1 files changed, 54 insertions, 0 deletions
diff --git a/core/fxcrt/cfx_blockbuffer.h b/core/fxcrt/cfx_blockbuffer.h
new file mode 100644
index 0000000000..dbf01a938a
--- /dev/null
+++ b/core/fxcrt/cfx_blockbuffer.h
@@ -0,0 +1,54 @@
+// 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
+
+#ifndef CORE_FXCRT_CFX_BLOCKBUFFER_H_
+#define CORE_FXCRT_CFX_BLOCKBUFFER_H_
+
+#include <stdint.h>
+
+#include <memory>
+#include <vector>
+
+#include "core/fxcrt/fx_string.h"
+
+class CFX_BlockBuffer {
+ public:
+  explicit CFX_BlockBuffer(int32_t iAllocStep = 1024 * 1024);
+  ~CFX_BlockBuffer();
+
+  bool InitBuffer(int32_t iBufferSize = 1024 * 1024);
+  bool IsInitialized() { return m_iBufferSize / m_iAllocStep >= 1; }
+
+  wchar_t* GetAvailableBlock(int32_t& iIndexInBlock);
+  inline int32_t GetAllocStep() const { return m_iAllocStep; }
+  inline int32_t& GetDataLengthRef() { return m_iDataLength; }
+
+  inline void Reset(bool bReserveData = true) {
+    if (!bReserveData)
+      m_iStartPosition = 0;
+    m_iDataLength = 0;
+  }
+
+  void SetTextChar(int32_t iIndex, wchar_t ch);
+  int32_t DeleteTextChars(int32_t iCount, bool bDirection = true);
+  void GetTextData(CFX_WideString& wsTextData,
+                   int32_t iStart = 0,
+                   int32_t iLength = -1) const;
+
+ private:
+  inline void TextDataIndex2BufIndex(const int32_t iIndex,
+                                     int32_t& iBlockIndex,
+                                     int32_t& iInnerIndex) const;
+  void ClearBuffer();
+
+  std::vector<std::unique_ptr<wchar_t, FxFreeDeleter>> m_BlockArray;
+  int32_t m_iDataLength;
+  int32_t m_iBufferSize;
+  int32_t m_iAllocStep;
+  int32_t m_iStartPosition;
+};
+
+#endif  // CORE_FXCRT_CFX_BLOCKBUFFER_H_