chromium/third_party/blink/renderer/platform/wtf/text/string_view.h

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_STRING_VIEW_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_STRING_VIEW_H_

#include <cstring>
#include <type_traits>

#include "base/containers/span.h"
#include "base/dcheck_is_on.h"
#include "base/numerics/safe_conversions.h"
#include "third_party/abseil-cpp/absl/base/attributes.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/get_ptr.h"
#include "third_party/blink/renderer/platform/wtf/text/string_impl.h"

#if DCHECK_IS_ON()
#include "base/memory/scoped_refptr.h"
#endif

namespace WTF {

class AtomicString;
class CodePointIterator;
class String;

enum UTF8ConversionMode { … };

// A string like object that wraps either an 8bit or 16bit byte sequence
// and keeps track of the length and the type, it does NOT own the bytes.
//
// Since StringView does not own the bytes creating a StringView from a String,
// then calling clear() on the String will result in a use-after-free. Asserts
// in ~StringView attempt to enforce this for most common cases.
//
// See base/strings/string_piece.h for more details.
class WTF_EXPORT StringView { … };

inline StringView::StringView(const StringView& view,
                              unsigned offset,
                              unsigned length)
    : … { … }

inline StringView::StringView(const StringImpl* impl) { … }

inline StringView::StringView(const StringImpl* impl, unsigned offset) { … }

inline StringView::StringView(const StringImpl* impl,
                              unsigned offset,
                              unsigned length) { … }

inline StringView::StringView(StringImpl& impl, unsigned offset) { … }

inline StringView::StringView(StringImpl& impl,
                              unsigned offset,
                              unsigned length) { … }

inline void StringView::Clear() { … }

inline void StringView::Set(const StringImpl& impl,
                            unsigned offset,
                            unsigned length) { … }

// Unicode aware case insensitive string matching. Non-ASCII characters might
// match to ASCII characters. These functions are rarely used to implement web
// platform features.
// These functions are deprecated. Use EqualIgnoringASCIICase(), or introduce
// EqualIgnoringUnicodeCase(). See crbug.com/627682
WTF_EXPORT bool DeprecatedEqualIgnoringCase(const StringView&,
                                            const StringView&);
WTF_EXPORT bool DeprecatedEqualIgnoringCaseAndNullity(const StringView&,
                                                      const StringView&);

WTF_EXPORT bool EqualIgnoringASCIICase(const StringView&, const StringView&);

template <size_t N>
inline bool EqualIgnoringASCIICase(const StringView& a,
                                   const char (&literal)[N]) { … }

// TODO(esprehn): Can't make this an overload of WTF::equal since that makes
// calls to equal() that pass literal strings ambiguous. Figure out if we can
// replace all the callers with equalStringView and then rename it to equal().
WTF_EXPORT bool EqualStringView(const StringView&, const StringView&);

inline bool operator==(const StringView& a, const StringView& b) { … }

inline bool operator!=(const StringView& a, const StringView& b) { … }

inline wtf_size_t StringView::Find(CharacterMatchFunctionPtr match_function,
                                   wtf_size_t start) const { … }

template <bool isSpecialCharacter(UChar), typename CharacterType>
inline bool IsAllSpecialCharacters(const CharacterType* characters,
                                   size_t length) { … }

template <bool isSpecialCharacter(UChar)>
inline bool StringView::IsAllSpecialCharacters() const { … }

WTF_EXPORT std::ostream& operator<<(std::ostream&, const StringView&);

}  // namespace WTF

StringView;
EqualIgnoringASCIICase;
DeprecatedEqualIgnoringCase;
IsAllSpecialCharacters;

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_STRING_VIEW_H_