cpl_vsi_virtual.h

00001 /******************************************************************************
00002  * $Id: cpl_vsi_virtual.h 27044 2014-03-16 23:41:27Z rouault $
00003  *
00004  * Project:  VSI Virtual File System
00005  * Purpose:  Declarations for classes related to the virtual filesystem.
00006  *           These would only be normally required by applications implmenting
00007  *           their own virtual file system classes which should be rare.  
00008  *           The class interface may be fragile through versions.
00009  * Author:   Frank Warmerdam, warmerdam@pobox.com
00010  *
00011  ******************************************************************************
00012  * Copyright (c) 2005, Frank Warmerdam <warmerdam@pobox.com>
00013  * Copyright (c) 2010-2014, Even Rouault <even dot rouault at mines-paris dot org>
00014  *
00015  * Permission is hereby granted, free of charge, to any person obtaining a
00016  * copy of this software and associated documentation files (the "Software"),
00017  * to deal in the Software without restriction, including without limitation
00018  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
00019  * and/or sell copies of the Software, and to permit persons to whom the
00020  * Software is furnished to do so, subject to the following conditions:
00021  *
00022  * The above copyright notice and this permission notice shall be included
00023  * in all copies or substantial portions of the Software.
00024  *
00025  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
00026  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00027  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
00028  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00029  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
00030  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
00031  * DEALINGS IN THE SOFTWARE.
00032  ****************************************************************************/
00033 
00034 #ifndef CPL_VSI_VIRTUAL_H_INCLUDED
00035 #define CPL_VSI_VIRTUAL_H_INCLUDED
00036 
00037 #include "cpl_vsi.h"
00038 #include "cpl_string.h"
00039 
00040 #if defined(WIN32CE)
00041 #  include "cpl_wince.h"
00042 #  include <wce_errno.h>
00043 #  pragma warning(disable:4786) /* Remove annoying warnings in eVC++ and VC++ 6.0 */
00044 #endif
00045 
00046 #include <map>
00047 #include <vector>
00048 #include <string>
00049 
00050 /************************************************************************/
00051 /*                           VSIVirtualHandle                           */
00052 /************************************************************************/
00053 
00054 class CPL_DLL VSIVirtualHandle { 
00055   public:
00056     virtual int       Seek( vsi_l_offset nOffset, int nWhence ) = 0;
00057     virtual vsi_l_offset Tell() = 0;
00058     virtual size_t    Read( void *pBuffer, size_t nSize, size_t nMemb ) = 0;
00059     virtual int       ReadMultiRange( int nRanges, void ** ppData, const vsi_l_offset* panOffsets, const size_t* panSizes );
00060     virtual size_t    Write( const void *pBuffer, size_t nSize,size_t nMemb)=0;
00061     virtual int       Eof() = 0;
00062     virtual int       Flush() {return 0;}
00063     virtual int       Close() = 0;
00064     virtual int       Truncate( vsi_l_offset nNewSize ) { return -1; }
00065     virtual void     *GetNativeFileDescriptor() { return NULL; }
00066     virtual           ~VSIVirtualHandle() { }
00067 };
00068 
00069 /************************************************************************/
00070 /*                         VSIFilesystemHandler                         */
00071 /************************************************************************/
00072 
00073 class CPL_DLL VSIFilesystemHandler {
00074 
00075 public:
00076 
00077     virtual ~VSIFilesystemHandler() {}
00078 
00079     virtual VSIVirtualHandle *Open( const char *pszFilename, 
00080                                     const char *pszAccess) = 0;
00081     virtual int Stat( const char *pszFilename, VSIStatBufL *pStatBuf, int nFlags) = 0;
00082     virtual int Unlink( const char *pszFilename )
00083                       { (void) pszFilename; errno=ENOENT; return -1; }
00084     virtual int Mkdir( const char *pszDirname, long nMode ) 
00085                       {(void)pszDirname; (void)nMode; errno=ENOENT; return -1;}
00086     virtual int Rmdir( const char *pszDirname ) 
00087                       { (void) pszDirname; errno=ENOENT; return -1; }
00088     virtual char **ReadDir( const char *pszDirname ) 
00089                       { (void) pszDirname; return NULL; }
00090     virtual int Rename( const char *oldpath, const char *newpath )
00091                       { (void) oldpath; (void)newpath; errno=ENOENT; return -1; }
00092     virtual int IsCaseSensitive( const char* pszFilename )
00093                       { (void) pszFilename; return TRUE; }
00094 };
00095 
00096 /************************************************************************/
00097 /*                            VSIFileManager                            */
00098 /************************************************************************/
00099 
00100 class CPL_DLL VSIFileManager 
00101 {
00102 private:
00103     VSIFilesystemHandler *poDefaultHandler;
00104     std::map<std::string, VSIFilesystemHandler *> oHandlers;
00105 
00106     VSIFileManager();
00107 
00108     static VSIFileManager *Get();
00109 
00110 public:
00111     ~VSIFileManager();
00112 
00113     static VSIFilesystemHandler *GetHandler( const char * );
00114     static void InstallHandler( const std::string& osPrefix, 
00115                                 VSIFilesystemHandler * );
00116     static void RemoveHandler( const std::string& osPrefix );
00117 };
00118 
00119 
00120 /************************************************************************/
00121 /* ==================================================================== */
00122 /*                       VSIArchiveFilesystemHandler                   */
00123 /* ==================================================================== */
00124 /************************************************************************/
00125 
00126 class VSIArchiveEntryFileOffset
00127 {
00128     public:
00129         virtual ~VSIArchiveEntryFileOffset();
00130 };
00131 
00132 typedef struct
00133 {
00134     char         *fileName;
00135     vsi_l_offset  uncompressed_size;
00136     VSIArchiveEntryFileOffset*      file_pos;
00137     int           bIsDir;
00138     GIntBig       nModifiedTime;
00139 } VSIArchiveEntry;
00140 
00141 typedef struct
00142 {
00143     int nEntries;
00144     VSIArchiveEntry* entries;
00145 } VSIArchiveContent;
00146 
00147 class VSIArchiveReader
00148 {
00149     public:
00150         virtual ~VSIArchiveReader();
00151 
00152         virtual int GotoFirstFile() = 0;
00153         virtual int GotoNextFile() = 0;
00154         virtual VSIArchiveEntryFileOffset* GetFileOffset() = 0;
00155         virtual GUIntBig GetFileSize() = 0;
00156         virtual CPLString GetFileName() = 0;
00157         virtual GIntBig GetModifiedTime() = 0;
00158         virtual int GotoFileOffset(VSIArchiveEntryFileOffset* pOffset) = 0;
00159 };
00160 
00161 class VSIArchiveFilesystemHandler : public VSIFilesystemHandler 
00162 {
00163 protected:
00164     void* hMutex;
00165     /* We use a cache that contains the list of files containes in a VSIArchive file as */
00166     /* unarchive.c is quite inefficient in listing them. This speeds up access to VSIArchive files */
00167     /* containing ~1000 files like a CADRG product */
00168     std::map<CPLString,VSIArchiveContent*>   oFileList;
00169 
00170     virtual const char* GetPrefix() = 0;
00171     virtual std::vector<CPLString> GetExtensions() = 0;
00172     virtual VSIArchiveReader* CreateReader(const char* pszArchiveFileName) = 0;
00173 
00174 public:
00175     VSIArchiveFilesystemHandler();
00176     virtual ~VSIArchiveFilesystemHandler();
00177 
00178     virtual int      Stat( const char *pszFilename, VSIStatBufL *pStatBuf, int nFlags );
00179     virtual int      Unlink( const char *pszFilename );
00180     virtual int      Rename( const char *oldpath, const char *newpath );
00181     virtual int      Mkdir( const char *pszDirname, long nMode );
00182     virtual int      Rmdir( const char *pszDirname );
00183     virtual char   **ReadDir( const char *pszDirname );
00184 
00185     virtual const VSIArchiveContent* GetContentOfArchive(const char* archiveFilename, VSIArchiveReader* poReader = NULL);
00186     virtual char* SplitFilename(const char *pszFilename, CPLString &osFileInArchive, int bCheckMainFileExists);
00187     virtual VSIArchiveReader* OpenArchiveFile(const char* archiveFilename, const char* fileInArchiveName);
00188     virtual int FindFileInArchive(const char* archiveFilename, const char* fileInArchiveName, const VSIArchiveEntry** archiveEntry);
00189 };
00190 
00191 VSIVirtualHandle* VSICreateBufferedReaderHandle(VSIVirtualHandle* poBaseHandle);
00192 VSIVirtualHandle* VSICreateCachedFile( VSIVirtualHandle* poBaseHandle, size_t nChunkSize = 32768, size_t nCacheSize = 0 );
00193 VSIVirtualHandle* VSICreateGZipWritable( VSIVirtualHandle* poBaseHandle, int bRegularZLibIn, int bAutoCloseBaseHandle );
00194 
00195 #endif /* ndef CPL_VSI_VIRTUAL_H_INCLUDED */

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