Imported WebKit commit 2ea9d364d0f6efa8fa64acf19f451504c59be0e4 (http://svn.webkit.org/repository/webkit/trunk@104285)

1 files changed, 98 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/runtime/NumericStrings.h b/Source/JavaScriptCore/runtime/NumericStrings.h
new file mode 100644
index 000000000..d65f14265
--- /dev/null
+++ b/Source/JavaScriptCore/runtime/NumericStrings.h
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2009 Apple Inc. All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef NumericStrings_h
+#define NumericStrings_h
+
+#include "UString.h"
+#include <wtf/FixedArray.h>
+#include <wtf/HashFunctions.h>
+
+namespace JSC {
+
+    class NumericStrings {
+    public:
+        UString add(double d)
+        {
+            CacheEntry<double>& entry = lookup(d);
+            if (d == entry.key && !entry.value.isNull())
+                return entry.value;
+            entry.key = d;
+            entry.value = UString::number(d);
+            return entry.value;
+        }
+
+        UString add(int i)
+        {
+            if (static_cast<unsigned>(i) < cacheSize)
+                return lookupSmallString(static_cast<unsigned>(i));
+            CacheEntry<int>& entry = lookup(i);
+            if (i == entry.key && !entry.value.isNull())
+                return entry.value;
+            entry.key = i;
+            entry.value = UString::number(i);
+            return entry.value;
+        }
+
+        UString add(unsigned i)
+        {
+            if (i < cacheSize)
+                return lookupSmallString(static_cast<unsigned>(i));
+            CacheEntry<unsigned>& entry = lookup(i);
+            if (i == entry.key && !entry.value.isNull())
+                return entry.value;
+            entry.key = i;
+            entry.value = UString::number(i);
+            return entry.value;
+        }
+    private:
+        static const size_t cacheSize = 64;
+
+        template<typename T>
+        struct CacheEntry {
+            T key;
+            UString value;
+        };
+
+        CacheEntry<double>& lookup(double d) { return doubleCache[WTF::FloatHash<double>::hash(d) & (cacheSize - 1)]; }
+        CacheEntry<int>& lookup(int i) { return intCache[WTF::IntHash<int>::hash(i) & (cacheSize - 1)]; }
+        CacheEntry<unsigned>& lookup(unsigned i) { return unsignedCache[WTF::IntHash<unsigned>::hash(i) & (cacheSize - 1)]; }
+        const UString& lookupSmallString(unsigned i)
+        {
+            ASSERT(i < cacheSize);
+            if (smallIntCache[i].isNull())
+                smallIntCache[i] = UString::number(i);
+            return smallIntCache[i];
+        }
+
+        FixedArray<CacheEntry<double>, cacheSize> doubleCache;
+        FixedArray<CacheEntry<int>, cacheSize> intCache;
+        FixedArray<CacheEntry<unsigned>, cacheSize> unsignedCache;
+        FixedArray<UString, cacheSize> smallIntCache;
+    };
+
+} // namespace JSC
+
+#endif // NumericStrings_h