bitmuncher: add missing methods from stream reader

d2common/d2datautils/bitmuncher.go

@@ -12,6 +12,7 @@ const (
 	byteLen                   = 8
 	oneBit                    = 0x01
 	fourBytes                 = byteLen * 4
+	twoBytes                  = byteLen * 2
 )
 
 // CreateBitMuncher Creates a BitMuncher
@@ -79,6 +80,16 @@ func (v *BitMuncher) GetByte() byte {
 	return byte(v.GetBits(byteLen))
 }
 
+// GetInt16 reads an int16 from data
+func (v *BitMuncher) GetInt16() int16 {
+	return int16(v.MakeSigned(v.GetBits(twoBytes), twoBytes))
+}
+
+// GetUInt16 reads an unsigned uint16 from data
+func (v *BitMuncher) GetUInt16() uint16 {
+	return uint16(v.GetBits(twoBytes))
+}
+
 // GetInt32 reads an int32 from data
 func (v *BitMuncher) GetInt32() int32 {
 	return v.MakeSigned(v.GetBits(fourBytes), fourBytes)
@@ -104,6 +115,16 @@ func (v *BitMuncher) GetBits(bits int) uint32 {
 	return result
 }
 
+// GetBytes returns byte slice of `n` length.
+func (v *BitMuncher) GetBytes(n int) (result []byte) {
+	result = make([]byte, n)
+	for i := 0; i < n; i++ {
+		result[i] = v.GetByte()
+	}
+
+	return result
+}
+
 // GetSignedBits Given a number of bits, reads that many bits and returns as int
 func (v *BitMuncher) GetSignedBits(bits int) int {
 	return int(v.MakeSigned(v.GetBits(bits), bits))

d2common/d2datautils/bitmuncher_test.go

@@ -50,6 +50,12 @@ func TestBitmuncherGetBits(t *testing.T) {
 	assert.Equal(t, byte(bm.GetBits(bitsPerByte)), testData[0], "get bits didn't return expected value")
 }
 
+func TestBitmuncherGetBytes(t *testing.T) {
+	bm := CreateBitMuncher(testData, 0)
+
+	assert.Equal(t, bm.GetBytes(4), testData[0:4], "get bytes didn't return expected value")
+}
+
 func TestBitmuncherGetNoBits(t *testing.T) {
 	bm := CreateBitMuncher(testData, 0)
 
@@ -82,6 +88,30 @@ func TestBitmuncherSkipBits(t *testing.T) {
 	assert.Equal(t, bm.GetByte(), testData[1], "skipping 8 bits didn't moved bit muncher's position into next byte")
 }
 
+func TestBitmuncherGetInt16(t *testing.T) {
+	bm := CreateBitMuncher(testData, 0)
+
+	var testInt int16
+
+	for i := 0; i < bytesPerint16; i++ {
+		testInt |= int16(testData[i]) << int16(bitsPerByte*i)
+	}
+
+	assert.Equal(t, bm.GetInt16(), testInt, "int16 value wasn't returned properly")
+}
+
+func TestBitmuncherGetUint16(t *testing.T) {
+	bm := CreateBitMuncher(testData, 0)
+
+	var testUint uint16
+
+	for i := 0; i < bytesPerint16; i++ {
+		testUint |= uint16(testData[i]) << uint16(bitsPerByte*i)
+	}
+
+	assert.Equal(t, bm.GetUInt16(), testUint, "uint16 value wasn't returned properly")
+}
+
 func TestBitmuncherGetInt32(t *testing.T) {
 	bm := CreateBitMuncher(testData, 0)