1 files changed, 167 insertions, 0 deletions
diff --git a/vendor/github.com/felix/go-bencode/decode.go b/vendor/github.com/felix/go-bencode/decode.go
new file mode 100644
index 0000000..e9f32fd
--- /dev/null
+++ b/vendor/github.com/felix/go-bencode/decode.go
@@ -0,0 +1,167 @@
+package bencode
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+)
+
+// Decode decodes a bencoded string to string, int, list or map.
+func Decode(data []byte) (r interface{}, err error) {
+	r, _, err = decodeItem(data, 0)
+	return r, err
+}
+
+// DecodeString decodes a string from a given offset.
+// It returns the string, the number of bytes successfully read.
+func DecodeString(data []byte, start int) (r string, n int, err error) {
+	if start >= len(data) || data[start] < '0' || data[start] > '9' {
+		err = errors.New("bencode: invalid string length")
+		return r, 1, err
+	}
+
+	prefix, i, err := readUntil(data, start, ':')
+	end := start + i
+	if err != nil {
+		return r, end - start, err
+	}
+
+	length, err := strconv.ParseInt(string(prefix), 10, 0)
+	if err != nil {
+		return r, end - start, err
+	}
+	end = end + int(length)
+
+	if end > len(data) || end < i {
+		err = errors.New("bencode: string length out of range")
+		return r, end - start, err
+	}
+
+	return string(data[start+i : end]), end - start, nil
+}
+
+// DecodeInt decodes an integer value.
+// It returns the integer and the number of bytes successfully read.
+func DecodeInt(data []byte, start int) (r int64, end int, err error) {
+	if start >= len(data) || data[start] != 'i' {
+		err = errors.New("bencode: invalid integer")
+		return r, end, err
+	}
+
+	prefix, n, err := readUntil(data, start, 'e')
+	if err != nil {
+		return r, n, err
+	}
+
+	r, err = strconv.ParseInt(string(prefix[1:]), 10, 64)
+	return r, n, err
+}
+
+// DecodeList decodes a list value.
+// It returns the array and the number of bytes successfully read.
+func DecodeList(data []byte, start int) (r []interface{}, end int, err error) {
+	if start >= len(data) {
+		return r, end, errors.New("bencode: list range error")
+	}
+	if data[start] != 'l' {
+		return r, end, errors.New("bencode: invalid list")
+	}
+
+	end = start + 1
+
+	// Empty list
+	if data[end] == 'e' {
+		return r, 2, nil
+	}
+
+	var item interface{}
+
+	var n int
+	for end < len(data) {
+		item, n, err = decodeItem(data, end)
+		end = end + n
+		if err != nil {
+			return r, end - start, err
+		}
+		r = append(r, item)
+
+		if data[end] == 'e' {
+			return r, end - start + 1, nil
+		}
+	}
+
+	return r, end, errors.New("bencode: invalid list termination")
+}
+
+// DecodeDict decodes a dict as a map.
+// It returns the map and the number of bytes successfully read.
+func DecodeDict(data []byte, start int) (map[string]interface{}, int, error) {
+	r := make(map[string]interface{})
+
+	if start >= len(data) {
+		return r, 0, errors.New("bencode: dict range error")
+	}
+
+	if data[start] != 'd' {
+		return r, 1, errors.New("bencode: invalid dict")
+	}
+
+	end := start + 1
+
+	// Empty dict
+	if data[end] == 'e' {
+		return r, 2, nil
+	}
+
+	for end < len(data) {
+		key, n, err := DecodeString(data, end)
+		end = end + n
+		if err != nil {
+			return r, end, errors.New("bencode: invalid dict key")
+		}
+
+		if end >= len(data) {
+			return r, end, errors.New("bencode: dict range error")
+		}
+
+		item, n, err := decodeItem(data, end)
+		end = end + n
+
+		if err != nil {
+			return r, end, err
+		}
+
+		r[key] = item
+
+		if data[end] == 'e' {
+			return r, end - start + 1, nil
+		}
+	}
+	return r, end, errors.New("bencode: invalid dict termination")
+}
+
+// decodeItem decodes the next type at the given index.
+func decodeItem(data []byte, start int) (r interface{}, n int, err error) {
+	switch data[start] {
+	case 'l':
+		return DecodeList(data, start)
+	case 'd':
+		return DecodeDict(data, start)
+	case 'i':
+		return DecodeInt(data, start)
+	default:
+		return DecodeString(data, start)
+	}
+}
+
+// Read until the given character.
+// Returns the slice before the character and the number of bytes successfully read.
+func readUntil(data []byte, start int, c byte) ([]byte, int, error) {
+	i := start
+	for ; i < len(data); i++ {
+		if data[i] == c {
+			return data[start:i], i - start + 1, nil
+		}
+	}
+	return data, i - start, fmt.Errorf("bencode: '%b' not found", c)
+}