github.com/blixtra/rkt@v0.8.1-0.20160204105720-ab0d1add1a43/rkt/flag/bitflags.go (about)

     1  // Copyright 2015 The rkt 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 flag
    16  
    17  import (
    18  	"errors"
    19  	"fmt"
    20  
    21  	"github.com/hashicorp/errwrap"
    22  )
    23  
    24  // bitFlags is a flag value type supporting a csv list of options stored as bits
    25  type bitFlags struct {
    26  	*OptionList
    27  	flags   int
    28  	flagMap map[string]int
    29  }
    30  
    31  func newBitFlags(permissibleOptions []string, defaultOptions string, flagMap map[string]int) (*bitFlags, error) {
    32  	ol, err := NewOptionList(permissibleOptions, defaultOptions)
    33  	if err != nil {
    34  		return nil, err
    35  	}
    36  
    37  	bf := &bitFlags{
    38  		OptionList: ol,
    39  		flagMap:    flagMap,
    40  	}
    41  	bf.typeName = "bitFlags"
    42  
    43  	if err := bf.Set(defaultOptions); err != nil {
    44  		return nil, errwrap.Wrap(errors.New("problem setting defaults"), err)
    45  	}
    46  
    47  	return bf, nil
    48  }
    49  
    50  func (bf *bitFlags) Set(s string) error {
    51  	if err := bf.OptionList.Set(s); err != nil {
    52  		return err
    53  	}
    54  	bf.flags = 0
    55  	for _, o := range bf.Options {
    56  		if b, ok := bf.flagMap[o]; ok {
    57  			bf.flags |= b
    58  		} else {
    59  			return fmt.Errorf("couldn't find flag for %v", o)
    60  		}
    61  	}
    62  	return nil
    63  }
    64  
    65  func (bf *bitFlags) hasFlag(f int) bool {
    66  	return (bf.flags & f) == f
    67  }