ulid.go

package ulid

import (
   "crypto/rand"
   "database/sql/driver"
   "fmt"
   "io"
   "strconv"
   "time"

   "github.com/oklog/ulid/v2"
)

// ID implements a ULID
type ID string

var defaultEntropySource *ulid.MonotonicEntropy

func init() {
   // Seed the default entropy source.
   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 ULID 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.Unmarshaller interface.
func (i *ID) UnmarshalGQL(v interface{}) error {
   return i.Scan(v)
}

// MarshalGQL implements the graphql.Marshaler interface.
func (i ID) MarshalGQL(w io.Writer) {
   _, _ = io.WriteString(w, strconv.Quote(string(i)))
}

// Scan implements the Scanner interface.
func (i *ID) Scan(src interface{}) error {
   if src == nil {
      return fmt.Errorf("ulid: expected a value")
   }

   switch s := src.(type) {
   case string:
      *i = ID(s)
   case []byte:
      str := string(s)
      *i = ID(str)
   default:
      return fmt.Errorf("ulid: expected a string %v", s)
   }

   return nil
}

// Value implements the driver Valuer interface.
func (i ID) Value() (driver.Value, error) {
   return string(i), nil
}