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
	buffer start address and current buffer address

UINT8 *	m_eos
	end of stream (first address beyond written area)

size_t	m_size
	buffer size

bool	m_allocated
	indicates a new allocated buffer

Detailed Description

Memory stream class.

A PGF stream subclass for internal memory.

Author: C. Stamm

Definition at line 106 of file PGFstream.h.

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 ( )

inlinevirtual

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

inlinevirtual

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

inlinevirtual

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

indicates a new allocated buffer

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

end of stream (first address beyond written area)

Definition at line 109 of file PGFstream.h.

UINT8 * CPGFMemoryStream::m_pos

protected

buffer start address and current buffer address

Definition at line 108 of file PGFstream.h.

size_t CPGFMemoryStream::m_size

protected

buffer size

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