TableSignature.java
/*
** Module : TableSignature.java
** Abstract : Records the structure of a table in a manner that can be compared, serialized and
** deserialized.
**
** Copyright (c) 2018-2020, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------Description---------------------------------
** 001 GES 20180418 Created initial version.
** 002 IAS 20200908 Rework (de)serialization.
** 003 IAS 20200922 Make class public.
** 004 CA 20200927 Use IdentityHashMap instead of plain map when the key is a Class.
*/
/*
** 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.persist;
import static com.goldencode.util.NativeTypeSerializer.*;
import java.io.*;
import java.util.*;
import com.goldencode.p2j.util.*;
/**
* Records the structure of a table in a manner that can be compared, serialized and
* deserialized. This class is used for {@code RAW-TRANSFER}. This is a basic implementation.
* The serialized form is not binary compatible with the 4GL.
*/
public class TableSignature
implements Externalizable
{
/** Class to byte mapping table. **/
private static final Map<Class<? extends BaseDataType>, Byte> c2b;
/** Number of fields in the table. */
private int num;
/** Each field's data type in ascending order by the POSITION attribute in the schema. */
private byte[] types;
/** Each field's extent value in ascending order by the POSITION attribute in the schema. */
private short[] extents;
static
{
c2b = new IdentityHashMap<Class<? extends BaseDataType>, Byte>();
c2b.put(character.class , (byte) 0x0001);
c2b.put(date.class , (byte) 0x0002);
c2b.put(logical.class , (byte) 0x0003);
c2b.put(integer.class , (byte) 0x0004);
c2b.put(decimal.class , (byte) 0x0005);
c2b.put(recid.class , (byte) 0x0007);
c2b.put(raw.class , (byte) 0x0008);
c2b.put(handle.class , (byte) 0x000A);
c2b.put(rowid.class , (byte) 0x000D);
c2b.put(datetime.class , (byte) 0x0022);
c2b.put(datetimetz.class , (byte) 0x0028);
c2b.put(int64.class , (byte) 0x0029);
}
/**
* Default constructor.
*/
public TableSignature()
{
}
/**
* Constructor.
*
* @param fields
* List of field descriptors.
*/
public TableSignature(List<TableMapper.LegacyFieldInfo> fields)
{
if (fields != null)
{
num = fields.size();
types = new byte[num];
extents = new short[num];
for (int i = 0; i < num; i++)
{
TableMapper.LegacyFieldInfo fld = fields.get(i);
Byte typ = c2b.get(fld.getDataType());
types[i] = (typ == null) ? (byte) 0x00FF : typ;
extents[i] = (short) fld.getExtent();
}
}
}
/**
* Test the equivalence of the current instance to the given object.
*
* @param that
* The instance for comparison.
* @return <code>true</code> if given object is equal to the current instance
*/
public boolean equals(Object that)
{
if (this == that)
return true;
if (that == null || !(that instanceof TableSignature))
return false;
TableSignature other = (TableSignature) that;
return (num == other.num &&
Arrays.equals(types, other.types) &&
Arrays.equals(extents, other.extents));
}
/**
* Replacement for the default object reading method. The latest
* state is read from the input source.
*
* @param in
* The input source from which fields will be restored.
*
* @throws IOException
* In case of I/O errors.
* @throws ClassNotFoundException
* If payload can't be instantiated.
*/
public void readExternal(ObjectInput in)
throws IOException,
ClassNotFoundException
{
num = in.readInt();
types = readByteArray(in);
extents = readShortArray(in);
}
/**
* Replacement for the default object writing method. The latest
* state is written to the output destination.
*
* @param out
* The output destination to which fields will be saved.
*
* @throws IOException
* In case of I/O errors.
*/
public void writeExternal(ObjectOutput out)
throws IOException
{
out.writeInt(num);
writeByteArray(out, types);
writeShortArray(out, extents);
}
}