From e2cdb05eac6726c59fe1831876fddd8037156d67 Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Sun, 28 Aug 2022 17:55:36 -0600
Subject: btrfs: Split off btrfstree and btrfsprim sub-packages

---
 lib/btrfs/btrfsprim/uuid.go | 96 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 lib/btrfs/btrfsprim/uuid.go

(limited to 'lib/btrfs/btrfsprim/uuid.go')

diff --git a/lib/btrfs/btrfsprim/uuid.go b/lib/btrfs/btrfsprim/uuid.go
new file mode 100644
index 0000000..4e3fd6b
--- /dev/null
+++ b/lib/btrfs/btrfsprim/uuid.go
@@ -0,0 +1,96 @@
+// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package btrfsprim
+
+import (
+	"encoding"
+	"encoding/hex"
+	"fmt"
+	"strings"
+
+	"git.lukeshu.com/btrfs-progs-ng/lib/fmtutil"
+)
+
+type UUID [16]byte
+
+var (
+	_ fmt.Stringer             = UUID{}
+	_ fmt.Formatter            = UUID{}
+	_ encoding.TextMarshaler   = UUID{}
+	_ encoding.TextUnmarshaler = (*UUID)(nil)
+)
+
+func (uuid UUID) String() string {
+	str := hex.EncodeToString(uuid[:])
+	return strings.Join([]string{
+		str[:8],
+		str[8:12],
+		str[12:16],
+		str[16:20],
+		str[20:32],
+	}, "-")
+}
+
+func (uuid UUID) MarshalText() ([]byte, error) {
+	return []byte(uuid.String()), nil
+}
+
+func (uuid *UUID) UnmarshalText(text []byte) error {
+	var err error
+	*uuid, err = ParseUUID(string(text))
+	return err
+}
+
+func (uuid UUID) Format(f fmt.State, verb rune) {
+	fmtutil.FormatByteArrayStringer(uuid, uuid[:], f, verb)
+}
+
+func (a UUID) Cmp(b UUID) int {
+	for i := range a {
+		if d := int(a[i]) - int(b[i]); d != 0 {
+			return d
+		}
+	}
+	return 0
+}
+
+func ParseUUID(str string) (UUID, error) {
+	var ret UUID
+	j := 0
+	for i := 0; i < len(str); i++ {
+		if j >= len(ret)*2 {
+			return UUID{}, fmt.Errorf("too long to be a UUID: %q|%q", str[:i], str[i:])
+		}
+		c := str[i]
+		var v byte
+		switch {
+		case '0' <= c && c <= '9':
+			v = c - '0'
+		case 'a' <= c && c <= 'f':
+			v = c - 'a' + 10
+		case 'A' <= c && c <= 'F':
+			v = c - 'A' + 10
+		case c == '-':
+			continue
+		default:
+			return UUID{}, fmt.Errorf("illegal byte in UUID: %q|%q|%q", str[:i], str[i:i+1], str[i+1:])
+		}
+		if j%2 == 0 {
+			ret[j/2] = v << 4
+		} else {
+			ret[j/2] = (ret[j/2] & 0xf0) | (v & 0x0f)
+		}
+		j++
+	}
+	return ret, nil
+}
+
+func MustParseUUID(str string) UUID {
+	ret, err := ParseUUID(str)
+	if err != nil {
+		panic(err)
+	}
+	return ret
+}
-- 
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