language change

language-change/excel-language/utils.go

@@ -0,0 +1,53 @@
+package excelLanguage
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+)
+
+func writeI8Varint(buf *bytes.Buffer, v int8) error {
+	uv := uint64((uint32(v) << 1) ^ uint32(v>>7)) // zigzag encode
+	b := make([]byte, binary.MaxVarintLen64)
+	n := binary.PutUvarint(b, uv)
+	_, err := buf.Write(b[:n])
+	return err
+}
+
+func readI8Varint(r *bytes.Reader) (int, error) {
+	uv, err := binary.ReadUvarint(r)
+	if err != nil {
+		return 0, err
+	}
+	// zigzag decode
+	v := int((uv >> 1) ^ uint64((int64(uv&1)<<63)>>63))
+	return v, nil
+}
+
+func readString(r *bytes.Reader) (string, error) {
+	l, err := r.ReadByte()
+	if err != nil {
+		return "", err
+	}
+	buf := make([]byte, l)
+	if _, err := io.ReadFull(r, buf); err != nil {
+		return "", err
+	}
+	return string(buf), nil
+}
+
+func readStringArray(r *bytes.Reader) ([]string, error) {
+	length, err := readI8Varint(r)
+	if err != nil {
+		return nil, err
+	}
+	arr := make([]string, 0, length)
+	for i := 0; i < length; i++ {
+		s, err := readString(r)
+		if err != nil {
+			return nil, err
+		}
+		arr = append(arr, s)
+	}
+	return arr, nil
+}