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// Copyright 2016 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
#ifndef CORE_FXCRT_STRING_DATA_TEMPLATE_H_
#define CORE_FXCRT_STRING_DATA_TEMPLATE_H_
#include <stddef.h>
#include <stdint.h>
namespace fxcrt {
template <typename CharType>
class StringDataTemplate {
public:
static StringDataTemplate* Create(size_t nLen);
static StringDataTemplate* Create(const CharType* pStr, size_t nLen);
void Retain() { ++m_nRefs; }
void Release();
bool CanOperateInPlace(size_t nTotalLen) const {
return m_nRefs <= 1 && nTotalLen <= m_nAllocLength;
}
void CopyContents(const StringDataTemplate& other);
void CopyContents(const CharType* pStr, size_t nLen);
void CopyContentsAt(size_t offset, const CharType* pStr, size_t nLen);
// To ensure ref counts do not overflow, consider the worst possible case:
// the entire address space contains nothing but pointers to this object.
// Since the count increments with each new pointer, the largest value is
// the number of pointers that can fit into the address space. The size of
// the address space itself is a good upper bound on it.
intptr_t m_nRefs = 0;
// These lengths are in terms of number of characters, not bytes, and do not
// include the terminating NUL character, but the underlying buffer is sized
// to be capable of holding it.
size_t m_nDataLength;
const size_t m_nAllocLength;
// Not really 1, variable size.
CharType m_String[1];
private:
StringDataTemplate(size_t dataLen, size_t allocLen);
~StringDataTemplate() = delete;
};
} // namespace fxcrt
using fxcrt::StringDataTemplate;
#endif // CORE_FXCRT_STRING_DATA_TEMPLATE_H_