NazaraEngine/src/Nazara/Core/MemoryStream.cpp

144 lines
2.9 KiB
C++

// Copyright (C) 2015 Jérôme Leclercq
// This file is part of the "Nazara Engine - Core module"
// For conditions of distribution and use, see copyright notice in Config.hpp
#include <Nazara/Core/MemoryStream.hpp>
#include <Nazara/Core/ByteArray.hpp>
#include <algorithm>
#include <cstring>
#include <Nazara/Core/Debug.hpp>
namespace Nz
{
/*!
* \class Nz::MemoryStream
* \brief Core class that represents a stream of memory
*/
/*!
* \brief Clears the content of the stream
*/
void MemoryStream::Clear()
{
m_buffer->Clear();
m_pos = 0;
}
/*!
* \brief Checks whether the stream reached the end of the stream
* \return true if cursor is at the end of the stream
*/
bool MemoryStream::EndOfStream() const
{
return m_pos >= m_buffer->size();
}
/*!
* \brief Gets the position of the cursor
* \return Position of the cursor
*/
UInt64 MemoryStream::GetCursorPos() const
{
return m_pos;
}
/*!
* \brief Gets the size of the raw memory
* \return Size of the memory
*/
UInt64 MemoryStream::GetSize() const
{
return m_buffer->GetSize();
}
/*!
* \brief Sets the buffer for the memory stream
*
* \param byteArray Bytes to stream
* \param openMode Reading/writing mode for the stream
*
* \remark Produces a NazaraAssert if byteArray is nullptr
*/
void MemoryStream::SetBuffer(ByteArray* byteArray, UInt32 openMode)
{
NazaraAssert(byteArray, "Invalid ByteArray");
m_buffer = byteArray;
m_openMode = openMode;
}
/*!
* \brief Sets the position of the cursor
* \return true
*
* \param offset Offset according to the beginning of the stream
*/
bool MemoryStream::SetCursorPos(UInt64 offset)
{
m_pos = offset;
return true;
}
/*!
* \brief Flushes the stream
*/
void MemoryStream::FlushStream()
{
// Nothing to flush
}
/*!
* \brief Reads blocks
* \return Number of blocks read
*
* \param buffer Preallocated buffer to contain information read
* \param size Size of the read and thus of the buffer
*/
std::size_t MemoryStream::ReadBlock(void* buffer, std::size_t size)
{
if (EndOfStream())
return 0;
std::size_t readSize = std::min<std::size_t>(size, static_cast<std::size_t>(m_buffer->GetSize() - m_pos));
if (buffer)
std::memcpy(buffer, m_buffer->GetConstBuffer() + m_pos, readSize);
m_pos += readSize;
return readSize;
}
/*!
* \brief Writes blocks
* \return Number of blocks written
*
* \param buffer Preallocated buffer containing information to write
* \param size Size of the writting and thus of the buffer
*
* \remark Produces a NazaraAssert if buffer is nullptr
*/
std::size_t MemoryStream::WriteBlock(const void* buffer, std::size_t size)
{
std::size_t endPos = static_cast<std::size_t>(m_pos + size);
if (endPos > m_buffer->GetSize())
m_buffer->Resize(endPos);
NazaraAssert(buffer, "Invalid buffer");
std::memcpy(m_buffer->GetBuffer() + m_pos, buffer, size);
m_pos = endPos;
return size;
}
}