Refactor StreamReader

d2common/d2datautils/stream_reader.go

@@ -4,12 +4,6 @@ import (
 	"io"
 )
 
-const (
-	bytesPerInt16 = 2
-	bytesPerInt32 = 4
-	bytesPerInt64 = 8
-)
-
 // StreamReader allows you to read data from a byte array in various formats
 type StreamReader struct {
 	data     []byte
@@ -26,16 +20,6 @@ func CreateStreamReader(source []byte) *StreamReader {
 	return result
 }
 
-// GetPosition returns the current stream position
-func (v *StreamReader) GetPosition() uint64 {
-	return v.position
-}
-
-// GetSize returns the total size of the stream in bytes
-func (v *StreamReader) GetSize() uint64 {
-	return uint64(len(v.data))
-}
-
 // GetByte returns a byte from the stream
 func (v *StreamReader) GetByte() byte {
 	result := v.data[v.position]
@@ -44,32 +28,46 @@ func (v *StreamReader) GetByte() byte {
 	return result
 }
 
-// GetUInt16 returns a uint16 word from the stream
-func (v *StreamReader) GetUInt16() uint16 {
-	var result uint16
-
-	for offset := uint64(0); offset < bytesPerInt16; offset++ {
-		shift := uint8(bitsPerByte * offset)
-		result += uint16(v.data[v.position+offset]) << shift
-	}
-
-	v.position += bytesPerInt16
-
-	return result
-}
-
 // GetInt16 returns a int16 word from the stream
 func (v *StreamReader) GetInt16() int16 {
-	var result int16
+	return int16(v.GetUInt16())
+}
 
-	for offset := uint64(0); offset < bytesPerInt16; offset++ {
-		shift := uint8(bitsPerByte * offset)
-		result += int16(v.data[v.position+offset]) << shift
-	}
+// GetUInt16 returns a uint16 word from the stream
+//nolint
+func (v *StreamReader) GetUInt16() uint16 {
+	b := v.ReadBytes(2)
+	return uint16(b[0]) | uint16(b[1])<<8
+}
 
-	v.position += bytesPerInt16
+// GetInt32 returns an int32 dword from the stream
+func (v *StreamReader) GetInt32() int32 {
+	return int32(v.GetUInt32())
+}
 
-	return result
+// GetUInt32 returns a uint32 dword from the stream
+//nolint
+func (v *StreamReader) GetUInt32() uint32 {
+	b := v.ReadBytes(4)
+	return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+}
+
+// GetInt64 returns a uint64 qword from the stream
+func (v *StreamReader) GetInt64() int64 {
+	return int64(v.GetUInt64())
+}
+
+// GetUInt64 returns a uint64 qword from the stream
+//nolint
+func (v *StreamReader) GetUInt64() uint64 {
+	b := v.ReadBytes(8)
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
+		uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+}
+
+// GetPosition returns the current stream position
+func (v *StreamReader) GetPosition() uint64 {
+	return v.position
 }
 
 // SetPosition sets the stream position with the given position
@@ -77,51 +75,9 @@ func (v *StreamReader) SetPosition(newPosition uint64) {
 	v.position = newPosition
 }
 
-// GetUInt32 returns a uint32 dword from the stream
-func (v *StreamReader) GetUInt32() uint32 {
-	var result uint32
-
-	for offset := uint64(0); offset < bytesPerInt32; offset++ {
-		shift := uint8(bitsPerByte * offset)
-		result += uint32(v.data[v.position+offset]) << shift
-	}
-
-	v.position += bytesPerInt32
-
-	return result
-}
-
-// GetInt32 returns an int32 dword from the stream
-func (v *StreamReader) GetInt32() int32 {
-	var result int32
-
-	for offset := uint64(0); offset < bytesPerInt32; offset++ {
-		shift := uint8(bitsPerByte * offset)
-		result += int32(v.data[v.position+offset]) << shift
-	}
-
-	v.position += bytesPerInt32
-
-	return result
-}
-
-// GetUint64 returns a uint64 qword from the stream
-func (v *StreamReader) GetUint64() uint64 {
-	var result uint64
-
-	for offset := uint64(0); offset < bytesPerInt64; offset++ {
-		shift := uint8(bitsPerByte * offset)
-		result += uint64(v.data[v.position+offset]) << shift
-	}
-
-	v.position += bytesPerInt64
-
-	return result
-}
-
-// GetInt64 returns a uint64 qword from the stream
-func (v *StreamReader) GetInt64() int64 {
-	return int64(v.GetUint64())
+// GetSize returns the total size of the stream in bytes
+func (v *StreamReader) GetSize() uint64 {
+	return uint64(len(v.data))
 }
 
 // ReadByte implements io.ByteReader