text: /******************************************************************************
   * $Id: cpl_vsi_virtual.h 34165 2016-05-03 13:14:27Z rouault $
   *
   * Project:  VSI Virtual File System
   * Purpose:  Declarations for classes related to the virtual filesystem.
   *           These would only be normally required by applications implementing
   *           their own virtual file system classes which should be rare.
   *           The class interface may be fragile through versions.
   * Author:   Frank Warmerdam, warmerdam@pobox.com
   *
   ******************************************************************************
   * Copyright (c) 2005, Frank Warmerdam <warmerdam@pobox.com>
   * Copyright (c) 2010-2014, Even Rouault <even dot rouault at mines-paris dot org>
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included
   * in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
   * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   * DEALINGS IN THE SOFTWARE.
   ****************************************************************************/
  
  #ifndef CPL_VSI_VIRTUAL_H_INCLUDED
  #define CPL_VSI_VIRTUAL_H_INCLUDED
  
  #include "cpl_vsi.h"
  #include "cpl_vsi_error.h"
  #include "cpl_string.h"
  #include "cpl_multiproc.h"
  
  #include <map>
  #include <vector>
  #include <string>
  
  /************************************************************************/
  /*                           VSIVirtualHandle                           */
  /************************************************************************/
  
  class CPL_DLL VSIVirtualHandle {
    public:
      virtual int       Seek( vsi_l_offset nOffset, int nWhence ) = 0;
      virtual vsi_l_offset Tell() = 0;
      virtual size_t    Read( void *pBuffer, size_t nSize, size_t nMemb ) = 0;
      virtual int       ReadMultiRange( int nRanges, void ** ppData, const vsi_l_offset* panOffsets, const size_t* panSizes );
      virtual size_t    Write( const void *pBuffer, size_t nSize,size_t nMemb)=0;
      virtual int       Eof() = 0;
      virtual int       Flush() {return 0;}
      virtual int       Close() = 0;
      virtual int       Truncate( CPL_UNUSED vsi_l_offset nNewSize ) { return -1; }
      virtual void     *GetNativeFileDescriptor() { return NULL; }
      virtual           ~VSIVirtualHandle() { }
  };
  
  /************************************************************************/
  /*                         VSIFilesystemHandler                         */
  /************************************************************************/
  
  class CPL_DLL VSIFilesystemHandler {
  
  public:
  
      virtual ~VSIFilesystemHandler() {}
  
      VSIVirtualHandle *Open( const char *pszFilename,
                              const char *pszAccess );
  
      virtual VSIVirtualHandle *Open( const char *pszFilename,
                                      const char *pszAccess,
                                      bool bSetError ) = 0;
      virtual int Stat( const char *pszFilename, VSIStatBufL *pStatBuf, int nFlags) = 0;
      virtual int Unlink( const char *pszFilename )
                        { (void) pszFilename; errno=ENOENT; return -1; }
      virtual int Mkdir( const char *pszDirname, long nMode )
                        {(void)pszDirname; (void)nMode; errno=ENOENT; return -1;}
      virtual int Rmdir( const char *pszDirname )
                        { (void) pszDirname; errno=ENOENT; return -1; }
      virtual char **ReadDir( const char *pszDirname )
                        { (void) pszDirname; return NULL; }
      virtual char **ReadDirEx( const char *pszDirname, int /* nMaxFiles */ )
                        { return ReadDir(pszDirname); }
      virtual int Rename( const char *oldpath, const char *newpath )
                        { (void) oldpath; (void)newpath; errno=ENOENT; return -1; }
      virtual int IsCaseSensitive( const char* pszFilename )
                        { (void) pszFilename; return TRUE; }
      virtual GIntBig GetDiskFreeSpace( const char* /* pszDirname */ ) { return -1; }
  };
  
  /************************************************************************/
  /*                            VSIFileManager                            */
  /************************************************************************/
  
  class CPL_DLL VSIFileManager
  {
  private:
      VSIFilesystemHandler *poDefaultHandler;
      std::map<std::string, VSIFilesystemHandler *> oHandlers;
  
      VSIFileManager();
  
      static VSIFileManager *Get();
  
  public:
      ~VSIFileManager();
  
      static VSIFilesystemHandler *GetHandler( const char * );
      static void InstallHandler( const std::string& osPrefix,
                                  VSIFilesystemHandler * );
      /* RemoveHandler is never defined. */
      /* static void RemoveHandler( const std::string& osPrefix ); */
  };
  
  
  /************************************************************************/
  /* ==================================================================== */
  /*                       VSIArchiveFilesystemHandler                   */
  /* ==================================================================== */
  /************************************************************************/
  
  class VSIArchiveEntryFileOffset
  {
      public:
          virtual ~VSIArchiveEntryFileOffset();
  };
  
  typedef struct
  {
      char         *fileName;
      vsi_l_offset  uncompressed_size;
      VSIArchiveEntryFileOffset*      file_pos;
      int           bIsDir;
      GIntBig       nModifiedTime;
  } VSIArchiveEntry;
  
  class VSIArchiveContent
  {
  public:
      time_t       mTime;
      vsi_l_offset nFileSize;
      int nEntries;
      VSIArchiveEntry* entries;
  
      VSIArchiveContent() : mTime(0), nFileSize(0), nEntries(0), entries(NULL) {}
      ~VSIArchiveContent();
  };
  
  class VSIArchiveReader
  {
      public:
          virtual ~VSIArchiveReader();
  
          virtual int GotoFirstFile() = 0;
          virtual int GotoNextFile() = 0;
          virtual VSIArchiveEntryFileOffset* GetFileOffset() = 0;
          virtual GUIntBig GetFileSize() = 0;
          virtual CPLString GetFileName() = 0;
          virtual GIntBig GetModifiedTime() = 0;
          virtual int GotoFileOffset(VSIArchiveEntryFileOffset* pOffset) = 0;
  };
  
  class VSIArchiveFilesystemHandler : public VSIFilesystemHandler
  {
  protected:
      CPLMutex* hMutex;
      /* We use a cache that contains the list of files contained in a VSIArchive file as */
      /* unarchive.c is quite inefficient in listing them. This speeds up access to VSIArchive files */
      /* containing ~1000 files like a CADRG product */
      std::map<CPLString,VSIArchiveContent*>   oFileList;
  
      virtual const char* GetPrefix() = 0;
      virtual std::vector<CPLString> GetExtensions() = 0;
      virtual VSIArchiveReader* CreateReader(const char* pszArchiveFileName) = 0;
  
  public:
      VSIArchiveFilesystemHandler();
      virtual ~VSIArchiveFilesystemHandler();
  
      virtual int      Stat( const char *pszFilename, VSIStatBufL *pStatBuf, int nFlags );
      virtual int      Unlink( const char *pszFilename );
      virtual int      Rename( const char *oldpath, const char *newpath );
      virtual int      Mkdir( const char *pszDirname, long nMode );
      virtual int      Rmdir( const char *pszDirname );
      virtual char   **ReadDirEx( const char *pszDirname, int nMaxFiles );
  
      virtual const VSIArchiveContent* GetContentOfArchive(const char* archiveFilename, VSIArchiveReader* poReader = NULL);
      virtual char* SplitFilename(const char *pszFilename, CPLString &osFileInArchive, int bCheckMainFileExists);
      virtual VSIArchiveReader* OpenArchiveFile(const char* archiveFilename, const char* fileInArchiveName);
      virtual int FindFileInArchive(const char* archiveFilename, const char* fileInArchiveName, const VSIArchiveEntry** archiveEntry);
  };
  
  VSIVirtualHandle CPL_DLL *VSICreateBufferedReaderHandle(VSIVirtualHandle* poBaseHandle);
  VSIVirtualHandle* VSICreateBufferedReaderHandle(VSIVirtualHandle* poBaseHandle,
                                                  const GByte* pabyBeginningContent,
                                                  vsi_l_offset nCheatFileSize);
  VSIVirtualHandle CPL_DLL *VSICreateCachedFile( VSIVirtualHandle* poBaseHandle, size_t nChunkSize = 32768, size_t nCacheSize = 0 );
  VSIVirtualHandle CPL_DLL *VSICreateGZipWritable( VSIVirtualHandle* poBaseHandle, int bRegularZLibIn, int bAutoCloseBaseHandle );
  
  #endif /* ndef CPL_VSI_VIRTUAL_H_INCLUDED */
  