/
pulid.go
76 lines (64 loc) · 2.22 KB
/
pulid.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
// Copyright 2019-present Facebook
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package pulid implements the pulid type.
// A pulid is an identifier that is a two-byte prefixed ULIDs, with the first two bytes encoding the type of the entity.
package pulid
import (
"crypto/rand"
"database/sql/driver"
"fmt"
"io"
"strconv"
"time"
"github.com/oklog/ulid/v2"
)
// ID implements a PULID - a prefixed ULID.
type ID string
// The default entropy source.
var defaultEntropySource *ulid.MonotonicEntropy
func init() {
// Seed the default entropy source.
// TODO: To improve testability, this package should allow control of entropy sources and the time.Now implementation.
defaultEntropySource = ulid.Monotonic(rand.Reader, 0)
}
// newULID returns a new ULID for time.Now() using the default entropy source.
func newULID() ulid.ULID {
return ulid.MustNew(ulid.Timestamp(time.Now()), defaultEntropySource)
}
// MustNew returns a new PULID for time.Now() given a prefix. This uses the default entropy source.
func MustNew(prefix string) ID { return ID(prefix + fmt.Sprint(newULID())) }
// UnmarshalGQL implements the graphql.Unmarshaler interface
func (u *ID) UnmarshalGQL(v interface{}) error {
return u.Scan(v)
}
// MarshalGQL implements the graphql.Marshaler interface
func (u ID) MarshalGQL(w io.Writer) {
_, _ = io.WriteString(w, strconv.Quote(string(u)))
}
// Scan implements the Scanner interface.
func (u *ID) Scan(src interface{}) error {
if src == nil {
return fmt.Errorf("pulid: expected a value")
}
s, ok := src.(string)
if !ok {
return fmt.Errorf("pulid: expected a string")
}
*u = ID(s)
return nil
}
// Value implements the driver Valuer interface.
func (u ID) Value() (driver.Value, error) {
return string(u), nil
}