mirror of https://github.com/v2ray/v2ray-core
111 lines
2.2 KiB
Go
111 lines
2.2 KiB
Go
package uuid
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import (
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"bytes"
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"crypto/md5"
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"crypto/rand"
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"encoding/hex"
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"errors"
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)
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var (
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byteGroups = []int{8, 4, 4, 4, 12}
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ErrorInvalidID = errors.New("Invalid ID.")
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)
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type UUID [16]byte
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// String returns the string representation of this UUID.
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func (this *UUID) String() string {
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return bytesToString(this.Bytes())
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}
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// Bytes returns the bytes representation of this UUID.
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func (this *UUID) Bytes() []byte {
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return this[:]
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}
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// Equals returns true if this UUID equals another UUID by value.
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func (this *UUID) Equals(another *UUID) bool {
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if this == nil && another == nil {
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return true
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}
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if this == nil || another == nil {
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return false
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}
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return bytes.Equal(this.Bytes(), another.Bytes())
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}
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// Next generates a deterministic random UUID based on this UUID.
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func (this *UUID) Next() *UUID {
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md5hash := md5.New()
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md5hash.Write(this.Bytes())
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md5hash.Write([]byte("16167dc8-16b6-4e6d-b8bb-65dd68113a81"))
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newid := new(UUID)
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for {
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md5hash.Sum(newid[:0])
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if !newid.Equals(this) {
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return newid
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}
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md5hash.Write([]byte("533eff8a-4113-4b10-b5ce-0f5d76b98cd2"))
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}
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}
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func bytesToString(bytes []byte) string {
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result := hex.EncodeToString(bytes[0 : byteGroups[0]/2])
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start := byteGroups[0] / 2
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for i := 1; i < len(byteGroups); i++ {
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nBytes := byteGroups[i] / 2
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result += "-"
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result += hex.EncodeToString(bytes[start : start+nBytes])
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start += nBytes
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}
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return result
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}
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// New creates an UUID with random value.
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func New() *UUID {
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uuid := new(UUID)
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rand.Read(uuid.Bytes())
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return uuid
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}
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// PraseBytes converts an UUID in byte form to object.
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func ParseBytes(b []byte) (*UUID, error) {
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if len(b) != 16 {
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return nil, ErrorInvalidID
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}
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uuid := new(UUID)
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copy(uuid[:], b)
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return uuid, nil
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}
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// ParseString converts an UUID in string form to object.
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func ParseString(str string) (*UUID, error) {
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text := []byte(str)
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if len(text) < 32 {
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return nil, ErrorInvalidID
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}
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uuid := new(UUID)
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b := uuid.Bytes()
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for _, byteGroup := range byteGroups {
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if text[0] == '-' {
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text = text[1:]
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}
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_, err := hex.Decode(b[:byteGroup/2], text[:byteGroup])
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if err != nil {
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return nil, err
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}
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text = text[byteGroup:]
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b = b[byteGroup/2:]
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}
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return uuid, nil
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}
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