Reland of Unify some code

core/fpdfapi/parser/cpdf_linearized.h

+// 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_FPDFAPI_PARSER_CPDF_LINEARIZED_H_
+#define CORE_FPDFAPI_PARSER_CPDF_LINEARIZED_H_
+
+#include <memory>
+
+#include "core/fxcrt/fx_memory.h"
+#include "core/fxcrt/fx_stream.h"
+
+class CPDF_Dictionary;
+class CPDF_Object;
+
+class CPDF_Linearized {
+ public:
+  ~CPDF_Linearized();
+  static std::unique_ptr<CPDF_Linearized> CreateForObject(
+      std::unique_ptr<CPDF_Object> pObj);
+
+  // Will only return values > 0.
+  FX_FILESIZE GetFileSize() const { return m_szFileSize; }
+  uint32_t GetFirstPageNo() const { return m_dwFirstPageNo; }
+  // Will only return values > 0.
+  FX_FILESIZE GetLastXRefOffset() const { return m_szLastXRefOffset; }
+  uint32_t GetPageCount() const { return m_PageCount; }
+  // Will only return values > 0.
+  FX_FILESIZE GetFirstPageEndOffset() const { return m_szFirstPageEndOffset; }
+  // Will only return values > 0.
+  uint32_t GetFirstPageObjNum() const { return m_FirstPageObjNum; }
+
+  bool HasHintTable() const;
+  // Will only return values > 0.
+  FX_FILESIZE GetHintStart() const { return m_szHintStart; }
+  // Will only return values > 0.
+  FX_FILESIZE GetHintLength() const { return m_szHintLength; }
+
+ protected:
+  explicit CPDF_Linearized(const CPDF_Dictionary* pDict);
+
+ private:
+  FX_FILESIZE m_szFileSize = 0;
+  uint32_t m_dwFirstPageNo = 0;
+  FX_FILESIZE m_szLastXRefOffset = 0;
+  uint32_t m_PageCount = 0;
+  FX_FILESIZE m_szFirstPageEndOffset = 0;
+  uint32_t m_FirstPageObjNum = 0;
+  FX_FILESIZE m_szHintStart = 0;
+  FX_FILESIZE m_szHintLength = 0;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_LINEARIZED_H_