/*
* [The "BSD licence"]
* Copyright (c) 2010 Ben Gruver (JesusFreke)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.jf.dexlib;
import org.jf.dexlib.Util.AnnotatedOutput;
import org.jf.dexlib.Util.Input;
public class FieldIdItem extends Item<FieldIdItem> {
private int hashCode = 0;
private TypeIdItem classType;
private TypeIdItem fieldType;
private StringIdItem fieldName;
/**
* Creates a new uninitialized <code>FieldIdItem</code>
* @param dexFile The <code>DexFile</code> that this item belongs to
*/
protected FieldIdItem(DexFile dexFile) {
super(dexFile);
}
/**
* Creates a new <code>FieldIdItem</code> for the given class, type and name
* @param dexFile The <code>DexFile</code> that this item belongs to
* @param classType the class that the field is a member of
* @param fieldType the type of the field
* @param fieldName the name of the field
*/
private FieldIdItem(DexFile dexFile, TypeIdItem classType, TypeIdItem fieldType, StringIdItem fieldName) {
this(dexFile);
assert classType.dexFile == dexFile;
assert fieldType.dexFile == dexFile;
assert fieldName.dexFile == dexFile;
this.classType = classType;
this.fieldType = fieldType;
this.fieldName = fieldName;
}
/**
* Returns a <code>FieldIdItem</code> for the given values, and that has been interned into
* the given <code>DexFile</code>
* @param dexFile The <code>DexFile</code> that this item belongs to
* @param classType the class that the field is a member of
* @param fieldType the type of the field
* @param fieldName the name of the field
* @return a <code>FieldIdItem</code> for the given values, and that has been interned into
* the given <code>DexFile</code>
*/
public static FieldIdItem internFieldIdItem(DexFile dexFile, TypeIdItem classType, TypeIdItem fieldType,
StringIdItem fieldName) {
FieldIdItem fieldIdItem = new FieldIdItem(dexFile, classType, fieldType, fieldName);
return dexFile.FieldIdsSection.intern(fieldIdItem);
}
/**
* Looks up a <code>FieldIdItem</code> from the given <code>DexFile</code> for the given
* values
* @param dexFile The <code>DexFile</code> that this item belongs to
* @param classType the class that the field is a member of
* @param fieldType the type of the field
* @param fieldName the name of the field
* @return a <code>FieldIdItem</code> from the given <code>DexFile</code> for the given
* values, or null if it doesn't exist
*/
public static FieldIdItem lookupFieldIdItem(DexFile dexFile, TypeIdItem classType, TypeIdItem fieldType,
StringIdItem fieldName) {
FieldIdItem fieldIdItem = new FieldIdItem(dexFile, classType, fieldType, fieldName);
return dexFile.FieldIdsSection.getInternedItem(fieldIdItem);
}
/** {@inheritDoc} */
protected void readItem(Input in, ReadContext readContext) {
classType = dexFile.TypeIdsSection.getItemByIndex(in.readShort());
fieldType = dexFile.TypeIdsSection.getItemByIndex(in.readShort());
fieldName = dexFile.StringIdsSection.getItemByIndex(in.readInt());
}
/** {@inheritDoc} */
protected int placeItem(int offset) {
return offset + 8;
}
/** {@inheritDoc} */
protected void writeItem(AnnotatedOutput out) {
if (out.annotates()) {
out.annotate(2, "class_type: " + classType.getTypeDescriptor());
out.annotate(2, "field_type: " + fieldType.getTypeDescriptor());
out.annotate(4, "field_name: " + fieldName.getStringValue());
}
out.writeShort(classType.getIndex());
out.writeShort(fieldType.getIndex());
out.writeInt(fieldName.getIndex());
}
/** {@inheritDoc} */
public ItemType getItemType() {
return ItemType.TYPE_FIELD_ID_ITEM;
}
/** {@inheritDoc} */
public String getConciseIdentity() {
return getFieldString();
}
/** {@inheritDoc} */
public int compareTo(FieldIdItem o) {
int result = classType.compareTo(o.classType);
if (result != 0) {
return result;
}
result = fieldName.compareTo(o.fieldName);
if (result != 0) {
return result;
}
return fieldType.compareTo(o.fieldType);
}
/**
* @return the class that this field is a member of
*/
public TypeIdItem getContainingClass() {
return classType;
}
/**
* @return the type of this field
*/
public TypeIdItem getFieldType() {
return fieldType;
}
/**
* @return the field name
*/
public StringIdItem getFieldName() {
return fieldName;
}
String cachedFieldString = null;
/**
* @return a string formatted like LclassName;->fieldName:fieldType
*/
public String getFieldString() {
if (cachedFieldString == null) {
String typeDescriptor = classType.getTypeDescriptor();
String fieldName = this.fieldName.getStringValue();
String fieldType = this.fieldType.getTypeDescriptor();
StringBuffer sb = new StringBuffer(typeDescriptor.length() + fieldName.length() + fieldType.length() + 3);
sb.append(typeDescriptor);
sb.append("->");
sb.append(fieldName);
sb.append(":");
sb.append(fieldType);
cachedFieldString = sb.toString();
}
return cachedFieldString;
}
/**
* calculate and cache the hashcode
*/
private void calcHashCode() {
hashCode = classType.hashCode();
hashCode = 31 * hashCode + fieldType.hashCode();
hashCode = 31 * hashCode + fieldName.hashCode();
}
@Override
public int hashCode() {
//there's a small possibility that the actual hash code will be 0. If so, we'll
//just end up recalculating it each time
if (hashCode == 0)
calcHashCode();
return hashCode;
}
@Override
public boolean equals(Object o) {
if (this==o) {
return true;
}
if (o==null || !this.getClass().equals(o.getClass())) {
return false;
}
//This assumes that the referenced items have been interned in both objects.
//This is a valid assumption because all outside code must use the static
//"getInterned..." style methods to make new items, and any item created
//internally is guaranteed to be interned
FieldIdItem other = (FieldIdItem)o;
return (classType == other.classType &&
fieldType == other.fieldType &&
fieldName == other.fieldName);
}
}