github.com/stffabi/git-lfs@v2.3.5-0.20180214015214-8eeaa8d88902+incompatible/config/environment.go (about)

     1  package config
     2  
     3  import (
     4  	"strconv"
     5  	"strings"
     6  )
     7  
     8  // An Environment adds additional behavior to a Fetcher, such a type conversion,
     9  // and default values.
    10  //
    11  // `Environment`s are the primary way to communicate with various configuration
    12  // sources, such as the OS environment variables, the `.gitconfig`, and even
    13  // `map[string]string`s.
    14  type Environment interface {
    15  	// Get is shorthand for calling `e.Fetcher.Get(key)`.
    16  	Get(key string) (val string, ok bool)
    17  
    18  	// Get is shorthand for calling `e.Fetcher.GetAll(key)`.
    19  	GetAll(key string) (vals []string)
    20  
    21  	// Bool returns the boolean state associated with a given key, or the
    22  	// value "def", if no value was associated.
    23  	//
    24  	// The "boolean state associated with a given key" is defined as the
    25  	// case-insensitive string comparison with the following:
    26  	//
    27  	// 1) true if...
    28  	//   "true", "1", "on", "yes", or "t"
    29  	// 2) false if...
    30  	//   "false", "0", "off", "no", "f", or otherwise.
    31  	Bool(key string, def bool) (val bool)
    32  
    33  	// Int returns the int value associated with a given key, or the value
    34  	// "def", if no value was associated.
    35  	//
    36  	// To convert from a the string value attached to a given key,
    37  	// `strconv.Atoi(val)` is called. If `Atoi` returned a non-nil error,
    38  	// then the value "def" will be returned instead.
    39  	//
    40  	// Otherwise, if the value was converted `string -> int` successfully,
    41  	// then it will be returned wholesale.
    42  	Int(key string, def int) (val int)
    43  
    44  	// All returns a copy of all the key/value pairs for the current
    45  	// environment.
    46  	All() map[string][]string
    47  }
    48  
    49  type environment struct {
    50  	// Fetcher is the `environment`'s source of data.
    51  	Fetcher Fetcher
    52  }
    53  
    54  // EnvironmentOf creates a new `Environment` initialized with the givne
    55  // `Fetcher`, "f".
    56  func EnvironmentOf(f Fetcher) Environment {
    57  	return &environment{f}
    58  }
    59  
    60  func (e *environment) Get(key string) (val string, ok bool) {
    61  	return e.Fetcher.Get(key)
    62  }
    63  
    64  func (e *environment) GetAll(key string) []string {
    65  	return e.Fetcher.GetAll(key)
    66  }
    67  
    68  func (e *environment) Bool(key string, def bool) bool {
    69  	s, _ := e.Fetcher.Get(key)
    70  	return Bool(s, def)
    71  }
    72  
    73  func (e *environment) Int(key string, def int) int {
    74  	s, _ := e.Fetcher.Get(key)
    75  	return Int(s, def)
    76  }
    77  
    78  func (e *environment) All() map[string][]string {
    79  	return e.Fetcher.All()
    80  }
    81  
    82  // Int returns the int value associated with the given value, or the value
    83  // "def", if the value is blank.
    84  //
    85  // To convert from a the string value attached to a given key,
    86  // `strconv.Atoi(val)` is called. If `Atoi` returned a non-nil error,
    87  // then the value "def" will be returned instead.
    88  //
    89  // Otherwise, if the value was converted `string -> int` successfully,
    90  // then it will be returned wholesale.
    91  func Int(value string, def int) int {
    92  	if len(value) == 0 {
    93  		return def
    94  	}
    95  
    96  	i, err := strconv.Atoi(value)
    97  	if err != nil {
    98  		return def
    99  	}
   100  
   101  	return i
   102  }
   103  
   104  // Bool returns the boolean state associated with the given value, or the
   105  // value "def", if the value is blank.
   106  //
   107  // The "boolean state associated with a given key" is defined as the
   108  // case-insensitive string comparison with the following:
   109  //
   110  // 1) true if...
   111  //   "true", "1", "on", "yes", or "t"
   112  // 2) false if...
   113  //   "false", "0", "off", "no", "f", or otherwise.
   114  func Bool(value string, def bool) bool {
   115  	if len(value) == 0 {
   116  		return def
   117  	}
   118  
   119  	switch strings.ToLower(value) {
   120  	case "true", "1", "on", "yes", "t":
   121  		return true
   122  	case "false", "0", "off", "no", "f":
   123  		return false
   124  	default:
   125  		return false
   126  	}
   127  }