Memory stream class. More...

#include <PGFstream.h>

Inheritance diagram for CPGFMemoryStream:

Public Member Functions
	CPGFMemoryStream (size_t size) THROW_
	CPGFMemoryStream (UINT8 *pBuffer, size_t size) THROW_
void	Reinitialize (UINT8 *pBuffer, size_t size) THROW_
virtual	~CPGFMemoryStream ()
virtual void	Write (int count, void buffer) THROW_
virtual void	Read (int count, void buffer)
virtual void	SetPos (short posMode, INT64 posOff) THROW_
virtual UINT64	GetPos () const
virtual bool	IsValid () const
size_t	GetSize () const
const UINT8 *	GetBuffer () const
UINT8 *	GetBuffer ()
UINT64	GetEOS () const
void	SetEOS (UINT64 length)
Protected Attributes
UINT8 *	m_buffer
UINT8 *	m_pos
UINT8 *	m_eos
size_t	m_size
bool	m_allocated

Detailed Description

Memory stream class.

A PGF stream subclass for internal memory.

Author:: C. Stamm

Constructor & Destructor Documentation

CPGFMemoryStream::CPGFMemoryStream ( size_t size )

Constructor

Parameters:

size	Size of new allocated memory buffer

Allocate memory block of given size

Parameters:

size	Memory size

Definition at line 78 of file PGFstream.cpp.

: m_size(size)
, m_allocated(true) {
        m_buffer = m_pos = m_eos = new(std::nothrow) UINT8[m_size];
        if (!m_buffer) ReturnWithError(InsufficientMemory);
}

CPGFMemoryStream::CPGFMemoryStream	(	UINT8 *	pBuffer,
		size_t	size
	)

Constructor. Use already allocated memory of given size

Parameters:

pBuffer	Memory location
size	Memory size

Use already allocated memory of given size

Parameters:

pBuffer	Memory location
size	Memory size

Definition at line 89 of file PGFstream.cpp.

: m_buffer(pBuffer)
, m_pos(pBuffer)
, m_eos(pBuffer + size)
, m_size(size)
, m_allocated(false) {
        ASSERT(IsValid());
}

virtual CPGFMemoryStream::~CPGFMemoryStream ( ) [inline, virtual]

Definition at line 126 of file PGFstream.h.

                                    { 
                m_pos = 0; 
                if (m_allocated) {
                        // the memory buffer has been allocated inside of CPMFmemoryStream constructor
                        delete[] m_buffer; m_buffer = 0;
                }
        }

Member Function Documentation

const UINT8* CPGFMemoryStream::GetBuffer ( ) const [inline]

Returns:: Memory buffer

Definition at line 143 of file PGFstream.h.

{ return m_buffer; }

UINT8* CPGFMemoryStream::GetBuffer ( ) [inline]

Returns:: Memory buffer

Definition at line 145 of file PGFstream.h.

{ return m_buffer; }

UINT64 CPGFMemoryStream::GetEOS ( ) const [inline]

Returns:: relative position of end of stream (= stream length)

Definition at line 147 of file PGFstream.h.

{ ASSERT(IsValid()); return m_eos - m_buffer; }

virtual UINT64 CPGFMemoryStream::GetPos ( ) const [inline, virtual]

Get current stream position.

Returns:: Current stream position

Implements CPGFStream.

Definition at line 137 of file PGFstream.h.

{ ASSERT(IsValid()); return m_pos - m_buffer; }

size_t CPGFMemoryStream::GetSize ( ) const [inline]

Returns:: Memory size

Definition at line 141 of file PGFstream.h.

{ return m_size; }

virtual bool CPGFMemoryStream::IsValid ( ) const [inline, virtual]

Check stream validity.

Returns:: True if stream and current position is valid

Implements CPGFStream.

Definition at line 138 of file PGFstream.h.

{ return m_buffer != 0; }

void CPGFMemoryStream::Read	(	int *	count,
		void *	buffer
	)		`[virtual]`

Read some bytes from this stream and stores them into a buffer.

Parameters:

count	A pointer to a value containing the number of bytes should be read. After this call it contains the number of read bytes.
buffer	A memory buffer

Implements CPGFStream.

Definition at line 148 of file PGFstream.cpp.

                                                     {
        ASSERT(IsValid());
        ASSERT(count);
        ASSERT(buffPtr);
        ASSERT(m_buffer + m_size >= m_eos);
        ASSERT(m_pos <= m_eos);
        
        if (m_pos + *count <= m_eos) {
                memcpy(buffPtr, m_pos, *count);
                m_pos += *count;
        } else {
                // end of memory block reached -> read only until end
                *count = (int)__max(0, m_eos - m_pos);
                memcpy(buffPtr, m_pos, *count);
                m_pos += *count;
        }
        ASSERT(m_pos <= m_eos);
}

void CPGFMemoryStream::Reinitialize	(	UINT8 *	pBuffer,
		size_t	size
	)

Constructor. Use already allocated memory of given size

Parameters:

pBuffer	Memory location
size	Memory size

Use already allocated memory of given size

Parameters:

pBuffer	Memory location
size	Memory size

Definition at line 102 of file PGFstream.cpp.

                                                                      {
        if (!m_allocated) {
                m_buffer = m_pos = pBuffer;
                m_size = size;
                m_eos = m_buffer + size;
        }
}

void CPGFMemoryStream::SetEOS ( UINT64 length ) [inline]

Parameters:

length Stream length (= relative position of end of stream)

Definition at line 149 of file PGFstream.h.

{ ASSERT(IsValid()); m_eos = m_buffer + length; }

void CPGFMemoryStream::SetPos	(	short	posMode,
		INT64	posOff
	)		`[virtual]`

Set stream position either absolute or relative.

Parameters:

posMode	A position mode (FSFromStart, FSFromCurrent, FSFromEnd)
posOff	A new stream position (absolute positioning) or a position offset (relative positioning)

Implements CPGFStream.

Definition at line 168 of file PGFstream.cpp.

                                                                {
        ASSERT(IsValid());
        switch(posMode) {
        case FSFromStart:
                m_pos = m_buffer + posOff;
                break;
        case FSFromCurrent:
                m_pos += posOff;
                break;
        case FSFromEnd:
                m_pos = m_eos + posOff;
                break;
        default:
                ASSERT(false);
        }
        if (m_pos > m_eos) 
                ReturnWithError(InvalidStreamPos);
}

void CPGFMemoryStream::Write	(	int *	count,
		void *	buffer
	)		`[virtual]`

Write some bytes out of a buffer into this stream.

Parameters:

count	A pointer to a value containing the number of bytes should be written. After this call it contains the number of written bytes.
buffer	A memory buffer

Implements CPGFStream.

Definition at line 111 of file PGFstream.cpp.

                                                             {
        ASSERT(count);
        ASSERT(buffPtr);
        ASSERT(IsValid());
        const size_t deltaSize = 0x4000 + *count;
        
        if (m_pos + *count <= m_buffer + m_size) {
                memcpy(m_pos, buffPtr, *count);
                m_pos += *count; 
                if (m_pos > m_eos) m_eos = m_pos;
        } else if (m_allocated) {
                // memory block is too small -> reallocate a deltaSize larger block
                size_t offset = m_pos - m_buffer;
                UINT8 *buf_tmp = (UINT8 *)realloc(m_buffer, m_size + deltaSize);
                if (!buf_tmp) {
                        delete[] m_buffer;
                        m_buffer = 0;
                        ReturnWithError(InsufficientMemory);
                } else {
                        m_buffer = buf_tmp;
                }
                m_size += deltaSize;

                // reposition m_pos
                m_pos = m_buffer + offset;

                // write block
                memcpy(m_pos, buffPtr, *count);
                m_pos += *count; 
                if (m_pos > m_eos) m_eos = m_pos;
        } else {
                ReturnWithError(InsufficientMemory);    
        }
        ASSERT(m_pos <= m_eos);
}

Member Data Documentation

bool CPGFMemoryStream::m_allocated [protected]

Definition at line 111 of file PGFstream.h.

UINT8* CPGFMemoryStream::m_buffer [protected]

Definition at line 108 of file PGFstream.h.

UINT8* CPGFMemoryStream::m_eos [protected]

Definition at line 109 of file PGFstream.h.

UINT8 * CPGFMemoryStream::m_pos [protected]

Definition at line 108 of file PGFstream.h.

size_t CPGFMemoryStream::m_size [protected]

Definition at line 110 of file PGFstream.h.

The documentation for this class was generated from the following files:

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation