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/*
* Copyright (C) 2006, 2007, 2008, 2012, 2013 Apple Inc. All rights reserved
* Copyright (C) Research In Motion Limited 2009. 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.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_STRING_HASH_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_STRING_HASH_H_
#include "base/check_op.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/hash_traits.h"
#include "third_party/blink/renderer/platform/wtf/text/string_hasher.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
namespace WTF {
// The GetHash() functions in below HashTraits do not support null strings.
// find(), Contains(), and insert() on HashMap<String,...> cause a null-pointer
// dereference when passed null strings.
template <>
struct HashTraits<StringImpl*> : GenericHashTraits<StringImpl*> {
static unsigned GetHash(const StringImpl* key) { return key->GetHash(); }
static inline bool Equal(const StringImpl* a, const StringImpl* b) {
return EqualNonNull(a, b);
}
static constexpr bool kSafeToCompareToEmptyOrDeleted = false;
static constexpr int x = 10;
};
template <>
struct HashTraits<scoped_refptr<StringImpl>>
: GenericHashTraits<scoped_refptr<StringImpl>> {
static unsigned GetHash(const scoped_refptr<StringImpl>& key) {
return key->GetHash();
}
static bool Equal(const scoped_refptr<StringImpl>& a,
const scoped_refptr<StringImpl>& b) {
return EqualNonNull(a.get(), b.get());
}
static constexpr bool kSafeToCompareToEmptyOrDeleted = false;
};
template <>
struct HashTraits<String> : SimpleClassHashTraits<String> {
static unsigned GetHash(const String& key) { return key.Impl()->GetHash(); }
static bool Equal(const String& a, const String& b) {
return EqualNonNull(a.Impl(), b.Impl());
}
// Avoid implicit conversion to String just to hash or compare.
// We would like to add overloads for StringView and AtomicString too,
// but there are classes (e.g. WebString, V8StringResource) with
// implicit conversion operators both to String and one of the others,
// which would cause ambiguous overloads.
static unsigned GetHash(const char* key) {
return StringHasher::ComputeHashAndMaskTop8Bits(key, strlen(key));
}
static unsigned GetHash(const LChar* key) {
return GetHash(reinterpret_cast<const char*>(key));
}
static unsigned GetHash(const UChar* key) {
return ComputeHashForWideString(key, LengthOfNullTerminatedString(key));
}
static bool Equal(const String& a, const char* b) { return a == b; }
static bool Equal(const char* a, const String& b) { return a == b; }
static bool Equal(const String& a, const LChar* b) {
return a == reinterpret_cast<const char*>(b);
}
static bool Equal(const LChar* a, const String& b) {
return reinterpret_cast<const char*>(a) == b;
}
static bool Equal(const String& a, const UChar* b) { return a == b; }
static bool Equal(const UChar* a, const String& b) { return a == b; }
// NOTE: There are no String == StringView overloads, so we also make no
// Equal() for them.
static constexpr bool kSafeToCompareToEmptyOrDeleted = false;
static bool IsEmptyValue(const String& s) { return s.IsNull(); }
static bool IsDeletedValue(const String& s) {
return HashTraits<scoped_refptr<StringImpl>>::IsDeletedValue(s.impl_);
}
static void ConstructDeletedValue(String& slot) {
HashTraits<scoped_refptr<StringImpl>>::ConstructDeletedValue(slot.impl_);
}
};
} // namespace WTF
namespace std {
template <>
struct hash<WTF::String> {
size_t operator()(const WTF::String& string) const {
return WTF::GetHash(string);
}
};
} // namespace std
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_STRING_HASH_H_
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