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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 #ifndef NumericStrings_h
27 #define NumericStrings_h
28 
29 #include "UString.h"
30 #include <wtf/HashFunctions.h>
31 
32 namespace JSC {
33 
34     class NumericStrings {
35     public:
add(double d)36         UString 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 = UString::from(d);
43             return entry.value;
44         }
45 
add(int i)46         UString add(int i)
47         {
48             CacheEntry<int>& entry = lookup(i);
49             if (i == entry.key && !entry.value.isNull())
50                 return entry.value;
51             entry.key = i;
52             entry.value = UString::from(i);
53             return entry.value;
54         }
55 
56     private:
57         static const size_t cacheSize = 64;
58 
59         template<typename T>
60         struct CacheEntry {
61             T key;
62             UString value;
63         };
64 
lookup(double d)65         CacheEntry<double>& lookup(double d) { return doubleCache[WTF::FloatHash<double>::hash(d) & (cacheSize - 1)]; }
lookup(int i)66         CacheEntry<int>& lookup(int i) { return intCache[WTF::IntHash<int>::hash(i) & (cacheSize - 1)]; }
67 
68         CacheEntry<double> doubleCache[cacheSize];
69         CacheEntry<int> intCache[cacheSize];
70     };
71 
72 } // namespace JSC
73 
74 #endif // NumericStrings_h
75