105 lines
2.2 KiB
Go
105 lines
2.2 KiB
Go
|
// Copyright 2013 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 implements bencoding of objects as defined in BEP 3 using
|
||
|
|
// type assertion rather than the use of reflection.
|
||
|
|
package bencode
|
||
|
|
|
||
|
|
import (
|
||
|
|
"bytes"
|
||
|
|
"errors"
|
||
|
|
"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:
|
||
|
|
fmt.Fprintf(w, "%d:%s", len(v), v)
|
||
|
|
|
||
|
|
case int:
|
||
|
|
fmt.Fprintf(w, "i%de", v)
|
||
|
|
|
||
|
|
case uint:
|
||
|
|
fmt.Fprintf(w, "i%se", strconv.FormatUint(uint64(v), 10))
|
||
|
|
|
||
|
|
case int64:
|
||
|
|
fmt.Fprintf(w, "i%se", strconv.FormatInt(v, 10))
|
||
|
|
|
||
|
|
case uint64:
|
||
|
|
fmt.Fprintf(w, "i%se", strconv.FormatUint(v, 10))
|
||
|
|
|
||
|
|
case time.Duration: // Assume seconds
|
||
|
|
fmt.Fprintf(w, "i%se", strconv.FormatInt(int64(v/time.Second), 10))
|
||
|
|
|
||
|
|
case map[string]interface{}:
|
||
|
|
fmt.Fprintf(w, "d")
|
||
|
|
for key, val := range v {
|
||
|
|
fmt.Fprintf(w, "%s:%s", strconv.Itoa(len(key)), key)
|
||
|
|
err := marshal(w, val)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
case []string:
|
||
|
|
fmt.Fprintf(w, "l")
|
||
|
|
for _, val := range v {
|
||
|
|
err := marshal(w, val)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
}
|
||
|
|
fmt.Fprintf(w, "e")
|
||
|
|
|
||
|
|
default:
|
||
|
|
// Although not currently necessary,
|
||
|
|
// should handle []interface{} manually; Go can't do it implicitly
|
||
|
|
return errors.New("bencode: attempted to marshal unsupported type")
|
||
|
|
}
|
||
|
|
|
||
|
|
return nil
|
||
|
|
}
|