go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/logdog/client/butlerlib/streamproto/streamName.go (about)

     1  // Copyright 2015 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package streamproto
    16  
    17  import (
    18  	"encoding/json"
    19  	"flag"
    20  
    21  	"go.chromium.org/luci/logdog/common/types"
    22  )
    23  
    24  // StreamNameFlag is a flag and JSON-compatible type that converts to/from a
    25  // types.StreamName. StreamName validation is part of the conversion.
    26  type StreamNameFlag types.StreamName
    27  
    28  var _ interface {
    29  	flag.Value
    30  	json.Marshaler
    31  	json.Unmarshaler
    32  } = (*StreamNameFlag)(nil)
    33  
    34  // Set implements flag.Value.
    35  func (f *StreamNameFlag) Set(v string) error {
    36  	if err := types.StreamName(v).Validate(); err != nil {
    37  		return err
    38  	}
    39  	*f = StreamNameFlag(v)
    40  	return nil
    41  }
    42  
    43  // String implements flag.Value.
    44  func (f *StreamNameFlag) String() string {
    45  	if f == nil {
    46  		return ""
    47  	}
    48  	return string(*f)
    49  }
    50  
    51  // UnmarshalJSON implements json.Unmarshaler.
    52  func (f *StreamNameFlag) UnmarshalJSON(data []byte) error {
    53  	s := ""
    54  	if err := json.Unmarshal(data, &s); err != nil {
    55  		return err
    56  	}
    57  	if err := types.StreamName(s).Validate(); err != nil {
    58  		return err
    59  	}
    60  	*f = StreamNameFlag(s)
    61  	return nil
    62  }
    63  
    64  // MarshalJSON implements json.Marshaler.
    65  func (f StreamNameFlag) MarshalJSON() ([]byte, error) {
    66  	s := string(f)
    67  	return json.Marshal(&s)
    68  }