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/*******************************************************************************
* Copyright (c) 2015, 2016 Google, Inc and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* Stefan Xenos (Google) - Initial implementation
*******************************************************************************/
package org.eclipse.jdt.internal.core.nd.field;
import org.eclipse.jdt.internal.core.nd.Nd;
import org.eclipse.jdt.internal.core.nd.db.ModificationLog;
import org.eclipse.jdt.internal.core.nd.db.ModificationLog.Tag;
import org.eclipse.jdt.internal.core.nd.db.Database;
import org.eclipse.jdt.internal.core.nd.db.EmptyString;
import org.eclipse.jdt.internal.core.nd.db.IString;
/**
* Declares a Nd field of type string. Can be used in place of {@link Field}<{@link String}> in order to
* avoid extra GC overhead.
*/
public class FieldString extends BaseField implements IDestructableField {
public static final int RECORD_SIZE = Database.STRING_SIZE;
private static final char[] EMPTY_CHAR_ARRAY = new char[0];
private final Tag putTag;
private final Tag destructTag;
public FieldString(String structName, int fieldNumber) {
this.putTag = ModificationLog.createTag("Writing field " + fieldNumber + ", a " + getClass().getSimpleName() //$NON-NLS-1$//$NON-NLS-2$
+ " in struct " + structName); //$NON-NLS-1$
this.destructTag = ModificationLog
.createTag("Destructing field " + fieldNumber + ", a " + getClass().getSimpleName() //$NON-NLS-1$//$NON-NLS-2$
+ " in struct " + structName); //$NON-NLS-1$
}
public IString get(Nd nd, long address) {
Database db = nd.getDB();
long namerec = db.getRecPtr(address + this.offset);
if (namerec == 0) {
return EmptyString.create();
}
return db.getString(namerec);
}
public void put(Nd nd, long address, char[] newString) {
Database db = nd.getDB();
db.getLog().start(this.putTag);
try {
if (newString == null) {
newString = EMPTY_CHAR_ARRAY;
}
IString name= get(nd, address);
if (name.compare(newString, true) != 0) {
name.delete();
if (newString != null && newString.length > 0) {
db.putRecPtr(address + this.offset, db.newString(newString).getRecord());
} else {
db.putRecPtr(address + this.offset, 0);
}
}
} finally {
db.getLog().end(this.putTag);
}
}
public void put(Nd nd, long address, String newString) {
put(nd, address, newString.toCharArray());
}
@Override
public void destruct(Nd nd, long address) {
Database db = nd.getDB();
db.getLog().start(this.destructTag);
try {
get(nd, address).delete();
nd.getDB().putRecPtr(address + this.offset, 0);
} finally {
db.getLog().end(this.destructTag);
}
}
@Override
public int getRecordSize() {
return RECORD_SIZE;
}
}
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