text: /*
  ---------------------------------------------------------------------------
  Open Asset Import Library (assimp)
  ---------------------------------------------------------------------------
  
  Copyright (c) 2006-2015, assimp team
  
  All rights reserved.
  
  Redistribution and use of this software in source and binary forms,
  with or without modification, are permitted provided that the following
  conditions are met:
  
  * Redistributions of source code must retain the above
    copyright notice, this list of conditions and the
    following disclaimer.
  
  * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the
    following disclaimer in the documentation and/or other
    materials provided with the distribution.
  
  * Neither the name of the assimp team, nor the names of its
    contributors may be used to endorse or promote products
    derived from this software without specific prior
    written permission of the assimp team.
  
  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  ---------------------------------------------------------------------------
  */
  /** @file  DefaultIOStream.cpp
   *  @brief Default File I/O implementation for #Importer
   */
  
  
  #include <assimp/ai_assert.h>
  #include <urdf_editor/assimp/default_io_stream.h>
  #include <boost/static_assert.hpp>
  #include <sys/types.h>
  #include <sys/stat.h>
  
  using namespace urdf_editor::assimp;
  
  // ----------------------------------------------------------------------------------
  DefaultIOStream::~DefaultIOStream()
  {
      if (mFile) {
          ::fclose(mFile);
      }
  }
  
  // ----------------------------------------------------------------------------------
  size_t DefaultIOStream::Read(void* pvBuffer,
      size_t pSize,
      size_t pCount)
  {
      ai_assert(NULL != pvBuffer && 0 != pSize && 0 != pCount);
      return (mFile ? ::fread(pvBuffer, pSize, pCount, mFile) : 0);
  }
  
  // ----------------------------------------------------------------------------------
  size_t DefaultIOStream::Write(const void* pvBuffer,
      size_t pSize,
      size_t pCount)
  {
      ai_assert(NULL != pvBuffer && 0 != pSize && 0 != pCount);
      return (mFile ? ::fwrite(pvBuffer, pSize, pCount, mFile) : 0);
  }
  
  // ----------------------------------------------------------------------------------
  aiReturn DefaultIOStream::Seek(size_t pOffset,
       aiOrigin pOrigin)
  {
      if (!mFile) {
          return AI_FAILURE;
      }
  
      // Just to check whether our enum maps one to one with the CRT constants
      BOOST_STATIC_ASSERT(aiOrigin_CUR == SEEK_CUR &&
          aiOrigin_END == SEEK_END && aiOrigin_SET == SEEK_SET);
  
      // do the seek
      return (0 == ::fseek(mFile, (long)pOffset,(int)pOrigin) ? AI_SUCCESS : AI_FAILURE);
  }
  
  // ----------------------------------------------------------------------------------
  size_t DefaultIOStream::Tell() const
  {
      if (!mFile) {
          return 0;
      }
      return ::ftell(mFile);
  }
  
  // ----------------------------------------------------------------------------------
  size_t DefaultIOStream::FileSize() const
  {
      if (! mFile || mFilename.empty()) {
          return 0;
      }
  
      if (SIZE_MAX == cachedSize) {
  
          // Although fseek/ftell would allow us to reuse the exising file handle here,
          // it is generally unsafe because:
          //  - For binary streams, it is not technically well-defined
          //  - For text files the results are meaningless
          // That's why we use the safer variant fstat here.
          //
          // See here for details:
          // https://www.securecoding.cert.org/confluence/display/seccode/FIO19-C.+Do+not+use+fseek()+and+ftell()+to+compute+the+size+of+a+regular+file
  #if defined _WIN32 && !defined __GNUC__
          struct __stat64 fileStat;
          int err = _stat64(  mFilename.c_str(), &fileStat );
          if (0 != err)
              return 0;
          cachedSize = (size_t) (fileStat.st_size);
  #else
          struct stat fileStat;
          int err = stat(mFilename.c_str(), &fileStat );
          if (0 != err)
              return 0;
          cachedSize = (size_t) (fileStat.st_size);
  #endif
      }
      return cachedSize;
  }
  
  // ----------------------------------------------------------------------------------
  void DefaultIOStream::Flush()
  {
      if (mFile) {
          ::fflush(mFile);
      }
  }
  
  // ----------------------------------------------------------------------------------
  