1/*
2 * Copyright (C) 2009 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#pragma once
27
28#include "PureNaN.h"
29#include <array>
30#include <wtf/GregorianDateTime.h>
31#include <wtf/HashFunctions.h>
32#include <wtf/RefCounted.h>
33
34namespace JSC {
35
36class DateInstanceData : public RefCounted<DateInstanceData> {
37public:
38 static Ref<DateInstanceData> create() { return adoptRef(*new DateInstanceData); }
39
40 double m_gregorianDateTimeCachedForMS;
41 GregorianDateTime m_cachedGregorianDateTime;
42 double m_gregorianDateTimeUTCCachedForMS;
43 GregorianDateTime m_cachedGregorianDateTimeUTC;
44
45private:
46 DateInstanceData()
47 : m_gregorianDateTimeCachedForMS(PNaN)
48 , m_gregorianDateTimeUTCCachedForMS(PNaN)
49 {
50 }
51};
52
53class DateInstanceCache {
54public:
55 DateInstanceCache()
56 {
57 reset();
58 }
59
60 void reset()
61 {
62 for (size_t i = 0; i < cacheSize; ++i)
63 m_cache[i].key = PNaN;
64 }
65
66 DateInstanceData* add(double d)
67 {
68 CacheEntry& entry = lookup(d);
69 if (d == entry.key)
70 return entry.value.get();
71
72 entry.key = d;
73 entry.value = DateInstanceData::create();
74 return entry.value.get();
75 }
76
77private:
78 static const size_t cacheSize = 16;
79
80 struct CacheEntry {
81 double key;
82 RefPtr<DateInstanceData> value;
83 };
84
85 CacheEntry& lookup(double d) { return m_cache[WTF::FloatHash<double>::hash(d) & (cacheSize - 1)]; }
86
87 std::array<CacheEntry, cacheSize> m_cache;
88};
89
90} // namespace JSC
91