MrSID Decode SDK for Raster Reference Manual  9.5.1.4427
LTIOMemStream Class Reference

Stream which wraps an array of bytes in memory. More...

#include <lt_ioMemStream.h>

Inheritance diagram for LTIOMemStream:
LTIOStreamInf

List of all members.

Public Member Functions

 LTIOMemStream ()
virtual ~LTIOMemStream ()
virtual bool isEOF ()
 Test for end-of-stream.
virtual bool isOpen ()
 Test for stream openness.
virtual LT_STATUS open ()
 Opens the stream.
virtual LT_STATUS close ()
 Closes the stream.
virtual lt_uint32 read (lt_uint8 *pDest, lt_uint32 numBytes)
 Retrieve the specified number of bytes from the data source and place them in pDest.
virtual lt_uint32 write (const lt_uint8 *pSrc, lt_uint32 numBytes)
 Store the specified number of bytes in the data source.
virtual LT_STATUS seek (lt_int64 offset, LTIOSeekDir origin)
 Moves the data access position to origin + offset.
virtual lt_int64 tell ()
 Returns the current data access position as an offset from the start of the data.
virtual LTIOStreamInfduplicate ()
 Clone the stream.
virtual LT_STATUS getLastError () const
 Get status code of last error event.
virtual const char * getID () const
 Get a URI describing the stream object.
Initialization functions
virtual LT_STATUS initialize (void *data, lt_uint32 size)
 Initializes the stream.
virtual LT_STATUS initialize (lt_uint32 size)
 Initializes the stream.

Protected Attributes

lt_uint8m_data
 pointer to buffer
lt_uint32 m_size
 size of buffer
lt_uint32 m_cur
 current position
bool m_ownsData
 data ownership
bool m_isOpen
 openness
bool m_isEOF

Detailed Description

The buffer is of a fixed size and does not grow or shrink.

Definition at line 27 of file lt_ioMemStream.h.


Constructor & Destructor Documentation

virtual LTIOMemStream::~LTIOMemStream ( ) [virtual]

Member Function Documentation

virtual LT_STATUS LTIOMemStream::close ( ) [virtual]

Puts the stream in a state that does not allow data access. May free up resources, but only in such a way that doesn't inhibit successful future calls to open()

Return values:
LT_STS_SuccessOn success, or if the stream is already closed.
LT_STS_FailureOtherwise.

Implements LTIOStreamInf.

virtual LTIOStreamInf* LTIOMemStream::duplicate ( ) [virtual]

Create new stream of the same type with the same initialization parameters. The transmission of these parameters is the responsibility of the derived type. The new stream should initially return false for isOpen().

Return values:
NULLthe stream could not be duplicated; valid LTIOStreamInf* otherwise.

Implements LTIOStreamInf.

virtual const char* LTIOMemStream::getID ( ) const [virtual]

This function returns a UTF-8, null-terminated string which is a URI describing the origin of the stream object -- for example, "file://foo.txt" or "lt_memstream:". This string is only intended for diagnostic purposes, i.e. it may not be valid to pass it to the ctor in an attempt to reopen the stream.

Return values:
urithe uri string

Implements LTIOStreamInf.

virtual LT_STATUS LTIOMemStream::getLastError ( ) const [virtual]

read(), write(), tell(), and duplicate() do not explicitly return status codes in the event of an error. When an error has occurred, this function returns the appropriate status code. Note calling this function after a successful I/O operation will return an undefined value.

Return values:
statusthe error code

Implements LTIOStreamInf.

virtual LT_STATUS LTIOMemStream::initialize ( void *  data,
lt_uint32  size 
) [virtual]
Parameters:
datapointer to start of buffer
sizesize of buffer in bytes
virtual LT_STATUS LTIOMemStream::initialize ( lt_uint32  size) [virtual]

This version internally allocates a buffer of the specified size.

Parameters:
sizesize of buffer in bytes
virtual bool LTIOMemStream::isEOF ( ) [virtual]

Returns true after the first read operation that attempts to read past the end of the stream. It returns false if the current position is not end of stream.

Return values:
trueend of stream
falseotherwise

Implements LTIOStreamInf.

virtual bool LTIOMemStream::isOpen ( ) [virtual]
Return values:
trueThe stream is open
falseotherwise

Implements LTIOStreamInf.

virtual LT_STATUS LTIOMemStream::open ( ) [virtual]

Opening a stream puts it in a state that allows data access based on cached initialization parameters.

Return values:
LT_STS_IOStreamUninitializedThe stream has not been initialized with enough information to open the stream
LT_STS_IOStreamInvalidStateThe stream is already open
LT_STS_SuccessOn success.
LT_STS_FailureFailure.
otherImplementations may return other codes

Implements LTIOStreamInf.

virtual lt_uint32 LTIOMemStream::read ( lt_uint8 pDest,
lt_uint32  numBytes 
) [virtual]
Parameters:
pDestbuffer in which to store read data
numBytesnumber of bytes to read from stream
Return values:
numBytesThe number of bytes actually read

Implements LTIOStreamInf.

virtual LT_STATUS LTIOMemStream::seek ( lt_int64  offset,
LTIOSeekDir  origin 
) [virtual]
Parameters:
offsetnumber of bytes from origin at which to the next read or write will take place
originplace in stream from which to seek
Return values:
LT_STS_IOStreamUnsupportedThe stream is not seekable
LT_STS_IOStreamInvalidArgsThe offset and origin do not specify a valid location in the stream
LT_STS_SuccessOn success
LT_STS_FailureOtherwise
otherImplementations may return other codes

Implements LTIOStreamInf.

virtual lt_int64 LTIOMemStream::tell ( ) [virtual]
Return values:
postionNumber of bytes from the start of the data
-1On error.
otherImplementations may return other codes

Implements LTIOStreamInf.

virtual lt_uint32 LTIOMemStream::write ( const lt_uint8 pSrc,
lt_uint32  numBytes 
) [virtual]
Parameters:
pSrcbuffer from which to store data
numBytesnumber of bytes to write to stream
Return values:
numBytesnumber of bytes actually written

Implements LTIOStreamInf.


Member Data Documentation

Definition at line 76 of file lt_ioMemStream.h.

Definition at line 70 of file lt_ioMemStream.h.

bool LTIOMemStream::m_isEOF [protected]

Definition at line 84 of file lt_ioMemStream.h.

bool LTIOMemStream::m_isOpen [protected]

Definition at line 82 of file lt_ioMemStream.h.

bool LTIOMemStream::m_ownsData [protected]

Definition at line 79 of file lt_ioMemStream.h.

Definition at line 73 of file lt_ioMemStream.h.


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