| // Copyright 2014 The LUCI Authors. |
| // |
| // 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 clockflag |
| |
| import ( |
| "encoding/json" |
| "flag" |
| "fmt" |
| "time" |
| ) |
| |
| // DurationHelp is generic Duration help. |
| const DurationHelp = "A duration string is a sequence of <number><unit> such as 2h15m. " + |
| "Supported units are 'ns', 'us'/'µs', 'ms', 's', 'm', and 'h'." |
| |
| // Duration is a Flag- and JSON-compatible Duration value. |
| type Duration time.Duration |
| |
| var _ flag.Value = (*Duration)(nil) |
| |
| // Set implements flag.Value. |
| func (d *Duration) Set(value string) (err error) { |
| *d, err = ParseDuration(value) |
| return |
| } |
| |
| func (d *Duration) String() string { |
| return FormatDuration(time.Duration(*d)) |
| } |
| |
| // IsZero tests if this Duration is the zero value. |
| func (d Duration) IsZero() bool { |
| return time.Duration(d) == time.Duration(0) |
| } |
| |
| // UnmarshalJSON implements json.Unmarshaler. |
| // |
| // Unmarshals a JSON entry into the underlying type. The entry is expected to |
| // contain a string corresponding to one of the enum's keys. |
| func (d *Duration) UnmarshalJSON(data []byte) error { |
| var s string |
| if err := json.Unmarshal(data, &s); err != nil { |
| return err |
| } |
| return d.Set(s) |
| } |
| |
| // MarshalJSON implements json.Marshaler. |
| // |
| // Marshals a Duration into a duration string. |
| func (d Duration) MarshalJSON() ([]byte, error) { |
| return []byte(fmt.Sprintf(`"%s"`, time.Duration(d).String())), nil |
| } |
| |
| // ParseDuration parses a clockflag Duration from a string. This is basically |
| // a typed fall-through to time.ParseDuration. |
| func ParseDuration(v string) (Duration, error) { |
| duration, err := time.ParseDuration(v) |
| if err != nil { |
| return 0, err |
| } |
| return Duration(duration), nil |
| } |
| |
| // FormatDuration formats a time.Duration into a string that can be parsed with |
| // ParseDuration. |
| func FormatDuration(d time.Duration) string { |
| return d.String() |
| } |