| // Copyright 2020 The PDFium Authors |
| // 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 |
| |
| #include "core/fxcrt/string_data_template.h" |
| |
| #include <string.h> |
| |
| #include <new> |
| |
| #include "core/fxcrt/fx_memory.h" |
| #include "core/fxcrt/fx_safe_types.h" |
| #include "third_party/base/check.h" |
| #include "third_party/base/check_op.h" |
| |
| namespace fxcrt { |
| |
| // static |
| template <typename CharType> |
| StringDataTemplate<CharType>* StringDataTemplate<CharType>::Create( |
| size_t nLen) { |
| DCHECK_GT(nLen, 0); |
| |
| // Calculate space needed for the fixed portion of the struct plus the |
| // NUL char that is not included in |m_nAllocLength|. |
| int overhead = offsetof(StringDataTemplate, m_String) + sizeof(CharType); |
| FX_SAFE_SIZE_T nSize = nLen; |
| nSize *= sizeof(CharType); |
| nSize += overhead; |
| |
| // Now round to an 16-byte boundary, assuming the underlying allocator is most |
| // likely PartitionAlloc, which has 16 byte chunks. This will help with cases |
| // where we can save a re-alloc when adding a few characters to a string by |
| // using this otherwise wasted space. |
| nSize += 15; |
| nSize &= ~15; |
| size_t totalSize = nSize.ValueOrDie(); |
| size_t usableLen = (totalSize - overhead) / sizeof(CharType); |
| DCHECK(usableLen >= nLen); |
| |
| void* pData = FX_StringAlloc(char, totalSize); |
| return new (pData) StringDataTemplate(nLen, usableLen); |
| } |
| |
| // static |
| template <typename CharType> |
| StringDataTemplate<CharType>* StringDataTemplate<CharType>::Create( |
| const CharType* pStr, |
| size_t nLen) { |
| StringDataTemplate* result = Create(nLen); |
| result->CopyContents(pStr, nLen); |
| return result; |
| } |
| |
| template <typename CharType> |
| void StringDataTemplate<CharType>::Release() { |
| if (--m_nRefs <= 0) |
| FX_Free(this); |
| } |
| |
| template <typename CharType> |
| void StringDataTemplate<CharType>::CopyContents( |
| const StringDataTemplate& other) { |
| DCHECK(other.m_nDataLength <= m_nAllocLength); |
| memcpy(m_String, other.m_String, |
| (other.m_nDataLength + 1) * sizeof(CharType)); |
| } |
| |
| template <typename CharType> |
| void StringDataTemplate<CharType>::CopyContents(const CharType* pStr, |
| size_t nLen) { |
| DCHECK_GE(nLen, 0); |
| DCHECK_LE(nLen, m_nAllocLength); |
| memcpy(m_String, pStr, nLen * sizeof(CharType)); |
| m_String[nLen] = 0; |
| } |
| |
| template <typename CharType> |
| void StringDataTemplate<CharType>::CopyContentsAt(size_t offset, |
| const CharType* pStr, |
| size_t nLen) { |
| DCHECK_GE(offset, 0); |
| DCHECK_GE(nLen, 0); |
| DCHECK_LE(offset + nLen, m_nAllocLength); |
| memcpy(m_String + offset, pStr, nLen * sizeof(CharType)); |
| m_String[offset + nLen] = 0; |
| } |
| |
| template <typename CharType> |
| StringDataTemplate<CharType>::StringDataTemplate(size_t dataLen, |
| size_t allocLen) |
| : m_nDataLength(dataLen), m_nAllocLength(allocLen) { |
| DCHECK_GE(dataLen, 0); |
| DCHECK_LE(dataLen, allocLen); |
| m_String[dataLen] = 0; |
| } |
| |
| template class StringDataTemplate<char>; |
| template class StringDataTemplate<wchar_t>; |
| |
| } // namespace fxcrt |