blob: 84f84995517b6bced35582e4890988cab474e934 [file] [log] [blame]
David K. Bainbridge528b3182017-01-23 08:51:59 -08001package yaml
2
3import (
4 "encoding"
5 "fmt"
6 "reflect"
7 "regexp"
8 "sort"
9 "strconv"
10 "strings"
11 "time"
12)
13
14type encoder struct {
15 emitter yaml_emitter_t
16 event yaml_event_t
17 out []byte
18 flow bool
19}
20
21func newEncoder() (e *encoder) {
22 e = &encoder{}
23 e.must(yaml_emitter_initialize(&e.emitter))
24 yaml_emitter_set_output_string(&e.emitter, &e.out)
25 yaml_emitter_set_unicode(&e.emitter, true)
26 e.must(yaml_stream_start_event_initialize(&e.event, yaml_UTF8_ENCODING))
27 e.emit()
28 e.must(yaml_document_start_event_initialize(&e.event, nil, nil, true))
29 e.emit()
30 return e
31}
32
33func (e *encoder) finish() {
34 e.must(yaml_document_end_event_initialize(&e.event, true))
35 e.emit()
36 e.emitter.open_ended = false
37 e.must(yaml_stream_end_event_initialize(&e.event))
38 e.emit()
39}
40
41func (e *encoder) destroy() {
42 yaml_emitter_delete(&e.emitter)
43}
44
45func (e *encoder) emit() {
46 // This will internally delete the e.event value.
47 if !yaml_emitter_emit(&e.emitter, &e.event) && e.event.typ != yaml_DOCUMENT_END_EVENT && e.event.typ != yaml_STREAM_END_EVENT {
48 e.must(false)
49 }
50}
51
52func (e *encoder) must(ok bool) {
53 if !ok {
54 msg := e.emitter.problem
55 if msg == "" {
56 msg = "unknown problem generating YAML content"
57 }
58 failf("%s", msg)
59 }
60}
61
62func (e *encoder) marshal(tag string, in reflect.Value) {
63 if !in.IsValid() {
64 e.nilv()
65 return
66 }
67 iface := in.Interface()
68 if m, ok := iface.(Marshaler); ok {
69 v, err := m.MarshalYAML()
70 if err != nil {
71 fail(err)
72 }
73 if v == nil {
74 e.nilv()
75 return
76 }
77 in = reflect.ValueOf(v)
78 } else if m, ok := iface.(encoding.TextMarshaler); ok {
79 text, err := m.MarshalText()
80 if err != nil {
81 fail(err)
82 }
83 in = reflect.ValueOf(string(text))
84 }
85 switch in.Kind() {
86 case reflect.Interface:
87 if in.IsNil() {
88 e.nilv()
89 } else {
90 e.marshal(tag, in.Elem())
91 }
92 case reflect.Map:
93 e.mapv(tag, in)
94 case reflect.Ptr:
95 if in.IsNil() {
96 e.nilv()
97 } else {
98 e.marshal(tag, in.Elem())
99 }
100 case reflect.Struct:
101 e.structv(tag, in)
102 case reflect.Slice:
103 if in.Type().Elem() == mapItemType {
104 e.itemsv(tag, in)
105 } else {
106 e.slicev(tag, in)
107 }
108 case reflect.String:
109 e.stringv(tag, in)
110 case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
111 if in.Type() == durationType {
112 e.stringv(tag, reflect.ValueOf(iface.(time.Duration).String()))
113 } else {
114 e.intv(tag, in)
115 }
116 case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
117 e.uintv(tag, in)
118 case reflect.Float32, reflect.Float64:
119 e.floatv(tag, in)
120 case reflect.Bool:
121 e.boolv(tag, in)
122 default:
123 panic("cannot marshal type: " + in.Type().String())
124 }
125}
126
127func (e *encoder) mapv(tag string, in reflect.Value) {
128 e.mappingv(tag, func() {
129 keys := keyList(in.MapKeys())
130 sort.Sort(keys)
131 for _, k := range keys {
132 e.marshal("", k)
133 e.marshal("", in.MapIndex(k))
134 }
135 })
136}
137
138func (e *encoder) itemsv(tag string, in reflect.Value) {
139 e.mappingv(tag, func() {
140 slice := in.Convert(reflect.TypeOf([]MapItem{})).Interface().([]MapItem)
141 for _, item := range slice {
142 e.marshal("", reflect.ValueOf(item.Key))
143 e.marshal("", reflect.ValueOf(item.Value))
144 }
145 })
146}
147
148func (e *encoder) structv(tag string, in reflect.Value) {
149 sinfo, err := getStructInfo(in.Type())
150 if err != nil {
151 panic(err)
152 }
153 e.mappingv(tag, func() {
154 for _, info := range sinfo.FieldsList {
155 var value reflect.Value
156 if info.Inline == nil {
157 value = in.Field(info.Num)
158 } else {
159 value = in.FieldByIndex(info.Inline)
160 }
161 if info.OmitEmpty && isZero(value) {
162 continue
163 }
164 e.marshal("", reflect.ValueOf(info.Key))
165 e.flow = info.Flow
166 e.marshal("", value)
167 }
168 if sinfo.InlineMap >= 0 {
169 m := in.Field(sinfo.InlineMap)
170 if m.Len() > 0 {
171 e.flow = false
172 keys := keyList(m.MapKeys())
173 sort.Sort(keys)
174 for _, k := range keys {
175 if _, found := sinfo.FieldsMap[k.String()]; found {
176 panic(fmt.Sprintf("Can't have key %q in inlined map; conflicts with struct field", k.String()))
177 }
178 e.marshal("", k)
179 e.flow = false
180 e.marshal("", m.MapIndex(k))
181 }
182 }
183 }
184 })
185}
186
187func (e *encoder) mappingv(tag string, f func()) {
188 implicit := tag == ""
189 style := yaml_BLOCK_MAPPING_STYLE
190 if e.flow {
191 e.flow = false
192 style = yaml_FLOW_MAPPING_STYLE
193 }
194 e.must(yaml_mapping_start_event_initialize(&e.event, nil, []byte(tag), implicit, style))
195 e.emit()
196 f()
197 e.must(yaml_mapping_end_event_initialize(&e.event))
198 e.emit()
199}
200
201func (e *encoder) slicev(tag string, in reflect.Value) {
202 implicit := tag == ""
203 style := yaml_BLOCK_SEQUENCE_STYLE
204 if e.flow {
205 e.flow = false
206 style = yaml_FLOW_SEQUENCE_STYLE
207 }
208 e.must(yaml_sequence_start_event_initialize(&e.event, nil, []byte(tag), implicit, style))
209 e.emit()
210 n := in.Len()
211 for i := 0; i < n; i++ {
212 e.marshal("", in.Index(i))
213 }
214 e.must(yaml_sequence_end_event_initialize(&e.event))
215 e.emit()
216}
217
218// isBase60 returns whether s is in base 60 notation as defined in YAML 1.1.
219//
220// The base 60 float notation in YAML 1.1 is a terrible idea and is unsupported
221// in YAML 1.2 and by this package, but these should be marshalled quoted for
222// the time being for compatibility with other parsers.
223func isBase60Float(s string) (result bool) {
224 // Fast path.
225 if s == "" {
226 return false
227 }
228 c := s[0]
229 if !(c == '+' || c == '-' || c >= '0' && c <= '9') || strings.IndexByte(s, ':') < 0 {
230 return false
231 }
232 // Do the full match.
233 return base60float.MatchString(s)
234}
235
236// From http://yaml.org/type/float.html, except the regular expression there
237// is bogus. In practice parsers do not enforce the "\.[0-9_]*" suffix.
238var base60float = regexp.MustCompile(`^[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+(?:\.[0-9_]*)?$`)
239
240func (e *encoder) stringv(tag string, in reflect.Value) {
241 var style yaml_scalar_style_t
242 s := in.String()
243 rtag, rs := resolve("", s)
244 if rtag == yaml_BINARY_TAG {
245 if tag == "" || tag == yaml_STR_TAG {
246 tag = rtag
247 s = rs.(string)
248 } else if tag == yaml_BINARY_TAG {
249 failf("explicitly tagged !!binary data must be base64-encoded")
250 } else {
251 failf("cannot marshal invalid UTF-8 data as %s", shortTag(tag))
252 }
253 }
254 if tag == "" && (rtag != yaml_STR_TAG || isBase60Float(s)) {
255 style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
256 } else if strings.Contains(s, "\n") {
257 style = yaml_LITERAL_SCALAR_STYLE
258 } else {
259 style = yaml_PLAIN_SCALAR_STYLE
260 }
261 e.emitScalar(s, "", tag, style)
262}
263
264func (e *encoder) boolv(tag string, in reflect.Value) {
265 var s string
266 if in.Bool() {
267 s = "true"
268 } else {
269 s = "false"
270 }
271 e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
272}
273
274func (e *encoder) intv(tag string, in reflect.Value) {
275 s := strconv.FormatInt(in.Int(), 10)
276 e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
277}
278
279func (e *encoder) uintv(tag string, in reflect.Value) {
280 s := strconv.FormatUint(in.Uint(), 10)
281 e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
282}
283
284func (e *encoder) floatv(tag string, in reflect.Value) {
285 // FIXME: Handle 64 bits here.
286 s := strconv.FormatFloat(float64(in.Float()), 'g', -1, 32)
287 switch s {
288 case "+Inf":
289 s = ".inf"
290 case "-Inf":
291 s = "-.inf"
292 case "NaN":
293 s = ".nan"
294 }
295 e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
296}
297
298func (e *encoder) nilv() {
299 e.emitScalar("null", "", "", yaml_PLAIN_SCALAR_STYLE)
300}
301
302func (e *encoder) emitScalar(value, anchor, tag string, style yaml_scalar_style_t) {
303 implicit := tag == ""
304 e.must(yaml_scalar_event_initialize(&e.event, []byte(anchor), []byte(tag), []byte(value), implicit, implicit, style))
305 e.emit()
306}