David K. Bainbridge | 528b318 | 2017-01-23 08:51:59 -0800 | [diff] [blame] | 1 | package yaml |
| 2 | |
| 3 | import ( |
| 4 | "encoding" |
| 5 | "fmt" |
| 6 | "reflect" |
| 7 | "regexp" |
| 8 | "sort" |
| 9 | "strconv" |
| 10 | "strings" |
| 11 | "time" |
| 12 | ) |
| 13 | |
| 14 | type encoder struct { |
| 15 | emitter yaml_emitter_t |
| 16 | event yaml_event_t |
| 17 | out []byte |
| 18 | flow bool |
| 19 | } |
| 20 | |
| 21 | func 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 | |
| 33 | func (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 | |
| 41 | func (e *encoder) destroy() { |
| 42 | yaml_emitter_delete(&e.emitter) |
| 43 | } |
| 44 | |
| 45 | func (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 | |
| 52 | func (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 | |
| 62 | func (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 | |
| 127 | func (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 | |
| 138 | func (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 | |
| 148 | func (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 | |
| 187 | func (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 | |
| 201 | func (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. |
| 223 | func 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. |
| 238 | var base60float = regexp.MustCompile(`^[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+(?:\.[0-9_]*)?$`) |
| 239 | |
| 240 | func (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 | |
| 264 | func (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 | |
| 274 | func (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 | |
| 279 | func (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 | |
| 284 | func (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 | |
| 298 | func (e *encoder) nilv() { |
| 299 | e.emitScalar("null", "", "", yaml_PLAIN_SCALAR_STYLE) |
| 300 | } |
| 301 | |
| 302 | func (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 | } |