LobCopy.java
/*
** Module : LobCopy.java
** Abstract : A configurable LOB copy operation.
**
** Copyright (c) 2019-2023, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description---------------------------------------
** 001 ECF 20190508 Created initial version to simplify API for COPY-LOB operations.
** 002 ECF 20190628 Added runtime implementation.
** 003 MED 20200331 Set codepage defaults based on 4GL defaults.
** CA 20200427 I18nOps.convmap2Java uses uppercase keys.
** 004 ME 20200528 Use getValue instead of toStringMessage to avoid unknown (?).
** OM 20210203 Added API to accept unknown parameter for fixCodePage() method.
** OM 20210312 Fixed error handling related to copy conversion errors. Rewrote copy operation.
** OM 20210328 Improved copy lob engine and validations.
** OM 20210404 Fine-tuned errors generated by edge-case in copy-lob statements.
** CA 20210609 Fixed a NPE when the target has no codepage set.
** ME 20210916 Fixed a NPE when destination codepage is null (not found).
** EVL 20220405 Target offset should be validated first for certain copy operations.
** 005 HC 20230118 Eliminated some of the uses of String.toUpperCase and/or String.toLowerCase
** for performance.
** 006 EVL 20230317 Changed target longchar handling for 'overlay at' option. The NULL byte in a source
** data handling is different in this case when source is binary and target is longchar.
** Fixed bug for memory allocation with recent changes.
** EVL 20230320 Optimized memory usage for character lob target with 'overlay at' option. We can avoid
** allocation of the another byte array. Just use a part of old one to create target.
** EVL 20230320 Fixed some deviations found with recent testcases. The source data array 0 length has
** the same effect as if data array pointer is NULL. Also the target longchar should emit
** 12012 error for any source data array length if data was not validated.
*/
/*
** 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 java.io.*;
import java.util.*;
import static com.goldencode.p2j.util.LobCopyParameter.*;
/**
* Object which performs a large object (LOB) copy operation. All configuration methods return
* the current object instance, to allow method chaining.
*/
public class LobCopy
{
/** Source DMO to be copied */
private final LobCopyInput source;
/** Target DMO into which to copy */
private final LobCopyOutput target;
/** Source content's code page; {@code null} for binary data */
private String sourceCodePage = null;
/** Test whether the CONVERT SOURCE CODEPAGE option was used, even if with unknown value. */
private boolean sourceCodePageSet = false;
/** Target content's code page; {@code null} for binary data */
private String targetCodePage = null;
/**
* Constructor which accepts a source and target large object on which to perform the copy.
*
* @param source
* Source object to be copied.
* @param target
* Target object into which to copy.
*/
public LobCopy(LobCopyInput source, LobCopyOutput target)
{
this.source = source;
this.target = target;
}
/**
* Assert that the given parameter is an instance of {@link LargeObject}.
*
* @param obj
* An object expected to be of type {@code LargeObject}.
*
* @return {@code obj} cast to {@code LargeObject}.
*
* @throws ConditionException
* if {@code lob} is not an instance of {@code LargeObject} and we are not in silent
* error mode.
*/
static LargeObject assertParameterType(Object obj)
{
if (!(obj instanceof LargeObject))
{
ErrorManager.recordOrThrowError(
11303,
"COPY-LOB object must be a large object (BLOB, MEMPTR, etc.)");
// Note: we will get here if we are in silent error mode. We have to return quietly here; otherwise,
// we will fall through and raise ClassCastException. We abort in the run method if a parameter
// is not correct.
return null;
}
return (LargeObject) obj;
}
/**
* Get the default code page of the given LOB. If the LOB does not itself maintain an explicit
* code page, the equivalent of {@code -cpinternal} is returned.
*
* @param lob
* Large object.
*
* @return Default 4GL code page name.
*/
static String getLobDefaultCodePage(LargeObject lob)
{
String cp = null;
// BLOB has no defined encoding
if (lob != null && !(lob instanceof blob))
{
// MEMPTR uses internal codepage
cp = lob.isCharacterData() ? lob._getCodePage() : I18nOps._getCPInternal();
}
return cp;
}
/**
* Set the source's code page.
*
* @param sourceCodePage
* Source code page.
*
* @return This object instance.
*/
public LobCopy sourceCodePage(Text sourceCodePage)
{
if (sourceCodePage.isUnknown())
{
return this;
}
return sourceCodePage(sourceCodePage.getValue());
}
/**
* Set the source's code page.
*
* @param sourceCodePage
* Source code page.
*
* @return This object instance.
*/
public LobCopy sourceCodePage(String sourceCodePage)
{
this.sourceCodePage = sourceCodePage;
this.sourceCodePageSet = true;
return this;
}
/**
* Set the target's code page.
*
* @param unk
* Unknown target code page.
*
* @return This object instance.
*/
public LobCopy targetCodePage(unknown unk)
{
return targetCodePage(new character());
}
/**
* Set the target's code page.
*
* @param targetCodePage
* Target code page.
*
* @return This object instance.
*/
public LobCopy targetCodePage(Text targetCodePage)
{
if (targetCodePage.isUnknown())
{
return this;
}
return targetCodePage(targetCodePage.getValue());
}
/**
* Set the target's code page.
*
* @param targetCodePage
* Target code page.
*
* @return This object instance.
*/
public LobCopy targetCodePage(String targetCodePage)
{
this.targetCodePage = targetCodePage;
return this;
}
/**
* Perform the copy. This method should only be invoked once all configuration methods
* have been invoked. In the typical use pattern, this method is called at the end of the
* method chain which starts with {@code new LobCopy(source, target)}.
*/
public void run()
{
if (!source.isLargeObject() || !target.isLargeObject())
{
// abort; ErrorManager will have recorded the error in assertParameterType
return;
}
int sourceType = source.getObjectType();
int targetType = target.getObjectType();
if (sourceCodePageSet && sourceType == TYPE_LONGCHAR)
{
ErrorManager.recordOrThrowError(11339); // this is actually a compile time error
// The source codepage can not be specified for a CLOB/LONGCHAR field
return;
}
if (sourceType + targetType == TYPE_CLOB + TYPE_BLOB)
{
ErrorManager.recordOrThrowError(11851);
// COPY-LOB operations between BLOB and CLOB fields are not supported. (11851)
return;
}
// to be checked first
if (!target.validateOffset(sourceType))
{
return;
}
else if (!source.validateOffset(targetType))
{
return;
}
else if (!target.validate(sourceType))
{
return;
}
else if (!source.validate(targetType))
{
return;
}
// we are working with character data; possibly need code page conversion
if (source.isCharacterData())
{
String sourceText = source.readString(source.getCodePage());
if (target.isCharacterData())
{
// case 1: both [source] and [target] are character
// solution: copy text information from source to target. Each of them will keep its CP
if (targetCodePage != null && !targetCodePage.equals(target.getCodePage()))
{
ErrorManager.recordOrThrowError(11341);
// The target codepage conflicts with the longchar's fixed codepage. (11341)
return;
}
if (targetCodePage == null && sourceCodePage == null) // NO-CONVERT ?
{
// if (!I18nOps.canConvert(source.getCodePage(), target.getCodePage()))
// {
// ErrorManager.recordOrThrowError(11395);
// // Large object assign or copy failed. (11395)
// return;
// }
}
target.write(sourceText, targetCodePage);
}
else
{
// case 2: [source] is character but [target] is binary
// solution: write into the [target] the text of [source] in desired CP
String destCP = (targetCodePage != null) ? targetCodePage
: ((sourceCodePage != null) ? sourceCodePage : source.getCodePage());
if (destCP == null)
{
destCP = I18nOps._getCPInternal();
}
String destCharset = I18nOps.convmap2Java.get(destCP);
try
{
target.write(sourceText == null ? null : sourceText.getBytes(destCharset));
}
catch (Exception e)
{
ErrorManager.recordOrThrowError(912, destCP, "convmap.p");
// Code page attribute table for <code-page> was not found in <filename>.
}
}
}
else
{
byte[] data;
try
{
data = source.readBytes();
}
catch (Exception e)
{
if (targetType == TYPE_FILE)
{
ErrorManager.recordOrThrowError(11350, ((TargetLobFile) target).getFilename(), "");
// Write to file '' failed during COPY-LOB (11350)
}
else
{
ErrorManager.recordOrThrowError(11334);
// Offset supplied for source large object is greater than object size. (11334)
}
return;
}
if (target.isCharacterData())
{
// case 3: [source] is binary but [target] is character
// solution: use the configured CP to decode the text in binary source and assign it to dest
if (targetCodePage != null &&
target.getCodePage() != null &&
!targetCodePage.equals(target.getCodePage()))
{
ErrorManager.recordOrThrowError(11341);
// The target codepage conflicts with the longchar's fixed codepage. (11341)
return;
}
String scp = sourceCodePage != null ? sourceCodePage : source.getCodePage();
if (scp == null)
{
scp = I18nOps._getCPInternal();
}
String sourceCharset = I18nOps.convmap2Java.get(scp);
String text = null;
if (data != null && data.length != 0)
{
// the effective data length can be changed below
int dataLength = data.length;
// the target is valid TargetLob
if (target instanceof TargetLob)
{
TargetLob tlob = (TargetLob)target;
int newLobLength = -1;
// and uses 'overlay at' option
if (tlob.isOverlay())
{
// remember initial data length
int dataLengthOrig = data.length;
// preprocess source data to remove NULL bytes, the effective array length
// could be changed
dataLength = getDataLengthForOverlay(data);
if (dataLength == 0)
{
// if the new data is empty, need to trim target lob
tlob.trim();
// but the length of the target object should be overridden
newLobLength = dataLengthOrig;
}
}
// sets up new internal target lob length, -1 resets this internal value to use regular
// approach of character based object length calculation
tlob.setOverrideLength(newLobLength);
}
if (sourceCharset != null)
{
if (!I18nOps.prevalidateData(data, 0, dataLength, scp))
{
if (sourceType == TYPE_MEMPTR && targetType == TYPE_LONGCHAR)
{
ErrorManager.recordOrThrowError(12012, scp.toUpperCase(), "");
// Invalid character data found in MEMPTR for codepage (12012)
}
else if (sourceType == TYPE_BLOB && targetType == TYPE_LONGCHAR && data.length <= 1)
{
// NOTE: sometimes error 11316 is thrown here:
// I could not find any documentation on this error. :(
ErrorManager.recordOrThrowError(11316, scp.toUpperCase(), "");
// Could not obtain LONGCHAR. (11316)
}
else
{
ErrorManager.recordOrThrowError(12008, scp.toUpperCase(), "");
// Invalid character code found in data for codepage (12008)
}
return;
}
try
{
text = new String(data, 0, dataLength, sourceCharset);
}
catch (UnsupportedEncodingException exc)
{
ErrorManager.recordOrThrowError(912, scp, "convmap.p");
// Code page attribute table for <code-page> was not found in <filename>.
return;
}
}
else
{
// failed to convert source CP to a charset. Try to autodetect it using BOM, if one exist
text = I18nOps.getStringWithBomCheck(data, 0, dataLength);
}
}
target.write(text, targetCodePage);
}
else
{
// case 4: both [source] and [target] are binary
// solution: just copy plain binary, without conversion whatsoever
target.write(data);
}
}
}
/**
* Gets data length for active 'overlay at' option. The NULL bytes are valid in this case and can be
* used to make new data length for array content before first NULL byte.
*
* @param data
* The byte array to process.
*
* @return The effective data length.
*/
private int getDataLengthForOverlay(byte[] data)
{
int lengthRes;
if (data == null || data.length == 0)
{
return 0;
}
for (lengthRes = 0; lengthRes < data.length; lengthRes++)
{
if (data[lengthRes] == 0)
{
break;
}
}
return lengthRes;
}
}