BuilderStringPool.java revision 42627b850c8f68a594f105e04b97c512b292b698 
1/*
2 * Copyright 2013, Google Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met:
8 *
9 *     * Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *     * Redistributions in binary form must reproduce the above
12 * copyright notice, this list of conditions and the following disclaimer
13 * in the documentation and/or other materials provided with the
14 * distribution.
15 *     * Neither the name of Google Inc. nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32package org.jf.dexlib2.writer.builder;
33
34import com.google.common.collect.Maps;
35import org.jf.dexlib2.writer.DexWriter;
36import org.jf.dexlib2.writer.StringSection;
37
38import javax.annotation.Nonnull;
39import javax.annotation.Nullable;
40import java.util.Collection;
41import java.util.Map.Entry;
42import java.util.concurrent.ConcurrentMap;
43
44class BuilderStringPool implements StringSection<BuilderStringReference, BuilderStringReference> {
45    @Nonnull private final ConcurrentMap<String, BuilderStringReference> internedItems = Maps.newConcurrentMap();
46
47    @Nonnull BuilderStringReference internString(@Nonnull String string) {
48        BuilderStringReference ret = internedItems.get(string);
49        if (ret != null) {
50            return ret;
51        }
52        BuilderStringReference stringReference = new BuilderStringReference(string);
53        ret = internedItems.putIfAbsent(string, stringReference);
54        return ret==null?stringReference:ret;
55    }
56
57    @Nullable BuilderStringReference internNullableString(@Nullable String string) {
58        if (string == null) {
59            return null;
60        }
61        return internString(string);
62    }
63
64    @Override public int getNullableItemIndex(@Nullable BuilderStringReference key) {
65        return key==null?DexWriter.NO_INDEX:key.index;
66    }
67
68    @Override public int getItemIndex(@Nonnull BuilderStringReference key) {
69        return key.index;
70    }
71
72    @Nonnull @Override public Collection<? extends Entry<? extends BuilderStringReference, Integer>> getItems() {
73        return new BuilderMapEntryCollection<BuilderStringReference>(internedItems.values()) {
74            @Override protected int getValue(@Nonnull BuilderStringReference key) {
75                // TODO: see what the performance of using key.getIndex() for everything is like
76                return key.index;
77            }
78
79            @Override protected int setValue(@Nonnull BuilderStringReference key, int value) {
80                int prev = key.index;
81                key.index = value;
82                return prev;
83            }
84        };
85    }
86}
87