Hulk did something

[bytom/vapor.git] / encoding / json / duration.go

diff --git a/encoding/json/duration.go b/encoding/json/duration.go
new file mode 100644 (file)
index 0000000..86452f7
--- /dev/null
+++ b/encoding/json/duration.go
@@ -0,0 +1,58 @@
+package json
+
+import (
+       "bytes"
+       "encoding/json"
+       "errors"
+       "strconv"
+       "time"
+)
+
+type Duration struct {
+       time.Duration
+}
+
+// UnmarshalJSON fulfills the encoding/json.Unmarshaler interface.
+// It attempts to parse text as a time.Duration string.
+// The Go documentation defines this as a possibly signed sequence of decimal
+// numbers, each with optional fraction and a unit suffix, such as
+// "300ms", "-1.5h" or "2h45m".
+// Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h").
+// If there is no time unit, UnmarshalJSON defaults to ms.
+func (d *Duration) UnmarshalJSON(b []byte) error {
+       if bytes.Equal(b, []byte("null")) {
+               return nil
+       }
+
+       dMS, err := strconv.ParseInt(string(b), 10, 64)
+       if err != nil {
+               // Assume this is a string instead, in which case we need to unmarshal it as a string
+               // before we try to parse it as a time.Duration.
+               var str string
+               err = json.Unmarshal(b, &str)
+               if err != nil {
+                       return errors.New("invalid json.Duration")
+               }
+
+               d0, err := time.ParseDuration(str)
+               if err != nil {
+                       return errors.New("invalid json.Duration")
+               }
+               if d0 < 0 {
+                       return errors.New("invalid json.Duration: Duration cannot be less than 0")
+               }
+               d.Duration = d0
+       } else {
+               if dMS < 0 {
+                       return errors.New("invalid json.Duration: Duration cannot be less than 0")
+               }
+               d.Duration = time.Duration(dMS) * time.Millisecond
+       }
+
+       return nil
+}
+
+// MarshalJSON implements json.Marshaler.
+func (d Duration) MarshalJSON() ([]byte, error) {
+       return json.Marshal(d.Duration.Nanoseconds() / int64(time.Millisecond))
+}