ossim::BlockBufInfo Class Reference

This is a utility class used by the BlockStreamBuffer. More...

#include <BlockStreamBuffer.h>

Public Member Functions
	BlockBufInfo ()
ossim_int64	getBlockIndex (ossim_int64 pos)
	Returns the index of a block. More...
bool	isWithinWindow (ossim_int64 pos) const
	This just tests if the given abolute position is within a block window. More...
bool	isWithinValidWindow (ossim_int64 pos) const
	This just tests if the given abolute position is within a valid window. More...
ossim_int64	getEndByte () const
	Convenient method to get the absolute byte position of the end byte. More...
const char *	getBufferStart (ossim_int64 absolutePosition) const
	Get the starting address in the buffer of the absolute position. More...
const char *	getBuffer () const
char *	getBuffer ()
bool	isLoaded () const
void	setBuffer (char *bufPtr, ossim_uint32 blockSize)
	Will set the buffer and then reset the loaded flag to be false. More...

Public Attributes
ossim_int64	m_startByte
	Is the starting absolute byte offset for the buffer. More...
ossim_int64	m_blockSize
	Is the size of the buffer. More...
ossim_int64	m_validSize
	is the valid size of the buffer. More...
char *	m_blockBufferPtr
	Starting address of the block. More...
bool	m_blockLoaded
	Variable used to invalidate a block or specify whether the block is loaded. More...

Detailed Description

This is a utility class used by the BlockStreamBuffer.

This class will hold information regarding the block that is currently loaded. It holds the start byte and the valid size and the block size of the buffer. The valid size is used because if we are at the end of a stream we could have a partial block.

Definition at line 18 of file BlockStreamBuffer.h.

Constructor & Destructor Documentation

BlockBufInfo()

ossim::BlockBufInfo::BlockBufInfo ( )

inline

Definition at line 20 of file BlockStreamBuffer.h.

                    :
      m_startByte(0),
      m_blockSize(0),
      m_validSize(0),         
      m_blockBufferPtr(0),
      m_blockLoaded(false){

      }

Member Function Documentation

getBlockIndex()

ossim_int64 ossim::BlockBufInfo::getBlockIndex ( ossim_int64  pos )

inline

Returns the index of a block.

Parameters

pos	Is the aboslute byte position

Returns

The block index for the abosolute position

Definition at line 36 of file BlockStreamBuffer.h.

                                                {
         ossim_int64 result = -1;
         if(m_blockSize&&m_blockBufferPtr&&(pos>=0))
         {
            result = pos/m_blockSize;
         }

         return result;
      }

getBuffer() [1/2]

const char* ossim::BlockBufInfo::getBuffer ( ) const

inline

Returns

The starting address of the block buffer

Definition at line 103 of file BlockStreamBuffer.h.

                                  {
         return m_blockBufferPtr;
      }

getBuffer() [2/2]

char* ossim::BlockBufInfo::getBuffer ( )

inline

Returns

The starting address of the block buffer

Definition at line 110 of file BlockStreamBuffer.h.

                       {
         return m_blockBufferPtr;
      }

getBufferStart()

const char* ossim::BlockBufInfo::getBufferStart ( ossim_int64  absolutePosition ) const

inline

Get the starting address in the buffer of the absolute position.

Parameters

absolutePosition

The absolute byte position

Returns

The starting address at the aboslute position or 0 if the absolute position is outside the windows

Definition at line 91 of file BlockStreamBuffer.h.

                                                                   {
         if(isWithinValidWindow(absolutePosition))
         {
            return m_blockBufferPtr+(absolutePosition-m_startByte);
         }

         return 0;
      }

getEndByte()

ossim_int64 ossim::BlockBufInfo::getEndByte ( ) const

inline

Convenient method to get the absolute byte position of the end byte.

Returns

the absolute byte position of the end byte

Definition at line 80 of file BlockStreamBuffer.h.

                                   {
         if(m_validSize>=0) return m_startByte+(m_validSize);
         return m_startByte;
      }

isLoaded()

bool ossim::BlockBufInfo::isLoaded ( ) const

inline

Returns

true if the the block is valid and loaded or false otherwise.

Definition at line 118 of file BlockStreamBuffer.h.

{return m_blockLoaded;}

isWithinValidWindow()

bool ossim::BlockBufInfo::isWithinValidWindow ( ossim_int64  pos ) const

inline

This just tests if the given abolute position is within a valid window.

A valid window represents partial blocks.

Parameters

pos	Absolute position

Returns

true if we are inside the defined window and false otherwise.

Definition at line 68 of file BlockStreamBuffer.h.

                                                    {
         return  (m_blockLoaded&&
                  (pos>=m_startByte)&&
                  (pos<getEndByte()));
      }

isWithinWindow()

bool ossim::BlockBufInfo::isWithinWindow ( ossim_int64  pos ) const

inline

This just tests if the given abolute position is within a block window.

We will usually call

See also

isWithinValidWindow.

Parameters

pos	Absolute position

Returns

true if we are inside the defined window and false otherwise.

Definition at line 54 of file BlockStreamBuffer.h.

                                               {
         return  (m_blockLoaded&&
                  (pos>=m_startByte)&&
                  (pos<(m_startByte+m_blockSize)));
      }

setBuffer()

void ossim::BlockBufInfo::setBuffer ( char *  bufPtr, ossim_uint32  blockSize  )

inline

Will set the buffer and then reset the loaded flag to be false.

Parameters

bufPtr	is the starting address of the block buffer
blockSize	is the size of the buffer

Definition at line 127 of file BlockStreamBuffer.h.

      {
         m_blockBufferPtr = bufPtr;
         m_blockSize      = blockSize;
         m_blockLoaded    = false;
      }

Member Data Documentation

m_blockBufferPtr

char* ossim::BlockBufInfo::m_blockBufferPtr

Starting address of the block.

This is not managed by this class and will not be deleted.

Definition at line 155 of file BlockStreamBuffer.h.

Referenced by ossim::BlockStreamBuffer::BlockStreamBuffer().

m_blockLoaded

bool ossim::BlockBufInfo::m_blockLoaded

Variable used to invalidate a block or specify whether the block is loaded.

Definition at line 160 of file BlockStreamBuffer.h.

m_blockSize

ossim_int64 ossim::BlockBufInfo::m_blockSize

Is the size of the buffer.

Definition at line 142 of file BlockStreamBuffer.h.

Referenced by ossim::BlockStreamBuffer::BlockStreamBuffer().

m_startByte

ossim_int64 ossim::BlockBufInfo::m_startByte

Is the starting absolute byte offset for the buffer.

Definition at line 137 of file BlockStreamBuffer.h.

m_validSize

ossim_int64 ossim::BlockBufInfo::m_validSize

is the valid size of the buffer.

In most cases this is equal to the blockSize but if at the end of a stream you could have a partial buffer.

Definition at line 149 of file BlockStreamBuffer.h.

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

• BlockStreamBuffer.h