stream_number.go

package jsoniter

import (
	"fmt"
	"math"
	"strconv"
)

var digits []uint32

func init() {
	digits = make([]uint32, 1000)
	for i := uint32(0); i < 1000; i++ {
		digits[i] = (((i / 100) + '0') << 16) + ((((i / 10) % 10) + '0') << 8) + i%10 + '0'
		if i < 10 {
			digits[i] += 2 << 24
		} else if i < 100 {
			digits[i] += 1 << 24
		}
	}
}

// WriteFloat32 write float32 to stream
func (stream *Stream) WriteFloat32(val float32) error {
	if math.IsInf(float64(val), 0) || math.IsNaN(float64(val)) {
		return stream.reportError(fmt.Errorf("unsupported value: %f", val))
	}
	abs := math.Abs(float64(val))
	fmt := byte('f')
	// Note: Must use float32 comparisons for underlying float32 value to get precise cutoffs right.
	if abs != 0 {
		if float32(abs) < 1e-6 || float32(abs) >= 1e21 {
			fmt = 'e'
		}
	}
	stream.buf = strconv.AppendFloat(stream.buf, float64(val), fmt, -1, 32)
	return nil
}

// WriteFloat64 write float64 to stream
func (stream *Stream) WriteFloat64(val float64) error {
	if math.IsInf(val, 0) || math.IsNaN(val) {
		return stream.reportError(fmt.Errorf("unsupported value: %f", val))
	}
	abs := math.Abs(val)
	fmt := byte('f')
	// Note: Must use float32 comparisons for underlying float32 value to get precise cutoffs right.
	if abs != 0 {
		if abs < 1e-6 || abs >= 1e21 {
			fmt = 'e'
		}
	}
	stream.buf = strconv.AppendFloat(stream.buf, float64(val), fmt, -1, 64)
	return nil
}

func writeFirstBuf(space []byte, v uint32) []byte {
	start := v >> 24
	if start == 0 {
		space = append(space, byte(v>>16), byte(v>>8))
	} else if start == 1 {
		space = append(space, byte(v>>8))
	}
	space = append(space, byte(v))
	return space
}

func writeBuf(buf []byte, v uint32) []byte {
	return append(buf, byte(v>>16), byte(v>>8), byte(v))
}

// WriteUint8 write uint8 to stream
func (stream *Stream) WriteUint8(val uint8) {
	stream.buf = writeFirstBuf(stream.buf, digits[val])
}

// WriteInt8 write int8 to stream
func (stream *Stream) WriteInt8(nval int8) {
	var val uint8
	if nval < 0 {
		val = uint8(-nval)
		stream.buf = append(stream.buf, '-')
	} else {
		val = uint8(nval)
	}
	stream.buf = writeFirstBuf(stream.buf, digits[val])
}

// WriteUint16 write uint16 to stream
func (stream *Stream) WriteUint16(val uint16) {
	q1 := val / 1000
	if q1 == 0 {
		stream.buf = writeFirstBuf(stream.buf, digits[val])
		return
	}
	r1 := val - q1*1000
	stream.buf = writeFirstBuf(stream.buf, digits[q1])
	stream.buf = writeBuf(stream.buf, digits[r1])
	return
}

// WriteInt16 write int16 to stream
func (stream *Stream) WriteInt16(nval int16) {
	var val uint16
	if nval < 0 {
		val = uint16(-nval)
		stream.buf = append(stream.buf, '-')
	} else {
		val = uint16(nval)
	}
	stream.WriteUint16(val)
}

// WriteUint32 write uint32 to stream
func (stream *Stream) WriteUint32(val uint32) {
	q1 := val / 1000
	if q1 == 0 {
		stream.buf = writeFirstBuf(stream.buf, digits[val])
		return
	}
	r1 := val - q1*1000
	q2 := q1 / 1000
	if q2 == 0 {
		stream.buf = writeFirstBuf(stream.buf, digits[q1])
		stream.buf = writeBuf(stream.buf, digits[r1])
		return
	}
	r2 := q1 - q2*1000
	q3 := q2 / 1000
	if q3 == 0 {
		stream.buf = writeFirstBuf(stream.buf, digits[q2])
	} else {
		r3 := q2 - q3*1000
		stream.buf = append(stream.buf, byte(q3+'0'))
		stream.buf = writeBuf(stream.buf, digits[r3])
	}
	stream.buf = writeBuf(stream.buf, digits[r2])
	stream.buf = writeBuf(stream.buf, digits[r1])
}

// WriteInt32 write int32 to stream
func (stream *Stream) WriteInt32(nval int32) {
	var val uint32
	if nval < 0 {
		val = uint32(-nval)
		stream.buf = append(stream.buf, '-')
	} else {
		val = uint32(nval)
	}
	stream.WriteUint32(val)
}

// WriteUint64 write uint64 to stream
func (stream *Stream) WriteUint64(val uint64) {
	q1 := val / 1000
	if q1 == 0 {
		stream.buf = writeFirstBuf(stream.buf, digits[val])
		return
	}
	r1 := val - q1*1000
	q2 := q1 / 1000
	if q2 == 0 {
		stream.buf = writeFirstBuf(stream.buf, digits[q1])
		stream.buf = writeBuf(stream.buf, digits[r1])
		return
	}
	r2 := q1 - q2*1000
	q3 := q2 / 1000
	if q3 == 0 {
		stream.buf = writeFirstBuf(stream.buf, digits[q2])
		stream.buf = writeBuf(stream.buf, digits[r2])
		stream.buf = writeBuf(stream.buf, digits[r1])
		return
	}
	r3 := q2 - q3*1000
	q4 := q3 / 1000
	if q4 == 0 {
		stream.buf = writeFirstBuf(stream.buf, digits[q3])
		stream.buf = writeBuf(stream.buf, digits[r3])
		stream.buf = writeBuf(stream.buf, digits[r2])
		stream.buf = writeBuf(stream.buf, digits[r1])
		return
	}
	r4 := q3 - q4*1000
	q5 := q4 / 1000
	if q5 == 0 {
		stream.buf = writeFirstBuf(stream.buf, digits[q4])
		stream.buf = writeBuf(stream.buf, digits[r4])
		stream.buf = writeBuf(stream.buf, digits[r3])
		stream.buf = writeBuf(stream.buf, digits[r2])
		stream.buf = writeBuf(stream.buf, digits[r1])
		return
	}
	r5 := q4 - q5*1000
	q6 := q5 / 1000
	if q6 == 0 {
		stream.buf = writeFirstBuf(stream.buf, digits[q5])
	} else {
		stream.buf = writeFirstBuf(stream.buf, digits[q6])
		r6 := q5 - q6*1000
		stream.buf = writeBuf(stream.buf, digits[r6])
	}
	stream.buf = writeBuf(stream.buf, digits[r5])
	stream.buf = writeBuf(stream.buf, digits[r4])
	stream.buf = writeBuf(stream.buf, digits[r3])
	stream.buf = writeBuf(stream.buf, digits[r2])
	stream.buf = writeBuf(stream.buf, digits[r1])
}

// WriteInt64 write int64 to stream
func (stream *Stream) WriteInt64(nval int64) {
	var val uint64
	if nval < 0 {
		val = uint64(-nval)
		stream.buf = append(stream.buf, '-')
	} else {
		val = uint64(nval)
	}
	stream.WriteUint64(val)
}

// WriteInt write int to stream
func (stream *Stream) WriteInt(val int) {
	stream.WriteInt64(int64(val))
}

// WriteUint write uint to stream
func (stream *Stream) WriteUint(val uint) {
	stream.WriteUint64(uint64(val))
}