spf13--viper/internal/encoding/decoder.go

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package encoding
import (
"sync"
)
// Decoder decodes the contents of b into v.
// It's primarily used for decoding contents of a file into a map[string]interface{}.
type Decoder interface {
Decode(b []byte, v map[string]interface{}) error
}
const (
// ErrDecoderNotFound is returned when there is no decoder registered for a format.
ErrDecoderNotFound = encodingError("decoder not found for this format")
// ErrDecoderFormatAlreadyRegistered is returned when an decoder is already registered for a format.
ErrDecoderFormatAlreadyRegistered = encodingError("decoder already registered for this format")
)
// DecoderRegistry can choose an appropriate Decoder based on the provided format.
type DecoderRegistry struct {
decoders map[string]Decoder
mu sync.RWMutex
}
// NewDecoderRegistry returns a new, initialized DecoderRegistry.
func NewDecoderRegistry() *DecoderRegistry {
return &DecoderRegistry{
decoders: make(map[string]Decoder),
}
}
// RegisterDecoder registers a Decoder for a format.
// Registering a Decoder for an already existing format is not supported.
func (e *DecoderRegistry) RegisterDecoder(format string, enc Decoder) error {
e.mu.Lock()
defer e.mu.Unlock()
if _, ok := e.decoders[format]; ok {
return ErrDecoderFormatAlreadyRegistered
}
e.decoders[format] = enc
return nil
}
// Decode calls the underlying Decoder based on the format.
func (e *DecoderRegistry) Decode(format string, b []byte, v map[string]interface{}) error {
e.mu.RLock()
decoder, ok := e.decoders[format]
e.mu.RUnlock()
if !ok {
return ErrDecoderNotFound
}
return decoder.Decode(b, v)
}