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      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.dx.dex.file;
     18 
     19 import com.android.dx.rop.cst.Constant;
     20 import com.android.dx.rop.cst.CstBaseMethodRef;
     21 import com.android.dx.util.AnnotatedOutput;
     22 import com.android.dx.util.Hex;
     23 import java.util.Collection;
     24 import java.util.TreeMap;
     25 
     26 /**
     27  * Method refs list section of a {@code .dex} file.
     28  */
     29 public final class MethodIdsSection extends MemberIdsSection {
     30     /**
     31      * {@code non-null;} map from method constants to {@link
     32      * MethodIdItem} instances
     33      */
     34     private final TreeMap<CstBaseMethodRef, MethodIdItem> methodIds;
     35 
     36     /**
     37      * Constructs an instance. The file offset is initially unknown.
     38      *
     39      * @param file {@code non-null;} file that this instance is part of
     40      */
     41     public MethodIdsSection(DexFile file) {
     42         super("method_ids", file);
     43 
     44         methodIds = new TreeMap<CstBaseMethodRef, MethodIdItem>();
     45     }
     46 
     47     /** {@inheritDoc} */
     48     @Override
     49     public Collection<? extends Item> items() {
     50         return methodIds.values();
     51     }
     52 
     53     /** {@inheritDoc} */
     54     @Override
     55     public IndexedItem get(Constant cst) {
     56         if (cst == null) {
     57             throw new NullPointerException("cst == null");
     58         }
     59 
     60         throwIfNotPrepared();
     61 
     62         IndexedItem result = methodIds.get((CstBaseMethodRef) cst);
     63 
     64         if (result == null) {
     65             throw new IllegalArgumentException("not found");
     66         }
     67 
     68         return result;
     69     }
     70 
     71     /**
     72      * Writes the portion of the file header that refers to this instance.
     73      *
     74      * @param out {@code non-null;} where to write
     75      */
     76     public void writeHeaderPart(AnnotatedOutput out) {
     77         throwIfNotPrepared();
     78 
     79         int sz = methodIds.size();
     80         int offset = (sz == 0) ? 0 : getFileOffset();
     81 
     82         if (out.annotates()) {
     83             out.annotate(4, "method_ids_size: " + Hex.u4(sz));
     84             out.annotate(4, "method_ids_off:  " + Hex.u4(offset));
     85         }
     86 
     87         out.writeInt(sz);
     88         out.writeInt(offset);
     89     }
     90 
     91     /**
     92      * Interns an element into this instance.
     93      *
     94      * @param method {@code non-null;} the reference to intern
     95      * @return {@code non-null;} the interned reference
     96      */
     97     public MethodIdItem intern(CstBaseMethodRef method) {
     98         if (method == null) {
     99             throw new NullPointerException("method == null");
    100         }
    101 
    102         throwIfPrepared();
    103 
    104         MethodIdItem result = methodIds.get(method);
    105 
    106         if (result == null) {
    107             result = new MethodIdItem(method);
    108             methodIds.put(method, result);
    109         }
    110 
    111         return result;
    112     }
    113 
    114     /**
    115      * Gets the index of the given reference, which must have been added
    116      * to this instance.
    117      *
    118      * @param ref {@code non-null;} the reference to look up
    119      * @return {@code >= 0;} the reference's index
    120      */
    121     public int indexOf(CstBaseMethodRef ref) {
    122         if (ref == null) {
    123             throw new NullPointerException("ref == null");
    124         }
    125 
    126         throwIfNotPrepared();
    127 
    128         MethodIdItem item = methodIds.get(ref);
    129 
    130         if (item == null) {
    131             throw new IllegalArgumentException("not found");
    132         }
    133 
    134         return item.getIndex();
    135     }
    136 }
    137