org.vishia.bridgeC

Class VaArgBuffer

java.lang.Object

org.vishia.bridgeC.VaArgBuffer

public class VaArgBuffer
extends java.lang.Object

This class represents a buffer, which stores variable arguments in the kind of C language: The Implementation in C is much other than in Java. In Java it is simple: All arguments are of type Object, and the variable argument list is a Object[]. The memory of all arguments are handled in garbage collection. It is really simple. But in C there are some problems:

• Type of arguments
• Location of arguments: Simple numeric values are in stack (only call by value is possible) but strings (const char*) may be non persistent. No safety memory management is present.

Therefore in C language some things should be done additionally. See the special C implementation in VaArgList.c.

Field Summary

Fields

Modifier and Type	Field and Description
private java.lang.Object[]	args
int	length
private Va_list	va_list

Constructor Summary

Constructors

Constructor and Description
VaArgBuffer(int size)
VaArgBuffer(java.lang.Object[] src)

Method Summary

Modifier and Type	Method and Description
void	clean() Cleans the values in Buffer.
void	copyFrom(java.lang.CharSequence formatText, Va_list input) Copies values from a source variable argument list.
Va_list	get_va_list()
java.lang.Object[]	get()
static VaArgBuffer	represent(java.lang.Object... inputArgs)
void	setArg(int ix, int value)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

args

private final java.lang.Object[] args

length

public final int length

va_list

private final Va_list va_list

Constructor Detail

VaArgBuffer

public VaArgBuffer(int size)

VaArgBuffer

public VaArgBuffer(java.lang.Object[] src)

Method Detail

copyFrom

public void copyFrom(java.lang.CharSequence formatText,
                     Va_list input)

Copies values from a source variable argument list. In C a variable argument list is only a byte sequence in stack, without any description. The meaning of the bytes is only known from the evaluating routine, at example printf(...). In Java a variable argument list is an array of instances.

Parameters:

formatText - This argument is only used in C/C++ if the input doesn't contain a type information. In java it's unnecessary because Va_list always contains the type.

inputVaArgs -

setArg

public void setArg(int ix,
                   int value)

represent

public static VaArgBuffer represent(java.lang.Object... inputArgs)

get_va_list

public Va_list get_va_list()

clean

public void clean()

Cleans the values in Buffer. For java-programming this action cleans up unnecessary references, the associated objects may be freed. For C-programming this action cleans up the storage to prevent errors. This maybe also an effect in Java.

get

public java.lang.Object[] get()