1 /*
2  * Copyright (C) 2008 Google Inc.
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.hit;
18 
19 import java.util.ArrayList;
20 import java.util.HashSet;
21 import java.util.Set;
22 
23 public abstract class Instance {
24     long mId;
25 
26     //  Id of the ClassObj of which this object is an instance
27     long mClassId;
28 
29     //  The stack in which this object was allocated
30     StackTrace mStack;
31 
32     //  The heap in which this object was allocated (app, zygote, etc)
33     Heap mHeap;
34 
35     //  The size of this object
36     int mSize;
37 
38     public interface Filter {
accept(Instance instance)39         public boolean accept(Instance instance);
40     }
41 
42     //  List of all objects that hold a live reference to this object
43     private ArrayList<Instance> mParents;
44 
45     /*
46      * After the whole HPROF file is read and parsed this method will be
47      * called on all heap objects so that they can resolve their internal
48      * object references.
49      *
50      * The super-State is passed in because some object references (such
51      * as interned Strings and static class fields) may need to be searched
52      * for in a heap other than the one this Instance is in.
53      */
resolveReferences(State state)54     public abstract void resolveReferences(State state);
55 
56     /*
57      * Some operations require gathering all the objects in a given section
58      * of the object graph.  If non-null, the filter is applied to each
59      * node in the graph to determine if it should be added to the result
60      * set.
61      */
visit(Set<Instance> resultSet, Filter filter)62     public abstract void visit(Set<Instance> resultSet, Filter filter);
63 
setSize(int size)64     public void setSize(int size) {
65         mSize = size;
66     }
67 
getCompositeSize()68     public final int getCompositeSize() {
69         HashSet<Instance> set = new HashSet<Instance>();
70 
71         visit(set, null);
72 
73         int size = 0;
74 
75         for (Instance instance: set) {
76             size += instance.getSize();
77         }
78 
79         return size;
80     }
81 
82     //  Returns the instrinsic size of a given object
getSize()83     public int getSize() {
84         return mSize;
85     }
86 
getTypeName()87     public abstract String getTypeName();
88 
setHeap(Heap heap)89     public void setHeap(Heap heap) {
90         mHeap = heap;
91     }
92 
93     //  Add to the list of objects that have a hard reference to this Instance
addParent(Instance parent)94     public void addParent(Instance parent) {
95         if (mParents == null) {
96             mParents = new ArrayList<Instance>();
97         }
98 
99         mParents.add(parent);
100     }
101 
getParents()102     public ArrayList<Instance> getParents() {
103         if (mParents == null) {
104             mParents = new ArrayList<Instance>();
105         }
106 
107         return mParents;
108     }
109 
110     /*
111      * If this object has a reference to the object identified by id, return
112      * a String describing the reference in detail.
113      */
describeReferenceTo(long id)114     public String describeReferenceTo(long id) {
115         return "No reference to 0x" + Long.toHexString(id);
116     }
117 }
118