/*******************************************************************************
* Copyright (c) 2015, 2016 Google, Inc and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Stefan Xenos (Google) - Initial implementation
*******************************************************************************/
package org.eclipse.jdt.internal.core.nd.field;
import org.eclipse.jdt.internal.core.nd.db.Database;
/**
* Represents a single field of a struct in the {@link Database}. Holds metadata for that field
* and permits laziy initialization of the field offset. Fields are normally instantiated as static
* variables. Collectively, they describe the database schema but they are not associated with any
* particular instance of data in the database.
* <p>
* Fields are temporarily mutable. On construction, a number of attributes (such as offset) are
* computed in a second pass or are initialized as other fields are constructed. Generally such
* attributes can't be computed in the constructor since they depend on knowledge of other fields
* that must be instantiated first. However, once {@link StructDef#done()} has been called on the
* last {@link StructDef}, fields are immutable and should not ever be modified again.
*/
public interface IField {
/**
* Sets the field offset (bytes from the start of the struct). This is invoked some time after field construction,
* after the sizes of all preceeding fields are known.
*/
void setOffset(int offset);
/**
* Returns the size of the field, in bytes.
*/
int getRecordSize();
/**
* Returns the required byte alignment for the field.
*/
default int getAlignment() {
return 1;
}
/**
* Returns the name of the field. This is mainly used for error messages, debug output, and diagnostic tools.
* Meant to be programmer-readable but not user-readable.
*/
String getFieldName();
/**
* Returns the field offset, in bytes from the start of the struct.
*/
int getOffset();
}