MemoryBuffer.java
/*
** Module : MemoryBuffer.java
** Abstract : Representation of a memptr value, when used from non-P2J code.
**
** Copyright (c) 2013-2020, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------Description----------------------------------
** 001 CA 20130626 Created initial version.
** 002 IAS 20200908 Rework (de)serialization.
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
**
** Additional terms under GNU Affero GPL version 3 section 7:
**
** Under Section 7 of the GNU Affero GPL version 3, the following additional
** terms apply to the works covered under the License. These additional terms
** are non-permissive additional terms allowed under Section 7 of the GNU
** Affero GPL version 3 and may not be removed by you.
**
** 0. Attribution Requirement.
**
** You must preserve all legal notices or author attributions in the covered
** work or Appropriate Legal Notices displayed by works containing the covered
** work. You may not remove from the covered work any author or developer
** credit already included within the covered work.
**
** 1. No License To Use Trademarks.
**
** This license does not grant any license or rights to use the trademarks
** Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
** of Golden Code Development Corporation. You are not authorized to use the
** name Golden Code, FWD, or the names of any author or contributor, for
** publicity purposes without written authorization.
**
** 2. No Misrepresentation of Affiliation.
**
** You may not represent yourself as Golden Code Development Corporation or FWD.
**
** You may not represent yourself for publicity purposes as associated with
** Golden Code Development Corporation, FWD, or any author or contributor to
** the covered work, without written authorization.
**
** 3. No Misrepresentation of Source or Origin.
**
** You may not represent the covered work as solely your work. All modified
** versions of the covered work must be marked in a reasonable way to make it
** clear that the modified work is not originating from Golden Code Development
** Corporation or FWD. All modified versions must contain the notices of
** attribution required in this license.
*/
package com.goldencode.p2j.util;
import static com.goldencode.util.NativeTypeSerializer.*;
import java.io.*;
import java.util.*;
/**
* Provides a byte buffer to be used from non-P2J code, when performing remote appserver calls.
* Instances of this class will be sent when the remote side expectes a memptr instance.
* <p>
* The remote side will be responsible of converting instances of this class to a {@link memptr}
* instance when it receives a {@link MemoryBuffer} instance and also to send back to the
* requester a {@link MemoryBuffer} instance, in case OUTPUT or INPUT-OUTPUT mode is used for the
* parameter.
*/
public final class MemoryBuffer
implements Externalizable
{
/** Stores the state of this instance as an array of bytes. */
private byte[] value;
/**
* Default c'tor, needed for deserialization purposes; not for public use.
*/
public MemoryBuffer()
{
}
/**
* Construct a new instance of this class, by saving a copy of the passed byte array.
* <p>
* Any changes made to the passed array will not be reflected in this instance.
*
* @param value
* The array of bytes representing the state of this instance.
* May be <code>null</code>.
*/
public MemoryBuffer(byte[] value)
{
this.value = getCopy(value);
}
/**
* Change the {@link #value array of bytes} of this instance by saving a copy of the passed
* array.
* <p>
* Any changes made to the passed array will not be reflected in this instance.
*
* @param value
* The array of bytes representing the new state of this instance.
* May be <code>null</code>.
*/
public void setValue(byte[] value)
{
this.value = getCopy(value);
}
/**
* Get the array of bytes for this instance, as a copy.
* <p>
* Any changes made to the returned array will not be reflected in this instance.
*
* @return See above.
*/
public byte[] getValue()
{
return getCopy(value);
}
/**
* Write the state of this instance to the specified stream.
*
* @param out
* The stream where the state of this instance will be sent.
* @throws IOException
*/
public void writeExternal(ObjectOutput out)
throws IOException
{
writeByteArray(out, value);
}
/**
* Initialize this instance by reading its state from the specified stream.
*
* @param in
* The stream from where the state of this instance will be read.
* @throws IOException
* @throws ClassNotFoundException
*/
public void readExternal(ObjectInput in)
throws IOException,
ClassNotFoundException
{
value = readByteArray(in);
}
/**
* Create a copy of the given array of bytes.
*
* @param bytes
* The array of bytes for which a copy is needed. May be <code>null</code>.
*
* @return If the given byte array is <code>null</code>, return <code>null</code>. Else,
* return a copy of the array.
*/
private byte[] getCopy(byte[] bytes)
{
byte[] copy = null;
if (bytes != null)
{
copy = Arrays.copyOf(bytes, bytes.length);
}
return copy;
}
}