casacore::Conversion Class Reference

A class with general conversion definitions. More...

#include <Conversion.h>

Public Types
typedef size_t	ValueFunction (void *to, const void *from, size_t nvalues)
	Define the signature of a function converting nvalues values from internal to external format or vice-versa. More...
typedef void *	ByteFunction (void *to, const void *from, size_t nbytes)
	Define the signature of a function converting from one format to another providing the number of bytes. More...

Static Public Member Functions
static size_t	boolToBit (void *to, const void *from, size_t nvalues)
	Convert a stream of Bools to output format (as bits). More...
static void	boolToBit (void *to, const void *from, size_t startBit, size_t nvalues)
static size_t	bitToBool (void *to, const void *from, size_t nvalues)
	Convert a stream of Bools to output format (as bits). More...
static void	bitToBool (void *to, const void *from, size_t startBit, size_t nvalues)
static size_t	valueCopy (void *to, const void *from, size_t nbytes)
	Copy a value using memcpy. More...
static ByteFunction *	getmemcpy ()
	Get a pointer to the memcpy function. More...

Static Private Member Functions
static size_t	bitToBool_ (void *to, const void *from, size_t nvalues)
	Copy bits to Bool in an unoptimized way needed when 'to' is not aligned properly. More...

Detailed Description

A class with general conversion definitions.

Intended use:

Public interface

Review Status

Reviewed By:

Friso Olnon

Date Reviewed:

1996/11/06

Test programs:

tConversion

Synopsis

This class contains the general definitions for the Conversion classes.

• It defines the signature for the functions converting from input to output format (e.g. from local to canonical format). There is a version where the number of values is given and a version where the number of bytes is given. The latter is there to be able to use memcpy as a conversion function (which will often be the case). Note that the signatures only differ in return value.
• It defines functions to convert Bools to bits and vice-versa. These are used elsewhere to store Bools as space efficient as possible. Note that these functions are machine independent (they work on little and big endian machines).
• It defines a private version of memcpy for compilers having a different signature for memcpy (e.g. ObjectCenter and DEC-Alpha).

Static functions in the classes CanonicalConversion, VAXConversion, and IBMConversion convert data from/to canonical, VAX, and IBM/360 format, resp..
Classes derived from DataConversion provide the same functionality in a polymorphic way.

Motivation

This provides a common place for definitions used elsewhere. It also provides a uniform interface to memcpy.

Definition at line 85 of file Conversion.h.

Member Typedef Documentation

typedef void* casacore::Conversion::ByteFunction(void *to, const void *from, size_t nbytes)

Define the signature of a function converting from one format to another providing the number of bytes.

It returns the to pointer (similar to memcpy). (For example the byteTo/FromLocalXXX functions in class CanonicalConversion.

Definition at line 108 of file Conversion.h.

typedef size_t casacore::Conversion::ValueFunction(void *to, const void *from, size_t nvalues)

Define the signature of a function converting nvalues values from internal to external format or vice-versa.

These functions are used in the IO framework , but are also used in the table system. Examples of such conversions are:
- local <-> canonical (when storing in canonical format)
- local <-> local (when storing in local format)
- binary <-> ASCII
It returns the number of bytes in external format. (For example the ToLocal/FromLocal functions in class CanonicalConversion return the number of bytes in canonical format).

Definition at line 100 of file Conversion.h.

Member Function Documentation

static size_t casacore::Conversion::bitToBool ( void *  to, const void *  from, size_t  nvalues  )

static

Convert a stream of Bools to output format (as bits).

The variable startBit (0-relative) indicates where to start in the from buffer.

static void casacore::Conversion::bitToBool ( void *  to, const void *  from, size_t  startBit, size_t  nvalues  )

static

static size_t casacore::Conversion::bitToBool_ ( void *  to, const void *  from, size_t  nvalues  )

staticprivate

Copy bits to Bool in an unoptimized way needed when 'to' is not aligned properly.

static size_t casacore::Conversion::boolToBit ( void *  to, const void *  from, size_t  nvalues  )

static

Convert a stream of Bools to output format (as bits).

The variable startBit (0-relative) indicates where to start in the to buffer.

static void casacore::Conversion::boolToBit ( void *  to, const void *  from, size_t  startBit, size_t  nvalues  )

static

Conversion::ByteFunction * casacore::Conversion::getmemcpy ( )

inlinestatic

Get a pointer to the memcpy function.

Definition at line 152 of file Conversion.h.

static size_t casacore::Conversion::valueCopy ( void *  to, const void *  from, size_t  nbytes  )

static

Copy a value using memcpy.

It differs from memcpy in the return value.
Note: This version has the ValueFunction signature, but it expects as input the number of bytes;

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

• casa/OS/Conversion.h