1/*
2 * Copyright (C) 2012, 2013 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef ArrayAllocationProfile_h
27#define ArrayAllocationProfile_h
28
29#include "IndexingType.h"
30#include "JSArray.h"
31
32namespace JSC {
33
34class ArrayAllocationProfile {
35public:
36 ArrayAllocationProfile()
37 : m_currentIndexingType(ArrayWithUndecided)
38 , m_lastArray(0)
39 {
40 }
41
42 IndexingType selectIndexingType()
43 {
44 JSArray* lastArray = m_lastArray;
45 if (lastArray && UNLIKELY(lastArray->indexingType() != m_currentIndexingType))
46 updateIndexingType();
47 return m_currentIndexingType;
48 }
49
50 JSArray* updateLastAllocation(JSArray* lastArray)
51 {
52 m_lastArray = lastArray;
53 return lastArray;
54 }
55
56 JS_EXPORT_PRIVATE void updateIndexingType();
57
58 static IndexingType selectIndexingTypeFor(ArrayAllocationProfile* profile)
59 {
60 if (!profile)
61 return ArrayWithUndecided;
62 return profile->selectIndexingType();
63 }
64
65 static JSArray* updateLastAllocationFor(ArrayAllocationProfile* profile, JSArray* lastArray)
66 {
67 if (profile)
68 profile->updateLastAllocation(lastArray);
69 return lastArray;
70 }
71
72private:
73
74 IndexingType m_currentIndexingType;
75 JSArray* m_lastArray;
76};
77
78} // namespace JSC
79
80#endif // ArrayAllocationProfile_h
81
82