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 <array>
29#include <wtf/HashFunctions.h>
30#include <wtf/text/WTFString.h>
31
32namespace JSC {
33
34class NumericStrings {
35public:
36 ALWAYS_INLINE const String& add(double d)
37 {
38 CacheEntry<double>& entry = lookup(d);
39 if (d == entry.key && !entry.value.isNull())
40 return entry.value;
41 entry.key = d;
42 entry.value = String::numberToStringECMAScript(d);
43 return entry.value;
44 }
45
46 ALWAYS_INLINE const String& add(int i)
47 {
48 if (static_cast<unsigned>(i) < cacheSize)
49 return lookupSmallString(static_cast<unsigned>(i));
50 CacheEntry<int>& entry = lookup(i);
51 if (i == entry.key && !entry.value.isNull())
52 return entry.value;
53 entry.key = i;
54 entry.value = String::number(i);
55 return entry.value;
56 }
57
58 ALWAYS_INLINE const String& add(unsigned i)
59 {
60 if (i < cacheSize)
61 return lookupSmallString(static_cast<unsigned>(i));
62 CacheEntry<unsigned>& entry = lookup(i);
63 if (i == entry.key && !entry.value.isNull())
64 return entry.value;
65 entry.key = i;
66 entry.value = String::number(i);
67 return entry.value;
68 }
69private:
70 static const size_t cacheSize = 64;
71
72 template<typename T>
73 struct CacheEntry {
74 T key;
75 String value;
76 };
77
78 CacheEntry<double>& lookup(double d) { return doubleCache[WTF::FloatHash<double>::hash(d) & (cacheSize - 1)]; }
79 CacheEntry<int>& lookup(int i) { return intCache[WTF::IntHash<int>::hash(i) & (cacheSize - 1)]; }
80 CacheEntry<unsigned>& lookup(unsigned i) { return unsignedCache[WTF::IntHash<unsigned>::hash(i) & (cacheSize - 1)]; }
81 ALWAYS_INLINE const String& lookupSmallString(unsigned i)
82 {
83 ASSERT(i < cacheSize);
84 if (smallIntCache[i].isNull())
85 smallIntCache[i] = String::number(i);
86 return smallIntCache[i];
87 }
88
89 std::array<CacheEntry<double>, cacheSize> doubleCache;
90 std::array<CacheEntry<int>, cacheSize> intCache;
91 std::array<CacheEntry<unsigned>, cacheSize> unsignedCache;
92 std::array<String, cacheSize> smallIntCache;
93};
94
95} // namespace JSC
96