feat: add streams

src/sp/common/VarInt.cpp

@@ -29,24 +29,29 @@ DataBuffer& operator<<(DataBuffer& out, const VarInt& var) {
 }
 
 DataBuffer& operator>>(DataBuffer& in, VarInt& var) {
-	var.m_Value = 0;
+	var.Read([&in](std::uint8_t& data){
+		in.ReadSome(&data, 1);
+	});
+	return in;
+}
+
+void VarInt::Read(const ReadFunc& read) {
+	m_Value = 0;
 	unsigned int position = 0;
 	std::uint8_t currentByte;
 
 	while (true) {
-		in.ReadSome(&currentByte, 1);
-		var.m_Value |= static_cast<std::uint64_t>(currentByte & SEGMENT_BITS) << position;
+		read(currentByte);
+		m_Value |= static_cast<std::uint64_t>(currentByte & SEGMENT_BITS) << position;
 
 		if ((currentByte & CONTINUE_BIT) == 0)
 			break;
 
 		position += 7;
 
-		if (position >= 8 * sizeof(var.m_Value))
+		if (position >= 8 * sizeof(m_Value))
 			throw std::runtime_error("VarInt is too big");
 	}
-
-	return in;
 }
 
 }  // namespace sp