Merge pull request #2028 from slingamn/channels_taketwo.1

refactor of channel persistence to use UUIDs

irc/utils/uuid.go

@@ -0,0 +1,56 @@
+// Copyright (c) 2022 Shivaram Lingamneni <slingamn@cs.stanford.edu>
+// released under the MIT license
+
+package utils
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"errors"
+)
+
+var (
+	ErrInvalidUUID = errors.New("Invalid uuid")
+)
+
+// Technically a UUIDv4 has version bits set, but this doesn't matter in practice
+type UUID [16]byte
+
+func (u UUID) MarshalJSON() (b []byte, err error) {
+	b = make([]byte, 24)
+	b[0] = '"'
+	base64.RawURLEncoding.Encode(b[1:], u[:])
+	b[23] = '"'
+	return
+}
+
+func (u *UUID) UnmarshalJSON(b []byte) (err error) {
+	if len(b) != 24 {
+		return ErrInvalidUUID
+	}
+	readLen, err := base64.RawURLEncoding.Decode(u[:], b[1:23])
+	if readLen != 16 {
+		return ErrInvalidUUID
+	}
+	return nil
+}
+
+func (u *UUID) String() string {
+	return base64.RawURLEncoding.EncodeToString(u[:])
+}
+
+func GenerateUUIDv4() (result UUID) {
+	_, err := rand.Read(result[:])
+	if err != nil {
+		panic(err)
+	}
+	return
+}
+
+func DecodeUUID(ustr string) (result UUID, err error) {
+	length, err := base64.RawURLEncoding.Decode(result[:], []byte(ustr))
+	if err == nil && length != 16 {
+		err = ErrInvalidUUID
+	}
+	return
+}