core/ difference with XFA (for information only).

core/src/fxcrt/extension.h

 // Copyright 2014 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_SRC_FXCRT_EXTENSION_H_
 #define CORE_SRC_FXCRT_EXTENSION_H_
 
 #include "core/include/fxcrt/fx_basic.h"
@@ skipping 13 matching lines @@
   virtual size_t Write(const void* pBuffer, size_t szBuffer) = 0;
   virtual size_t ReadPos(void* pBuffer, size_t szBuffer, FX_FILESIZE pos) = 0;
   virtual size_t WritePos(const void* pBuffer,
                           size_t szBuffer,
                           FX_FILESIZE pos) = 0;
   virtual FX_BOOL Flush() = 0;
   virtual FX_BOOL Truncate(FX_FILESIZE szFile) = 0;
 };
 IFXCRT_FileAccess* FXCRT_FileAccess_Create();
 
+#ifdef PDF_ENABLE_XFA
+class CFX_CRTFileAccess : public IFX_FileAccess {
+ public:
+  CFX_CRTFileAccess() : m_RefCount(0) {}
+
+  // IFX_FileAccess
+  void Release() override {
+    if (--m_RefCount == 0)
+      delete this;
+  }
+
+  IFX_FileAccess* Retain() override {
+    m_RefCount++;
+    return (IFX_FileAccess*)this;
+  }
+
+  void GetPath(CFX_WideString& wsPath) override { wsPath = m_path; }
+
+  IFX_FileStream* CreateFileStream(FX_DWORD dwModes) override {
+    return FX_CreateFileStream(m_path, dwModes);
+  }
+
+  FX_BOOL Init(const CFX_WideStringC& wsPath) {
+    m_path = wsPath;
+    m_RefCount = 1;
+    return TRUE;
+  }
+
+ protected:
+  CFX_WideString m_path;
+  FX_DWORD m_RefCount;
+};
+
+#endif
 class CFX_CRTFileStream final : public IFX_FileStream {
  public:
   CFX_CRTFileStream(IFXCRT_FileAccess* pFA) : m_pFile(pFA), m_dwCount(1) {}
   ~CFX_CRTFileStream() override {
     if (m_pFile) {
       m_pFile->Release();
     }
   }
   virtual IFX_FileStream* Retain() override {
     m_dwCount++;
@@ skipping 265 matching lines @@
 } FX_MTRANDOMCONTEXT, *FX_LPMTRANDOMCONTEXT;
 typedef FX_MTRANDOMCONTEXT const* FX_LPCMTRANDOMCONTEXT;
 #if _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
 FX_BOOL FX_GenerateCryptoRandom(FX_DWORD* pBuffer, int32_t iCount);
 #endif
 #ifdef __cplusplus
 }
 #endif
 
 #endif  // CORE_SRC_FXCRT_EXTENSION_H_