301 lines
8.5 KiB
Go
301 lines
8.5 KiB
Go
// Package goyaml implements YAML support for the Go language.
|
|
package goyaml
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"reflect"
|
|
"runtime"
|
|
"strings"
|
|
"sync"
|
|
)
|
|
|
|
func handleErr(err *error) {
|
|
if r := recover(); r != nil {
|
|
if _, ok := r.(runtime.Error); ok {
|
|
panic(r)
|
|
} else if _, ok := r.(*reflect.ValueError); ok {
|
|
panic(r)
|
|
} else if _, ok := r.(externalPanic); ok {
|
|
panic(r)
|
|
} else if s, ok := r.(string); ok {
|
|
*err = errors.New("YAML error: " + s)
|
|
} else if e, ok := r.(error); ok {
|
|
*err = e
|
|
} else {
|
|
panic(r)
|
|
}
|
|
}
|
|
}
|
|
|
|
// Objects implementing the goyaml.Setter interface will receive the YAML
|
|
// tag and value via the SetYAML method during unmarshaling, rather than
|
|
// being implicitly assigned by the goyaml machinery. If setting the value
|
|
// works, the method should return true. If it returns false, the given
|
|
// value will be omitted from maps and slices.
|
|
type Setter interface {
|
|
SetYAML(tag string, value interface{}) bool
|
|
}
|
|
|
|
// Objects implementing the goyaml.Getter interface will get the GetYAML()
|
|
// method called when goyaml is requested to marshal the given value, and
|
|
// the result of this method will be marshaled in place of the actual object.
|
|
type Getter interface {
|
|
GetYAML() (tag string, value interface{})
|
|
}
|
|
|
|
// Unmarshal decodes the first document found within the in byte slice
|
|
// and assigns decoded values into the object pointed by out.
|
|
//
|
|
// Maps, pointers to structs and ints, etc, may all be used as out values.
|
|
// If an internal pointer within a struct is not initialized, goyaml
|
|
// will initialize it if necessary for unmarshalling the provided data,
|
|
// but the struct provided as out must not be a nil pointer.
|
|
//
|
|
// The type of the decoded values and the type of out will be considered,
|
|
// and Unmarshal() will do the best possible job to unmarshal values
|
|
// appropriately. It is NOT considered an error, though, to skip values
|
|
// because they are not available in the decoded YAML, or if they are not
|
|
// compatible with the out value. To ensure something was properly
|
|
// unmarshaled use a map or compare against the previous value for the
|
|
// field (usually the zero value).
|
|
//
|
|
// Struct fields are only unmarshalled if they are exported (have an
|
|
// upper case first letter), and will be unmarshalled using the field
|
|
// name lowercased by default. When custom field names are desired, the
|
|
// tag value may be used to tweak the name. Everything before the first
|
|
// comma in the field tag will be used as the name. The values following
|
|
// the comma 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
|
|
// goyaml.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) {
|
|
defer handleErr(&err)
|
|
d := newDecoder()
|
|
p := newParser(in)
|
|
defer p.destroy()
|
|
node := p.parse()
|
|
if node != nil {
|
|
d.unmarshal(node, reflect.ValueOf(out))
|
|
}
|
|
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, pointers to structs and ints, etc, may all be used as the in value.
|
|
//
|
|
// In the case of struct values, only exported fields will be serialized.
|
|
// The lowercased field name is used as the key for each exported field,
|
|
// but this behavior may be changed using the respective field tag.
|
|
// The tag may also contain flags to tweak the marshalling behavior for
|
|
// the field. Conflicting names result in a runtime error. The 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.
|
|
// Does not apply to zero valued structs.
|
|
//
|
|
// flow Marshal using a flow style (useful for structs,
|
|
// sequences and maps.
|
|
//
|
|
// inline Inline the struct it's applied to, so its fields
|
|
// are processed as if they were part of the outer
|
|
// struct.
|
|
//
|
|
// In addition, if the key is "-", the field is ignored.
|
|
//
|
|
// For example:
|
|
//
|
|
// type T struct {
|
|
// F int "a,omitempty"
|
|
// B int
|
|
// }
|
|
// goyaml.Marshal(&T{B: 2}) // Returns "b: 2\n"
|
|
// goyaml.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.marshal("", reflect.ValueOf(in))
|
|
e.finish()
|
|
out = e.out
|
|
return
|
|
}
|
|
|
|
// --------------------------------------------------------------------------
|
|
// Maintain a mapping of keys to structure field indexes
|
|
|
|
// The code in this section was copied from gobson.
|
|
|
|
// 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
|
|
|
|
// 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
|
|
|
|
type externalPanic string
|
|
|
|
func (e externalPanic) String() string {
|
|
return string(e)
|
|
}
|
|
|
|
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 != "" {
|
|
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:
|
|
msg := fmt.Sprintf("Unsupported flag %q in tag %q of type %s", flag, tag, st)
|
|
panic(externalPanic(msg))
|
|
}
|
|
}
|
|
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...)
|
|
}
|
|
fieldsMap[finfo.Key] = finfo
|
|
fieldsList = append(fieldsList, finfo)
|
|
}
|
|
default:
|
|
//panic("Option ,inline needs a struct value or map field")
|
|
panic("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)
|
|
}
|
|
|
|
fieldsList = append(fieldsList, info)
|
|
fieldsMap[info.Key] = info
|
|
}
|
|
|
|
sinfo = &structInfo{fieldsMap, fieldsList, inlineMap}
|
|
|
|
fieldMapMutex.Lock()
|
|
structMap[st] = sinfo
|
|
fieldMapMutex.Unlock()
|
|
return sinfo, nil
|
|
}
|
|
|
|
func isZero(v reflect.Value) bool {
|
|
switch v.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.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
|
|
return v.Uint() == 0
|
|
case reflect.Bool:
|
|
return !v.Bool()
|
|
}
|
|
return false
|
|
}
|