summaryrefslogtreecommitdiff
path: root/vendor/gopkg.in/yaml.v2/yaml.go
blob: de85aa4cdb71b6adf499209d5441c844d6181ff6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
// Package yaml implements YAML support for the Go language.
//
// Source code and other details for the project are available at GitHub:
//
//   https://github.com/go-yaml/yaml
//
package yaml

import (
	"errors"
	"fmt"
	"io"
	"reflect"
	"strings"
	"sync"
)

// MapSlice encodes and decodes as a YAML map.
// The order of keys is preserved when encoding and decoding.
type MapSlice []MapItem

// MapItem is an item in a MapSlice.
type MapItem struct {
	Key, Value interface{}
}

// The Unmarshaler interface may be implemented by types to customize their
// behavior when being unmarshaled from a YAML document. The UnmarshalYAML
// method receives a function that may be called to unmarshal the original
// YAML value into a field or variable. It is safe to call the unmarshal
// function parameter more than once if necessary.
type Unmarshaler interface {
	UnmarshalYAML(unmarshal func(interface{}) error) error
}

// The Marshaler interface may be implemented by types to customize their
// behavior when being marshaled into a YAML document. The returned value
// is marshaled in place of the original value implementing Marshaler.
//
// If an error is returned by MarshalYAML, the marshaling procedure stops
// and returns with the provided error.
type Marshaler interface {
	MarshalYAML() (interface{}, error)
}

// Unmarshal decodes the first document found within the in byte slice
// and assigns decoded values into the out value.
//
// Maps and pointers (to a struct, string, int, etc) are accepted as out
// values. If an internal pointer within a struct is not initialized,
// the yaml package will initialize it if necessary for unmarshalling
// the provided data. The out parameter must not be nil.
//
// The type of the decoded values should be compatible with the respective
// values in out. If one or more values cannot be decoded due to a type
// mismatches, decoding continues partially until the end of the YAML
// content, and a *yaml.TypeError is returned with details for all
// missed values.
//
// Struct fields are only unmarshalled if they are exported (have an
// upper case first letter), and are unmarshalled using the field name
// lowercased as the default key. Custom keys may be defined via the
// "yaml" name in the field tag: the content preceding the first comma
// is used as the key, and the following comma-separated options are
// used to tweak the marshalling process (see Marshal).
// Conflicting names result in a runtime error.
//
// For example:
//
//     type T struct {
//         F int `yaml:"a,omitempty"`
//         B int
//     }
//     var t T
//     yaml.Unmarshal([]byte("a: 1\nb: 2"), &t)
//
// See the documentation of Marshal for the format of tags and a list of
// supported tag options.
//
func Unmarshal(in []byte, out interface{}) (err error) {
	return unmarshal(in, out, false)
}

// UnmarshalStrict is like Unmarshal except that any fields that are found
// in the data that do not have corresponding struct members, or mapping
// keys that are duplicates, will result in
// an error.
func UnmarshalStrict(in []byte, out interface{}) (err error) {
	return unmarshal(in, out, true)
}

// A Decorder reads and decodes YAML values from an input stream.
type Decoder struct {
	strict bool
	parser *parser
}

// NewDecoder returns a new decoder that reads from r.
//
// The decoder introduces its own buffering and may read
// data from r beyond the YAML values requested.
func NewDecoder(r io.Reader) *Decoder {
	return &Decoder{
		parser: newParserFromReader(r),
	}
}

// SetStrict sets whether strict decoding behaviour is enabled when
// decoding items in the data (see UnmarshalStrict). By default, decoding is not strict.
func (dec *Decoder) SetStrict(strict bool) {
	dec.strict = strict
}

// Decode reads the next YAML-encoded value from its input
// and stores it in the value pointed to by v.
//
// See the documentation for Unmarshal for details about the
// conversion of YAML into a Go value.
func (dec *Decoder) Decode(v interface{}) (err error) {
	d := newDecoder(dec.strict)
	defer handleErr(&err)
	node := dec.parser.parse()
	if node == nil {
		return io.EOF
	}
	out := reflect.ValueOf(v)
	if out.Kind() == reflect.Ptr && !out.IsNil() {
		out = out.Elem()
	}
	d.unmarshal(node, out)
	if len(d.terrors) > 0 {
		return &TypeError{d.terrors}
	}
	return nil
}

func unmarshal(in []byte, out interface{}, strict bool) (err error) {
	defer handleErr(&err)
	d := newDecoder(strict)
	p := newParser(in)
	defer p.destroy()
	node := p.parse()
	if node != nil {
		v := reflect.ValueOf(out)
		if v.Kind() == reflect.Ptr && !v.IsNil() {
			v = v.Elem()
		}
		d.unmarshal(node, v)
	}
	if len(d.terrors) > 0 {
		return &TypeError{d.terrors}
	}
	return nil
}

// Marshal serializes the value provided into a YAML document. The structure
// of the generated document will reflect the structure of the value itself.
// Maps and pointers (to struct, string, int, etc) are accepted as the in value.
//
// Struct fields are only marshalled if they are exported (have an upper case
// first letter), and are marshalled using the field name lowercased as the
// default key. Custom keys may be defined via the "yaml" name in the field
// tag: the content preceding the first comma is used as the key, and the
// following comma-separated options are used to tweak the marshalling process.
// Conflicting names result in a runtime error.
//
// The field tag format accepted is:
//
//     `(...) yaml:"[<key>][,<flag1>[,<flag2>]]" (...)`
//
// The following flags are currently supported:
//
//     omitempty    Only include the field if it's not set to the zero
//                  value for the type or to empty slices or maps.
//                  Zero valued structs will be omitted if all their public
//                  fields are zero, unless they implement an IsZero
//                  method (see the IsZeroer interface type), in which
//                  case the field will be included if that method returns true.
//
//     flow         Marshal using a flow style (useful for structs,
//                  sequences and maps).
//
//     inline       Inline the field, which must be a struct or a map,
//                  causing all of its fields or keys to be processed as if
//                  they were part of the outer struct. For maps, keys must
//                  not conflict with the yaml keys of other struct fields.
//
// In addition, if the key is "-", the field is ignored.
//
// For example:
//
//     type T struct {
//         F int `yaml:"a,omitempty"`
//         B int
//     }
//     yaml.Marshal(&T{B: 2}) // Returns "b: 2\n"
//     yaml.Marshal(&T{F: 1}} // Returns "a: 1\nb: 0\n"
//
func Marshal(in interface{}) (out []byte, err error) {
	defer handleErr(&err)
	e := newEncoder()
	defer e.destroy()
	e.marshalDoc("", reflect.ValueOf(in))
	e.finish()
	out = e.out
	return
}

// An Encoder writes YAML values to an output stream.
type Encoder struct {
	encoder *encoder
}

// NewEncoder returns a new encoder that writes to w.
// The Encoder should be closed after use to flush all data
// to w.
func NewEncoder(w io.Writer) *Encoder {
	return &Encoder{
		encoder: newEncoderWithWriter(w),
	}
}

// Encode writes the YAML encoding of v to the stream.
// If multiple items are encoded to the stream, the
// second and subsequent document will be preceded
// with a "---" document separator, but the first will not.
//
// See the documentation for Marshal for details about the conversion of Go
// values to YAML.
func (e *Encoder) Encode(v interface{}) (err error) {
	defer handleErr(&err)
	e.encoder.marshalDoc("", reflect.ValueOf(v))
	return nil
}

// Close closes the encoder by writing any remaining data.
// It does not write a stream terminating string "...".
func (e *Encoder) Close() (err error) {
	defer handleErr(&err)
	e.encoder.finish()
	return nil
}

func handleErr(err *error) {
	if v := recover(); v != nil {
		if e, ok := v.(yamlError); ok {
			*err = e.err
		} else {
			panic(v)
		}
	}
}

type yamlError struct {
	err error
}

func fail(err error) {
	panic(yamlError{err})
}

func failf(format string, args ...interface{}) {
	panic(yamlError{fmt.Errorf("yaml: "+format, args...)})
}

// A TypeError is returned by Unmarshal when one or more fields in
// the YAML document cannot be properly decoded into the requested
// types. When this error is returned, the value is still
// unmarshaled partially.
type TypeError struct {
	Errors []string
}

func (e *TypeError) Error() string {
	return fmt.Sprintf("yaml: unmarshal errors:\n  %s", strings.Join(e.Errors, "\n  "))
}

// --------------------------------------------------------------------------
// Maintain a mapping of keys to structure field indexes

// The code in this section was copied from mgo/bson.

// structInfo holds details for the serialization of fields of
// a given struct.
type structInfo struct {
	FieldsMap  map[string]fieldInfo
	FieldsList []fieldInfo

	// InlineMap is the number of the field in the struct that
	// contains an ,inline map, or -1 if there's none.
	InlineMap int
}

type fieldInfo struct {
	Key       string
	Num       int
	OmitEmpty bool
	Flow      bool
	// Id holds the unique field identifier, so we can cheaply
	// check for field duplicates without maintaining an extra map.
	Id int

	// Inline holds the field index if the field is part of an inlined struct.
	Inline []int
}

var structMap = make(map[reflect.Type]*structInfo)
var fieldMapMutex sync.RWMutex

func getStructInfo(st reflect.Type) (*structInfo, error) {
	fieldMapMutex.RLock()
	sinfo, found := structMap[st]
	fieldMapMutex.RUnlock()
	if found {
		return sinfo, nil
	}

	n := st.NumField()
	fieldsMap := make(map[string]fieldInfo)
	fieldsList := make([]fieldInfo, 0, n)
	inlineMap := -1
	for i := 0; i != n; i++ {
		field := st.Field(i)
		if field.PkgPath != "" && !field.Anonymous {
			continue // Private field
		}

		info := fieldInfo{Num: i}

		tag := field.Tag.Get("yaml")
		if tag == "" && strings.Index(string(field.Tag), ":") < 0 {
			tag = string(field.Tag)
		}
		if tag == "-" {
			continue
		}

		inline := false
		fields := strings.Split(tag, ",")
		if len(fields) > 1 {
			for _, flag := range fields[1:] {
				switch flag {
				case "omitempty":
					info.OmitEmpty = true
				case "flow":
					info.Flow = true
				case "inline":
					inline = true
				default:
					return nil, errors.New(fmt.Sprintf("Unsupported flag %q in tag %q of type %s", flag, tag, st))
				}
			}
			tag = fields[0]
		}

		if inline {
			switch field.Type.Kind() {
			case reflect.Map:
				if inlineMap >= 0 {
					return nil, errors.New("Multiple ,inline maps in struct " + st.String())
				}
				if field.Type.Key() != reflect.TypeOf("") {
					return nil, errors.New("Option ,inline needs a map with string keys in struct " + st.String())
				}
				inlineMap = info.Num
			case reflect.Struct:
				sinfo, err := getStructInfo(field.Type)
				if err != nil {
					return nil, err
				}
				for _, finfo := range sinfo.FieldsList {
					if _, found := fieldsMap[finfo.Key]; found {
						msg := "Duplicated key '" + finfo.Key + "' in struct " + st.String()
						return nil, errors.New(msg)
					}
					if finfo.Inline == nil {
						finfo.Inline = []int{i, finfo.Num}
					} else {
						finfo.Inline = append([]int{i}, finfo.Inline...)
					}
					finfo.Id = len(fieldsList)
					fieldsMap[finfo.Key] = finfo
					fieldsList = append(fieldsList, finfo)
				}
			default:
				//return nil, errors.New("Option ,inline needs a struct value or map field")
				return nil, errors.New("Option ,inline needs a struct value field")
			}
			continue
		}

		if tag != "" {
			info.Key = tag
		} else {
			info.Key = strings.ToLower(field.Name)
		}

		if _, found = fieldsMap[info.Key]; found {
			msg := "Duplicated key '" + info.Key + "' in struct " + st.String()
			return nil, errors.New(msg)
		}

		info.Id = len(fieldsList)
		fieldsList = append(fieldsList, info)
		fieldsMap[info.Key] = info
	}

	sinfo = &structInfo{
		FieldsMap:  fieldsMap,
		FieldsList: fieldsList,
		InlineMap:  inlineMap,
	}

	fieldMapMutex.Lock()
	structMap[st] = sinfo
	fieldMapMutex.Unlock()
	return sinfo, nil
}

// IsZeroer is used to check whether an object is zero to
// determine whether it should be omitted when marshaling
// with the omitempty flag. One notable implementation
// is time.Time.
type IsZeroer interface {
	IsZero() bool
}

func isZero(v reflect.Value) bool {
	kind := v.Kind()
	if z, ok := v.Interface().(IsZeroer); ok {
		if (kind == reflect.Ptr || kind == reflect.Interface) && v.IsNil() {
			return true
		}
		return z.IsZero()
	}
	switch kind {
	case reflect.String:
		return len(v.String()) == 0
	case reflect.Interface, reflect.Ptr:
		return v.IsNil()
	case reflect.Slice:
		return v.Len() == 0
	case reflect.Map:
		return v.Len() == 0
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return v.Int() == 0
	case reflect.Float32, reflect.Float64:
		return v.Float() == 0
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		return v.Uint() == 0
	case reflect.Bool:
		return !v.Bool()
	case reflect.Struct:
		vt := v.Type()
		for i := v.NumField() - 1; i >= 0; i-- {
			if vt.Field(i).PkgPath != "" {
				continue // Private field
			}
			if !isZero(v.Field(i)) {
				return false
			}
		}
		return true
	}
	return false
}