skewed character distribution compression is lost.
+// Default value depends on the compression level selected.
+func WithAllLitEntropyCompression(b bool) EOption {
+	return func(o *encoderOptions) error {
+		o.customALEntropy = true
+		o.allLitEntropy = b
+		return nil
+	}
+}
+
 // WithNoEntropyCompression will always skip entropy compression of literals.
 // This can be useful if content has matches, but unlikely to benefit from entropy
 // compression. Usually the slight speed improvement is not worth enabling this.
diff --git a/vendor/github.com/klauspost/compress/zstd/framedec.go b/vendor/github.com/klauspost/compress/zstd/framedec.go
index cda590b5f7..fc4a566d39 100644
--- a/vendor/github.com/klauspost/compress/zstd/framedec.go
+++ b/vendor/github.com/klauspost/compress/zstd/framedec.go
@@ -16,16 +16,11 @@ import (
 )
 
 type frameDec struct {
-	o         decoderOptions
-	crc       hash.Hash64
-	frameDone sync.WaitGroup
-	offset    int64
+	o      decoderOptions
+	crc    hash.Hash64
+	offset int64
 
-	WindowSize       uint64
-	DictionaryID     uint32
-	FrameContentSize uint64
-	HasCheckSum      bool
-	SingleSegment    bool
+	WindowSize uint64
 
 	// maxWindowSize is the maximum windows size to support.
 	// should never be bigger than max-int.
@@ -42,9 +37,16 @@ type frameDec struct {
 	// Byte buffer that can be reused for small input blocks.
 	bBuf byteBuf
 
+	FrameContentSize uint64
+	frameDone        sync.WaitGroup
+
+	DictionaryID  *uint32
+	HasCheckSum   bool
+	SingleSegment bool
+
 	// asyncRunning indicates whether the async routine processes input on 'decoding'.
-	asyncRunning   bool
 	asyncRunningMu sync.Mutex
+	asyncRunning   bool
 }
 
 const (
@@ -140,7 +142,7 @@ func (d *frameDec) reset(br byteBuffer) error {
 
 	// Read Dictionary_ID
 	// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#dictionary_id
-	d.DictionaryID = 0
+	d.DictionaryID = nil
 	if size := fhd & 3; size != 0 {
 		if size == 3 {
 			size = 4
@@ -152,19 +154,22 @@ func (d *frameDec) reset(br byteBuffer) error {
 			}
 			return io.ErrUnexpectedEOF
 		}
+		var id uint32
 		switch size {
 		case 1:
-			d.DictionaryID = uint32(b[0])
+			id = uint32(b[0])
 		case 2:
-			d.DictionaryID = uint32(b[0]) | (uint32(b[1]) << 8)
+			id = uint32(b[0]) | (uint32(b[1]) << 8)
 		case 4:
-			d.DictionaryID = uint32(b[0]) | (uint32(b[1]) << 8) | (uint32(b[2]) << 16) | (uint32(b[3]) << 24)
+			id = uint32(b[0]) | (uint32(b[1]) << 8) | (uint32(b[2]) << 16) | (uint32(b[3]) << 24)
 		}
 		if debug {
-			println("Dict size", size, "ID:", d.DictionaryID)
+			println("Dict size", size, "ID:", id)
 		}
-		if d.DictionaryID != 0 {
-			return ErrUnknownDictionary
+		if id > 0 {
+			// ID 0 means "sorry, no dictionary anyway".
+			// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#dictionary-format
+			d.DictionaryID = &id
 		}
 	}
 
@@ -231,7 +236,11 @@ func (d *frameDec) reset(br byteBuffer) error {
 		return ErrWindowSizeTooSmall
 	}
 	d.history.windowSize = int(d.WindowSize)
-	d.history.maxSize = d.history.windowSize + maxBlockSize
+	if d.o.lowMem && d.history.windowSize < maxBlockSize {
+		d.history.maxSize = d.history.windowSize * 2
+	} else {
+		d.history.maxSize = d.history.windowSize + maxBlockSize
+	}
 	// history contains input - maybe we do something
 	d.rawInput = br
 	return nil
@@ -318,8 +327,8 @@ func (d *frameDec) checkCRC() error {
 
 func (d *frameDec) initAsync() {
 	if !d.o.lowMem && !d.SingleSegment {
-		// set max extra size history to 20MB.
-		d.history.maxSize = d.history.windowSize + maxBlockSize*10
+		// set max extra size history to 10MB.
+		d.history.maxSize = d.history.windowSize + maxBlockSize*5
 	}
 	// re-alloc if more than one extra block size.
 	if d.o.lowMem && cap(d.history.b) > d.history.maxSize+maxBlockSize {
@@ -345,8 +354,6 @@ func (d *frameDec) initAsync() {
 // When the frame has finished decoding the *bufio.Reader
 // containing the remaining input will be sent on frameDec.frameDone.
 func (d *frameDec) startDecoder(output chan decodeOutput) {
-	// TODO: Init to dictionary
-	d.history.reset()
 	written := int64(0)
 
 	defer func() {
@@ -439,8 +446,6 @@ func (d *frameDec) startDecoder(output chan decodeOutput) {
 
 // runDecoder will create a sync decoder that will decode a block of data.
 func (d *frameDec) runDecoder(dst []byte, dec *blockDec) ([]byte, error) {
-	// TODO: Init to dictionary
-	d.history.reset()
 	saved := d.history.b
 
 	// We use the history for output to avoid copying it.
diff --git a/vendor/github.com/klauspost/compress/zstd/fse_decoder.go b/vendor/github.com/klauspost/compress/zstd/fse_decoder.go
index e002be98b9..e6d3d49b39 100644
--- a/vendor/github.com/klauspost/compress/zstd/fse_decoder.go
+++ b/vendor/github.com/klauspost/compress/zstd/fse_decoder.go
@@ -19,7 +19,7 @@ const (
 	 *  Increasing memory usage improves compression ratio
 	 *  Reduced memory usage can improve speed, due to cache effect
 	 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
-	maxMemoryUsage = 11
+	maxMemoryUsage = tablelogAbsoluteMax + 2
 
 	maxTableLog    = maxMemoryUsage - 2
 	maxTablesize   = 1 << maxTableLog
@@ -55,7 +55,7 @@ func (s *fseDecoder) readNCount(b *byteReader, maxSymbol uint16) error {
 	if b.remain() < 4 {
 		return errors.New("input too small")
 	}
-	bitStream := b.Uint32()
+	bitStream := b.Uint32NC()
 	nbBits := uint((bitStream & 0xF) + minTablelog) // extract tableLog
 	if nbBits > tablelogAbsoluteMax {
 		println("Invalid tablelog:", nbBits)
@@ -79,7 +79,8 @@ func (s *fseDecoder) readNCount(b *byteReader, maxSymbol uint16) error {
 				n0 += 24
 				if r := b.remain(); r > 5 {
 					b.advance(2)
-					bitStream = b.Uint32() >> bitCount
+					// The check above should make sure we can read 32 bits
+					bitStream = b.Uint32NC() >> bitCount
 				} else {
 					// end of bit stream
 					bitStream >>= 16
@@ -104,10 +105,11 @@ func (s *fseDecoder) readNCount(b *byteReader, maxSymbol uint16) error {
 				charnum++
 			}
 
-			if r := b.remain(); r >= 7 || r+int(bitCount>>3) >= 4 {
+			if r := b.remain(); r >= 7 || r-int(bitCount>>3) >= 4 {
 				b.advance(bitCount >> 3)
 				bitCount &= 7
-				bitStream = b.Uint32() >> bitCount
+				// The check above should make sure we can read 32 bits
+				bitStream = b.Uint32NC() >> bitCount
 			} else {
 				bitStream >>= 2
 			}
@@ -148,17 +150,16 @@ func (s *fseDecoder) readNCount(b *byteReader, maxSymbol uint16) error {
 			threshold >>= 1
 		}
 
-		//println("b.off:", b.off, "len:", len(b.b), "bc:", bitCount, "remain:", b.remain())
-		if r := b.remain(); r >= 7 || r+int(bitCount>>3) >= 4 {
+		if r := b.remain(); r >= 7 || r-int(bitCount>>3) >= 4 {
 			b.advance(bitCount >> 3)
 			bitCount &= 7
+			// The check above should make sure we can read 32 bits
+			bitStream = b.Uint32NC() >> (bitCount & 31)
 		} else {
 			bitCount -= (uint)(8 * (len(b.b) - 4 - b.off))
 			b.off = len(b.b) - 4
-			//println("b.off:", b.off, "len:", len(b.b), "bc:", bitCount, "iend", iend)
+			bitStream = b.Uint32() >> (bitCount & 31)
 		}
-		bitStream = b.Uint32() >> (bitCount & 31)
-		//printf("bitstream is now: 0b%b", bitStream)
 	}
 	s.symbolLen = charnum
 	if s.symbolLen <= 1 {
diff --git a/vendor/github.com/klauspost/compress/zstd/history.go b/vendor/github.com/klauspost/compress/zstd/history.go
index e8c419bd53..f418f50fcd 100644
--- a/vendor/github.com/klauspost/compress/zstd/history.go
+++ b/vendor/github.com/klauspost/compress/zstd/history.go
@@ -17,6 +17,7 @@ type history struct {
 	windowSize    int
 	maxSize       int
 	error         bool
+	dict          *dict
 }
 
 // reset will reset the history to initial state of a frame.
@@ -36,12 +37,27 @@ func (h *history) reset() {
 	}
 	h.decoders = sequenceDecs{}
 	if h.huffTree != nil {
-		huffDecoderPool.Put(h.huffTree)
+		if h.dict == nil || h.dict.litDec != h.huffTree {
+			huffDecoderPool.Put(h.huffTree)
+		}
 	}
 	h.huffTree = nil
+	h.dict = nil
 	//printf("history created: %+v (l: %d, c: %d)", *h, len(h.b), cap(h.b))
 }
 
+func (h *history) setDict(dict *dict) {
+	if dict == nil {
+		return
+	}
+	h.dict = dict
+	h.decoders.litLengths = dict.llDec
+	h.decoders.offsets = dict.ofDec
+	h.decoders.matchLengths = dict.mlDec
+	h.recentOffsets = dict.offsets
+	h.huffTree = dict.litDec
+}
+
 // append bytes to history.
 // This function will make sure there is space for it,
 // if the buffer has been allocated with enough extra space.
diff --git a/vendor/github.com/klauspost/compress/zstd/seqdec.go b/vendor/github.com/klauspost/compress/zstd/seqdec.go
index 15a45f7b50..7ff870400d 100644
--- a/vendor/github.com/klauspost/compress/zstd/seqdec.go
+++ b/vendor/github.com/klauspost/compress/zstd/seqdec.go
@@ -62,8 +62,10 @@ type sequenceDecs struct {
 	matchLengths sequenceDec
 	prevOffset   [3]int
 	hist         []byte
+	dict         []byte
 	literals     []byte
 	out          []byte
+	windowSize   int
 	maxBits      uint8
 }
 
@@ -82,7 +84,12 @@ func (s *sequenceDecs) initialize(br *bitReader, hist *history, literals, out []
 	s.hist = hist.b
 	s.prevOffset = hist.recentOffsets
 	s.maxBits = s.litLengths.fse.maxBits + s.offsets.fse.maxBits + s.matchLengths.fse.maxBits
+	s.windowSize = hist.windowSize
 	s.out = out
+	s.dict = nil
+	if hist.dict != nil {
+		s.dict = hist.dict.content
+	}
 	return nil
 }
 
@@ -98,23 +105,78 @@ func (s *sequenceDecs) decode(seqs int, br *bitReader, hist []byte) error {
 			printf("reading sequence %d, exceeded available data\n", seqs-i)
 			return io.ErrUnexpectedEOF
 		}
-		var litLen, matchOff, matchLen int
+		var ll, mo, ml int
 		if br.off > 4+((maxOffsetBits+16+16)>>3) {
-			litLen, matchOff, matchLen = s.nextFast(br, llState, mlState, ofState)
+			// inlined function:
+			// ll, mo, ml = s.nextFast(br, llState, mlState, ofState)
+
+			// Final will not read from stream.
+			var llB, mlB, moB uint8
+			ll, llB = llState.final()
+			ml, mlB = mlState.final()
+			mo, moB = ofState.final()
+
+			// extra bits are stored in reverse order.
+			br.fillFast()
+			mo += br.getBits(moB)
+			if s.maxBits > 32 {
+				br.fillFast()
+			}
+			ml += br.getBits(mlB)
+			ll += br.getBits(llB)
+
+			if moB > 1 {
+				s.prevOffset[2] = s.prevOffset[1]
+				s.prevOffset[1] = s.prevOffset[0]
+				s.prevOffset[0] = mo
+			} else {
+				// mo = s.adjustOffset(mo, ll, moB)
+				// Inlined for rather big speedup
+				if ll == 0 {
+					// There is an exception though, when current sequence's literals_length = 0.
+					// In this case, repeated offsets are shifted by one, so an offset_value of 1 means Repeated_Offset2,
+					// an offset_value of 2 means Repeated_Offset3, and an offset_value of 3 means Repeated_Offset1 - 1_byte.
+					mo++
+				}
+
+				if mo == 0 {
+					mo = s.prevOffset[0]
+				} else {
+					var temp int
+					if mo == 3 {
+						temp = s.prevOffset[0] - 1
+					} else {
+						temp = s.prevOffset[mo]
+					}
+
+					if temp == 0 {
+						// 0 is not valid; input is corrupted; force offset to 1
+						println("temp was 0")
+						temp = 1
+					}
+
+					if mo != 1 {
+						s.prevOffset[2] = s.prevOffset[1]
+					}
+					s.prevOffset[1] = s.prevOffset[0]
+					s.prevOffset[0] = temp
+					mo = temp
+				}
+			}
 			br.fillFast()
 		} else {
-			litLen, matchOff, matchLen = s.next(br, llState, mlState, ofState)
+			ll, mo, ml = s.next(br, llState, mlState, ofState)
 			br.fill()
 		}
 
 		if debugSequences {
-			println("Seq", seqs-i-1, "Litlen:", litLen, "matchOff:", matchOff, "(abs) matchLen:", matchLen)
+			println("Seq", seqs-i-1, "Litlen:", ll, "mo:", mo, "(abs) ml:", ml)
 		}
 
-		if litLen > len(s.literals) {
-			return fmt.Errorf("unexpected literal count, want %d bytes, but only %d is available", litLen, len(s.literals))
+		if ll > len(s.literals) {
+			return fmt.Errorf("unexpected literal count, want %d bytes, but only %d is available", ll, len(s.literals))
 		}
-		size := litLen + matchLen + len(s.out)
+		size := ll + ml + len(s.out)
 		if size-startSize > maxBlockSize {
 			return fmt.Errorf("output (%d) bigger than max block size", size)
 		}
@@ -125,49 +187,70 @@ func (s *sequenceDecs) decode(seqs int, br *bitReader, hist []byte) error {
 			s.out = append(s.out, make([]byte, maxBlockSize)...)
 			s.out = s.out[:len(s.out)-maxBlockSize]
 		}
-		if matchLen > maxMatchLen {
-			return fmt.Errorf("match len (%d) bigger than max allowed length", matchLen)
-		}
-		if matchOff > len(s.out)+len(hist)+litLen {
-			return fmt.Errorf("match offset (%d) bigger than current history (%d)", matchOff, len(s.out)+len(hist)+litLen)
-		}
-		if matchOff == 0 && matchLen > 0 {
-			return fmt.Errorf("zero matchoff and matchlen > 0")
+		if ml > maxMatchLen {
+			return fmt.Errorf("match len (%d) bigger than max allowed length", ml)
 		}
 
-		s.out = append(s.out, s.literals[:litLen]...)
-		s.literals = s.literals[litLen:]
+		// Add literals
+		s.out = append(s.out, s.literals[:ll]...)
+		s.literals = s.literals[ll:]
 		out := s.out
 
+		if mo > len(s.out)+len(hist) || mo > s.windowSize {
+			if len(s.dict) == 0 {
+				return fmt.Errorf("match offset (%d) bigger than current history (%d)", mo, len(s.out)+len(hist))
+			}
+
+			// we may be in dictionary.
+			dictO := len(s.dict) - (mo - (len(s.out) + len(hist)))
+			if dictO < 0 || dictO >= len(s.dict) {
+				return fmt.Errorf("match offset (%d) bigger than current history (%d)", mo, len(s.out)+len(hist))
+			}
+			end := dictO + ml
+			if end > len(s.dict) {
+				out = append(out, s.dict[dictO:]...)
+				mo -= len(s.dict) - dictO
+				ml -= len(s.dict) - dictO
+			} else {
+				out = append(out, s.dict[dictO:end]...)
+				mo = 0
+				ml = 0
+			}
+		}
+
+		if mo == 0 && ml > 0 {
+			return fmt.Errorf("zero matchoff and matchlen (%d) > 0", ml)
+		}
+
 		// Copy from history.
 		// TODO: Blocks without history could be made to ignore this completely.
-		if v := matchOff - len(s.out); v > 0 {
+		if v := mo - len(s.out); v > 0 {
 			// v is the start position in history from end.
 			start := len(s.hist) - v
-			if matchLen > v {
+			if ml > v {
 				// Some goes into current block.
 				// Copy remainder of history
 				out = append(out, s.hist[start:]...)
-				matchOff -= v
-				matchLen -= v
+				mo -= v
+				ml -= v
 			} else {
-				out = append(out, s.hist[start:start+matchLen]...)
-				matchLen = 0
+				out = append(out, s.hist[start:start+ml]...)
+				ml = 0
 			}
 		}
 		// We must be in current buffer now
-		if matchLen > 0 {
-			start := len(s.out) - matchOff
-			if matchLen <= len(s.out)-start {
+		if ml > 0 {
+			start := len(s.out) - mo
+			if ml <= len(s.out)-start {
 				// No overlap
-				out = append(out, s.out[start:start+matchLen]...)
+				out = append(out, s.out[start:start+ml]...)
 			} else {
 				// Overlapping copy
 				// Extend destination slice and copy one byte at the time.
-				out = out[:len(out)+matchLen]
-				src := out[start : start+matchLen]
+				out = out[:len(out)+ml]
+				src := out[start : start+ml]
 				// Destination is the space we just added.
-				dst := out[len(out)-matchLen:]
+				dst := out[len(out)-ml:]
 				dst = dst[:len(src)]
 				for i := range src {
 					dst[i] = src[i]
diff --git a/vendor/github.com/klauspost/compress/zstd/snappy.go b/vendor/github.com/klauspost/compress/zstd/snappy.go
index 356956ba25..690428cd24 100644
--- a/vendor/github.com/klauspost/compress/zstd/snappy.go
+++ b/vendor/github.com/klauspost/compress/zstd/snappy.go
@@ -178,7 +178,7 @@ func (r *SnappyConverter) Convert(in io.Reader, w io.Writer) (int64, error) {
 				r.err = ErrSnappyCorrupt
 				return written, r.err
 			}
-			err = r.block.encode(false)
+			err = r.block.encode(false, false)
 			switch err {
 			case errIncompressible:
 				r.block.popOffsets()
diff --git a/vendor/github.com/klauspost/compress/zstd/zstd.go b/vendor/github.com/klauspost/compress/zstd/zstd.go
index 5e0b64cccf..0807719c8b 100644
--- a/vendor/github.com/klauspost/compress/zstd/zstd.go
+++ b/vendor/github.com/klauspost/compress/zstd/zstd.go
@@ -87,6 +87,17 @@ func printf(format string, a ...interface{}) {
 	}
 }
 
+// matchLenFast does matching, but will not match the last up to 7 bytes.
+func matchLenFast(a, b []byte) int {
+	endI := len(a) & (math.MaxInt32 - 7)
+	for i := 0; i < endI; i += 8 {
+		if diff := load64(a, i) ^ load64(b, i); diff != 0 {
+			return i + bits.TrailingZeros64(diff)>>3
+		}
+	}
+	return endI
+}
+
 // matchLen returns the maximum length.
 // a must be the shortest of the two.
 // The function also returns whether all bytes matched.
@@ -97,33 +108,18 @@ func matchLen(a, b []byte) int {
 			return i + (bits.TrailingZeros64(diff) >> 3)
 		}
 	}
+
 	checked := (len(a) >> 3) << 3
 	a = a[checked:]
 	b = b[checked:]
-	// TODO: We could do a 4 check.
 	for i := range a {
 		if a[i] != b[i] {
-			return int(i) + checked
+			return i + checked
 		}
 	}
 	return len(a) + checked
 }
 
-// matchLen returns a match length in src between index s and t
-func matchLenIn(src []byte, s, t int32) int32 {
-	s1 := len(src)
-	b := src[t:]
-	a := src[s:s1]
-	b = b[:len(a)]
-	// Extend the match to be as long as possible.
-	for i := range a {
-		if a[i] != b[i] {
-			return int32(i)
-		}
-	}
-	return int32(len(a))
-}
-
 func load3232(b []byte, i int32) uint32 {
 	// Help the compiler eliminate bounds checks on the read so it can be done in a single read.
 	b = b[i:]