org.snapscript.dx.io.instructions.BaseCodeCursor Maven / Gradle / Ivy
/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.snapscript.dx.io.instructions;
import java.io.EOFException;
/**
* Base implementation of {@link CodeCursor}.
*/
public abstract class BaseCodeCursor implements CodeCursor {
/** base address map */
private final AddressMap baseAddressMap;
/** next index within {@link #array} to read from or write to */
private int cursor;
/**
* Constructs an instance.
*/
public BaseCodeCursor() {
this.baseAddressMap = new AddressMap();
this.cursor = 0;
}
/** @inheritDoc */
public final int cursor() {
return cursor;
}
/** @inheritDoc */
public final int baseAddressForCursor() {
int mapped = baseAddressMap.get(cursor);
return (mapped >= 0) ? mapped : cursor;
}
/** @inheritDoc */
public final void setBaseAddress(int targetAddress, int baseAddress) {
baseAddressMap.put(targetAddress, baseAddress);
}
/**
* Advance the cursor by the indicated amount.
*/
protected final void advance(int amount) {
cursor += amount;
}
}