112 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			112 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| package jsoniter
 | |
| 
 | |
| import (
 | |
| 	"fmt"
 | |
| 	"math"
 | |
| 	"strconv"
 | |
| )
 | |
| 
 | |
| var pow10 []uint64
 | |
| 
 | |
| func init() {
 | |
| 	pow10 = []uint64{1, 10, 100, 1000, 10000, 100000, 1000000}
 | |
| }
 | |
| 
 | |
| // WriteFloat32 write float32 to stream
 | |
| func (stream *Stream) WriteFloat32(val float32) {
 | |
| 	if math.IsInf(float64(val), 0) || math.IsNaN(float64(val)) {
 | |
| 		stream.Error = fmt.Errorf("unsupported value: %f", val)
 | |
| 		return
 | |
| 	}
 | |
| 	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)
 | |
| }
 | |
| 
 | |
| // WriteFloat32Lossy write float32 to stream with ONLY 6 digits precision although much much faster
 | |
| func (stream *Stream) WriteFloat32Lossy(val float32) {
 | |
| 	if math.IsInf(float64(val), 0) || math.IsNaN(float64(val)) {
 | |
| 		stream.Error = fmt.Errorf("unsupported value: %f", val)
 | |
| 		return
 | |
| 	}
 | |
| 	if val < 0 {
 | |
| 		stream.writeByte('-')
 | |
| 		val = -val
 | |
| 	}
 | |
| 	if val > 0x4ffffff {
 | |
| 		stream.WriteFloat32(val)
 | |
| 		return
 | |
| 	}
 | |
| 	precision := 6
 | |
| 	exp := uint64(1000000) // 6
 | |
| 	lval := uint64(float64(val)*float64(exp) + 0.5)
 | |
| 	stream.WriteUint64(lval / exp)
 | |
| 	fval := lval % exp
 | |
| 	if fval == 0 {
 | |
| 		return
 | |
| 	}
 | |
| 	stream.writeByte('.')
 | |
| 	for p := precision - 1; p > 0 && fval < pow10[p]; p-- {
 | |
| 		stream.writeByte('0')
 | |
| 	}
 | |
| 	stream.WriteUint64(fval)
 | |
| 	for stream.buf[len(stream.buf)-1] == '0' {
 | |
| 		stream.buf = stream.buf[:len(stream.buf)-1]
 | |
| 	}
 | |
| }
 | |
| 
 | |
| // WriteFloat64 write float64 to stream
 | |
| func (stream *Stream) WriteFloat64(val float64) {
 | |
| 	if math.IsInf(val, 0) || math.IsNaN(val) {
 | |
| 		stream.Error = fmt.Errorf("unsupported value: %f", val)
 | |
| 		return
 | |
| 	}
 | |
| 	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)
 | |
| }
 | |
| 
 | |
| // WriteFloat64Lossy write float64 to stream with ONLY 6 digits precision although much much faster
 | |
| func (stream *Stream) WriteFloat64Lossy(val float64) {
 | |
| 	if math.IsInf(val, 0) || math.IsNaN(val) {
 | |
| 		stream.Error = fmt.Errorf("unsupported value: %f", val)
 | |
| 		return
 | |
| 	}
 | |
| 	if val < 0 {
 | |
| 		stream.writeByte('-')
 | |
| 		val = -val
 | |
| 	}
 | |
| 	if val > 0x4ffffff {
 | |
| 		stream.WriteFloat64(val)
 | |
| 		return
 | |
| 	}
 | |
| 	precision := 6
 | |
| 	exp := uint64(1000000) // 6
 | |
| 	lval := uint64(val*float64(exp) + 0.5)
 | |
| 	stream.WriteUint64(lval / exp)
 | |
| 	fval := lval % exp
 | |
| 	if fval == 0 {
 | |
| 		return
 | |
| 	}
 | |
| 	stream.writeByte('.')
 | |
| 	for p := precision - 1; p > 0 && fval < pow10[p]; p-- {
 | |
| 		stream.writeByte('0')
 | |
| 	}
 | |
| 	stream.WriteUint64(fval)
 | |
| 	for stream.buf[len(stream.buf)-1] == '0' {
 | |
| 		stream.buf = stream.buf[:len(stream.buf)-1]
 | |
| 	}
 | |
| }
 |