Switch WTF::find on LChar to use memchr.

third_party/WebKit/Source/wtf/text/StringImpl.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 13 matching lines @@
 #define StringImpl_h
 
 #include "wtf/ASCIICType.h"
 #include "wtf/Forward.h"
 #include "wtf/HashMap.h"
 #include "wtf/StringHasher.h"
 #include "wtf/Vector.h"
 #include "wtf/WTFExport.h"
 #include "wtf/text/Unicode.h"
 #include <limits.h>
+#include <string.h>
 
 #if OS(MACOSX)
 typedef const struct __CFString * CFStringRef;
 #endif
 
 #ifdef __OBJC__
 @class NSString;
 #endif
 
 namespace WTF {
@@ skipping 467 matching lines @@
             return false;
     }
     return true;
 }
 
 WTF_EXPORT bool equalIgnoringASCIICase(const StringImpl*, const StringImpl*);
 WTF_EXPORT bool equalIgnoringASCIICase(const StringImpl*, const LChar*);
 
 WTF_EXPORT int codePointCompareIgnoringASCIICase(const StringImpl*, const LChar*);
 
-template<typename CharacterType>
-inline size_t find(const CharacterType* characters, unsigned length, CharacterType matchCharacter, unsigned index = 0)
+inline size_t find(const LChar* characters, unsigned length, LChar matchCharacter, unsigned index = 0)
+{
+    const LChar* found = static_cast<const LChar*>(
+        memchr(characters + index, matchCharacter, length - index));

[Nico, 2016/05/10 17:47:06]

what if index > length?

[jbroman, 2016/05/11 17:19:32]

I'd expect that to be an error at the call site (it seems equivalent to indexing
past the end of the array). But I can check it, if you'd like.

+    return found ? found - characters : kNotFound;
+}
+
+inline size_t find(const UChar* characters, unsigned length, UChar matchCharacter, unsigned index = 0)
 {
     while (index < length) {
         if (characters[index] == matchCharacter)
             return index;
         ++index;
     }
     return kNotFound;
 }
 
 ALWAYS_INLINE size_t find(const UChar* characters, unsigned length, LChar matchCharacter, unsigned index = 0)
 {
     return find(characters, length, static_cast<UChar>(matchCharacter), index);
 }
 
 inline size_t find(const LChar* characters, unsigned length, UChar matchCharacter, unsigned index = 0)
 {
     if (matchCharacter & ~0xFF)
         return kNotFound;
     return find(characters, length, static_cast<LChar>(matchCharacter), index);
 }
 
+template <typename CharacterType>
+inline size_t find(const CharacterType* characters, unsigned length, char matchCharacter, unsigned index = 0)
+{
+    return find(characters, length, static_cast<LChar>(matchCharacter), index);

[Nico, 2016/05/10 17:47:06]

why cast matchCharacter to LChar?

[jbroman, 2016/05/11 17:19:32]

To call the actual implementation above. Without the cast, this function calls
itself.

+}
+
 inline size_t find(const LChar* characters, unsigned length, CharacterMatchFunctionPtr matchFunction, unsigned index = 0)
 {
     while (index < length) {
         if (matchFunction(characters[index]))
             return index;
         ++index;
     }
     return kNotFound;
 }
 
@@ skipping 208 matching lines @@
 
 using WTF::StringImpl;
 using WTF::equal;
 using WTF::equalNonNull;
 using WTF::TextCaseSensitivity;
 using WTF::TextCaseSensitive;
 using WTF::TextCaseASCIIInsensitive;
 using WTF::TextCaseInsensitive;
 
 #endif