X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/b9d2799dfebae724dda3b3e28641116ca5daf5c7..09cbdc3074b3f1e69c9c537875146f6da0a6ed8f:/sdk/go/arvados/duration.go

diff --git a/sdk/go/arvados/duration.go b/sdk/go/arvados/duration.go
index a64eaacf83..9df210ccb0 100644
--- a/sdk/go/arvados/duration.go
+++ b/sdk/go/arvados/duration.go
@@ -1,8 +1,14 @@
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+
 package arvados
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
+	"strings"
 	"time"
 )
 
@@ -10,30 +16,43 @@ import (
 // a number of nanoseconds.
 type Duration time.Duration
 
-// UnmarshalJSON implements json.Unmarshaler
+// UnmarshalJSON implements json.Unmarshaler.
 func (d *Duration) UnmarshalJSON(data []byte) error {
+	if bytes.Equal(data, []byte(`"0"`)) || bytes.Equal(data, []byte(`0`)) {
+		// Unitless 0 is not accepted by ParseDuration, but we
+		// accept it as a reasonable spelling of 0
+		// nanoseconds.
+		*d = 0
+		return nil
+	}
 	if data[0] == '"' {
 		return d.Set(string(data[1 : len(data)-1]))
 	}
-	return fmt.Errorf("duration must be given as a string like \"600s\" or \"1h30m\"")
+	// Mimic error message returned by ParseDuration for a number
+	// without units.
+	return fmt.Errorf("missing unit in duration %q", data)
 }
 
-// MarshalJSON implements json.Marshaler
-func (d *Duration) MarshalJSON() ([]byte, error) {
+// MarshalJSON implements json.Marshaler.
+func (d Duration) MarshalJSON() ([]byte, error) {
 	return json.Marshal(d.String())
 }
 
-// String implements fmt.Stringer
+// String returns a format similar to (time.Duration)String() but with
+// "0m" and "0s" removed: e.g., "1h" instead of "1h0m0s".
 func (d Duration) String() string {
-	return time.Duration(d).String()
+	s := time.Duration(d).String()
+	s = strings.Replace(s, "m0s", "m", 1)
+	s = strings.Replace(s, "h0m", "h", 1)
+	return s
 }
 
-// Duration returns a time.Duration
+// Duration returns a time.Duration.
 func (d Duration) Duration() time.Duration {
 	return time.Duration(d)
 }
 
-// Value implements flag.Value
+// Set implements the flag.Value interface and sets the duration value by using time.ParseDuration to parse the string.
 func (d *Duration) Set(s string) error {
 	dur, err := time.ParseDuration(s)
 	*d = Duration(dur)