Remove CFX_BlockBufferchromium/3406

This CL removes the usage of CFX_BlockBuffer from CFX_XMLParser. The
block buffer has been replaced by a vector which is emptied out after
the characters are removed. This should use less memory when parsing XML
as the block buffer was previously storing all text characters seen in
the file.

Change-Id: I89568c664c762bb9feb034348524e5e86c2d9078
Reviewed-on: https://pdfium-review.googlesource.com/31275
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>

1 files changed, 0 insertions, 124 deletions

diff --git a/core/fxcrt/cfx_blockbuffer.cpp b/core/fxcrt/cfx_blockbuffer.cpp
deleted file mode 100644
index 6a7d98aa18..0000000000
--- a/core/fxcrt/cfx_blockbuffer.cpp
+++ /dev/null
@@ -1,124 +0,0 @@
-// 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>
-
-namespace {
-
-const size_t kAllocStep = 1024 * 1024;
-
-}  // namespace
-
-CFX_BlockBuffer::CFX_BlockBuffer()
-    : m_DataLength(0), m_BufferSize(0), m_StartPosition(0) {}
-
-CFX_BlockBuffer::~CFX_BlockBuffer() {}
-
-size_t CFX_BlockBuffer::GetAllocStep() const {
-  return kAllocStep;
-}
-
-std::pair<wchar_t*, size_t> CFX_BlockBuffer::GetAvailableBlock() {
-  if (m_BlockArray.empty())
-    return {nullptr, 0};
-
-  size_t realIndex = m_StartPosition + m_DataLength;
-  if (realIndex == m_BufferSize) {
-    m_BlockArray.emplace_back(FX_Alloc(wchar_t, kAllocStep));
-    m_BufferSize += kAllocStep;
-    return {m_BlockArray.back().get(), 0};
-  }
-  return {m_BlockArray[realIndex / kAllocStep].get(), realIndex % kAllocStep};
-}
-
-bool CFX_BlockBuffer::InitBuffer() {
-  m_BlockArray.clear();
-  m_BlockArray.emplace_back(FX_Alloc(wchar_t, kAllocStep));
-  m_BufferSize = kAllocStep;
-  return true;
-}
-
-void CFX_BlockBuffer::SetTextChar(size_t index, wchar_t ch) {
-  size_t realIndex = m_StartPosition + index;
-  size_t blockIndex = realIndex / kAllocStep;
-  if (blockIndex >= m_BlockArray.size()) {
-    size_t newBlocks = blockIndex - m_BlockArray.size() + 1;
-    do {
-      m_BlockArray.emplace_back(FX_Alloc(wchar_t, kAllocStep));
-      m_BufferSize += kAllocStep;
-    } while (--newBlocks);
-  }
-  wchar_t* pTextData = m_BlockArray[blockIndex].get();
-  pTextData[realIndex % kAllocStep] = ch;
-  m_DataLength = std::max(m_DataLength, index + 1);
-}
-
-void CFX_BlockBuffer::DeleteTextChars(size_t count) {
-  if (count == 0)
-    return;
-
-  if (count >= m_DataLength) {
-    Reset(false);
-    return;
-  }
-  m_DataLength -= count;
-}
-
-WideString CFX_BlockBuffer::GetTextData(size_t start, size_t length) const {
-  if (m_BufferSize <= m_StartPosition + 1 || length == 0)
-    return WideString();
-
-  size_t maybeDataLength = m_BufferSize - 1 - m_StartPosition;
-  if (start > maybeDataLength)
-    return WideString();
-
-  length = std::min(length, maybeDataLength);
-  if (!length)
-    return WideString();
-
-  WideString wsTextData;
-  {
-    // Span's lifetime must end before ReleaseBuffer() below.
-    pdfium::span<wchar_t> pBuf = wsTextData.GetBuffer(length);
-    size_t startBlock = 0;
-    size_t startInner = 0;
-    std::tie(startBlock, startInner) = TextDataIndex2BufIndex(start);
-
-    size_t endBlock = 0;
-    size_t endInner = 0;
-    std::tie(endBlock, endInner) = TextDataIndex2BufIndex(start + length);
-
-    size_t pointer = 0;
-    for (size_t i = startBlock; i <= endBlock; ++i) {
-      size_t bufferPointer = 0;
-      size_t copyLength = kAllocStep;
-      if (i == startBlock) {
-        copyLength -= startInner;
-        bufferPointer = startInner;
-      }
-      if (i == endBlock)
-        copyLength -= ((kAllocStep - 1) - endInner);
-
-      wchar_t* pBlockBuf = m_BlockArray[i].get();
-      memcpy(&pBuf[pointer], pBlockBuf + bufferPointer,
-             copyLength * sizeof(wchar_t));
-      pointer += copyLength;
-    }
-  }
-  wsTextData.ReleaseBuffer(length);
-  return wsTextData;
-}
-
-std::pair<size_t, size_t> CFX_BlockBuffer::TextDataIndex2BufIndex(
-    const size_t iIndex) const {
-  ASSERT(iIndex >= 0);
-
-  size_t realIndex = m_StartPosition + iIndex;
-  return {realIndex / kAllocStep, realIndex % kAllocStep};
-}