GDAL
cpl_vsi_virtual.h
1 /******************************************************************************
2  * $Id: cpl_vsi_virtual.h a044c83f8091becdd11e27be6e9c08d0d3478126 2021-02-24 11:38:17 +0100 Even Rouault $
3  *
4  * Project: VSI Virtual File System
5  * Purpose: Declarations for classes related to the virtual filesystem.
6  * These would only be normally required by applications implementing
7  * their own virtual file system classes which should be rare.
8  * The class interface may be fragile through versions.
9  * Author: Frank Warmerdam, warmerdam@pobox.com
10  *
11  ******************************************************************************
12  * Copyright (c) 2005, Frank Warmerdam <warmerdam@pobox.com>
13  * Copyright (c) 2010-2014, Even Rouault <even dot rouault at spatialys.com>
14  *
15  * Permission is hereby granted, free of charge, to any person obtaining a
16  * copy of this software and associated documentation files (the "Software"),
17  * to deal in the Software without restriction, including without limitation
18  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
19  * and/or sell copies of the Software, and to permit persons to whom the
20  * Software is furnished to do so, subject to the following conditions:
21  *
22  * The above copyright notice and this permission notice shall be included
23  * in all copies or substantial portions of the Software.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
26  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
28  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
31  * DEALINGS IN THE SOFTWARE.
32  ****************************************************************************/
33 
34 #ifndef CPL_VSI_VIRTUAL_H_INCLUDED
35 #define CPL_VSI_VIRTUAL_H_INCLUDED
36 
37 #include "cpl_vsi.h"
38 #include "cpl_vsi_error.h"
39 #include "cpl_string.h"
40 #include "cpl_multiproc.h"
41 
42 #include <map>
43 #include <vector>
44 #include <string>
45 
46 // To avoid aliasing to GetDiskFreeSpace to GetDiskFreeSpaceA on Windows
47 #ifdef GetDiskFreeSpace
48 #undef GetDiskFreeSpace
49 #endif
50 
51 /************************************************************************/
52 /* VSIVirtualHandle */
53 /************************************************************************/
54 
56 class CPL_DLL VSIVirtualHandle {
57  public:
58  virtual int Seek( vsi_l_offset nOffset, int nWhence ) = 0;
59  virtual vsi_l_offset Tell() = 0;
60  virtual size_t Read( void *pBuffer, size_t nSize, size_t nCount ) = 0;
61  virtual int ReadMultiRange( int nRanges, void ** ppData,
62  const vsi_l_offset* panOffsets,
63  const size_t* panSizes );
64  virtual size_t Write( const void *pBuffer, size_t nSize,size_t nCount)=0;
65  virtual int Eof() = 0;
66  virtual int Flush() {return 0;}
67  virtual int Close() = 0;
68  // Base implementation that only supports file extension.
69  virtual int Truncate( vsi_l_offset nNewSize );
70  virtual void *GetNativeFileDescriptor() { return nullptr; }
72  CPL_UNUSED vsi_l_offset nLength )
73  { return VSI_RANGE_STATUS_UNKNOWN; }
74 
75  virtual ~VSIVirtualHandle() { }
76 };
77 
78 /************************************************************************/
79 /* VSIFilesystemHandler */
80 /************************************************************************/
81 
82 #ifndef DOXYGEN_SKIP
83 class CPL_DLL VSIFilesystemHandler {
84 
85 public:
86 
87  virtual ~VSIFilesystemHandler() {}
88 
89  VSIVirtualHandle *Open( const char *pszFilename,
90  const char *pszAccess );
91 
92  virtual VSIVirtualHandle *Open( const char *pszFilename,
93  const char *pszAccess,
94  bool bSetError,
95  CSLConstList papszOptions ) = 0;
96  virtual int Stat( const char *pszFilename, VSIStatBufL *pStatBuf, int nFlags) = 0;
97  virtual int Unlink( const char *pszFilename )
98  { (void) pszFilename; errno=ENOENT; return -1; }
99  virtual int* UnlinkBatch( CSLConstList papszFiles );
100  virtual int Mkdir( const char *pszDirname, long nMode )
101  {(void)pszDirname; (void)nMode; errno=ENOENT; return -1;}
102  virtual int Rmdir( const char *pszDirname )
103  { (void) pszDirname; errno=ENOENT; return -1; }
104  virtual int RmdirRecursive( const char *pszDirname );
105  virtual char **ReadDir( const char *pszDirname )
106  { (void) pszDirname; return nullptr; }
107  virtual char **ReadDirEx( const char *pszDirname, int /* nMaxFiles */ )
108  { return ReadDir(pszDirname); }
109  virtual char **SiblingFiles( const char * /*pszFilename*/ )
110  { return nullptr; }
111  virtual int Rename( const char *oldpath, const char *newpath )
112  { (void) oldpath; (void)newpath; errno=ENOENT; return -1; }
113  virtual int IsCaseSensitive( const char* pszFilename )
114  { (void) pszFilename; return TRUE; }
115  virtual GIntBig GetDiskFreeSpace( const char* /* pszDirname */ ) { return -1; }
116  virtual int SupportsSparseFiles( const char* /* pszPath */ ) { return FALSE; }
117  virtual int HasOptimizedReadMultiRange(const char* /* pszPath */) { return FALSE; }
118  virtual const char* GetActualURL(const char* /*pszFilename*/) { return nullptr; }
119  virtual const char* GetOptions() { return nullptr; }
120  virtual char* GetSignedURL(const char* /*pszFilename*/, CSLConstList /* papszOptions */) { return nullptr; }
121  virtual bool Sync( const char* pszSource, const char* pszTarget,
122  const char* const * papszOptions,
123  GDALProgressFunc pProgressFunc,
124  void *pProgressData,
125  char*** ppapszOutputs );
126 
127  virtual VSIDIR* OpenDir( const char *pszPath, int nRecurseDepth,
128  const char* const *papszOptions);
129 
130  virtual char** GetFileMetadata( const char * pszFilename, const char* pszDomain,
131  CSLConstList papszOptions );
132 
133  virtual bool SetFileMetadata( const char * pszFilename,
134  CSLConstList papszMetadata,
135  const char* pszDomain,
136  CSLConstList papszOptions );
137 };
138 #endif /* #ifndef DOXYGEN_SKIP */
139 
140 /************************************************************************/
141 /* VSIFileManager */
142 /************************************************************************/
143 
144 #ifndef DOXYGEN_SKIP
145 class CPL_DLL VSIFileManager
146 {
147 private:
148  VSIFilesystemHandler *poDefaultHandler = nullptr;
149  std::map<std::string, VSIFilesystemHandler *> oHandlers{};
150 
151  VSIFileManager();
152 
153  static VSIFileManager *Get();
154 
155  CPL_DISALLOW_COPY_ASSIGN(VSIFileManager)
156 
157 public:
158  ~VSIFileManager();
159 
160  static VSIFilesystemHandler *GetHandler( const char * );
161  static void InstallHandler( const std::string& osPrefix,
162  VSIFilesystemHandler * );
163  /* RemoveHandler is never defined. */
164  /* static void RemoveHandler( const std::string& osPrefix ); */
165 
166  static char** GetPrefixes();
167 };
168 #endif /* #ifndef DOXYGEN_SKIP */
169 
170 /************************************************************************/
171 /* ==================================================================== */
172 /* VSIArchiveFilesystemHandler */
173 /* ==================================================================== */
174 /************************************************************************/
175 
176 #ifndef DOXYGEN_SKIP
177 
178 class VSIArchiveEntryFileOffset
179 {
180  public:
181  virtual ~VSIArchiveEntryFileOffset();
182 };
183 
184 typedef struct
185 {
186  char *fileName;
187  vsi_l_offset uncompressed_size;
188  VSIArchiveEntryFileOffset* file_pos;
189  int bIsDir;
190  GIntBig nModifiedTime;
191 } VSIArchiveEntry;
192 
193 class VSIArchiveContent
194 {
195 public:
196  time_t mTime = 0;
197  vsi_l_offset nFileSize = 0;
198  int nEntries = 0;
199  VSIArchiveEntry* entries = nullptr;
200 
201  ~VSIArchiveContent();
202 };
203 
204 class VSIArchiveReader
205 {
206  public:
207  virtual ~VSIArchiveReader();
208 
209  virtual int GotoFirstFile() = 0;
210  virtual int GotoNextFile() = 0;
211  virtual VSIArchiveEntryFileOffset* GetFileOffset() = 0;
212  virtual GUIntBig GetFileSize() = 0;
213  virtual CPLString GetFileName() = 0;
214  virtual GIntBig GetModifiedTime() = 0;
215  virtual int GotoFileOffset(VSIArchiveEntryFileOffset* pOffset) = 0;
216 };
217 
218 class VSIArchiveFilesystemHandler : public VSIFilesystemHandler
219 {
220  CPL_DISALLOW_COPY_ASSIGN(VSIArchiveFilesystemHandler)
221 
222 protected:
223  CPLMutex* hMutex = nullptr;
224  /* We use a cache that contains the list of files contained in a VSIArchive file as */
225  /* unarchive.c is quite inefficient in listing them. This speeds up access to VSIArchive files */
226  /* containing ~1000 files like a CADRG product */
227  std::map<CPLString,VSIArchiveContent*> oFileList{};
228 
229  virtual const char* GetPrefix() = 0;
230  virtual std::vector<CPLString> GetExtensions() = 0;
231  virtual VSIArchiveReader* CreateReader(const char* pszArchiveFileName) = 0;
232 
233 public:
234  VSIArchiveFilesystemHandler();
235  virtual ~VSIArchiveFilesystemHandler();
236 
237  int Stat( const char *pszFilename, VSIStatBufL *pStatBuf,
238  int nFlags ) override;
239  int Unlink( const char *pszFilename ) override;
240  int Rename( const char *oldpath, const char *newpath ) override;
241  int Mkdir( const char *pszDirname, long nMode ) override;
242  int Rmdir( const char *pszDirname ) override;
243  char **ReadDirEx( const char *pszDirname, int nMaxFiles ) override;
244 
245  virtual const VSIArchiveContent* GetContentOfArchive(const char* archiveFilename, VSIArchiveReader* poReader = nullptr);
246  virtual char* SplitFilename(const char *pszFilename, CPLString &osFileInArchive, int bCheckMainFileExists);
247  virtual VSIArchiveReader* OpenArchiveFile(const char* archiveFilename, const char* fileInArchiveName);
248  virtual int FindFileInArchive(const char* archiveFilename, const char* fileInArchiveName, const VSIArchiveEntry** archiveEntry);
249 };
250 
251 /************************************************************************/
252 /* VSIDIR */
253 /************************************************************************/
254 
255 struct CPL_DLL VSIDIR
256 {
257  VSIDIR() = default;
258  virtual ~VSIDIR();
259 
260  virtual const VSIDIREntry* NextDirEntry() = 0;
261 
262  private:
263  VSIDIR(const VSIDIR&) = delete;
264  VSIDIR& operator=(const VSIDIR&) = delete;
265 };
266 
267 #endif /* #ifndef DOXYGEN_SKIP */
268 
269 VSIVirtualHandle CPL_DLL *VSICreateBufferedReaderHandle(VSIVirtualHandle* poBaseHandle);
270 VSIVirtualHandle* VSICreateBufferedReaderHandle(VSIVirtualHandle* poBaseHandle,
271  const GByte* pabyBeginningContent,
272  vsi_l_offset nCheatFileSize);
273 VSIVirtualHandle CPL_DLL *VSICreateCachedFile( VSIVirtualHandle* poBaseHandle, size_t nChunkSize = 32768, size_t nCacheSize = 0 );
274 
275 const int CPL_DEFLATE_TYPE_GZIP = 0;
276 const int CPL_DEFLATE_TYPE_ZLIB = 1;
277 const int CPL_DEFLATE_TYPE_RAW_DEFLATE = 2;
278 VSIVirtualHandle CPL_DLL *VSICreateGZipWritable( VSIVirtualHandle* poBaseHandle, int nDeflateType, int bAutoCloseBaseHandle );
279 
280 VSIVirtualHandle *VSICreateUploadOnCloseFile( VSIVirtualHandle* poBaseHandle );
281 
282 #endif /* ndef CPL_VSI_VIRTUAL_H_INCLUDED */
Convenient string class based on std::string.
Definition: cpl_string.h:333
Virtual file handle.
Definition: cpl_vsi_virtual.h:56
virtual int Flush()
Flush pending writes to disk.
Definition: cpl_vsi_virtual.h:66
virtual int Close()=0
Close file.
virtual VSIRangeStatus GetRangeStatus(vsi_l_offset nOffset, vsi_l_offset nLength)
Return if a given file range contains data or holes filled with zeroes.
Definition: cpl_vsi_virtual.h:71
virtual vsi_l_offset Tell()=0
Tell current file offset.
virtual int Seek(vsi_l_offset nOffset, int nWhence)=0
Seek to requested offset.
virtual size_t Read(void *pBuffer, size_t nSize, size_t nCount)=0
Read bytes from file.
virtual void * GetNativeFileDescriptor()
Returns the "native" file descriptor for the virtual handle.
Definition: cpl_vsi_virtual.h:70
virtual int ReadMultiRange(int nRanges, void **ppData, const vsi_l_offset *panOffsets, const size_t *panSizes)
Read several ranges of bytes from file.
virtual size_t Write(const void *pBuffer, size_t nSize, size_t nCount)=0
Write bytes to file.
virtual int Eof()=0
Test for end of file.
virtual int Truncate(vsi_l_offset nNewSize)
Truncate/expand the file to the specified size.
unsigned long long GUIntBig
Large unsigned integer type (generally 64-bit unsigned integer type).
Definition: cpl_port.h:251
#define CPL_UNUSED
Qualifier for an argument that is unused.
Definition: cpl_port.h:955
#define CPL_DISALLOW_COPY_ASSIGN(ClassName)
Helper to remove the copy and assignment constructors so that the compiler will not generate the defa...
Definition: cpl_port.h:1007
char ** CSLConstList
Type of a constant null-terminated list of nul terminated strings.
Definition: cpl_port.h:1216
unsigned char GByte
Unsigned byte type.
Definition: cpl_port.h:215
long long GIntBig
Large signed integer type (generally 64-bit integer type).
Definition: cpl_port.h:248
Various convenience functions for working with strings and string lists.
Standard C Covers.
VSIRangeStatus
Range status.
Definition: cpl_vsi.h:177
@ VSI_RANGE_STATUS_UNKNOWN
Unknown.
Definition: cpl_vsi.h:178
struct VSIDIR VSIDIR
Opaque type for a directory iterator.
Definition: cpl_vsi.h:319
struct VSI_STAT64_T VSIStatBufL
Type for VSIStatL()
Definition: cpl_vsi.h:195
GUIntBig vsi_l_offset
Type for a file offset.
Definition: cpl_vsi.h:140
Directory entry.
Definition: cpl_vsi.h:331