blockio.h

Classes

BlockIO -- fixed-length blocked sequentual I/O base class (full description)

BlockInput -- fixed-length blocked sequential input base class (full description)

BlockOutput -- fixed-length blocked sequential output base class (full description)

class BlockIO

Types

enum IOErrs

OK

NOSUCHFILE

NOMEM

OPENERR

CLOSEERR

READERR

WRITEERR

Interface

Public Members

int err() const

int blockno() const

int recno() const

const char *fname() const

int fdes() const

Protected Members

BlockIO(const char *, int, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)

BlockIO(int, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)

virtual ~BlockIO()

void errmsg(IOErrs, char *)

See Also

FitsIO for some BlockIO derived classes.

Description

Synopsis

BlockIO is a low level base class that implements fixed-length blocked sequential I/O. Its derived classes, BlockInput and BlockOutput are used by the FitsInput and FitsOutput classes. Users will hardly ever need to use this class directly.

To Do

ifdef kludges until OS dependent flags are developed for the compilation system.

Member Description

enum IOErrs

error return code

int err() const

int blockno() const

number of physical blocks read/written

int recno() const

number of logical records read/written

const char *fname() const

name of file associated with I/O stream, if applicable

int fdes() const

file descriptor associated with I/O stream, if applicable

BlockIO(const char *, int, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)
BlockIO(int, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)
virtual ~BlockIO()

Construction can be done either from a filename with open options or from a file descriptor.

The remaining arguments are the the logical record size and number of records that make up a physical record followed by the output stream that is used to write error messages to.

void errmsg(IOErrs, char *)

set the error message and error number for later recovery

class BlockInput : public BlockIO

Interface

Public Members

BlockInput(const char *, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)

BlockInput(int, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)

virtual ~BlockInput()

virtual char *read()

virtual char *skip(int)

See Also

FitsInput (click here)

Description

Prerequisite

BlockIO

Member Description

BlockInput(const char *, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)
BlockInput(int, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)
virtual ~BlockInput()

Construction can be done either from a filename or from a file descriptor.

The remaining arguments are the the logical record size and number of records that make up a physical record followed by the output stream that is used to write error messages to.

virtual char read()
virtual char skip(int)

read the next logical record or first skip N logical records and then read the next one. (note it is not possible to skip a record without reading a record).

these functions return a pointer to an internal record. The user must make sure that after destruction of this class no dangling pointers are left.

class BlockOutput : public BlockIO

Interface

BlockOutput(const char *, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)

BlockOutput(int, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)

virtual ~BlockOutput()

virtual int write(char *)

Description

Prerequisite

BlockIO

Member Description

BlockOutput(const char *, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)
BlockOutput(int, int, int = 1, FITSErrorHandler errhandler = FITSError::defaultHandler)
virtual ~BlockOutput()

Construction can be done either from a filename or from a file descriptor.

The remaining arguments are the the logical record size and number of records that make up a physical record followed by the output stream that is used to write error messages to.

virtual int write(char *)

write the next logical record. The input must point to a logical record