157 lines
2.8 KiB
Go
157 lines
2.8 KiB
Go
// Copyright 2016 The Chihaya Authors. All rights reserved.
|
|
// Use of this source code is governed by the BSD 2-Clause license,
|
|
// which can be found in the LICENSE file.
|
|
|
|
package bencode
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"io"
|
|
"strconv"
|
|
"time"
|
|
)
|
|
|
|
// An Encoder writes bencoded objects to an output stream.
|
|
type Encoder struct {
|
|
w io.Writer
|
|
}
|
|
|
|
// NewEncoder returns a new encoder that writes to w.
|
|
func NewEncoder(w io.Writer) *Encoder {
|
|
return &Encoder{w: w}
|
|
}
|
|
|
|
// Encode writes the bencoding of v to the stream.
|
|
func (enc *Encoder) Encode(v interface{}) error {
|
|
return marshal(enc.w, v)
|
|
}
|
|
|
|
// Marshal returns the bencoding of v.
|
|
func Marshal(v interface{}) ([]byte, error) {
|
|
buf := &bytes.Buffer{}
|
|
err := marshal(buf, v)
|
|
return buf.Bytes(), err
|
|
}
|
|
|
|
// Marshaler is the interface implemented by objects that can marshal
|
|
// themselves.
|
|
type Marshaler interface {
|
|
MarshalBencode() ([]byte, error)
|
|
}
|
|
|
|
// marshal writes types bencoded to an io.Writer
|
|
func marshal(w io.Writer, data interface{}) error {
|
|
switch v := data.(type) {
|
|
case Marshaler:
|
|
bencoded, err := v.MarshalBencode()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
_, err = w.Write(bencoded)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
case string:
|
|
marshalString(w, v)
|
|
|
|
case int:
|
|
marshalInt(w, int64(v))
|
|
|
|
case uint:
|
|
marshalUint(w, uint64(v))
|
|
|
|
case int16:
|
|
marshalInt(w, int64(v))
|
|
|
|
case uint16:
|
|
marshalUint(w, uint64(v))
|
|
|
|
case int64:
|
|
marshalInt(w, v)
|
|
|
|
case uint64:
|
|
marshalUint(w, v)
|
|
|
|
case []byte:
|
|
marshalBytes(w, v)
|
|
|
|
case time.Duration: // Assume seconds
|
|
marshalInt(w, int64(v/time.Second))
|
|
|
|
case Dict:
|
|
marshal(w, map[string]interface{}(v))
|
|
|
|
case []Dict:
|
|
w.Write([]byte{'l'})
|
|
for _, val := range v {
|
|
err := marshal(w, val)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
w.Write([]byte{'e'})
|
|
|
|
case map[string]interface{}:
|
|
w.Write([]byte{'d'})
|
|
for key, val := range v {
|
|
marshalString(w, key)
|
|
err := marshal(w, val)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
w.Write([]byte{'e'})
|
|
|
|
case []string:
|
|
w.Write([]byte{'l'})
|
|
for _, val := range v {
|
|
err := marshal(w, val)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
w.Write([]byte{'e'})
|
|
|
|
case List:
|
|
marshal(w, []interface{}(v))
|
|
|
|
case []interface{}:
|
|
w.Write([]byte{'l'})
|
|
for _, val := range v {
|
|
err := marshal(w, val)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
w.Write([]byte{'e'})
|
|
|
|
default:
|
|
return fmt.Errorf("attempted to marshal unsupported type:\n%t", v)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func marshalInt(w io.Writer, v int64) {
|
|
w.Write([]byte{'i'})
|
|
w.Write([]byte(strconv.FormatInt(v, 10)))
|
|
w.Write([]byte{'e'})
|
|
}
|
|
|
|
func marshalUint(w io.Writer, v uint64) {
|
|
w.Write([]byte{'i'})
|
|
w.Write([]byte(strconv.FormatUint(v, 10)))
|
|
w.Write([]byte{'e'})
|
|
}
|
|
|
|
func marshalBytes(w io.Writer, v []byte) {
|
|
w.Write([]byte(strconv.Itoa(len(v))))
|
|
w.Write([]byte{':'})
|
|
w.Write(v)
|
|
}
|
|
|
|
func marshalString(w io.Writer, v string) {
|
|
marshalBytes(w, []byte(v))
|
|
}
|