Input/Output Data Stream Utility Functions

Classes
struct	OSRTSTREAM
Defines
#define	OSRTSTRMF_INPUT 0x0001
#define	OSRTSTRMF_OUTPUT 0x0002
#define	OSRTSTRMF_BUFFERED 0x8000
#define	OSRTSTRMF_UNBUFFERED 0x4000
#define	OSRTSTRMF_POSMARKED 0x2000
#define	OSRTSTRMF_FIXINMEM 0x1000
#define	OSRTSTRMF_BUF_INPUT (OSRTSTRMF_INPUT\|OSRTSTRMF_BUFFERED)
#define	OSRTSTRMF_BUF_OUTPUT (OSRTSTRMF_OUTPUT\|OSRTSTRMF_BUFFERED)
#define	OSRTSTRMID_FILE 1
#define	OSRTSTRMID_SOCKET 2
#define	OSRTSTRMID_MEMORY 3
#define	OSRTSTRMID_BUFFERED 4
#define	OSRTSTRMID_DIRECTBUF 5
#define	OSRTSTRMID_CTXTBUF 6
#define	OSRTSTRMID_ZLIB 7
#define	OSRTSTRMID_USER 1000
#define	OSRTSTRM_K_BUFSIZE 1024
#define	OSRTSTRM_K_INVALIDMARK ((size_t)-1)
#define	OSRTSTREAM_BYTEINDEX(pctxt)
#define	OSRTSTREAM_ID(pctxt) ((pctxt)->pStream->id)
#define	OSRTSTREAM_FLAGS(pctxt) ((pctxt)->pStream->flags)
Typedefs
typedef long(*	OSRTStreamReadProc )(struct OSRTSTREAM pStream, OSOCTET pbuffer, size_t bufSize)
typedef long(*	OSRTStreamBlockingReadProc )(struct OSRTSTREAM pStream, OSOCTET pbuffer, size_t toReadBytes)
typedef long(*	OSRTStreamWriteProc )(struct OSRTSTREAM pStream, const OSOCTET data, size_t numocts)
typedef int(*	OSRTStreamFlushProc )(struct OSRTSTREAM *pStream)
typedef int(*	OSRTStreamCloseProc )(struct OSRTSTREAM *pStream)
typedef int(*	OSRTStreamSkipProc )(struct OSRTSTREAM *pStream, size_t skipBytes)
typedef int(*	OSRTStreamMarkProc )(struct OSRTSTREAM *pStream, size_t readAheadLimit)
typedef int(*	OSRTStreamResetProc )(struct OSRTSTREAM *pStream)
typedef int(*	OSRTStreamGetPosProc )(struct OSRTSTREAM pStream, size_t ppos)
typedef int(*	OSRTStreamSetPosProc )(struct OSRTSTREAM *pStream, size_t pos)
typedef struct OSRTSTREAM	OSRTSTREAM
Functions
int	rtxStreamClose (OSCTXT *pctxt)
int	rtxStreamFlush (OSCTXT *pctxt)
int	rtxStreamInit (OSCTXT *pctxt)
long	rtxStreamRead (OSCTXT pctxt, OSOCTET pbuffer, size_t bufSize)
long	rtxStreamBlockingRead (OSCTXT pctxt, OSOCTET pbuffer, size_t readBytes)
int	rtxStreamSkip (OSCTXT *pctxt, size_t skipBytes)
long	rtxStreamWrite (OSCTXT pctxt, const OSOCTET data, size_t numocts)
int	rtxStreamGetIOBytes (OSCTXT pctxt, size_t pPos)
int	rtxStreamMark (OSCTXT *pctxt, size_t readAheadLimit)
int	rtxStreamReset (OSCTXT *pctxt)
OSBOOL	rtxStreamMarkSupported (OSCTXT *pctxt)
OSBOOL	rtxStreamIsOpened (OSCTXT *pctxt)
OSBOOL	rtxStreamIsReadable (OSCTXT *pctxt)
OSBOOL	rtxStreamIsWritable (OSCTXT *pctxt)
int	rtxStreamRelease (OSCTXT *pctxt)
void	rtxStreamSetCapture (OSCTXT pctxt, OSRTMEMBUF pmembuf)
OSRTMEMBUF *	rtxStreamGetCapture (OSCTXT *pctxt)
int	rtxStreamGetPos (OSCTXT pctxt, size_t ppos)
int	rtxStreamSetPos (OSCTXT *pctxt, size_t pos)

Detailed Description

Stream functions are used for unbuffered stream operations. All of the operations with streams are performed using a context block to maintain state information.

These functions may be used for any input/output operations with streams. Each stream should be initialized first by call to the rtxStreamInit function. After initialization, the stream may be opened for reading or writing by calling one of the following functions:

rtxStreamFileOpen
rtxStreamFileAttach
rtxStreamSocketAttach
rtxStreamMemoryCreate
rtxStreamMemoryAttach

Define Documentation

#define OSRTSTREAM_BYTEINDEX ( pctxt )

Value:

(((pctxt)->pStream->id == OSRTSTRMID_DIRECTBUF) ?                    \
 ((pctxt)->pStream->bytesProcessed + (pctxt)->buffer.byteIndex) :    \
 ((pctxt)->pStream->bytesProcessed /* was ioBytes */ ))

Typedef Documentation

typedef struct OSRTSTREAM OSRTSTREAM

The stream control block. A user may implement a customized stream by defining read, skip, close functions for input streams and write, flush, close for output streams.

typedef long(* OSRTStreamBlockingReadProc)(struct OSRTSTREAM *pStream, OSOCTET *pbuffer, size_t toReadBytes)

Stream blockingRead function pointer type. A user may implement a customized read function for specific input streams. The blockingRead function is defined in the OSRTSTREAM control structure.

typedef int(* OSRTStreamCloseProc)(struct OSRTSTREAM *pStream)

Stream close function pointer type. A user may implement a customized close function for any specific input or output streams. The close function is defined in the OSRTSTREAM control structure.

typedef int(* OSRTStreamFlushProc)(struct OSRTSTREAM *pStream)

Stream flush function pointer type. A user may implement a customized flush function for any specific output streams. The flush function is defined in the OSRTSTREAM control structure.

typedef int(* OSRTStreamGetPosProc)(struct OSRTSTREAM *pStream, size_t *ppos)

Stream get position function pointer type. A user may implement a customized function for a specific input stream type. The mark function is defined in the OSRTSTREAM control structure.

typedef int(* OSRTStreamMarkProc)(struct OSRTSTREAM *pStream, size_t readAheadLimit)

Stream mark function pointer type. A user may implement a customized function for a specific input stream type. The mark function is defined in the OSRTSTREAM control structure.

typedef long(* OSRTStreamReadProc)(struct OSRTSTREAM *pStream, OSOCTET *pbuffer, size_t bufSize)

Stream read function pointer type. A user may implement a customized read function for specific input streams. The read function is defined in the OSRTSTREAM control structure.

typedef int(* OSRTStreamResetProc)(struct OSRTSTREAM *pStream)

Stream reset function pointer type. A user may implement a customized function for a specific input stream type. The reset function is defined in the OSRTSTREAM control structure.

typedef int(* OSRTStreamSetPosProc)(struct OSRTSTREAM *pStream, size_t pos)

Stream set position function pointer type. A user may implement a customized function for a specific input stream type. The mark function is defined in the OSRTSTREAM control structure.

typedef int(* OSRTStreamSkipProc)(struct OSRTSTREAM *pStream, size_t skipBytes)

Stream skip function pointer type. A user may implement a customized function for a specific input stream type. The skip function is defined in the OSRTSTREAM control structure.

typedef long(* OSRTStreamWriteProc)(struct OSRTSTREAM *pStream, const OSOCTET *data, size_t numocts)

Stream write function pointer type. A user may implement a customized write function for any specific output streams. The write function is defined in the OSRTSTREAM control structure.

Function Documentation

long rtxStreamBlockingRead	(	OSCTXT *	pctxt,
		OSOCTET *	pbuffer,
		size_t	readBytes
	)

This function reads up to 'bufsize' bytes of data from the input stream into an array of octets. An attempt is made to read as many as bufsize octets, but a smaller number may be read, possibly zero. The number of octets actually read is returned as an integer. This functions blocks until input data is available, end of file is detected, or another error is occurred.

Parameters:

	pctxt	Pointer to a context structure variable which has been initialized for stream operations via a call to rtxStreamInit.
	pbuffer	Pointer to a buffer to receive data.
	readBytes	Number of bytes to read.

Returns:: The total number of octets read into the buffer, or negative value with error code if any error is occurred.

int rtxStreamClose ( OSCTXT * pctxt )

This function closes the input or output stream and releases any system resources associated with the stream. For output streams this function also flushes all internal buffers to the stream.

Parameters:

pctxt Pointer to a context structure variable which has been initialized for stream operations via a call to rtxStreamInit.

int rtxStreamFlush ( OSCTXT * pctxt )

This function flushes the output stream and forces any buffered output octets to be written out.

Parameters:

pctxt Pointer to a context structure variable which has been initialized for stream operations via a call to rtxStreamInit.

Returns:: Completion status of operation: 0 = success, negative return value is error.

OSRTMEMBUF* rtxStreamGetCapture ( OSCTXT * pctxt )

This function returns the capture buffer currently assigned to the stream.

Parameters:

pctxt

Pointer to a context structure variable that has been initialized for stream operations.

Returns:: Pointer to memory buffer that was previously assigned as a capture buffer to the stream.

int rtxStreamGetIOBytes	(	OSCTXT *	pctxt,
		size_t *	pPos
	)

This function returns the number of processed octets. If the stream was opened as an input stream, then it returns the total number of read octets. If the stream was opened as an output stream, then it returns the total number of written octets. Otherwise, this function returns an error code.

Parameters:

	pctxt	Pointer to a context structure variable which has been initialized for stream operations via a call to `rtxStreamInit`.
	pPos	Pointer to argument to receive total number of processed octets.

Returns:: The total number of processed octets or error code (negative value).

int rtxStreamGetPos	(	OSCTXT *	pctxt,
		size_t *	ppos
	)

Get the current position in input stream.

Parameters:

	pctxt	Pointer to a context structure variable that has been initialized for stream operations.
	ppos	Pointer to a variable to receive position.

Returns:: Completion status of operation: 0 = success, negative return value is error.

int rtxStreamInit ( OSCTXT * pctxt )

This function initializes a stream part of the context block. This function should be called first before any operation with a stream.

Parameters:

pctxt

Pointer to context structure variable, for which stream to be initialized.

Returns:: Completion status of operation: 0 = success, negative return value is error.

OSBOOL rtxStreamIsOpened ( OSCTXT * pctxt )

Tests if this stream opened (for reading or writing).

Parameters:

pctxt

Pointer to a context structure variable that has been initialized for stream operations.

Returns:: TRUE if this stream is opened for reading or writing; FALSE otherwise.

OSBOOL rtxStreamIsReadable ( OSCTXT * pctxt )

Tests if this stream opened for reading.

Parameters:

pctxt

Pointer to a context structure variable that has been initialized for stream operations.

Returns:: TRUE if this stream is opened for reading; FALSE otherwise.

OSBOOL rtxStreamIsWritable ( OSCTXT * pctxt )

Tests if this stream opened for writing.

Parameters:

pctxt

Pointer to a context structure variable that has been initialized for stream operations.

Returns:: TRUE if this stream is opened for writing; FALSE otherwise.

int rtxStreamMark	(	OSCTXT *	pctxt,
		size_t	readAheadLimit
	)

Marks the current position in this input stream. A subsequent call to the rtxStreamReset function repositions this stream at the last marked position so that subsequent reads re-read the same bytes. The readAheadLimit argument tells this input stream to allow many bytes to be read before the mark position gets invalidated.

Parameters:

	pctxt	Pointer to a context structure variable that has been initialized for stream operations.
	readAheadLimit	The maximum limit of bytes that can be read before the mark position becomes invalid.

Returns:: Completion status of operation: 0 = success, negative return value is error.

OSBOOL rtxStreamMarkSupported ( OSCTXT * pctxt )

Tests if this input stream supports the mark and reset methods. Whether or not mark and reset are supported is an invariant property of a particular input stream instance. By default, it returns FALSE.

Parameters:

pctxt

Pointer to a context structure variable that has been initialized for stream operations.

Returns:: TRUE if this stream instance supports the mark and reset methods; FALSE otherwise.

long rtxStreamRead	(	OSCTXT *	pctxt,
		OSOCTET *	pbuffer,
		size_t	bufSize
	)

This function reads up to 'bufsize' bytes of data from the input stream into an array of octets. An attempt is made to read as many as bufsize octets, but a smaller number may be read, possibly zero. The number of octets actually read is returned as an integer. This functions blocks until input data is available, end of file is detected, or another error is occurred.

Parameters:

	pctxt	Pointer to a context structure variable which has been initialized for stream operations via a call to rtxStreamInit.
	pbuffer	Pointer to a buffer to receive data.
	bufSize	Size of the buffer.

Returns:: The total number of octets read into the buffer, or negative value with error code if any error is occurred.

int rtxStreamRelease ( OSCTXT * pctxt )

This function releases the stream's resources. If it is opened for reading or writing it will be closed.

Parameters:

pctxt

Pointer to a context structure variable that has been initialized for stream operations.

Returns:: Completion status of operation: 0 = success, negative return value is error.

int rtxStreamReset ( OSCTXT * pctxt )

Repositions this stream to the position recorded by the last call to the rtxStreamMark function.

Parameters:

pctxt

Pointer to a context structure variable that has been initialized for stream operations.

Returns:: Completion status of operation: 0 = success, negative return value is error.

void rtxStreamSetCapture	(	OSCTXT *	pctxt,
		OSRTMEMBUF *	pmembuf
	)

This function sets a capture buffer for the stream. This is used to record all data read from the stream.

Parameters:

	pctxt	Pointer to a context structure variable that has been initialized for stream operations.
	pmembuf	Pointer to an initialized memory buffer structure. This argument may be set to NULL to disable capture if previously set.

int rtxStreamSetPos	(	OSCTXT *	pctxt,
		size_t	pos
	)

Set the current position in input stream.

Parameters:

	pctxt	Pointer to a context structure variable that has been initialized for stream operations.
	pos	Stream position.

Returns:: Completion status of operation: 0 = success, negative return value is error.

int rtxStreamSkip	(	OSCTXT *	pctxt,
		size_t	skipBytes
	)

This function skips over and discards the specified amount of data octets from this input stream.

Parameters:

	pctxt	Pointer to a context structure variable which has been initialized for stream operations via a call to rtxStreamInit.
	skipBytes	The number of octets to be skipped.

Returns:: Completion status of operation: 0 = success, negative return value is error.

long rtxStreamWrite	(	OSCTXT *	pctxt,
		const OSOCTET *	data,
		size_t	numocts
	)

This function writes the specified amount of octets from the specified array to the output stream.

Parameters:

	pctxt	Pointer to a context structure variable which has been initialized for stream operations via a call to rtxStreamInit.
	data	The pointer to data to be written.
	numocts	The number of octets to write.

Returns:: Completion status of operation: 0 = success, negative return value is error.

Input/Output Data Stream Utility Functions

Classes

Defines

Typedefs

Functions

Detailed Description

Define Documentation

Typedef Documentation

Function Documentation