diff options
Diffstat (limited to 'vendor/github.com/goccy/go-json/internal/encoder/int.go')
-rw-r--r-- | vendor/github.com/goccy/go-json/internal/encoder/int.go | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/vendor/github.com/goccy/go-json/internal/encoder/int.go b/vendor/github.com/goccy/go-json/internal/encoder/int.go new file mode 100644 index 0000000000..3a3482d5b1 --- /dev/null +++ b/vendor/github.com/goccy/go-json/internal/encoder/int.go @@ -0,0 +1,130 @@ +package encoder + +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 numMask(numBitSize uint8) uint64 { + return 1<<numBitSize - 1 +} + +func AppendInt(_ *RuntimeContext, out []byte, u64 uint64, code *Opcode) []byte { + mask := numMask(code.NumBitSize) + n := u64 & mask + negative := (u64>>(code.NumBitSize-1))&1 == 1 + 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 & mask + } + + 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:]...) +} + +func AppendUint(_ *RuntimeContext, out []byte, u64 uint64, code *Opcode) []byte { + mask := numMask(code.NumBitSize) + n := u64 & mask + if n < 10 { + return append(out, byte(n+'0')) + } else if n < 100 { + u := intLELookup[n] + return append(out, byte(u), byte(u>>8)) + } + + 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 + } + return append(out, b[i:]...) +} |