Merge pull request #1003 from Intyre/d2datautils

Refactored Stream Writer and Reader

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++ {
+// GetUInt16 returns a uint16 word from the stream
-		shift := uint8(bitsPerByte * offset)
+//nolint
-		result += int16(v.data[v.position+offset]) << shift
+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
+// GetSize returns the total size of the stream in bytes
-func (v *StreamReader) GetUInt32() uint32 {
+func (v *StreamReader) GetSize() uint64 {
-	var result uint32
+	return uint64(len(v.data))
-
-	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())
 }
 
 // ReadByte implements io.ByteReader

d2common/d2datautils/stream_writer.go

@@ -2,10 +2,6 @@ package d2datautils
 
 import "bytes"
 
-const (
-	byteMask = 0xFF
-)
-
 // StreamWriter allows you to create a byte array by streaming in writes of various sizes
 type StreamWriter struct {
 	data *bytes.Buffer
@@ -20,41 +16,40 @@ func CreateStreamWriter() *StreamWriter {
 	return result
 }
 
+// GetBytes returns the the byte slice of the underlying data
+func (v *StreamWriter) GetBytes() []byte {
+	return v.data.Bytes()
+}
+
 // PushByte writes a byte to the stream
 func (v *StreamWriter) PushByte(val byte) {
 	v.data.WriteByte(val)
 }
 
-// PushUint16 writes an uint16 word to the stream
-func (v *StreamWriter) PushUint16(val uint16) {
-	for count := 0; count < bytesPerInt16; count++ {
-		shift := count * bitsPerByte
-		v.data.WriteByte(byte(val>>shift) & byteMask)
-	}
-}
-
 // PushInt16 writes a int16 word to the stream
 func (v *StreamWriter) PushInt16(val int16) {
-	for count := 0; count < bytesPerInt16; count++ {
+	v.PushUint16(uint16(val))
-		shift := count * bitsPerByte
+}
-		v.data.WriteByte(byte(val>>shift) & byteMask)
+
-	}
+// PushUint16 writes an uint16 word to the stream
+//nolint
+func (v *StreamWriter) PushUint16(val uint16) {
+	v.data.WriteByte(byte(val))
+	v.data.WriteByte(byte(val >> 8))
+}
+
+// PushInt32 writes a int32 dword to the stream
+func (v *StreamWriter) PushInt32(val int32) {
+	v.PushUint32(uint32(val))
 }
 
 // PushUint32 writes a uint32 dword to the stream
+//nolint
 func (v *StreamWriter) PushUint32(val uint32) {
-	for count := 0; count < bytesPerInt32; count++ {
+	v.data.WriteByte(byte(val))
-		shift := count * bitsPerByte
+	v.data.WriteByte(byte(val >> 8))
-		v.data.WriteByte(byte(val>>shift) & byteMask)
+	v.data.WriteByte(byte(val >> 16))
-	}
+	v.data.WriteByte(byte(val >> 24))
-}
-
-// PushUint64 writes a uint64 qword to the stream
-func (v *StreamWriter) PushUint64(val uint64) {
-	for count := 0; count < bytesPerInt64; count++ {
-		shift := count * bitsPerByte
-		v.data.WriteByte(byte(val>>shift) & byteMask)
-	}
 }
 
 // PushInt64 writes a uint64 qword to the stream
@@ -62,7 +57,15 @@ func (v *StreamWriter) PushInt64(val int64) {
 	v.PushUint64(uint64(val))
 }
 
-// GetBytes returns the the byte slice of the underlying data
+// PushUint64 writes a uint64 qword to the stream
-func (v *StreamWriter) GetBytes() []byte {
+//nolint
-	return v.data.Bytes()
+func (v *StreamWriter) PushUint64(val uint64) {
+	v.data.WriteByte(byte(val))
+	v.data.WriteByte(byte(val >> 8))
+	v.data.WriteByte(byte(val >> 16))
+	v.data.WriteByte(byte(val >> 24))
+	v.data.WriteByte(byte(val >> 32))
+	v.data.WriteByte(byte(val >> 40))
+	v.data.WriteByte(byte(val >> 48))
+	v.data.WriteByte(byte(val >> 56))
 }