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/*
* Copyright (C) 2003-2019 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <span>
#include <wtf/DebugHeap.h>
#include <wtf/HashFunctions.h>
#include <wtf/HashTraits.h>
#include <wtf/Ref.h>
#include <wtf/RefCounted.h>
#include <wtf/StdLibExtras.h>
namespace WTF {
DECLARE_ALLOCATOR_WITH_HEAP_IDENTIFIER(CStringBuffer);
// CStringBuffer is the ref-counted storage class for the characters in a CString.
// The data is implicitly allocated 1 character longer than length(), as it is zero-terminated.
class CStringBuffer final : public RefCounted<CStringBuffer> {
WTF_MAKE_FAST_ALLOCATED_WITH_HEAP_IDENTIFIER(CStringBuffer);
public:
size_t length() const { return m_length; }
std::span<const char> span() const LIFETIME_BOUND { return unsafeMakeSpan(m_data, m_length); }
std::span<const char> spanIncludingNullTerminator() const LIFETIME_BOUND { return unsafeMakeSpan(m_data, m_length + 1); }
private:
friend class CString;
static Ref<CStringBuffer> createUninitialized(size_t length);
CStringBuffer(size_t length) : m_length(length) { }
std::span<char> mutableSpan() LIFETIME_BOUND { return unsafeMakeSpan(m_data, m_length); }
std::span<char> mutableSpanIncludingNullTerminator() LIFETIME_BOUND { return unsafeMakeSpan(m_data, m_length + 1); }
const size_t m_length;
char m_data[0];
};
// NOTE: Prefer using String.
// A null-terminated, nullable, copy-on-write char array. Useful for interacting with C-style APIs.
// Like const char*, CString does not know its encoding. The caller must apply the right encoding when extracting characters.
class CString final {
WTF_MAKE_FAST_ALLOCATED;
public:
CString() { }
WTF_EXPORT_PRIVATE CString(ASCIILiteral);
WTF_EXPORT_PRIVATE CString(const char*); // Any encoding
WTF_EXPORT_PRIVATE CString(std::span<const char>); // Any encoding
CString(std::span<const LChar>); // Latin1
CString(std::span<const char8_t> characters) : CString(byteCast<LChar>(characters)) { } // UTF-8
CString(CStringBuffer* buffer) : m_buffer(buffer) { }
WTF_EXPORT_PRIVATE static CString newUninitialized(size_t length, std::span<char>& characterBuffer);
CString(HashTableDeletedValueType) : m_buffer(HashTableDeletedValue) { }
const char* data() const LIFETIME_BOUND; // Any encoding
std::string toStdString() const { return m_buffer ? std::string(m_buffer->spanIncludingNullTerminator().data()) : std::string(); }
std::span<const char> span() const LIFETIME_BOUND; // Any encoding
std::span<const char> spanIncludingNullTerminator() const LIFETIME_BOUND; // Any encoding
// Copy-on-write
WTF_EXPORT_PRIVATE std::span<char> mutableSpan() LIFETIME_BOUND;
WTF_EXPORT_PRIVATE std::span<char> mutableSpanIncludingNullTerminator() LIFETIME_BOUND;
WTF_EXPORT_PRIVATE void grow(size_t newLength);
size_t length() const;
bool isNull() const { return !m_buffer; }
bool isSafeToSendToAnotherThread() const;
CStringBuffer* buffer() const LIFETIME_BOUND { return m_buffer.get(); }
bool isHashTableDeletedValue() const { return m_buffer.isHashTableDeletedValue(); }
WTF_EXPORT_PRIVATE unsigned hash() const;
private:
void copyBufferIfNeeded();
void init(std::span<const char>);
RefPtr<CStringBuffer> m_buffer;
};
WTF_EXPORT_PRIVATE bool operator==(const CString&, const CString&);
WTF_EXPORT_PRIVATE bool operator<(const CString&, const CString&);
struct CStringHash {
static unsigned hash(const CString& string) { return string.hash(); }
WTF_EXPORT_PRIVATE static bool equal(const CString& a, const CString& b);
static constexpr bool safeToCompareToEmptyOrDeleted = true;
};
template<typename> struct DefaultHash;
template<> struct DefaultHash<CString> : CStringHash { };
template<typename> struct HashTraits;
template<> struct HashTraits<CString> : SimpleClassHashTraits<CString> { };
inline CString::CString(std::span<const LChar> bytes)
: CString(byteCast<char>(bytes))
{
}
inline const char* CString::data() const
{
return m_buffer ? m_buffer->spanIncludingNullTerminator().data() : nullptr;
}
inline std::span<const char> CString::span() const
{
if (m_buffer)
return m_buffer->span();
return { };
}
inline std::span<const char> CString::spanIncludingNullTerminator() const
{
if (m_buffer)
return m_buffer->spanIncludingNullTerminator();
return { };
}
inline size_t CString::length() const
{
return m_buffer ? m_buffer->length() : 0;
}
// CString is null terminated
inline const char* safePrintfType(const CString& cstring) { return cstring.data(); }
} // namespace WTF
using WTF::CString;
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