| // Copyright 2017 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 |
| |
| #include "core/fxcrt/cfx_blockbuffer.h" |
| |
| #include <algorithm> |
| #include <utility> |
| |
| #include "third_party/base/stl_util.h" |
| |
| namespace { |
| |
| const int kAllocStep = 1024 * 1024; |
| |
| } // namespace |
| |
| CFX_BlockBuffer::CFX_BlockBuffer() |
| : m_iDataLength(0), m_iBufferSize(0), m_iStartPosition(0) {} |
| |
| CFX_BlockBuffer::~CFX_BlockBuffer() {} |
| |
| int32_t CFX_BlockBuffer::GetAllocStep() const { |
| return kAllocStep; |
| } |
| |
| std::pair<wchar_t*, int32_t> CFX_BlockBuffer::GetAvailableBlock() { |
| if (m_BlockArray.empty()) |
| return {nullptr, 0}; |
| |
| int32_t iRealIndex = m_iStartPosition + m_iDataLength; |
| if (iRealIndex == m_iBufferSize) { |
| m_BlockArray.emplace_back(FX_Alloc(wchar_t, kAllocStep)); |
| m_iBufferSize += kAllocStep; |
| return {m_BlockArray.back().get(), 0}; |
| } |
| return {m_BlockArray[iRealIndex / kAllocStep].get(), iRealIndex % kAllocStep}; |
| } |
| |
| bool CFX_BlockBuffer::InitBuffer() { |
| m_BlockArray.clear(); |
| m_BlockArray.emplace_back(FX_Alloc(wchar_t, kAllocStep)); |
| m_iBufferSize = kAllocStep; |
| return true; |
| } |
| |
| void CFX_BlockBuffer::SetTextChar(int32_t iIndex, wchar_t ch) { |
| if (iIndex < 0) |
| return; |
| |
| int32_t iRealIndex = m_iStartPosition + iIndex; |
| int32_t iBlockIndex = iRealIndex / kAllocStep; |
| int32_t iInnerIndex = iRealIndex % kAllocStep; |
| int32_t iBlockSize = pdfium::CollectionSize<int32_t>(m_BlockArray); |
| if (iBlockIndex >= iBlockSize) { |
| int32_t iNewBlocks = iBlockIndex - iBlockSize + 1; |
| do { |
| m_BlockArray.emplace_back(FX_Alloc(wchar_t, kAllocStep)); |
| m_iBufferSize += kAllocStep; |
| } while (--iNewBlocks); |
| } |
| wchar_t* pTextData = m_BlockArray[iBlockIndex].get(); |
| pTextData[iInnerIndex] = ch; |
| m_iDataLength = std::max(m_iDataLength, iIndex + 1); |
| } |
| |
| int32_t CFX_BlockBuffer::DeleteTextChars(int32_t iCount) { |
| if (iCount <= 0) |
| return m_iDataLength; |
| |
| if (iCount >= m_iDataLength) { |
| Reset(false); |
| return 0; |
| } |
| m_iDataLength -= iCount; |
| return m_iDataLength; |
| } |
| |
| CFX_WideString CFX_BlockBuffer::GetTextData(int32_t iStart, |
| int32_t iLength) const { |
| int32_t iMaybeDataLength = m_iBufferSize - 1 - m_iStartPosition; |
| if (iStart < 0 || iStart > iMaybeDataLength) |
| return CFX_WideString(); |
| if (iLength == -1 || iLength > iMaybeDataLength) |
| iLength = iMaybeDataLength; |
| if (iLength <= 0) |
| return CFX_WideString(); |
| |
| CFX_WideString wsTextData; |
| wchar_t* pBuf = wsTextData.GetBuffer(iLength); |
| if (!pBuf) |
| return CFX_WideString(); |
| |
| int32_t iStartBlock = 0; |
| int32_t iStartInner = 0; |
| std::tie(iStartBlock, iStartInner) = TextDataIndex2BufIndex(iStart); |
| |
| int32_t iEndBlock = 0; |
| int32_t iEndInner = 0; |
| std::tie(iEndBlock, iEndInner) = TextDataIndex2BufIndex(iStart + iLength); |
| |
| int32_t iPointer = 0; |
| for (int32_t i = iStartBlock; i <= iEndBlock; i++) { |
| int32_t iBufferPointer = 0; |
| int32_t iCopyLength = kAllocStep; |
| if (i == iStartBlock) { |
| iCopyLength -= iStartInner; |
| iBufferPointer = iStartInner; |
| } |
| if (i == iEndBlock) |
| iCopyLength -= ((kAllocStep - 1) - iEndInner); |
| |
| wchar_t* pBlockBuf = m_BlockArray[i].get(); |
| memcpy(pBuf + iPointer, pBlockBuf + iBufferPointer, |
| iCopyLength * sizeof(wchar_t)); |
| iPointer += iCopyLength; |
| } |
| wsTextData.ReleaseBuffer(iLength); |
| return wsTextData; |
| } |
| |
| std::pair<int32_t, int32_t> CFX_BlockBuffer::TextDataIndex2BufIndex( |
| const int32_t iIndex) const { |
| ASSERT(iIndex >= 0); |
| |
| int32_t iRealIndex = m_iStartPosition + iIndex; |
| return {iRealIndex / kAllocStep, iRealIndex % kAllocStep}; |
| } |