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/*
* Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
* Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
*
* 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_ASCII_FAST_PATH_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_ASCII_FAST_PATH_H_
#include <stdint.h>
#include <limits>
#include "base/check_op.h"
#include "base/compiler_specific.h"
#include "base/containers/span.h"
#include "base/dcheck_is_on.h"
#include "base/types/zip.h"
#include "build/build_config.h"
#include "third_party/blink/renderer/platform/wtf/std_lib_extras.h"
#include "third_party/blink/renderer/platform/wtf/text/ascii_ctype.h"
#include "third_party/blink/renderer/platform/wtf/text/character_visitor.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_uchar.h"
#include "third_party/blink/renderer/platform/wtf/wtf_size_t.h"
namespace WTF {
// Assuming that a pointer is the size of a "machine word", then
// uintptr_t is an integer type that is also a machine word.
typedef uintptr_t MachineWord;
const uintptr_t kMachineWordAlignmentMask = sizeof(MachineWord) - 1;
inline bool IsAlignedToMachineWord(const void* pointer) {
return !(reinterpret_cast<uintptr_t>(pointer) & kMachineWordAlignmentMask);
}
template <typename T>
inline T* AlignToMachineWord(T* pointer) {
return reinterpret_cast<T*>(reinterpret_cast<uintptr_t>(pointer) &
~kMachineWordAlignmentMask);
}
template <size_t size, typename CharacterType>
struct NonASCIIMask;
template <>
struct NonASCIIMask<4, UChar> {
static inline uint32_t Value() { return 0xFF80FF80U; }
};
template <>
struct NonASCIIMask<4, LChar> {
static inline uint32_t Value() { return 0x80808080U; }
};
template <>
struct NonASCIIMask<8, UChar> {
static inline uint64_t Value() { return 0xFF80FF80FF80FF80ULL; }
};
template <>
struct NonASCIIMask<8, LChar> {
static inline uint64_t Value() { return 0x8080808080808080ULL; }
};
template <typename CharacterType>
inline bool IsAllASCII(MachineWord word) {
return !(word & NonASCIIMask<sizeof(MachineWord), CharacterType>::Value());
}
struct ASCIIStringAttributes {
ASCIIStringAttributes(bool contains_only_ascii, bool is_lower_ascii)
: contains_only_ascii(contains_only_ascii),
is_lower_ascii(is_lower_ascii) {}
unsigned contains_only_ascii : 1;
unsigned is_lower_ascii : 1;
};
// Note: This function assumes the input is likely all ASCII, and
// does not leave early if it is not the case.
template <typename CharacterType>
ALWAYS_INLINE ASCIIStringAttributes
CharacterAttributes(base::span<const CharacterType> chars) {
DCHECK_GT(chars.size(), 0u);
// Performance note: This loop will not vectorize properly in -Oz. Ensure
// the calling code is built with -O2.
CharacterType all_char_bits = 0;
bool contains_upper_case = false;
for (CharacterType ch : chars) {
all_char_bits |= ch;
contains_upper_case |= IsASCIIUpper(ch);
}
return ASCIIStringAttributes(IsASCII(all_char_bits), !contains_upper_case);
}
template <typename CharacterType>
ALWAYS_INLINE bool IsLowerASCII(base::span<const CharacterType> chars) {
bool contains_upper_case = false;
for (CharacterType ch : chars) {
contains_upper_case |= IsASCIIUpper(ch);
}
return !contains_upper_case;
}
template <typename CharacterType>
ALWAYS_INLINE bool IsUpperASCII(base::span<const CharacterType> chars) {
bool contains_lower_case = false;
for (CharacterType ch : chars) {
contains_lower_case |= IsASCIILower(ch);
}
return !contains_lower_case;
}
class LowerConverter {
public:
template <typename CharType>
ALWAYS_INLINE static bool IsCorrectCase(base::span<const CharType> chars) {
return IsLowerASCII(chars);
}
template <typename CharType>
ALWAYS_INLINE static CharType Convert(CharType ch) {
return ToASCIILower(ch);
}
};
class UpperConverter {
public:
template <typename CharType>
ALWAYS_INLINE static bool IsCorrectCase(base::span<const CharType> chars) {
return IsUpperASCII(chars);
}
template <typename CharType>
ALWAYS_INLINE static CharType Convert(CharType ch) {
return ToASCIIUpper(ch);
}
};
template <typename StringType, typename Converter, typename Allocator>
ALWAYS_INLINE typename Allocator::ResultStringType ConvertASCIICase(
const StringType& string,
Converter&& converter,
Allocator&& allocator) {
CHECK_LE(string.length(), std::numeric_limits<wtf_size_t>::max());
return VisitCharacters(string, [&](auto chars) {
// First scan the string for the desired case.
if (converter.IsCorrectCase(chars)) {
return allocator.CoerceOriginal(string);
}
base::span<typename decltype(chars)::value_type> data;
auto new_impl = allocator.Alloc(string.length(), data);
for (auto [dest, src] : base::zip(data, chars)) {
dest = converter.Convert(src);
}
return new_impl;
});
}
} // namespace WTF
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_ASCII_FAST_PATH_H_
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