Lots of stuff

PortabilityLayer/MemReaderStream.cpp

@@ -0,0 +1,110 @@
+#include "MemReaderStream.h"
+
+#include <string.h>
+
+namespace PortabilityLayer
+{
+	MemReaderStream::MemReaderStream(const void *memStream, size_t size)
+		: m_bytes(static_cast<const uint8_t*>(memStream))
+		, m_size(size)
+		, m_loc(0)
+	{
+	}
+
+	size_t MemReaderStream::Read(void *bytesOut, size_t size)
+	{
+		size_t available = m_size - m_loc;
+		if (size > available)
+			size = available;
+
+		memcpy(bytesOut, m_bytes + m_loc, size);
+		m_loc += size;
+
+		return size;
+	}
+
+	size_t MemReaderStream::Write(const void *bytes, size_t size)
+	{
+		return 0;
+	}
+
+	bool IsSeekable()
+	{
+		return true;
+	}
+
+	bool MemReaderStream::IsSeekable() const
+	{
+		return true;
+	}
+
+	bool MemReaderStream::IsReadOnly() const
+	{
+		return true;
+	}
+
+	bool MemReaderStream::IsWriteOnly() const
+	{
+		return false;
+	}
+
+	bool MemReaderStream::SeekStart(UFilePos_t loc)
+	{
+		if (loc > m_size)
+			m_loc = m_size;
+		else
+			m_loc = static_cast<size_t>(loc);
+
+		return true;
+	}
+
+	bool MemReaderStream::SeekCurrent(FilePos_t loc)
+	{
+		if (loc < 0)
+		{
+			if (static_cast<FilePos_t>(m_loc) + loc < 0)
+				m_loc = 0;
+			else
+				m_loc = static_cast<size_t>(static_cast<FilePos_t>(m_loc) + loc);
+		}
+		else
+		{
+			const size_t available = m_size - m_loc;
+			if (static_cast<UFilePos_t>(loc) > available)
+				m_loc = m_size;
+			else
+				m_loc = static_cast<size_t>(static_cast<FilePos_t>(m_loc) + loc);
+		}
+
+		return true;
+	}
+
+	bool MemReaderStream::SeekEnd(UFilePos_t loc)
+	{
+		if (m_size < loc)
+			m_loc = 0;
+		else
+			m_loc = m_size - static_cast<size_t>(loc);
+
+		return true;
+	}
+
+	bool MemReaderStream::Truncate(UFilePos_t loc)
+	{
+		return false;
+	}
+
+	UFilePos_t MemReaderStream::Size() const
+	{
+		return m_size;
+	}
+
+	UFilePos_t MemReaderStream::Tell() const
+	{
+		return static_cast<UFilePos_t>(m_loc);
+	}
+
+	void MemReaderStream::Close()
+	{
+	}
+}