diff --git a/vendor/github.com/pierrec/lz4/block.go b/vendor/github.com/pierrec/lz4/block.go
new file mode 100644
index 0000000..664d9be
--- /dev/null
+++ b/vendor/github.com/pierrec/lz4/block.go
@@ -0,0 +1,413 @@
+package lz4
+
+import (
+	"encoding/binary"
+	"math/bits"
+	"sync"
+)
+
+// blockHash hashes the lower 6 bytes into a value < htSize.
+func blockHash(x uint64) uint32 {
+	const prime6bytes = 227718039650203
+	return uint32(((x << (64 - 48)) * prime6bytes) >> (64 - hashLog))
+}
+
+// CompressBlockBound returns the maximum size of a given buffer of size n, when not compressible.
+func CompressBlockBound(n int) int {
+	return n + n/255 + 16
+}
+
+// UncompressBlock uncompresses the source buffer into the destination one,
+// and returns the uncompressed size.
+//
+// The destination buffer must be sized appropriately.
+//
+// An error is returned if the source data is invalid or the destination buffer is too small.
+func UncompressBlock(src, dst []byte) (int, error) {
+	if len(src) == 0 {
+		return 0, nil
+	}
+	if di := decodeBlock(dst, src); di >= 0 {
+		return di, nil
+	}
+	return 0, ErrInvalidSourceShortBuffer
+}
+
+// CompressBlock compresses the source buffer into the destination one.
+// This is the fast version of LZ4 compression and also the default one.
+//
+// The argument hashTable is scratch space for a hash table used by the
+// compressor. If provided, it should have length at least 1<<16. If it is
+// shorter (or nil), CompressBlock allocates its own hash table.
+//
+// The size of the compressed data is returned.
+//
+// If the destination buffer size is lower than CompressBlockBound and
+// the compressed size is 0 and no error, then the data is incompressible.
+//
+// An error is returned if the destination buffer is too small.
+func CompressBlock(src, dst []byte, hashTable []int) (_ int, err error) {
+	defer recoverBlock(&err)
+
+	// Return 0, nil only if the destination buffer size is < CompressBlockBound.
+	isNotCompressible := len(dst) < CompressBlockBound(len(src))
+
+	// adaptSkipLog sets how quickly the compressor begins skipping blocks when data is incompressible.
+	// This significantly speeds up incompressible data and usually has very small impact on compression.
+	// bytes to skip =  1 + (bytes since last match >> adaptSkipLog)
+	const adaptSkipLog = 7
+	if len(hashTable) < htSize {
+		htIface := htPool.Get()
+		defer htPool.Put(htIface)
+		hashTable = (*(htIface).(*[htSize]int))[:]
+	}
+	// Prove to the compiler the table has at least htSize elements.
+	// The compiler can see that "uint32() >> hashShift" cannot be out of bounds.
+	hashTable = hashTable[:htSize]
+
+	// si: Current position of the search.
+	// anchor: Position of the current literals.
+	var si, di, anchor int
+	sn := len(src) - mfLimit
+	if sn <= 0 {
+		goto lastLiterals
+	}
+
+	// Fast scan strategy: the hash table only stores the last 4 bytes sequences.
+	for si < sn {
+		// Hash the next 6 bytes (sequence)...
+		match := binary.LittleEndian.Uint64(src[si:])
+		h := blockHash(match)
+		h2 := blockHash(match >> 8)
+
+		// We check a match at s, s+1 and s+2 and pick the first one we get.
+		// Checking 3 only requires us to load the source one.
+		ref := hashTable[h]
+		ref2 := hashTable[h2]
+		hashTable[h] = si
+		hashTable[h2] = si + 1
+		offset := si - ref
+
+		// If offset <= 0 we got an old entry in the hash table.
+		if offset <= 0 || offset >= winSize || // Out of window.
+			uint32(match) != binary.LittleEndian.Uint32(src[ref:]) { // Hash collision on different matches.
+			// No match. Start calculating another hash.
+			// The processor can usually do this out-of-order.
+			h = blockHash(match >> 16)
+			ref = hashTable[h]
+
+			// Check the second match at si+1
+			si += 1
+			offset = si - ref2
+
+			if offset <= 0 || offset >= winSize ||
+				uint32(match>>8) != binary.LittleEndian.Uint32(src[ref2:]) {
+				// No match. Check the third match at si+2
+				si += 1
+				offset = si - ref
+				hashTable[h] = si
+
+				if offset <= 0 || offset >= winSize ||
+					uint32(match>>16) != binary.LittleEndian.Uint32(src[ref:]) {
+					// Skip one extra byte (at si+3) before we check 3 matches again.
+					si += 2 + (si-anchor)>>adaptSkipLog
+					continue
+				}
+			}
+		}
+
+		// Match found.
+		lLen := si - anchor // Literal length.
+		// We already matched 4 bytes.
+		mLen := 4
+
+		// Extend backwards if we can, reducing literals.
+		tOff := si - offset - 1
+		for lLen > 0 && tOff >= 0 && src[si-1] == src[tOff] {
+			si--
+			tOff--
+			lLen--
+			mLen++
+		}
+
+		// Add the match length, so we continue search at the end.
+		// Use mLen to store the offset base.
+		si, mLen = si+mLen, si+minMatch
+
+		// Find the longest match by looking by batches of 8 bytes.
+		for si+8 < sn {
+			x := binary.LittleEndian.Uint64(src[si:]) ^ binary.LittleEndian.Uint64(src[si-offset:])
+			if x == 0 {
+				si += 8
+			} else {
+				// Stop is first non-zero byte.
+				si += bits.TrailingZeros64(x) >> 3
+				break
+			}
+		}
+
+		mLen = si - mLen
+		if mLen < 0xF {
+			dst[di] = byte(mLen)
+		} else {
+			dst[di] = 0xF
+		}
+
+		// Encode literals length.
+		if lLen < 0xF {
+			dst[di] |= byte(lLen << 4)
+		} else {
+			dst[di] |= 0xF0
+			di++
+			l := lLen - 0xF
+			for ; l >= 0xFF; l -= 0xFF {
+				dst[di] = 0xFF
+				di++
+			}
+			dst[di] = byte(l)
+		}
+		di++
+
+		// Literals.
+		copy(dst[di:di+lLen], src[anchor:anchor+lLen])
+		di += lLen + 2
+		anchor = si
+
+		// Encode offset.
+		_ = dst[di] // Bound check elimination.
+		dst[di-2], dst[di-1] = byte(offset), byte(offset>>8)
+
+		// Encode match length part 2.
+		if mLen >= 0xF {
+			for mLen -= 0xF; mLen >= 0xFF; mLen -= 0xFF {
+				dst[di] = 0xFF
+				di++
+			}
+			dst[di] = byte(mLen)
+			di++
+		}
+		// Check if we can load next values.
+		if si >= sn {
+			break
+		}
+		// Hash match end-2
+		h = blockHash(binary.LittleEndian.Uint64(src[si-2:]))
+		hashTable[h] = si - 2
+	}
+
+lastLiterals:
+	if isNotCompressible && anchor == 0 {
+		// Incompressible.
+		return 0, nil
+	}
+
+	// Last literals.
+	lLen := len(src) - anchor
+	if lLen < 0xF {
+		dst[di] = byte(lLen << 4)
+	} else {
+		dst[di] = 0xF0
+		di++
+		for lLen -= 0xF; lLen >= 0xFF; lLen -= 0xFF {
+			dst[di] = 0xFF
+			di++
+		}
+		dst[di] = byte(lLen)
+	}
+	di++
+
+	// Write the last literals.
+	if isNotCompressible && di >= anchor {
+		// Incompressible.
+		return 0, nil
+	}
+	di += copy(dst[di:di+len(src)-anchor], src[anchor:])
+	return di, nil
+}
+
+// Pool of hash tables for CompressBlock.
+var htPool = sync.Pool{
+	New: func() interface{} {
+		return new([htSize]int)
+	},
+}
+
+// blockHash hashes 4 bytes into a value < winSize.
+func blockHashHC(x uint32) uint32 {
+	const hasher uint32 = 2654435761 // Knuth multiplicative hash.
+	return x * hasher >> (32 - winSizeLog)
+}
+
+// CompressBlockHC compresses the source buffer src into the destination dst
+// with max search depth (use 0 or negative value for no max).
+//
+// CompressBlockHC compression ratio is better than CompressBlock but it is also slower.
+//
+// The size of the compressed data is returned.
+//
+// If the destination buffer size is lower than CompressBlockBound and
+// the compressed size is 0 and no error, then the data is incompressible.
+//
+// An error is returned if the destination buffer is too small.
+func CompressBlockHC(src, dst []byte, depth int) (_ int, err error) {
+	defer recoverBlock(&err)
+
+	// Return 0, nil only if the destination buffer size is < CompressBlockBound.
+	isNotCompressible := len(dst) < CompressBlockBound(len(src))
+
+	// adaptSkipLog sets how quickly the compressor begins skipping blocks when data is incompressible.
+	// This significantly speeds up incompressible data and usually has very small impact on compression.
+	// bytes to skip =  1 + (bytes since last match >> adaptSkipLog)
+	const adaptSkipLog = 7
+
+	var si, di, anchor int
+
+	// hashTable: stores the last position found for a given hash
+	// chainTable: stores previous positions for a given hash
+	var hashTable, chainTable [winSize]int
+
+	if depth <= 0 {
+		depth = winSize
+	}
+
+	sn := len(src) - mfLimit
+	if sn <= 0 {
+		goto lastLiterals
+	}
+
+	for si < sn {
+		// Hash the next 4 bytes (sequence).
+		match := binary.LittleEndian.Uint32(src[si:])
+		h := blockHashHC(match)
+
+		// Follow the chain until out of window and give the longest match.
+		mLen := 0
+		offset := 0
+		for next, try := hashTable[h], depth; try > 0 && next > 0 && si-next < winSize; next = chainTable[next&winMask] {
+			// The first (mLen==0) or next byte (mLen>=minMatch) at current match length
+			// must match to improve on the match length.
+			if src[next+mLen] != src[si+mLen] {
+				continue
+			}
+			ml := 0
+			// Compare the current position with a previous with the same hash.
+			for ml < sn-si {
+				x := binary.LittleEndian.Uint64(src[next+ml:]) ^ binary.LittleEndian.Uint64(src[si+ml:])
+				if x == 0 {
+					ml += 8
+				} else {
+					// Stop is first non-zero byte.
+					ml += bits.TrailingZeros64(x) >> 3
+					break
+				}
+			}
+			if ml < minMatch || ml <= mLen {
+				// Match too small (<minMath) or smaller than the current match.
+				continue
+			}
+			// Found a longer match, keep its position and length.
+			mLen = ml
+			offset = si - next
+			// Try another previous position with the same hash.
+			try--
+		}
+		chainTable[si&winMask] = hashTable[h]
+		hashTable[h] = si
+
+		// No match found.
+		if mLen == 0 {
+			si += 1 + (si-anchor)>>adaptSkipLog
+			continue
+		}
+
+		// Match found.
+		// Update hash/chain tables with overlapping bytes:
+		// si already hashed, add everything from si+1 up to the match length.
+		winStart := si + 1
+		if ws := si + mLen - winSize; ws > winStart {
+			winStart = ws
+		}
+		for si, ml := winStart, si+mLen; si < ml; {
+			match >>= 8
+			match |= uint32(src[si+3]) << 24
+			h := blockHashHC(match)
+			chainTable[si&winMask] = hashTable[h]
+			hashTable[h] = si
+			si++
+		}
+
+		lLen := si - anchor
+		si += mLen
+		mLen -= minMatch // Match length does not include minMatch.
+
+		if mLen < 0xF {
+			dst[di] = byte(mLen)
+		} else {
+			dst[di] = 0xF
+		}
+
+		// Encode literals length.
+		if lLen < 0xF {
+			dst[di] |= byte(lLen << 4)
+		} else {
+			dst[di] |= 0xF0
+			di++
+			l := lLen - 0xF
+			for ; l >= 0xFF; l -= 0xFF {
+				dst[di] = 0xFF
+				di++
+			}
+			dst[di] = byte(l)
+		}
+		di++
+
+		// Literals.
+		copy(dst[di:di+lLen], src[anchor:anchor+lLen])
+		di += lLen
+		anchor = si
+
+		// Encode offset.
+		di += 2
+		dst[di-2], dst[di-1] = byte(offset), byte(offset>>8)
+
+		// Encode match length part 2.
+		if mLen >= 0xF {
+			for mLen -= 0xF; mLen >= 0xFF; mLen -= 0xFF {
+				dst[di] = 0xFF
+				di++
+			}
+			dst[di] = byte(mLen)
+			di++
+		}
+	}
+
+	if isNotCompressible && anchor == 0 {
+		// Incompressible.
+		return 0, nil
+	}
+
+	// Last literals.
+lastLiterals:
+	lLen := len(src) - anchor
+	if lLen < 0xF {
+		dst[di] = byte(lLen << 4)
+	} else {
+		dst[di] = 0xF0
+		di++
+		lLen -= 0xF
+		for ; lLen >= 0xFF; lLen -= 0xFF {
+			dst[di] = 0xFF
+			di++
+		}
+		dst[di] = byte(lLen)
+	}
+	di++
+
+	// Write the last literals.
+	if isNotCompressible && di >= anchor {
+		// Incompressible.
+		return 0, nil
+	}
+	di += copy(dst[di:di+len(src)-anchor], src[anchor:])
+	return di, nil
+}