diff --git a/lib/encoding/int.go b/lib/encoding/int.go
index 7814d6ac7..55c7554b3 100644
--- a/lib/encoding/int.go
+++ b/lib/encoding/int.go
@@ -3,6 +3,7 @@ package encoding
 import (
 	"encoding/binary"
 	"fmt"
+	"math/bits"
 	"sync"
 )
 
@@ -91,21 +92,35 @@ func MarshalVarInt64(dst []byte, v int64) []byte {
 // MarshalVarInt64s appends marshaled vs to dst and returns the result.
 func MarshalVarInt64s(dst []byte, vs []int64) []byte {
 	for _, v := range vs {
-		if v < 0x40 && v > -0x40 {
-			// Fast path
-			c := int8(v)
-			v := (c << 1) ^ (c >> 7) // zig-zag encoding without branching.
-			dst = append(dst, byte(v))
+		n := uint64((v << 1) ^ (v >> 63))
+		if n < (1 << 7) {
+			dst = append(dst, byte(n))
 			continue
 		}
-
-		v = (v << 1) ^ (v >> 63) // zig-zag encoding without branching.
-		u := uint64(v)
-		for u > 0x7f {
-			dst = append(dst, 0x80|byte(u))
-			u >>= 7
+		switch (64 - bits.LeadingZeros64(n>>1)) / 7 {
+		case 0:
+			dst = append(dst, byte(n))
+		case 1:
+			dst = append(dst, byte(n|0x80), byte(n>>7))
+		case 2:
+			dst = append(dst, byte(n|0x80), byte((n>>7)|0x80), byte(n>>14))
+		case 3:
+			dst = append(dst, byte(n|0x80), byte((n>>7)|0x80), byte((n>>14)|0x80), byte(n>>21))
+		case 4:
+			dst = append(dst, byte(n|0x80), byte((n>>7)|0x80), byte((n>>14)|0x80), byte((n>>21)|0x80), byte(n>>28))
+		case 5:
+			dst = append(dst, byte(n|0x80), byte((n>>7)|0x80), byte((n>>14)|0x80), byte((n>>21)|0x80), byte(n>>28|0x80), byte(n>>35))
+		case 6:
+			dst = append(dst, byte(n|0x80), byte((n>>7)|0x80), byte((n>>14)|0x80), byte((n>>21)|0x80), byte(n>>28|0x80), byte(n>>35|0x80), byte(n>>42))
+		case 7:
+			dst = append(dst, byte(n|0x80), byte((n>>7)|0x80), byte((n>>14)|0x80), byte((n>>21)|0x80), byte(n>>28|0x80), byte(n>>35|0x80), byte(n>>42|0x80), byte(n>>49))
+		case 8:
+			dst = append(dst, byte(n|0x80), byte((n>>7)|0x80), byte((n>>14)|0x80), byte((n>>21)|0x80), byte(n>>28|0x80), byte(n>>35|0x80), byte(n>>42|0x80), byte(n>>49|0x80), byte(n>>56))
+		case 9:
+			fallthrough
+		default:
+			dst = append(dst, byte(n|0x80), byte((n>>7)|0x80), byte((n>>14)|0x80), byte((n>>21)|0x80), byte(n>>28|0x80), byte(n>>35|0x80), byte(n>>42|0x80), byte(n>>49|0x80), byte(n>>56|0x80), byte(n>>63))
 		}
-		dst = append(dst, byte(u))
 	}
 	return dst
 }
@@ -134,30 +149,57 @@ func UnmarshalVarInt64s(dst []int64, src []byte) ([]byte, error) {
 			dst[i] = int64(v)
 			continue
 		}
-
-		// Slow path
-		u := uint64(c & 0x7f)
-		startIdx := idx - 1
-		shift := uint8(0)
-		for c >= 0x80 {
-			if idx >= uint(len(src)) {
-				return nil, fmt.Errorf("unexpected end of encoded varint at byte %d; src=%x", idx-startIdx, src[startIdx:])
-			}
-			if idx-startIdx > 9 {
-				return src[idx:], fmt.Errorf("too long encoded varint; the maximum allowed length is 10 bytes; got %d bytes; src=%x",
-					(idx-startIdx)+1, src[startIdx:])
-			}
-			c = src[idx]
+		if idx < uint(len(src)) && src[idx] < 0x80 {
+			// Fast path, for 2 bytes
+			n := uint64(c&0x7f) | (uint64(src[idx]&0x7f) << 7)
+			dst[i] = int64(n>>1) ^ (int64(n<<63) >> 63)
 			idx++
-			shift += 7
-			u |= uint64(c&0x7f) << shift
+			continue
 		}
-		v := int64(u>>1) ^ (int64(u<<63) >> 63) // zig-zag decoding without branching.
-		dst[i] = v
+		j := idx + 1
+		for ; j < uint(len(src)); j++ { // find end loc
+			if src[j] < 0x80 {
+				break
+			}
+		}
+		if j-idx > 10 {
+			return nil, fmt.Errorf("cannot unmarshal varint, buffer too long, len=%d", j-idx)
+		}
+		dst[i] = unmarshalVarInt64ForOne(src[idx-1 : j+1])
+		idx = j + 1
 	}
 	return src[idx:], nil
 }
 
+func unmarshalVarInt64ForOne(buf []byte) int64 {
+	var n uint64
+	switch len(buf) {
+	case 1:
+		n = uint64(buf[0] & 0x7F)
+	case 2:
+		n = uint64(buf[0]&0x7F) | (uint64(buf[1]&0x7F) << 7)
+	case 3:
+		n = uint64(buf[0]&0x7F) | (uint64(buf[1]&0x7F) << 7) | (uint64(buf[2]&0x7F) << 14)
+	case 4:
+		n = uint64(buf[0]&0x7F) | (uint64(buf[1]&0x7F) << 7) | (uint64(buf[2]&0x7F) << 14) | (uint64(buf[3]&0x7F) << 21)
+	case 5:
+		n = uint64(buf[0]&0x7F) | (uint64(buf[1]&0x7F) << 7) | (uint64(buf[2]&0x7F) << 14) | (uint64(buf[3]&0x7F) << 21) | (uint64(buf[4]&0x7F) << 28)
+	case 6:
+		n = uint64(buf[0]&0x7F) | (uint64(buf[1]&0x7F) << 7) | (uint64(buf[2]&0x7F) << 14) | (uint64(buf[3]&0x7F) << 21) | (uint64(buf[4]&0x7F) << 28) | (uint64(buf[5]&0x7F) << 35)
+	case 7:
+		n = uint64(buf[0]&0x7F) | (uint64(buf[1]&0x7F) << 7) | (uint64(buf[2]&0x7F) << 14) | (uint64(buf[3]&0x7F) << 21) | (uint64(buf[4]&0x7F) << 28) | (uint64(buf[5]&0x7F) << 35) | (uint64(buf[6]&0x7F) << 42)
+	case 8:
+		n = uint64(buf[0]&0x7F) | (uint64(buf[1]&0x7F) << 7) | (uint64(buf[2]&0x7F) << 14) | (uint64(buf[3]&0x7F) << 21) | (uint64(buf[4]&0x7F) << 28) | (uint64(buf[5]&0x7F) << 35) | (uint64(buf[6]&0x7F) << 42) | (uint64(buf[7]&0x7F) << 49)
+	case 9:
+		n = uint64(buf[0]&0x7F) | (uint64(buf[1]&0x7F) << 7) | (uint64(buf[2]&0x7F) << 14) | (uint64(buf[3]&0x7F) << 21) | (uint64(buf[4]&0x7F) << 28) | (uint64(buf[5]&0x7F) << 35) | (uint64(buf[6]&0x7F) << 42) | (uint64(buf[7]&0x7F) << 49) | (uint64(buf[8]&0x7F) << 56)
+	case 10:
+		n = uint64(buf[0]&0x7F) | (uint64(buf[1]&0x7F) << 7) | (uint64(buf[2]&0x7F) << 14) | (uint64(buf[3]&0x7F) << 21) | (uint64(buf[4]&0x7F) << 28) | (uint64(buf[5]&0x7F) << 35) | (uint64(buf[6]&0x7F) << 42) | (uint64(buf[7]&0x7F) << 49) | (uint64(buf[8]&0x7F) << 56) | (uint64(buf[9]&0x7F) << 63)
+	default:
+		panic("impossible error: buf length must be 1 to 10")
+	}
+	return int64(n>>1) ^ (int64(n<<63) >> 63)
+}
+
 // MarshalVarUint64 appends marshaled u to dst and returns the result.
 func MarshalVarUint64(dst []byte, u uint64) []byte {
 	var tmp [1]uint64