ShortEncodedValue.java revision 9ab2b45ec8531658e3acf0b96b11a214ce8d3b60
1/* 2 * [The "BSD licence"] 3 * Copyright (c) 2009 Ben Gruver 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29package org.jf.dexlib.EncodedValue; 30 31import org.jf.dexlib.Util.Input; 32import org.jf.dexlib.Util.EncodedValueUtils; 33import org.jf.dexlib.Util.AnnotatedOutput; 34 35public class ShortEncodedValue extends EncodedValue { 36 public final short value; 37 38 /** 39 * Constructs a new <code>ShortEncodedValue</code> by reading the value from the given <code>Input</code> object. 40 * The <code>Input</code>'s cursor should be set to the 2nd byte of the encoded value, and the high 3 bits of 41 * the first byte should be passed as the valueArg parameter 42 * @param in The <code>Input</code> object to read from 43 * @param valueArg The high 3 bits of the first byte of this encoded value 44 */ 45 protected ShortEncodedValue(Input in, byte valueArg) { 46 value = (short) EncodedValueUtils.decodeSignedIntegralValue(in.readBytes(valueArg+1)); 47 } 48 49 /** 50 * Constructs a new <code>ShortEncodedValue</code> with the given value 51 * @param value The value 52 */ 53 public ShortEncodedValue(short value) { 54 this.value = value; 55 } 56 57 /** {@inheritDoc} */ 58 public void writeValue(AnnotatedOutput out) { 59 byte[] bytes = EncodedValueUtils.encodeSignedIntegralValue(value); 60 61 if (out.annotates()) { 62 out.annotate(1, "value_type=" + ValueType.VALUE_SHORT.name() + ",value_arg=" + (bytes.length - 1)); 63 out.annotate(bytes.length, "value: 0x" + Integer.toHexString(value) + " (" + value + ")"); 64 } 65 66 out.writeByte(ValueType.VALUE_SHORT.value | ((bytes.length - 1) << 5)); 67 out.write(bytes); 68 } 69 70 /** {@inheritDoc} */ 71 public int placeValue(int offset) { 72 return offset + EncodedValueUtils.getRequiredBytesForSignedIntegralValue(value) + 1; 73 } 74 75 /** {@inheritDoc} */ 76 protected int compareValue(EncodedValue o) { 77 ShortEncodedValue other = (ShortEncodedValue)o; 78 79 return (value<other.value?-1:(value>other.value?1:0)); 80 } 81 82 /** {@inheritDoc} */ 83 public ValueType getValueType() { 84 return ValueType.VALUE_SHORT; 85 } 86 87 @Override 88 public int hashCode() { 89 return value; 90 } 91} 92