refactoring the project structure

Author: IncSW

bencode.go

@@ -0,0 +1,18 @@
+package bencode
+
+import (
+	"github.com/IncSW/go-bencode/internal/decoder"
+	"github.com/IncSW/go-bencode/internal/encoder"
+)
+
+func MarshalTo(dst []byte, data interface{}) ([]byte, error) {
+	return encoder.MarshalTo(dst, data)
+}
+
+func Marshal(data interface{}) ([]byte, error) {
+	return encoder.MarshalTo(make([]byte, 512), data)
+}
+
+func Unmarshal(data []byte) (interface{}, error) {
+	return decoder.Unmarshal(data)
+}

unmarshaler_test.go renamed to decoder_test.go

@@ -1,9 +1,11 @@
-package bencode
+package decoder
 
 import (
 	"bytes"
 	"errors"
 	"strconv"
+
+	"github.com/IncSW/go-bencode/internal"
 )
 
 func Unmarshal(data []byte) (interface{}, error) {
@@ -28,7 +30,7 @@ func (u *unmarshaler) unmarshal() (interface{}, error) {
 			return nil, errors.New("bencode: invalid integer field")
 		}
 		index += u.cursor
-		integer, err := strconv.ParseInt(b2s(u.data[u.cursor:index]), 10, 64)
+		integer, err := strconv.ParseInt(internal.B2S(u.data[u.cursor:index]), 10, 64)
 		if err != nil {
 			return nil, err
 		}
@@ -72,7 +74,7 @@ func (u *unmarshaler) unmarshal() (interface{}, error) {
 			if err != nil {
 				return nil, err
 			}
-			dictionary[b2s(key)] = value
+			dictionary[internal.B2S(key)] = value
 		}
 
 	default:
@@ -89,7 +91,7 @@ func (u *unmarshaler) unmarshalString() ([]byte, error) {
 		return nil, errors.New("bencode: invalid string field")
 	}
 	index += u.cursor
-	stringLength, err := strconv.ParseInt(b2s(u.data[u.cursor:index]), 10, 64)
+	stringLength, err := strconv.ParseInt(internal.B2S(u.data[u.cursor:index]), 10, 64)
 	if err != nil {
 		return nil, err
 	}

marshaler_test.go renamed to encoder_test.go

@@ -1,6 +1,10 @@
-package bencode
+package encoder
 
-import "fmt"
+import (
+	"fmt"
+
+	"github.com/IncSW/go-bencode/internal"
+)
 
 func prepareBuffer(result *[]byte, offset int, length int, neededLength int) int {
 	availableLength := length - offset
@@ -22,10 +26,6 @@ func prepareBuffer(result *[]byte, offset int, length int, neededLength int) int
 	return length
 }
 
-func Marshal(data interface{}) ([]byte, error) {
-	return MarshalTo(make([]byte, 512), data)
-}
-
 func MarshalTo(dst []byte, data interface{}) ([]byte, error) {
 	if cap(dst) > len(dst) {
 		dst = dst[:cap(dst)]
@@ -86,7 +86,7 @@ func marshal(data interface{}, result *[]byte, offset int, length int) (int, int
 		return offset, length, nil
 
 	case string:
-		offset, length = marshalBytes(s2b(value), result, offset, length)
+		offset, length = marshalBytes(internal.S2B(value), result, offset, length)
 		return offset, length, nil
 
 	case []interface{}:
@@ -143,10 +143,10 @@ func marshalDictionary(data map[string]interface{}, result *[]byte, offset int,
 	for key, _ := range data {
 		keys = append(keys, key)
 	}
-	sortStrings(keys)
+	internal.SortStrings(keys)
 
 	for _, key := range keys {
-		offset, length = marshalBytes(s2b(key), result, offset, length)
+		offset, length = marshalBytes(internal.S2B(key), result, offset, length)
 		var err error
 		offset, length, err = marshal(data[key], result, offset, length)
 		if err != nil {

unmarshaler.go renamed to internal/decoder/unmarshaler.go

@@ -1,4 +1,4 @@
-package bencode
+package encoder
 
 import "unsafe"
 

marshaler.go renamed to internal/encoder/encoder.go

@@ -0,0 +1,21 @@
+package internal
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+// https://github.com/valyala/fastjson/blob/master/util.go
+
+func B2S(b []byte) string {
+	return *(*string)(unsafe.Pointer(&b))
+}
+
+func S2B(s string) (b []byte) {
+	strh := (*reflect.StringHeader)(unsafe.Pointer(&s))
+	sh := (*reflect.SliceHeader)(unsafe.Pointer(&b))
+	sh.Data = strh.Data
+	sh.Len = strh.Len
+	sh.Cap = strh.Len
+	return b
+}

encoder_int.go renamed to internal/encoder/int.go

@@ -0,0 +1,20 @@
+package internal
+
+import "sort"
+
+const strSliceLen = 20
+
+func SortStrings(ss []string) {
+	if len(ss) <= strSliceLen {
+		for i := 1; i < len(ss); i++ {
+			for j := i; j > 0; j-- {
+				if ss[j] >= ss[j-1] {
+					break
+				}
+				ss[j], ss[j-1] = ss[j-1], ss[j]
+			}
+		}
+	} else {
+		sort.Strings(ss)
+	}
+}