1 /* 2 * Copyright (C) 2007 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.dexgen.rop.code; 18 19 import com.android.dexgen.rop.cst.CstUtf8; 20 21 /** 22 * A local variable item: either a name or a signature or both. 23 */ 24 public class LocalItem implements Comparable<LocalItem> { 25 /** {@code null-ok;} local variable name */ 26 private final CstUtf8 name; 27 28 /** {@code null-ok;} local variable signature */ 29 private final CstUtf8 signature; 30 31 /** 32 * Make a new item. If both name and signature are null, null is returned. 33 * 34 * TODO: intern these 35 * 36 * @param name {@code null-ok;} local variable name 37 * @param signature {@code null-ok;} local variable signature 38 * @return {@code non-null;} appropriate instance. 39 */ make(CstUtf8 name, CstUtf8 signature)40 public static LocalItem make(CstUtf8 name, CstUtf8 signature) { 41 if (name == null && signature == null) { 42 return null; 43 } 44 45 return new LocalItem (name, signature); 46 } 47 48 /** 49 * Constructs instance. 50 * 51 * @param name {@code null-ok;} local variable name 52 * @param signature {@code null-ok;} local variable signature 53 */ LocalItem(CstUtf8 name, CstUtf8 signature)54 private LocalItem(CstUtf8 name, CstUtf8 signature) { 55 this.name = name; 56 this.signature = signature; 57 } 58 59 /** {@inheritDoc} */ 60 @Override equals(Object other)61 public boolean equals(Object other) { 62 if (!(other instanceof LocalItem)) { 63 return false; 64 } 65 66 LocalItem local = (LocalItem) other; 67 68 return 0 == compareTo(local); 69 } 70 71 /** 72 * Compares two strings like String.compareTo(), excepts treats a null 73 * as the least-possible string value. 74 * 75 * @return negative integer, zero, or positive integer in accordance 76 * with Comparable.compareTo() 77 */ compareHandlesNulls(CstUtf8 a, CstUtf8 b)78 private static int compareHandlesNulls(CstUtf8 a, CstUtf8 b) { 79 if (a == b) { 80 return 0; 81 } else if (a == null) { 82 return -1; 83 } else if (b == null) { 84 return 1; 85 } else { 86 return a.compareTo(b); 87 } 88 } 89 90 /** {@inheritDoc} */ compareTo(LocalItem local)91 public int compareTo(LocalItem local) { 92 int ret; 93 94 ret = compareHandlesNulls(name, local.name); 95 96 if (ret != 0) { 97 return ret; 98 } 99 100 ret = compareHandlesNulls(signature, local.signature); 101 102 return ret; 103 } 104 105 106 /** {@inheritDoc} */ 107 @Override hashCode()108 public int hashCode() { 109 return (name == null ? 0 : name.hashCode()) * 31 110 + (signature == null ? 0 : signature.hashCode()); 111 } 112 113 /** {@inheritDoc} */ 114 @Override toString()115 public String toString() { 116 if (name != null && signature == null) { 117 return name.toQuoted(); 118 } else if (name == null && signature == null) { 119 return ""; 120 } 121 122 return "[" + (name == null ? "" : name.toQuoted()) 123 + "|" + (signature == null ? "" : signature.toQuoted()); 124 } 125 126 /** 127 * Gets name. 128 * 129 * @return {@code null-ok;} name 130 */ getName()131 public CstUtf8 getName() { 132 return name; 133 } 134 135 /** 136 * Gets signature. 137 * 138 * @return {@code null-ok;} signature 139 */ getSignature()140 public CstUtf8 getSignature() { 141 return signature; 142 } 143 } 144