优化性能

pack.go

@@ -2,67 +2,44 @@ package unibase2n
 
 import (
 	"encoding/binary"
+	"errors"
 	"unsafe"
 )
 
 type Pack uint64
 
 var (
-	// Base16384 CJK Unified Ideographs
-	//    see https://github.com/fumiama/base16384
-	Base16384 = newbasepack(0x4e00, 0x3d00, 14)
-	// Base8192 谚文音節 Hangul Syllables
-	Base8192 = newbasepack(0xac00, 0xcc00, 13)
-	// Base256 谚文字母 Hangul Jamo
-	Base256 = newbasepack(0x1100, 0, 8)
-	// BaseMath (256) 數學運算符 Mathematical Operators
-	BaseMath = newbasepack(0x2200, 0, 8)
-	// Base128 帶圈或括號的字母數字 Enclosed Alphanumerics
-	Base128 = newbasepack(0x2460, 0x24f4, 7)
-	// Base64 箭頭 Arrows
-	Base64 = newbasepack(0x2190, 0x21d0, 6)
-	// Base64Gua 六十四卦 YiJing Hexagram Symbols
-	Base64Gua = newbasepack(0x3400, 0x262f, 6)
-	// Base32 方塊元素 Block Elements
-	Base32 = newbasepack(0x2580, 0x259f, 5)
-	// Base16 漢文訓讀點 Kanbun Kundoku Den
-	Base16 = newbasepack(0x3190, 0, 4)
-	// Base8 八卦 YiJing Hexagram Symbols
-	Base8 = newbasepack(0x2630, 0x2689, 3)
+	ErrInvalidPack = errors.New("invalid pack")
 )
 
-func newbasepack(off, til uint16, bit uint8) Pack {
-	b, err := NewBase(off, til, bit)
-	if err != nil {
-		panic(err)
-	}
-	return b.Pack()
-}
-
 // New base2n from a packed config
-func New(pack Pack) *Base {
-	b := &Base{}
+func New(pack Pack) (bs Base, err error) {
+	if pack&0xff == 0 && pack&0xff000000_00000000 == 0 {
+		err = ErrInvalidPack
+		return
+	}
 	ismele := isLittleEndian()
 	isitle := pack&0xffffff != 0
 	if ismele == isitle { // same endian
-		*(*Pack)(unsafe.Pointer(b)) = pack
-		return b
+		*(*Pack)(unsafe.Pointer(&bs)) = pack
+	} else {
+		field := (*[8]byte)(unsafe.Pointer(&pack))
+		if isitle { // packed in little endian but I am big
+			bs.off = binary.BigEndian.Uint16(field[6:8])
+			bs.til = binary.BigEndian.Uint16(field[4:6])
+		} else { // packed in big endian but I am little
+			bs.off = binary.LittleEndian.Uint16(field[6:8])
+			bs.til = binary.LittleEndian.Uint16(field[4:6])
+		}
+		bs.bit = field[3]
 	}
-	field := (*[8]byte)(unsafe.Pointer(&pack))
-	if isitle { // packed in little endian but I am big
-		b.off = binary.BigEndian.Uint16(field[6:8])
-		b.til = binary.BigEndian.Uint16(field[4:6])
-	} else { // packed in big endian but I am little
-		b.off = binary.LittleEndian.Uint16(field[6:8])
-		b.til = binary.LittleEndian.Uint16(field[4:6])
-	}
-	b.bit = field[3]
-	return b
+	err = bs.check()
+	return
 }
 
 // Pack this config into an integer
-func (bs *Base) Pack() Pack {
-	return *(*Pack)(unsafe.Pointer(bs))
+func (bs Base) Pack() Pack {
+	return *(*Pack)(unsafe.Pointer(&bs))
 }
 
 func isLittleEndian() bool {