GDAL

cpl_vsi_virtual.h
1 /******************************************************************************
2 * $Id$
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; }
71 virtual VSIRangeStatus GetRangeStatus( CPL_UNUSED vsi_l_offset nOffset,
72 CPL_UNUSED vsi_l_offset nLength )
73 { return VSI_RANGE_STATUS_UNKNOWN; }
74 virtual bool HasPRead() const;
75 virtual size_t PRead( void* pBuffer, size_t nSize, vsi_l_offset nOffset ) const;
76
77 // NOTE: when adding new methods, besides the "actual" implementations,
78 // also consider the VSICachedFile one.
79
80 virtual ~VSIVirtualHandle() { }
81 };
82
83 /************************************************************************/
84 /* VSIFilesystemHandler */
85 /************************************************************************/
86
87 #ifndef DOXYGEN_SKIP
88 class CPL_DLL VSIFilesystemHandler {
89
90 public:
91
92 virtual ~VSIFilesystemHandler() {}
93
94 VSIVirtualHandle *Open( const char *pszFilename,
95 const char *pszAccess );
96
97 virtual VSIVirtualHandle *Open( const char *pszFilename,
98 const char *pszAccess,
99 bool bSetError,
100 CSLConstList papszOptions ) = 0;
101 virtual int Stat( const char *pszFilename, VSIStatBufL *pStatBuf, int nFlags) = 0;
102 virtual int Unlink( const char *pszFilename )
103 { (void) pszFilename; errno=ENOENT; return -1; }
104 virtual int* UnlinkBatch( CSLConstList papszFiles );
105 virtual int Mkdir( const char *pszDirname, long nMode )
106 {(void)pszDirname; (void)nMode; errno=ENOENT; return -1;}
107 virtual int Rmdir( const char *pszDirname )
108 { (void) pszDirname; errno=ENOENT; return -1; }
109 virtual int RmdirRecursive( const char *pszDirname );
110 virtual char **ReadDir( const char *pszDirname )
111 { (void) pszDirname; return nullptr; }
112 virtual char **ReadDirEx( const char *pszDirname, int /* nMaxFiles */ )
113 { return ReadDir(pszDirname); }
114 virtual char **SiblingFiles( const char * /*pszFilename*/ )
115 { return nullptr; }
116 virtual int Rename( const char *oldpath, const char *newpath )
117 { (void) oldpath; (void)newpath; errno=ENOENT; return -1; }
118 virtual int IsCaseSensitive( const char* pszFilename )
119 { (void) pszFilename; return TRUE; }
120 virtual GIntBig GetDiskFreeSpace( const char* /* pszDirname */ ) { return -1; }
121 virtual int SupportsSparseFiles( const char* /* pszPath */ ) { return FALSE; }
122 virtual int HasOptimizedReadMultiRange(const char* /* pszPath */) { return FALSE; }
123 virtual const char* GetActualURL(const char* /*pszFilename*/) { return nullptr; }
124 virtual const char* GetOptions() { return nullptr; }
125 virtual char* GetSignedURL(const char* /*pszFilename*/, CSLConstList /* papszOptions */) { return nullptr; }
126 virtual bool Sync( const char* pszSource, const char* pszTarget,
127 const char* const * papszOptions,
128 GDALProgressFunc pProgressFunc,
129 void *pProgressData,
130 char*** ppapszOutputs );
131
132 virtual VSIDIR* OpenDir( const char *pszPath, int nRecurseDepth,
133 const char* const *papszOptions);
134
135 virtual char** GetFileMetadata( const char * pszFilename, const char* pszDomain,
136 CSLConstList papszOptions );
137
138 virtual bool SetFileMetadata( const char * pszFilename,
139 CSLConstList papszMetadata,
140 const char* pszDomain,
141 CSLConstList papszOptions );
142
143 virtual bool AbortPendingUploads(const char* /*pszFilename*/) { return true;}
144
145 virtual std::string GetStreamingFilename(const std::string& osFilename) const { return osFilename; }
146
147 virtual bool IsLocal( const char* /* pszPath */ ) { return true; }
148 virtual bool SupportsSequentialWrite( const char* /* pszPath */, bool /* bAllowLocalTempFile */ ) { return true; }
149 virtual bool SupportsRandomWrite( const char* /* pszPath */, bool /* bAllowLocalTempFile */ ) { return true; }
150 virtual bool SupportsRead( const char* /* pszPath */ ) { return true; }
151 };
152 #endif /* #ifndef DOXYGEN_SKIP */
153
154 /************************************************************************/
155 /* VSIFileManager */
156 /************************************************************************/
157
158 #ifndef DOXYGEN_SKIP
159 class CPL_DLL VSIFileManager
160 {
161 private:
162 VSIFilesystemHandler *poDefaultHandler = nullptr;
163 std::map<std::string, VSIFilesystemHandler *> oHandlers{};
164
165 VSIFileManager();
166
167 static VSIFileManager *Get();
168
169 CPL_DISALLOW_COPY_ASSIGN(VSIFileManager)
170
171 public:
172 ~VSIFileManager();
173
174 static VSIFilesystemHandler *GetHandler( const char * );
175 static void InstallHandler( const std::string& osPrefix,
176 VSIFilesystemHandler * );
177 /* RemoveHandler is never defined. */
178 /* static void RemoveHandler( const std::string& osPrefix ); */
179
180 static char** GetPrefixes();
181 };
182 #endif /* #ifndef DOXYGEN_SKIP */
183
184 /************************************************************************/
185 /* ==================================================================== */
186 /* VSIArchiveFilesystemHandler */
187 /* ==================================================================== */
188 /************************************************************************/
189
190 #ifndef DOXYGEN_SKIP
191
192 class VSIArchiveEntryFileOffset
193 {
194 public:
195 virtual ~VSIArchiveEntryFileOffset();
196 };
197
198 typedef struct
199 {
200 char *fileName;
201 vsi_l_offset uncompressed_size;
202 VSIArchiveEntryFileOffset* file_pos;
203 int bIsDir;
204 GIntBig nModifiedTime;
205 } VSIArchiveEntry;
206
207 class VSIArchiveContent
208 {
209 public:
210 time_t mTime = 0;
211 vsi_l_offset nFileSize = 0;
212 int nEntries = 0;
213 VSIArchiveEntry* entries = nullptr;
214
215 ~VSIArchiveContent();
216 };
217
218 class VSIArchiveReader
219 {
220 public:
221 virtual ~VSIArchiveReader();
222
223 virtual int GotoFirstFile() = 0;
224 virtual int GotoNextFile() = 0;
225 virtual VSIArchiveEntryFileOffset* GetFileOffset() = 0;
226 virtual GUIntBig GetFileSize() = 0;
227 virtual CPLString GetFileName() = 0;
228 virtual GIntBig GetModifiedTime() = 0;
229 virtual int GotoFileOffset(VSIArchiveEntryFileOffset* pOffset) = 0;
230 };
231
232 class VSIArchiveFilesystemHandler : public VSIFilesystemHandler
233 {
234 CPL_DISALLOW_COPY_ASSIGN(VSIArchiveFilesystemHandler)
235
236 protected:
237 CPLMutex* hMutex = nullptr;
238 /* We use a cache that contains the list of files contained in a VSIArchive file as */
239 /* unarchive.c is quite inefficient in listing them. This speeds up access to VSIArchive files */
240 /* containing ~1000 files like a CADRG product */
241 std::map<CPLString,VSIArchiveContent*> oFileList{};
242
243 virtual const char* GetPrefix() = 0;
244 virtual std::vector<CPLString> GetExtensions() = 0;
245 virtual VSIArchiveReader* CreateReader(const char* pszArchiveFileName) = 0;
246
247 public:
248 VSIArchiveFilesystemHandler();
249 virtual ~VSIArchiveFilesystemHandler();
250
251 int Stat( const char *pszFilename, VSIStatBufL *pStatBuf,
252 int nFlags ) override;
253 int Unlink( const char *pszFilename ) override;
254 int Rename( const char *oldpath, const char *newpath ) override;
255 int Mkdir( const char *pszDirname, long nMode ) override;
256 int Rmdir( const char *pszDirname ) override;
257 char **ReadDirEx( const char *pszDirname, int nMaxFiles ) override;
258
259 virtual const VSIArchiveContent* GetContentOfArchive(const char* archiveFilename, VSIArchiveReader* poReader = nullptr);
260 virtual char* SplitFilename(const char *pszFilename, CPLString &osFileInArchive, int bCheckMainFileExists);
261 virtual VSIArchiveReader* OpenArchiveFile(const char* archiveFilename, const char* fileInArchiveName);
262 virtual int FindFileInArchive(const char* archiveFilename, const char* fileInArchiveName, const VSIArchiveEntry** archiveEntry);
263
264 virtual bool IsLocal( const char* pszPath ) override;
265 virtual bool SupportsSequentialWrite( const char* /* pszPath */, bool /* bAllowLocalTempFile */ ) override { return false; }
266 virtual bool SupportsRandomWrite( const char* /* pszPath */, bool /* bAllowLocalTempFile */ ) override { return false; }
267 };
268
269 /************************************************************************/
270 /* VSIDIR */
271 /************************************************************************/
272
273 struct CPL_DLL VSIDIR
274 {
275 VSIDIR() = default;
276 virtual ~VSIDIR();
277
278 virtual const VSIDIREntry* NextDirEntry() = 0;
279
280 private:
281 VSIDIR(const VSIDIR&) = delete;
282 VSIDIR& operator=(const VSIDIR&) = delete;
283 };
284
285 #endif /* #ifndef DOXYGEN_SKIP */
286
287 VSIVirtualHandle CPL_DLL *VSICreateBufferedReaderHandle(VSIVirtualHandle* poBaseHandle);
288 VSIVirtualHandle* VSICreateBufferedReaderHandle(VSIVirtualHandle* poBaseHandle,
289 const GByte* pabyBeginningContent,
290 vsi_l_offset nCheatFileSize);
291 VSIVirtualHandle CPL_DLL *VSICreateCachedFile( VSIVirtualHandle* poBaseHandle, size_t nChunkSize = 32768, size_t nCacheSize = 0 );
292
293 const int CPL_DEFLATE_TYPE_GZIP = 0;
294 const int CPL_DEFLATE_TYPE_ZLIB = 1;
295 const int CPL_DEFLATE_TYPE_RAW_DEFLATE = 2;
296 VSIVirtualHandle CPL_DLL *VSICreateGZipWritable( VSIVirtualHandle* poBaseHandle, int nDeflateType, int bAutoCloseBaseHandle );
297
298 VSIVirtualHandle *VSICreateUploadOnCloseFile( VSIVirtualHandle* poBaseHandle );
299
300 #endif /* ndef CPL_VSI_VIRTUAL_H_INCLUDED */
GByte
unsigned char GByte
Unsigned byte type.
Definition: cpl_port.h:203
cpl_vsi.h
VSIRangeStatus
VSIRangeStatus
Range status.
Definition: cpl_vsi.h:178
CPLString
Convenient string class based on std::string.
Definition: cpl_string.h:320
VSI_RANGE_STATUS_UNKNOWN
@ VSI_RANGE_STATUS_UNKNOWN
Unknown.
Definition: cpl_vsi.h:180
CSLConstList
char ** CSLConstList
Type of a constant null-terminated list of nul terminated strings.
Definition: cpl_port.h:1056
GUIntBig
unsigned long long GUIntBig
Large unsigned integer type (generally 64-bit unsigned integer type).
Definition: cpl_port.h:233
VSIDIREntry
Directory entry.
Definition: cpl_vsi.h:366
cpl_string.h
vsi_l_offset
GUIntBig vsi_l_offset
Type for a file offset.
Definition: cpl_vsi.h:142
GIntBig
long long GIntBig
Large signed integer type (generally 64-bit integer type).
Definition: cpl_port.h:230
CPL_UNUSED
#define CPL_UNUSED
Qualifier for an argument that is unused.
Definition: cpl_port.h:878
VSIDIR
struct VSIDIR VSIDIR
Opaque type for a directory iterator.
Definition: cpl_vsi.h:355
VSIStatBufL
#define VSIStatBufL
Type for VSIStatL()
Definition: cpl_vsi.h:200
VSIVirtualHandle
Virtual file handle.
Definition: cpl_vsi_virtual.h:56
CPL_DISALLOW_COPY_ASSIGN
#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:930