tge/engine/core/memStream.cc
2025-02-17 23:17:30 -06:00

158 lines
4.2 KiB
C++
Executable File

//-----------------------------------------------------------------------------
// Torque Game Engine
// Copyright (C) GarageGames.com, Inc.
//-----------------------------------------------------------------------------
#include "platform/platform.h"
#include "core/memstream.h"
MemStream::MemStream(const U32 in_bufferSize,
void* io_pBuffer,
const bool in_allowRead,
const bool in_allowWrite)
: cm_bufferSize(in_bufferSize),
m_pBufferBase(io_pBuffer),
m_instCaps(0),
m_currentPosition(0)
{
AssertFatal(io_pBuffer != NULL, "Invalid buffer pointer");
AssertFatal(in_bufferSize > 0, "Invalid buffer size");
AssertFatal(in_allowRead || in_allowWrite, "Either write or read must be allowed");
if (in_allowRead)
m_instCaps |= Stream::StreamRead;
if (in_allowWrite)
m_instCaps |= Stream::StreamWrite;
setStatus(Ok);
}
MemStream::~MemStream()
{
m_pBufferBase = NULL;
m_currentPosition = 0;
setStatus(Closed);
}
U32 MemStream::getStreamSize()
{
AssertFatal(getStatus() != Closed, "Stream not open, size undefined");
return cm_bufferSize;
}
bool MemStream::hasCapability(const Capability in_cap) const
{
// Closed streams can't do anything
//
if (getStatus() == Closed)
return false;
U32 totalCaps = U32(Stream::StreamPosition) | m_instCaps;
return (U32(in_cap) & totalCaps) != 0;
}
U32 MemStream::getPosition() const
{
AssertFatal(getStatus() != Closed, "Position of a closed stream is undefined");
return m_currentPosition;
}
bool MemStream::setPosition(const U32 in_newPosition)
{
AssertFatal(getStatus() != Closed, "SetPosition of a closed stream is not allowed");
AssertFatal(in_newPosition <= cm_bufferSize, "Invalid position");
m_currentPosition = in_newPosition;
if (m_currentPosition > cm_bufferSize) {
// Never gets here in debug version, this is for the release builds...
//
setStatus(UnknownError);
return false;
} else if (m_currentPosition == cm_bufferSize) {
setStatus(EOS);
} else {
setStatus(Ok);
}
return true;
}
bool MemStream::_read(const U32 in_numBytes, void *out_pBuffer)
{
AssertFatal(getStatus() != Closed, "Attempted read from a closed stream");
if (in_numBytes == 0)
return true;
AssertFatal(out_pBuffer != NULL, "Invalid output buffer");
if (hasCapability(StreamRead) == false) {
AssertWarn(false, "Reading is disallowed on this stream");
setStatus(IllegalCall);
return false;
}
bool success = true;
U32 actualBytes = in_numBytes;
if ((m_currentPosition + in_numBytes) > cm_bufferSize) {
success = false;
actualBytes = cm_bufferSize - m_currentPosition;
}
// Obtain a current pointer, and do the copy
const void* pCurrent = (const void*)((const U8*)m_pBufferBase + m_currentPosition);
dMemcpy(out_pBuffer, pCurrent, actualBytes);
// Advance the stream position
m_currentPosition += actualBytes;
if (!success)
setStatus(EOS);
else
setStatus(Ok);
return success;
}
bool MemStream::_write(const U32 in_numBytes, const void *in_pBuffer)
{
AssertFatal(getStatus() != Closed, "Attempted write to a closed stream");
if (in_numBytes == 0)
return true;
AssertFatal(in_pBuffer != NULL, "Invalid input buffer");
if (hasCapability(StreamWrite) == false) {
AssertWarn(0, "Writing is disallowed on this stream");
setStatus(IllegalCall);
return false;
}
bool success = true;
U32 actualBytes = in_numBytes;
if ((m_currentPosition + in_numBytes) > cm_bufferSize) {
success = false;
actualBytes = cm_bufferSize - m_currentPosition;
}
// Obtain a current pointer, and do the copy
void* pCurrent = (void*)((U8*)m_pBufferBase + m_currentPosition);
dMemcpy(pCurrent, in_pBuffer, actualBytes);
// Advance the stream position
m_currentPosition += actualBytes;
if (m_currentPosition == cm_bufferSize)
setStatus(EOS);
else
setStatus(Ok);
return success;
}