ca.idms.io
Class NativeBase

java.lang.Object
  ca.idms.io.TraceObject
      ca.idms.io.NativeObject
          ca.idms.io.NativeBase

All Implemented Interfaces:

Native, Trace

Direct Known Subclasses:

IdmsXid

public class NativeBase
extends NativeObject

Base class for the implementations of Native objects. Provides additional methods to support reading and writing both converted and byte array formats.

Since:

CA IDMS Server 4.2 OS/390 Edition

Version:

2.00, 11/20/04

Author:

Dave Ross

Field Summary

protected int	options Options that control how the object reads and writes native data.
static int	READ_BOTH Read both bytes and objects from the input buffer.
static int	SET_LENGTH Set len after writing.

Fields inherited from class ca.idms.io.NativeObject

buffer, length, offset

Fields inherited from class ca.idms.io.TraceObject

exclude, EXCLUDE, FALSE, include, INCLUDE, logWriter, PREFIX, PROPERTIES_FILE, PROPERTIES_KEY, snap, SNAP, SNAP_BYTES, SNAP_NATIVE, SNAP_OBJECT, SNAP_SQL, snapBytes, snapNative, snapObject, snapSql, stub, trace, TRACE, TRACE_FILE, TRACE_LIFE, TRACE_NATIVE, TRACE_PRODUCT, traceLife, traceNative, traceStream, TRUE

Constructor Summary

NativeBase()
Base constructor.

NativeBase(int len)
Base constructor to read a byte array from a stream.

Method Summary

int	getOptions()
int	length(NativeFormat fmt, int nat, int utf, int uni) Computes the estimated size of the native form of the object.
boolean	readBuffer(NativeDataInputStream in) Conditionally reads bytes from a stream.
void	setOptions(int i)
boolean	writeBuffer(NativeDataOutputStream out) Conditionally writes bytes to a stream.

Methods inherited from class ca.idms.io.NativeObject

get, getBuffer, getClient, getOffset, length, length, readNative, snap, writeNative

Methods inherited from class ca.idms.io.TraceObject

finalize, getBoolean, getClasses, getInteger, getProperty, listProperties, message, parseList, print, print, print, println, println, snap, snap, snap, snap, snap, snap, toHex, toHex, toHex, toHex, toHex, toString, trace, trace, trace, trace, trace, trace, traceEntry, unloadProperties

Methods inherited from class java.lang.Object

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

Field Detail

READ_BOTH

public static final int READ_BOTH

Read both bytes and objects from the input buffer. The next read will link to the byte array buffer but inform the caller that it didn't. The caller should then convert the byte array buffer into objects, which positions the input stream properly.

See Also:

Constant Field Values

SET_LENGTH

public static final int SET_LENGTH

Set len after writing. The next read will then link to the byte array buffer instead of converting it to objects.

See Also:

Constant Field Values

options

protected int options

Options that control how the object reads and writes native data.

See Also:

READ_BOTH, SET_LENGTH

Constructor Detail

NativeBase

public NativeBase()

Base constructor.

NativeBase

public NativeBase(int len)

Base constructor to read a byte array from a stream. No buffer is actually allocated.

The readNative method gets the buffer and current offset from the TraceBufferInputStream contained in the input stream. When READ_BOTH is set the readNative method does not advance the current offset in the input stream, allowing the data to also be read as objects.

The writeNative method writes data directly from the input stream's byte array. If data has not been read yet it writes nulls for the absolute value of the length specified to allocate an output buffer.

Parameters:

len - the length of the array.

See Also:

options

Method Detail

length

public int length(NativeFormat fmt,
                  int nat,
                  int utf,
                  int uni)

Computes the estimated size of the native form of the object.

Parameters:

fmt - NativeFormat object or null.

nat - actual native length.

utf - estimated UTF-8 length.

uni - estimated Unicode length.

Returns:

length in bytes.

getOptions

public int getOptions()

Returns:

options in effect

setOptions

public void setOptions(int i)

Parameters:

i - read write options

See Also:

READ_BOTH, SET_LENGTH

readBuffer

public boolean readBuffer(NativeDataInputStream in)
                   throws java.io.IOException

Conditionally reads bytes from a stream. This method extends the base NativeObject readBuffer method to get the buffer and offset from the input stream when buf == null && len != 0 . When len < 0 the input stream position remains unchanged, allowing the data to be read into objects as well as a buffer.

This can be used to read data directly from a TraceBufferInputStream byte array into an output stream.

Overrides:

readBuffer in class NativeObject

Parameters:

in - the native buffered input stream

Returns:

true if bytes were "read".

Throws:

java.io.IOException - if an IO error occurs

See Also:

NativeBase(int), NativeObject.readBuffer(ca.idms.io.NativeDataInputStream)

writeBuffer

public boolean writeBuffer(NativeDataOutputStream out)
                    throws java.io.IOException

Conditionally writes bytes to a stream. This method extends the base NativeObject writeNative(out) method to write an empty array of bytes to the output stream when the underlying buf == null && len != 0 .

This can be used to allocate space in a larger buffer contained in a TraceBufferOutputStream. No buffer remains allocated in this object.

Overrides:

writeBuffer in class NativeObject

Parameters:

out - the native buffered output stream.

Returns:

true if bytes were "written".

Throws:

java.io.IOException - if an IO error occurs

See Also:

NativeBase(int), NativeObject.writeBuffer(ca.idms.io.NativeDataOutputStream)