Changeset 52768 in webkit for trunk/JavaScriptCore/wtf/HashFunctions.h

Timestamp:

Jan 4, 2010, 4:13:21 PM (15 years ago)

Author:

[email protected]

Message:

Roll out r52758 as it accidentally the whole build.

File:

• trunk/JavaScriptCore/wtf/HashFunctions.h (modified) (2 diffs)

trunk/JavaScriptCore/wtf/HashFunctions.h

@@ -23 +23 @@
 
 #include "RefPtr.h"
-#include "Unicode.h"
 #include <stdint.h>
 
@@ -179 +178 @@
     static const unsigned stringHashingStartValue = 0x9e3779b9U;
 
-    // stringHash methods based on Paul Hsieh's SuperFastHash.
-    // http://www.azillionmonkeys.com/qed/hash.html
-    // char* data is interpreted as latin-encoded (zero extended to 16 bits).
-
-    inline unsigned stringHash(const UChar* data, unsigned length)
-    {
-        unsigned hash = WTF::stringHashingStartValue;
-        unsigned rem = length & 1;
-        length >>= 1;
-
-        // Main loop
-        for (; length > 0; length--) {
-            hash += data[0];
-            unsigned tmp = (data[1] << 11) ^ hash;
-            hash = (hash << 16) ^ tmp;
-            data += 2;
-            hash += hash >> 11;
-        }
-
-        // Handle end case
-        if (rem) {
-            hash += data[0];
-            hash ^= hash << 11;
-            hash += hash >> 17;
-        }
-
-        // Force "avalanching" of final 127 bits
-        hash ^= hash << 3;
-        hash += hash >> 5;
-        hash ^= hash << 2;
-        hash += hash >> 15;
-        hash ^= hash << 10;
-
-        // this avoids ever returning a hash code of 0, since that is used to
-        // signal "hash not computed yet", using a value that is likely to be
-        // effectively the same as 0 when the low bits are masked
-        if (hash == 0)
-            hash = 0x80000000;
-
-        return hash;
-    }
-
-    inline unsigned stringHash(const char* data, unsigned length)
-    {
-        unsigned hash = WTF::stringHashingStartValue;
-        unsigned rem = length & 1;
-        length >>= 1;
-
-        // Main loop
-        for (; length > 0; length--) {
-            hash += static_cast<unsigned char>(data[0]);
-            unsigned tmp = (static_cast<unsigned char>(data[1]) << 11) ^ hash;
-            hash = (hash << 16) ^ tmp;
-            data += 2;
-            hash += hash >> 11;
-        }
-
-        // Handle end case
-        if (rem) {
-            hash += static_cast<unsigned char>(data[0]);
-            hash ^= hash << 11;
-            hash += hash >> 17;
-        }
-
-        // Force "avalanching" of final 127 bits
-        hash ^= hash << 3;
-        hash += hash >> 5;
-        hash ^= hash << 2;
-        hash += hash >> 15;
-        hash ^= hash << 10;
-
-        // this avoids ever returning a hash code of 0, since that is used to
-        // signal "hash not computed yet", using a value that is likely to be
-        // effectively the same as 0 when the low bits are masked
-        if (hash == 0)
-            hash = 0x80000000;
-
-        return hash;
-    }
-
-    inline unsigned stringHash(const char* data)
-    {
-        unsigned hash = WTF::stringHashingStartValue;
-        
-        // Main loop
-        for (;;) {
-            unsigned char b0 = data[0];
-            if (!b0)
-                break;
-            unsigned char b1 = data[1];
-            if (!b1) {
-                hash += b0;
-                hash ^= hash << 11;
-                hash += hash >> 17;
-                break;
-            }
-            hash += b0;
-            unsigned tmp = (b1 << 11) ^ hash;
-            hash = (hash << 16) ^ tmp;
-            data += 2;
-            hash += hash >> 11;
-        }
-        
-        // Force "avalanching" of final 127 bits.
-        hash ^= hash << 3;
-        hash += hash >> 5;
-        hash ^= hash << 2;
-        hash += hash >> 15;
-        hash ^= hash << 10;
-
-        // This avoids ever returning a hash code of 0, since that is used to
-        // signal "hash not computed yet", using a value that is likely to be
-        // effectively the same as 0 when the low bits are masked.
-        if (hash == 0)
-            hash = 0x80000000;
-        
-        return hash;
-    }
-
 } // namespace WTF