Replace int/uint encoding implementation

encode.go

@@ -252,43 +252,43 @@ func (e *Encoder) encode(v interface{}) ([]byte, error) {
 }
 
 func encodeInt(b []byte, v int) []byte {
-	return strconv.AppendInt(b, int64(v), 10)
+	return appendInt(b, int64(v))
 }
 
 func encodeInt8(b []byte, v int8) []byte {
-	return strconv.AppendInt(b, int64(v), 10)
+	return appendInt(b, int64(v))
 }
 
 func encodeInt16(b []byte, v int16) []byte {
-	return strconv.AppendInt(b, int64(v), 10)
+	return appendInt(b, int64(v))
 }
 
 func encodeInt32(b []byte, v int32) []byte {
-	return strconv.AppendInt(b, int64(v), 10)
+	return appendInt(b, int64(v))
 }
 
 func encodeInt64(b []byte, v int64) []byte {
-	return strconv.AppendInt(b, v, 10)
+	return appendInt(b, v)
 }
 
 func encodeUint(b []byte, v uint) []byte {
-	return strconv.AppendUint(b, uint64(v), 10)
+	return appendUint(b, uint64(v))
 }
 
 func encodeUint8(b []byte, v uint8) []byte {
-	return strconv.AppendUint(b, uint64(v), 10)
+	return appendUint(b, uint64(v))
 }
 
 func encodeUint16(b []byte, v uint16) []byte {
-	return strconv.AppendUint(b, uint64(v), 10)
+	return appendUint(b, uint64(v))
 }
 
 func encodeUint32(b []byte, v uint32) []byte {
-	return strconv.AppendUint(b, uint64(v), 10)
+	return appendUint(b, uint64(v))
 }
 
 func encodeUint64(b []byte, v uint64) []byte {
-	return strconv.AppendUint(b, v, 10)
+	return appendUint(b, v)
 }
 
 func encodeFloat32(b []byte, v float32) []byte {

encode_int.go

@@ -0,0 +1,98 @@
+package json
+
+import (
+	"unsafe"
+)
+
+var endianness int
+
+func init() {
+	var b [2]byte
+	*(*uint16)(unsafe.Pointer(&b)) = uint16(0xABCD)
+
+	switch b[0] {
+	case 0xCD:
+		endianness = 0 // LE
+	case 0xAB:
+		endianness = 1 // BE
+	default:
+		panic("could not determine endianness")
+	}
+}
+
+// "00010203...96979899" cast to []uint16
+var intLELookup = [100]uint16{
+	0x3030, 0x3130, 0x3230, 0x3330, 0x3430, 0x3530, 0x3630, 0x3730, 0x3830, 0x3930,
+	0x3031, 0x3131, 0x3231, 0x3331, 0x3431, 0x3531, 0x3631, 0x3731, 0x3831, 0x3931,
+	0x3032, 0x3132, 0x3232, 0x3332, 0x3432, 0x3532, 0x3632, 0x3732, 0x3832, 0x3932,
+	0x3033, 0x3133, 0x3233, 0x3333, 0x3433, 0x3533, 0x3633, 0x3733, 0x3833, 0x3933,
+	0x3034, 0x3134, 0x3234, 0x3334, 0x3434, 0x3534, 0x3634, 0x3734, 0x3834, 0x3934,
+	0x3035, 0x3135, 0x3235, 0x3335, 0x3435, 0x3535, 0x3635, 0x3735, 0x3835, 0x3935,
+	0x3036, 0x3136, 0x3236, 0x3336, 0x3436, 0x3536, 0x3636, 0x3736, 0x3836, 0x3936,
+	0x3037, 0x3137, 0x3237, 0x3337, 0x3437, 0x3537, 0x3637, 0x3737, 0x3837, 0x3937,
+	0x3038, 0x3138, 0x3238, 0x3338, 0x3438, 0x3538, 0x3638, 0x3738, 0x3838, 0x3938,
+	0x3039, 0x3139, 0x3239, 0x3339, 0x3439, 0x3539, 0x3639, 0x3739, 0x3839, 0x3939,
+}
+
+var intBELookup = [100]uint16{
+	0x3030, 0x3031, 0x3032, 0x3033, 0x3034, 0x3035, 0x3036, 0x3037, 0x3038, 0x3039,
+	0x3130, 0x3131, 0x3132, 0x3133, 0x3134, 0x3135, 0x3136, 0x3137, 0x3138, 0x3139,
+	0x3230, 0x3231, 0x3232, 0x3233, 0x3234, 0x3235, 0x3236, 0x3237, 0x3238, 0x3239,
+	0x3330, 0x3331, 0x3332, 0x3333, 0x3334, 0x3335, 0x3336, 0x3337, 0x3338, 0x3339,
+	0x3430, 0x3431, 0x3432, 0x3433, 0x3434, 0x3435, 0x3436, 0x3437, 0x3438, 0x3439,
+	0x3530, 0x3531, 0x3532, 0x3533, 0x3534, 0x3535, 0x3536, 0x3537, 0x3538, 0x3539,
+	0x3630, 0x3631, 0x3632, 0x3633, 0x3634, 0x3635, 0x3636, 0x3637, 0x3638, 0x3639,
+	0x3730, 0x3731, 0x3732, 0x3733, 0x3734, 0x3735, 0x3736, 0x3737, 0x3738, 0x3739,
+	0x3830, 0x3831, 0x3832, 0x3833, 0x3834, 0x3835, 0x3836, 0x3837, 0x3838, 0x3839,
+	0x3930, 0x3931, 0x3932, 0x3933, 0x3934, 0x3935, 0x3936, 0x3937, 0x3938, 0x3939,
+}
+
+var intLookup = [2]*[100]uint16{&intLELookup, &intBELookup}
+
+func appendInt(b []byte, n int64) []byte {
+	return formatInteger(b, uint64(n), n < 0)
+}
+
+func appendUint(b []byte, n uint64) []byte {
+	return formatInteger(b, n, false)
+}
+
+func formatInteger(out []byte, n uint64, negative bool) []byte {
+	if !negative {
+		if n < 10 {
+			return append(out, byte(n+'0'))
+		} else if n < 100 {
+			u := intLELookup[n]
+			return append(out, byte(u), byte(u>>8))
+		}
+	} else {
+		n = -n
+	}
+
+	lookup := intLookup[endianness]
+
+	var b [22]byte
+	u := (*[11]uint16)(unsafe.Pointer(&b))
+	i := 11
+
+	for n >= 100 {
+		j := n % 100
+		n /= 100
+		i--
+		u[i] = lookup[j]
+	}
+
+	i--
+	u[i] = lookup[n]
+
+	i *= 2 // convert to byte index
+	if n < 10 {
+		i++ // remove leading zero
+	}
+	if negative {
+		i--
+		b[i] = '-'
+	}
+
+	return append(out, b[i:]...)
+}