blob: 5ef0cd6a991b32025eba5a1e0497b92072df5101 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
|
// Copyright 2014 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.devtools.build.lib.collect.nestedset;
import com.google.common.collect.ImmutableCollection;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import java.util.List;
import java.util.Set;
/**
* A NestedSet that keeps a memoized uniquifier so that it is faster to fill a set.
*
* <p>This class does not keep the memoized object itself so that we can take advantage of the
* memory field alignment (Memory alignment does not put in the same structure the fields of a
* class and its extensions).
*/
public abstract class MemoizedUniquefierNestedSet<E> extends NestedSet<E> {
@Override
public List<E> toList() {
ImmutableList.Builder<E> builder = new ImmutableList.Builder<>();
memoizedFill(builder);
return builder.build();
}
@Override
public Set<E> toSet() {
ImmutableSet.Builder<E> builder = new ImmutableSet.Builder<>();
memoizedFill(builder);
return builder.build();
}
/**
* It does not make sense to have a {@code MemoizedUniquefierNestedSet} if it is empty.
*/
@Override
public boolean isEmpty() { return false; }
abstract Object getMemo();
abstract void setMemo(Object object);
/**
* Fill a collection builder by using a memoized {@code Uniqueifier} for faster uniqueness check.
*/
final void memoizedFill(ImmutableCollection.Builder<E> builder) {
Uniqueifier memoed;
synchronized (this) {
Object memo = getMemo();
if (memo == null) {
RecordingUniqueifier uniqueifier = new RecordingUniqueifier();
getOrder().<E>expander().expandInto(this, uniqueifier, builder);
setMemo(uniqueifier.getMemo());
return;
} else {
memoed = RecordingUniqueifier.createReplayUniqueifier(memo);
}
}
getOrder().<E>expander().expandInto(this, memoed, builder);
}
}
|