v0.1.0

helper.go

@@ -0,0 +1,60 @@
+package imoto
+
+import (
+	"crypto/md5"
+	"encoding/binary"
+	"encoding/hex"
+	"errors"
+	"strconv"
+	"strings"
+	"unsafe"
+)
+
+func GetMD5(u string) (m [md5.Size]byte, err error) {
+	u = strings.Trim(u, "/ ?&\n\t")
+	if len(u) != md5.Size*2 && len(u) != md5.Size {
+		err = errors.New("invalid path len: " + strconv.Itoa(len(u)))
+		return
+	}
+	_, err = hex.Decode(m[:], StringToBytes(u))
+	return
+}
+
+func SplitMD5(m [md5.Size]byte) (path uint64, key uint64) {
+	path = binary.LittleEndian.Uint64(m[:8])
+	key = binary.LittleEndian.Uint64(m[8:])
+	return
+}
+
+func Uint64String(x uint64) string {
+	var buf [8]byte
+	binary.LittleEndian.PutUint64(buf[:], x)
+	return hex.EncodeToString(buf[:])
+}
+
+// slice is the runtime representation of a slice.
+// It cannot be used safely or portably and its representation may
+// change in a later release.
+//
+// Unlike reflect.SliceHeader, its Data field is sufficient to guarantee the
+// data it references will not be garbage collected.
+type slice struct {
+	data unsafe.Pointer
+	len  int
+	cap  int
+}
+
+// BytesToString 没有内存开销的转换
+func BytesToString(b []byte) string {
+	return *(*string)(unsafe.Pointer(&b))
+}
+
+// StringToBytes 没有内存开销的转换
+func StringToBytes(s string) (b []byte) {
+	bh := (*slice)(unsafe.Pointer(&b))
+	sh := (*slice)(unsafe.Pointer(&s))
+	bh.data = sh.data
+	bh.len = sh.len
+	bh.cap = sh.len
+	return b
+}