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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.dexgen.dex.file;
     18 
     19 import com.android.dexgen.rop.cst.Constant;
     20 import com.android.dexgen.rop.cst.CstBaseMethodRef;
     21 import com.android.dexgen.util.AnnotatedOutput;
     22 import com.android.dexgen.util.Hex;
     23 
     24 import java.util.Collection;
     25 import java.util.TreeMap;
     26 
     27 /**
     28  * Method refs list section of a {@code .dex} file.
     29  */
     30 public final class MethodIdsSection extends MemberIdsSection {
     31     /**
     32      * {@code non-null;} map from method constants to {@link
     33      * MethodIdItem} instances
     34      */
     35     private final TreeMap<CstBaseMethodRef, MethodIdItem> methodIds;
     36 
     37     /**
     38      * Constructs an instance. The file offset is initially unknown.
     39      *
     40      * @param file {@code non-null;} file that this instance is part of
     41      */
     42     public MethodIdsSection(DexFile file) {
     43         super("method_ids", file);
     44 
     45         methodIds = new TreeMap<CstBaseMethodRef, MethodIdItem>();
     46     }
     47 
     48     /** {@inheritDoc} */
     49     @Override
     50     public Collection<? extends Item> items() {
     51         return methodIds.values();
     52     }
     53 
     54     /** {@inheritDoc} */
     55     @Override
     56     public IndexedItem get(Constant cst) {
     57         if (cst == null) {
     58             throw new NullPointerException("cst == null");
     59         }
     60 
     61         throwIfNotPrepared();
     62 
     63         IndexedItem result = methodIds.get((CstBaseMethodRef) cst);
     64 
     65         if (result == null) {
     66             throw new IllegalArgumentException("not found");
     67         }
     68 
     69         return result;
     70     }
     71 
     72     /**
     73      * Writes the portion of the file header that refers to this instance.
     74      *
     75      * @param out {@code non-null;} where to write
     76      */
     77     public void writeHeaderPart(AnnotatedOutput out) {
     78         throwIfNotPrepared();
     79 
     80         int sz = methodIds.size();
     81         int offset = (sz == 0) ? 0 : getFileOffset();
     82 
     83         if (out.annotates()) {
     84             out.annotate(4, "method_ids_size: " + Hex.u4(sz));
     85             out.annotate(4, "method_ids_off:  " + Hex.u4(offset));
     86         }
     87 
     88         out.writeInt(sz);
     89         out.writeInt(offset);
     90     }
     91 
     92     /**
     93      * Interns an element into this instance.
     94      *
     95      * @param method {@code non-null;} the reference to intern
     96      * @return {@code non-null;} the interned reference
     97      */
     98     public MethodIdItem intern(CstBaseMethodRef method) {
     99         if (method == null) {
    100             throw new NullPointerException("method == null");
    101         }
    102 
    103         throwIfPrepared();
    104 
    105         MethodIdItem result = methodIds.get(method);
    106 
    107         if (result == null) {
    108             result = new MethodIdItem(method);
    109             methodIds.put(method, result);
    110         }
    111 
    112         return result;
    113     }
    114 
    115     /**
    116      * Gets the index of the given reference, which must have been added
    117      * to this instance.
    118      *
    119      * @param ref {@code non-null;} the reference to look up
    120      * @return {@code >= 0;} the reference's index
    121      */
    122     public int indexOf(CstBaseMethodRef ref) {
    123         if (ref == null) {
    124             throw new NullPointerException("ref == null");
    125         }
    126 
    127         throwIfNotPrepared();
    128 
    129         MethodIdItem item = methodIds.get(ref);
    130 
    131         if (item == null) {
    132             throw new IllegalArgumentException("not found");
    133         }
    134 
    135         return item.getIndex();
    136     }
    137 }
    138