1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.dx.io.instructions; 18 19 import java.io.EOFException; 20 21 /** 22 * Base implementation of {@link CodeCursor}. 23 */ 24 public abstract class BaseCodeCursor implements CodeCursor { 25 /** base address map */ 26 private final AddressMap baseAddressMap; 27 28 /** next index within {@link #array} to read from or write to */ 29 private int cursor; 30 31 /** 32 * Constructs an instance. 33 */ BaseCodeCursor()34 public BaseCodeCursor() { 35 this.baseAddressMap = new AddressMap(); 36 this.cursor = 0; 37 } 38 39 /** @inheritDoc */ cursor()40 public final int cursor() { 41 return cursor; 42 } 43 44 /** @inheritDoc */ baseAddressForCursor()45 public final int baseAddressForCursor() { 46 int mapped = baseAddressMap.get(cursor); 47 return (mapped >= 0) ? mapped : cursor; 48 } 49 50 /** @inheritDoc */ setBaseAddress(int targetAddress, int baseAddress)51 public final void setBaseAddress(int targetAddress, int baseAddress) { 52 baseAddressMap.put(targetAddress, baseAddress); 53 } 54 55 /** 56 * Advance the cursor by the indicated amount. 57 */ advance(int amount)58 protected final void advance(int amount) { 59 cursor += amount; 60 } 61 } 62