gtsocial-umbx

encode.go (9812B)

---

 package yaml
 
 import (
 	"encoding"
 	"fmt"
 	"io"
 	"reflect"
 	"regexp"
 	"sort"
 	"strconv"
 	"strings"
 	"time"
 	"unicode/utf8"
 )
 
 // jsonNumber is the interface of the encoding/json.Number datatype.
 // Repeating the interface here avoids a dependency on encoding/json, and also
 // supports other libraries like jsoniter, which use a similar datatype with
 // the same interface. Detecting this interface is useful when dealing with
 // structures containing json.Number, which is a string under the hood. The
 // encoder should prefer the use of Int64(), Float64() and string(), in that
 // order, when encoding this type.
 type jsonNumber interface {
 	Float64() (float64, error)
 	Int64() (int64, error)
 	String() string
 }
 
 type encoder struct {
 	emitter yaml_emitter_t
 	event   yaml_event_t
 	out     []byte
 	flow    bool
 	// doneInit holds whether the initial stream_start_event has been
 	// emitted.
 	doneInit bool
 }
 
 func newEncoder() *encoder {
 	e := &encoder{}
 	yaml_emitter_initialize(&e.emitter)
 	yaml_emitter_set_output_string(&e.emitter, &e.out)
 	yaml_emitter_set_unicode(&e.emitter, true)
 	return e
 }
 
 func newEncoderWithWriter(w io.Writer) *encoder {
 	e := &encoder{}
 	yaml_emitter_initialize(&e.emitter)
 	yaml_emitter_set_output_writer(&e.emitter, w)
 	yaml_emitter_set_unicode(&e.emitter, true)
 	return e
 }
 
 func (e *encoder) init() {
 	if e.doneInit {
 		return
 	}
 	yaml_stream_start_event_initialize(&e.event, yaml_UTF8_ENCODING)
 	e.emit()
 	e.doneInit = true
 }
 
 func (e *encoder) finish() {
 	e.emitter.open_ended = false
 	yaml_stream_end_event_initialize(&e.event)
 	e.emit()
 }
 
 func (e *encoder) destroy() {
 	yaml_emitter_delete(&e.emitter)
 }
 
 func (e *encoder) emit() {
 	// This will internally delete the e.event value.
 	e.must(yaml_emitter_emit(&e.emitter, &e.event))
 }
 
 func (e *encoder) must(ok bool) {
 	if !ok {
 		msg := e.emitter.problem
 		if msg == "" {
 			msg = "unknown problem generating YAML content"
 		}
 		failf("%s", msg)
 	}
 }
 
 func (e *encoder) marshalDoc(tag string, in reflect.Value) {
 	e.init()
 	yaml_document_start_event_initialize(&e.event, nil, nil, true)
 	e.emit()
 	e.marshal(tag, in)
 	yaml_document_end_event_initialize(&e.event, true)
 	e.emit()
 }
 
 func (e *encoder) marshal(tag string, in reflect.Value) {
 	if !in.IsValid() || in.Kind() == reflect.Ptr && in.IsNil() {
 		e.nilv()
 		return
 	}
 	iface := in.Interface()
 	switch m := iface.(type) {
 	case jsonNumber:
 		integer, err := m.Int64()
 		if err == nil {
 			// In this case the json.Number is a valid int64
 			in = reflect.ValueOf(integer)
 			break
 		}
 		float, err := m.Float64()
 		if err == nil {
 			// In this case the json.Number is a valid float64
 			in = reflect.ValueOf(float)
 			break
 		}
 		// fallback case - no number could be obtained
 		in = reflect.ValueOf(m.String())
 	case time.Time, *time.Time:
 		// Although time.Time implements TextMarshaler,
 		// we don't want to treat it as a string for YAML
 		// purposes because YAML has special support for
 		// timestamps.
 	case Marshaler:
 		v, err := m.MarshalYAML()
 		if err != nil {
 			fail(err)
 		}
 		if v == nil {
 			e.nilv()
 			return
 		}
 		in = reflect.ValueOf(v)
 	case encoding.TextMarshaler:
 		text, err := m.MarshalText()
 		if err != nil {
 			fail(err)
 		}
 		in = reflect.ValueOf(string(text))
 	case nil:
 		e.nilv()
 		return
 	}
 	switch in.Kind() {
 	case reflect.Interface:
 		e.marshal(tag, in.Elem())
 	case reflect.Map:
 		e.mapv(tag, in)
 	case reflect.Ptr:
 		if in.Type() == ptrTimeType {
 			e.timev(tag, in.Elem())
 		} else {
 			e.marshal(tag, in.Elem())
 		}
 	case reflect.Struct:
 		if in.Type() == timeType {
 			e.timev(tag, in)
 		} else {
 			e.structv(tag, in)
 		}
 	case reflect.Slice, reflect.Array:
 		if in.Type().Elem() == mapItemType {
 			e.itemsv(tag, in)
 		} else {
 			e.slicev(tag, in)
 		}
 	case reflect.String:
 		e.stringv(tag, in)
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
 		if in.Type() == durationType {
 			e.stringv(tag, reflect.ValueOf(iface.(time.Duration).String()))
 		} else {
 			e.intv(tag, in)
 		}
 	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
 		e.uintv(tag, in)
 	case reflect.Float32, reflect.Float64:
 		e.floatv(tag, in)
 	case reflect.Bool:
 		e.boolv(tag, in)
 	default:
 		panic("cannot marshal type: " + in.Type().String())
 	}
 }
 
 func (e *encoder) mapv(tag string, in reflect.Value) {
 	e.mappingv(tag, func() {
 		keys := keyList(in.MapKeys())
 		sort.Sort(keys)
 		for _, k := range keys {
 			e.marshal("", k)
 			e.marshal("", in.MapIndex(k))
 		}
 	})
 }
 
 func (e *encoder) itemsv(tag string, in reflect.Value) {
 	e.mappingv(tag, func() {
 		slice := in.Convert(reflect.TypeOf([]MapItem{})).Interface().([]MapItem)
 		for _, item := range slice {
 			e.marshal("", reflect.ValueOf(item.Key))
 			e.marshal("", reflect.ValueOf(item.Value))
 		}
 	})
 }
 
 func (e *encoder) structv(tag string, in reflect.Value) {
 	sinfo, err := getStructInfo(in.Type())
 	if err != nil {
 		panic(err)
 	}
 	e.mappingv(tag, func() {
 		for _, info := range sinfo.FieldsList {
 			var value reflect.Value
 			if info.Inline == nil {
 				value = in.Field(info.Num)
 			} else {
 				value = in.FieldByIndex(info.Inline)
 			}
 			if info.OmitEmpty && isZero(value) {
 				continue
 			}
 			e.marshal("", reflect.ValueOf(info.Key))
 			e.flow = info.Flow
 			e.marshal("", value)
 		}
 		if sinfo.InlineMap >= 0 {
 			m := in.Field(sinfo.InlineMap)
 			if m.Len() > 0 {
 				e.flow = false
 				keys := keyList(m.MapKeys())
 				sort.Sort(keys)
 				for _, k := range keys {
 					if _, found := sinfo.FieldsMap[k.String()]; found {
 						panic(fmt.Sprintf("Can't have key %q in inlined map; conflicts with struct field", k.String()))
 					}
 					e.marshal("", k)
 					e.flow = false
 					e.marshal("", m.MapIndex(k))
 				}
 			}
 		}
 	})
 }
 
 func (e *encoder) mappingv(tag string, f func()) {
 	implicit := tag == ""
 	style := yaml_BLOCK_MAPPING_STYLE
 	if e.flow {
 		e.flow = false
 		style = yaml_FLOW_MAPPING_STYLE
 	}
 	yaml_mapping_start_event_initialize(&e.event, nil, []byte(tag), implicit, style)
 	e.emit()
 	f()
 	yaml_mapping_end_event_initialize(&e.event)
 	e.emit()
 }
 
 func (e *encoder) slicev(tag string, in reflect.Value) {
 	implicit := tag == ""
 	style := yaml_BLOCK_SEQUENCE_STYLE
 	if e.flow {
 		e.flow = false
 		style = yaml_FLOW_SEQUENCE_STYLE
 	}
 	e.must(yaml_sequence_start_event_initialize(&e.event, nil, []byte(tag), implicit, style))
 	e.emit()
 	n := in.Len()
 	for i := 0; i < n; i++ {
 		e.marshal("", in.Index(i))
 	}
 	e.must(yaml_sequence_end_event_initialize(&e.event))
 	e.emit()
 }
 
 // isBase60 returns whether s is in base 60 notation as defined in YAML 1.1.
 //
 // The base 60 float notation in YAML 1.1 is a terrible idea and is unsupported
 // in YAML 1.2 and by this package, but these should be marshalled quoted for
 // the time being for compatibility with other parsers.
 func isBase60Float(s string) (result bool) {
 	// Fast path.
 	if s == "" {
 		return false
 	}
 	c := s[0]
 	if !(c == '+' || c == '-' || c >= '0' && c <= '9') || strings.IndexByte(s, ':') < 0 {
 		return false
 	}
 	// Do the full match.
 	return base60float.MatchString(s)
 }
 
 // From http://yaml.org/type/float.html, except the regular expression there
 // is bogus. In practice parsers do not enforce the "\.[0-9_]*" suffix.
 var base60float = regexp.MustCompile(`^[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+(?:\.[0-9_]*)?$`)
 
 func (e *encoder) stringv(tag string, in reflect.Value) {
 	var style yaml_scalar_style_t
 	s := in.String()
 	canUsePlain := true
 	switch {
 	case !utf8.ValidString(s):
 		if tag == yaml_BINARY_TAG {
 			failf("explicitly tagged !!binary data must be base64-encoded")
 		}
 		if tag != "" {
 			failf("cannot marshal invalid UTF-8 data as %s", shortTag(tag))
 		}
 		// It can't be encoded directly as YAML so use a binary tag
 		// and encode it as base64.
 		tag = yaml_BINARY_TAG
 		s = encodeBase64(s)
 	case tag == "":
 		// Check to see if it would resolve to a specific
 		// tag when encoded unquoted. If it doesn't,
 		// there's no need to quote it.
 		rtag, _ := resolve("", s)
 		canUsePlain = rtag == yaml_STR_TAG && !isBase60Float(s)
 	}
 	// Note: it's possible for user code to emit invalid YAML
 	// if they explicitly specify a tag and a string containing
 	// text that's incompatible with that tag.
 	switch {
 	case strings.Contains(s, "\n"):
 		style = yaml_LITERAL_SCALAR_STYLE
 	case canUsePlain:
 		style = yaml_PLAIN_SCALAR_STYLE
 	default:
 		style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
 	}
 	e.emitScalar(s, "", tag, style)
 }
 
 func (e *encoder) boolv(tag string, in reflect.Value) {
 	var s string
 	if in.Bool() {
 		s = "true"
 	} else {
 		s = "false"
 	}
 	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
 }
 
 func (e *encoder) intv(tag string, in reflect.Value) {
 	s := strconv.FormatInt(in.Int(), 10)
 	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
 }
 
 func (e *encoder) uintv(tag string, in reflect.Value) {
 	s := strconv.FormatUint(in.Uint(), 10)
 	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
 }
 
 func (e *encoder) timev(tag string, in reflect.Value) {
 	t := in.Interface().(time.Time)
 	s := t.Format(time.RFC3339Nano)
 	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
 }
 
 func (e *encoder) floatv(tag string, in reflect.Value) {
 	// Issue #352: When formatting, use the precision of the underlying value
 	precision := 64
 	if in.Kind() == reflect.Float32 {
 		precision = 32
 	}
 
 	s := strconv.FormatFloat(in.Float(), 'g', -1, precision)
 	switch s {
 	case "+Inf":
 		s = ".inf"
 	case "-Inf":
 		s = "-.inf"
 	case "NaN":
 		s = ".nan"
 	}
 	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
 }
 
 func (e *encoder) nilv() {
 	e.emitScalar("null", "", "", yaml_PLAIN_SCALAR_STYLE)
 }
 
 func (e *encoder) emitScalar(value, anchor, tag string, style yaml_scalar_style_t) {
 	implicit := tag == ""
 	e.must(yaml_scalar_event_initialize(&e.event, []byte(anchor), []byte(tag), []byte(value), implicit, implicit, style))
 	e.emit()
 }