src/test_devsym.c

   1 /*
   2 ** 2008 Jan 22
   3 **
   4 ** The author disclaims copyright to this source code.  In place of
   5 ** a legal notice, here is a blessing:
   6 **
   7 **    May you do good and not evil.
   8 **    May you find forgiveness for yourself and forgive others.
   9 **    May you share freely, never taking more than you give.
  10 **
  11 ******************************************************************************
  12 **
  13 ** This file contains code that modified the OS layer in order to simulate
  14 ** different device types (by overriding the return values of the
  15 ** xDeviceCharacteristics() and xSectorSize() methods).
  16 */
  17 #if SQLITE_TEST          /* This file is used for testing only */
  18
  19 #include "sqlite3.h"
  20 #include "sqliteInt.h"
  21
  22 /*
  23 ** Maximum pathname length supported by the devsym backend.
  24 */
  25 #define DEVSYM_MAX_PATHNAME 512
  26
  27 /*
  28 ** Name used to identify this VFS.
  29 */
  30 #define DEVSYM_VFS_NAME "devsym"
  31 #define WRITECRASH_NAME "writecrash"
  32
  33 typedef struct devsym_file devsym_file;
  34 struct devsym_file {
  35   sqlite3_file base;
  36   sqlite3_file *pReal;
  37 };
  38
  39 /*
  40 ** Method declarations for devsym_file.
  41 */
  42 static int devsymClose(sqlite3_file*);
  43 static int devsymRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
  44 static int devsymWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
  45 static int devsymTruncate(sqlite3_file*, sqlite3_int64 size);
  46 static int devsymSync(sqlite3_file*, int flags);
  47 static int devsymFileSize(sqlite3_file*, sqlite3_int64 *pSize);
  48 static int devsymLock(sqlite3_file*, int);
  49 static int devsymUnlock(sqlite3_file*, int);
  50 static int devsymCheckReservedLock(sqlite3_file*, int *);
  51 static int devsymFileControl(sqlite3_file*, int op, void *pArg);
  52 static int devsymSectorSize(sqlite3_file*);
  53 static int devsymDeviceCharacteristics(sqlite3_file*);
  54 static int devsymShmLock(sqlite3_file*,int,int,int);
  55 static int devsymShmMap(sqlite3_file*,int,int,int, void volatile **);
  56 static void devsymShmBarrier(sqlite3_file*);
  57 static int devsymShmUnmap(sqlite3_file*,int);
  58
  59 /*
  60 ** Method declarations for devsym_vfs.
  61 */
  62 static int devsymOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
  63 static int devsymDelete(sqlite3_vfs*, const char *zName, int syncDir);
  64 static int devsymAccess(sqlite3_vfs*, const char *zName, int flags, int *);
  65 static int devsymFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
  66 #ifndef SQLITE_OMIT_LOAD_EXTENSION
  67 static void *devsymDlOpen(sqlite3_vfs*, const char *zFilename);
  68 static void devsymDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
  69 static void (*devsymDlSym(sqlite3_vfs*,void*, const char *zSymbol))(void);
  70 static void devsymDlClose(sqlite3_vfs*, void*);
  71 #endif /* SQLITE_OMIT_LOAD_EXTENSION */
  72 static int devsymRandomness(sqlite3_vfs*, int nByte, char *zOut);
  73 static int devsymSleep(sqlite3_vfs*, int microseconds);
  74 static int devsymCurrentTime(sqlite3_vfs*, double*);
  75
  76 struct DevsymGlobal {
  77   sqlite3_vfs *pVfs;
  78   int iDeviceChar;
  79   int iSectorSize;
  80   int nWriteCrash;
  81 };
  82 struct DevsymGlobal g = {0, 0, 512, 0};
  83
  84 /*
  85 ** Close an devsym-file.
  86 */
  87 static int devsymClose(sqlite3_file *pFile){
  88   devsym_file *p = (devsym_file *)pFile;
  89   sqlite3OsClose(p->pReal);
  90   return SQLITE_OK;
  91 }
  92
  93 /*
  94 ** Read data from an devsym-file.
  95 */
  96 static int devsymRead(
  97   sqlite3_file *pFile,
  98   void *zBuf,
  99   int iAmt,
 100   sqlite_int64 iOfst
 101 ){
 102   devsym_file *p = (devsym_file *)pFile;
 103   return sqlite3OsRead(p->pReal, zBuf, iAmt, iOfst);
 104 }
 105
 106 /*
 107 ** Write data to an devsym-file.
 108 */
 109 static int devsymWrite(
 110   sqlite3_file *pFile,
 111   const void *zBuf,
 112   int iAmt,
 113   sqlite_int64 iOfst
 114 ){
 115   devsym_file *p = (devsym_file *)pFile;
 116   return sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
 117 }
 118
 119 /*
 120 ** Truncate an devsym-file.
 121 */
 122 static int devsymTruncate(sqlite3_file *pFile, sqlite_int64 size){
 123   devsym_file *p = (devsym_file *)pFile;
 124   return sqlite3OsTruncate(p->pReal, size);
 125 }
 126
 127 /*
 128 ** Sync an devsym-file.
 129 */
 130 static int devsymSync(sqlite3_file *pFile, int flags){
 131   devsym_file *p = (devsym_file *)pFile;
 132   return sqlite3OsSync(p->pReal, flags);
 133 }
 134
 135 /*
 136 ** Return the current file-size of an devsym-file.
 137 */
 138 static int devsymFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
 139   devsym_file *p = (devsym_file *)pFile;
 140   return sqlite3OsFileSize(p->pReal, pSize);
 141 }
 142
 143 /*
 144 ** Lock an devsym-file.
 145 */
 146 static int devsymLock(sqlite3_file *pFile, int eLock){
 147   devsym_file *p = (devsym_file *)pFile;
 148   return sqlite3OsLock(p->pReal, eLock);
 149 }
 150
 151 /*
 152 ** Unlock an devsym-file.
 153 */
 154 static int devsymUnlock(sqlite3_file *pFile, int eLock){
 155   devsym_file *p = (devsym_file *)pFile;
 156   return sqlite3OsUnlock(p->pReal, eLock);
 157 }
 158
 159 /*
 160 ** Check if another file-handle holds a RESERVED lock on an devsym-file.
 161 */
 162 static int devsymCheckReservedLock(sqlite3_file *pFile, int *pResOut){
 163   devsym_file *p = (devsym_file *)pFile;
 164   return sqlite3OsCheckReservedLock(p->pReal, pResOut);
 165 }
 166
 167 /*
 168 ** File control method. For custom operations on an devsym-file.
 169 */
 170 static int devsymFileControl(sqlite3_file *pFile, int op, void *pArg){
 171   devsym_file *p = (devsym_file *)pFile;
 172   return sqlite3OsFileControl(p->pReal, op, pArg);
 173 }
 174
 175 /*
 176 ** Return the sector-size in bytes for an devsym-file.
 177 */
 178 static int devsymSectorSize(sqlite3_file *pFile){
 179   return g.iSectorSize;
 180 }
 181
 182 /*
 183 ** Return the device characteristic flags supported by an devsym-file.
 184 */
 185 static int devsymDeviceCharacteristics(sqlite3_file *pFile){
 186   return g.iDeviceChar;
 187 }
 188
 189 /*
 190 ** Shared-memory methods are all pass-thrus.
 191 */
 192 static int devsymShmLock(sqlite3_file *pFile, int ofst, int n, int flags){
 193   devsym_file *p = (devsym_file *)pFile;
 194   return p->pReal->pMethods->xShmLock(p->pReal, ofst, n, flags);
 195 }
 196 static int devsymShmMap(
 197   sqlite3_file *pFile,
 198   int iRegion,
 199   int szRegion,
 200   int isWrite,
 201   void volatile **pp
 202 ){
 203   devsym_file *p = (devsym_file *)pFile;
 204   return p->pReal->pMethods->xShmMap(p->pReal, iRegion, szRegion, isWrite, pp);
 205 }
 206 static void devsymShmBarrier(sqlite3_file *pFile){
 207   devsym_file *p = (devsym_file *)pFile;
 208   p->pReal->pMethods->xShmBarrier(p->pReal);
 209 }
 210 static int devsymShmUnmap(sqlite3_file *pFile, int delFlag){
 211   devsym_file *p = (devsym_file *)pFile;
 212   return p->pReal->pMethods->xShmUnmap(p->pReal, delFlag);
 213 }
 214
 215
 216
 217 /*
 218 ** Open an devsym file handle.
 219 */
 220 static int devsymOpen(
 221   sqlite3_vfs *pVfs,
 222   const char *zName,
 223   sqlite3_file *pFile,
 224   int flags,
 225   int *pOutFlags
 226 ){
 227 static sqlite3_io_methods devsym_io_methods = {
 228   2,                                /* iVersion */
 229   devsymClose,                      /* xClose */
 230   devsymRead,                       /* xRead */
 231   devsymWrite,                      /* xWrite */
 232   devsymTruncate,                   /* xTruncate */
 233   devsymSync,                       /* xSync */
 234   devsymFileSize,                   /* xFileSize */
 235   devsymLock,                       /* xLock */
 236   devsymUnlock,                     /* xUnlock */
 237   devsymCheckReservedLock,          /* xCheckReservedLock */
 238   devsymFileControl,                /* xFileControl */
 239   devsymSectorSize,                 /* xSectorSize */
 240   devsymDeviceCharacteristics,      /* xDeviceCharacteristics */
 241   devsymShmMap,                     /* xShmMap */
 242   devsymShmLock,                    /* xShmLock */
 243   devsymShmBarrier,                 /* xShmBarrier */
 244   devsymShmUnmap                    /* xShmUnmap */
 245 };
 246
 247   int rc;
 248   devsym_file *p = (devsym_file *)pFile;
 249   p->pReal = (sqlite3_file *)&p[1];
 250   rc = sqlite3OsOpen(g.pVfs, zName, p->pReal, flags, pOutFlags);
 251   if( p->pReal->pMethods ){
 252     pFile->pMethods = &devsym_io_methods;
 253   }
 254   return rc;
 255 }
 256
 257 /*
 258 ** Delete the file located at zPath. If the dirSync argument is true,
 259 ** ensure the file-system modifications are synced to disk before
 260 ** returning.
 261 */
 262 static int devsymDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
 263   return sqlite3OsDelete(g.pVfs, zPath, dirSync);
 264 }
 265
 266 /*
 267 ** Test for access permissions. Return true if the requested permission
 268 ** is available, or false otherwise.
 269 */
 270 static int devsymAccess(
 271   sqlite3_vfs *pVfs,
 272   const char *zPath,
 273   int flags,
 274   int *pResOut
 275 ){
 276   return sqlite3OsAccess(g.pVfs, zPath, flags, pResOut);
 277 }
 278
 279 /*
 280 ** Populate buffer zOut with the full canonical pathname corresponding
 281 ** to the pathname in zPath. zOut is guaranteed to point to a buffer
 282 ** of at least (DEVSYM_MAX_PATHNAME+1) bytes.
 283 */
 284 static int devsymFullPathname(
 285   sqlite3_vfs *pVfs,
 286   const char *zPath,
 287   int nOut,
 288   char *zOut
 289 ){
 290   return sqlite3OsFullPathname(g.pVfs, zPath, nOut, zOut);
 291 }
 292
 293 #ifndef SQLITE_OMIT_LOAD_EXTENSION
 294 /*
 295 ** Open the dynamic library located at zPath and return a handle.
 296 */
 297 static void *devsymDlOpen(sqlite3_vfs *pVfs, const char *zPath){
 298   return sqlite3OsDlOpen(g.pVfs, zPath);
 299 }
 300
 301 /*
 302 ** Populate the buffer zErrMsg (size nByte bytes) with a human readable
 303 ** utf-8 string describing the most recent error encountered associated
 304 ** with dynamic libraries.
 305 */
 306 static void devsymDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
 307   sqlite3OsDlError(g.pVfs, nByte, zErrMsg);
 308 }
 309
 310 /*
 311 ** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
 312 */
 313 static void (*devsymDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){
 314   return sqlite3OsDlSym(g.pVfs, p, zSym);
 315 }
 316
 317 /*
 318 ** Close the dynamic library handle pHandle.
 319 */
 320 static void devsymDlClose(sqlite3_vfs *pVfs, void *pHandle){
 321   sqlite3OsDlClose(g.pVfs, pHandle);
 322 }
 323 #endif /* SQLITE_OMIT_LOAD_EXTENSION */
 324
 325 /*
 326 ** Populate the buffer pointed to by zBufOut with nByte bytes of
 327 ** random data.
 328 */
 329 static int devsymRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
 330   return sqlite3OsRandomness(g.pVfs, nByte, zBufOut);
 331 }
 332
 333 /*
 334 ** Sleep for nMicro microseconds. Return the number of microseconds
 335 ** actually slept.
 336 */
 337 static int devsymSleep(sqlite3_vfs *pVfs, int nMicro){
 338   return sqlite3OsSleep(g.pVfs, nMicro);
 339 }
 340
 341 /*
 342 ** Return the current time as a Julian Day number in *pTimeOut.
 343 */
 344 static int devsymCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
 345   return g.pVfs->xCurrentTime(g.pVfs, pTimeOut);
 346 }
 347
 348 /*
 349 ** Return the sector-size in bytes for an writecrash-file.
 350 */
 351 static int writecrashSectorSize(sqlite3_file *pFile){
 352   devsym_file *p = (devsym_file *)pFile;
 353   return sqlite3OsSectorSize(p->pReal);
 354 }
 355
 356 /*
 357 ** Return the device characteristic flags supported by an writecrash-file.
 358 */
 359 static int writecrashDeviceCharacteristics(sqlite3_file *pFile){
 360   devsym_file *p = (devsym_file *)pFile;
 361   return sqlite3OsDeviceCharacteristics(p->pReal);
 362 }
 363
 364 /*
 365 ** Write data to an writecrash-file.
 366 */
 367 static int writecrashWrite(
 368   sqlite3_file *pFile,
 369   const void *zBuf,
 370   int iAmt,
 371   sqlite_int64 iOfst
 372 ){
 373   devsym_file *p = (devsym_file *)pFile;
 374   if( g.nWriteCrash>0 ){
 375     g.nWriteCrash--;
 376     if( g.nWriteCrash==0 ) abort();
 377   }
 378   return sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
 379 }
 380
 381 /*
 382 ** Open an writecrash file handle.
 383 */
 384 static int writecrashOpen(
 385   sqlite3_vfs *pVfs,
 386   const char *zName,
 387   sqlite3_file *pFile,
 388   int flags,
 389   int *pOutFlags
 390 ){
 391 static sqlite3_io_methods writecrash_io_methods = {
 392   2,                                /* iVersion */
 393   devsymClose,                      /* xClose */
 394   devsymRead,                       /* xRead */
 395   writecrashWrite,                  /* xWrite */
 396   devsymTruncate,                   /* xTruncate */
 397   devsymSync,                       /* xSync */
 398   devsymFileSize,                   /* xFileSize */
 399   devsymLock,                       /* xLock */
 400   devsymUnlock,                     /* xUnlock */
 401   devsymCheckReservedLock,          /* xCheckReservedLock */
 402   devsymFileControl,                /* xFileControl */
 403   writecrashSectorSize,             /* xSectorSize */
 404   writecrashDeviceCharacteristics,  /* xDeviceCharacteristics */
 405   devsymShmMap,                     /* xShmMap */
 406   devsymShmLock,                    /* xShmLock */
 407   devsymShmBarrier,                 /* xShmBarrier */
 408   devsymShmUnmap                    /* xShmUnmap */
 409 };
 410
 411   int rc;
 412   devsym_file *p = (devsym_file *)pFile;
 413   p->pReal = (sqlite3_file *)&p[1];
 414   rc = sqlite3OsOpen(g.pVfs, zName, p->pReal, flags, pOutFlags);
 415   if( p->pReal->pMethods ){
 416     pFile->pMethods = &writecrash_io_methods;
 417   }
 418   return rc;
 419 }
 420
 421 static sqlite3_vfs devsym_vfs = {
 422   2,                     /* iVersion */
 423   sizeof(devsym_file),      /* szOsFile */
 424   DEVSYM_MAX_PATHNAME,      /* mxPathname */
 425   0,                     /* pNext */
 426   DEVSYM_VFS_NAME,          /* zName */
 427   0,                     /* pAppData */
 428   devsymOpen,               /* xOpen */
 429   devsymDelete,             /* xDelete */
 430   devsymAccess,             /* xAccess */
 431   devsymFullPathname,       /* xFullPathname */
 432 #ifndef SQLITE_OMIT_LOAD_EXTENSION
 433   devsymDlOpen,             /* xDlOpen */
 434   devsymDlError,            /* xDlError */
 435   devsymDlSym,              /* xDlSym */
 436   devsymDlClose,            /* xDlClose */
 437 #else
 438   0,                        /* xDlOpen */
 439   0,                        /* xDlError */
 440   0,                        /* xDlSym */
 441   0,                        /* xDlClose */
 442 #endif /* SQLITE_OMIT_LOAD_EXTENSION */
 443   devsymRandomness,         /* xRandomness */
 444   devsymSleep,              /* xSleep */
 445   devsymCurrentTime,        /* xCurrentTime */
 446   0,                        /* xGetLastError */
 447   0                         /* xCurrentTimeInt64 */
 448 };
 449
 450 static sqlite3_vfs writecrash_vfs = {
 451   2,                     /* iVersion */
 452   sizeof(devsym_file),      /* szOsFile */
 453   DEVSYM_MAX_PATHNAME,      /* mxPathname */
 454   0,                     /* pNext */
 455   WRITECRASH_NAME,          /* zName */
 456   0,                     /* pAppData */
 457   writecrashOpen,           /* xOpen */
 458   devsymDelete,             /* xDelete */
 459   devsymAccess,             /* xAccess */
 460   devsymFullPathname,       /* xFullPathname */
 461 #ifndef SQLITE_OMIT_LOAD_EXTENSION
 462   devsymDlOpen,             /* xDlOpen */
 463   devsymDlError,            /* xDlError */
 464   devsymDlSym,              /* xDlSym */
 465   devsymDlClose,            /* xDlClose */
 466 #else
 467   0,                        /* xDlOpen */
 468   0,                        /* xDlError */
 469   0,                        /* xDlSym */
 470   0,                        /* xDlClose */
 471 #endif /* SQLITE_OMIT_LOAD_EXTENSION */
 472   devsymRandomness,         /* xRandomness */
 473   devsymSleep,              /* xSleep */
 474   devsymCurrentTime,        /* xCurrentTime */
 475   0,                        /* xGetLastError */
 476   0                         /* xCurrentTimeInt64 */
 477 };
 478
 479
 480 /*
 481 ** This procedure registers the devsym vfs with SQLite. If the argument is
 482 ** true, the devsym vfs becomes the new default vfs. It is the only publicly
 483 ** available function in this file.
 484 */
 485 void devsym_register(int iDeviceChar, int iSectorSize){
 486
 487   if( g.pVfs==0 ){
 488     g.pVfs = sqlite3_vfs_find(0);
 489     devsym_vfs.szOsFile += g.pVfs->szOsFile;
 490     writecrash_vfs.szOsFile += g.pVfs->szOsFile;
 491     sqlite3_vfs_register(&devsym_vfs, 0);
 492     sqlite3_vfs_register(&writecrash_vfs, 0);
 493   }
 494   if( iDeviceChar>=0 ){
 495     g.iDeviceChar = iDeviceChar;
 496   }else{
 497     g.iDeviceChar = 0;
 498   }
 499   if( iSectorSize>=0 ){
 500     g.iSectorSize = iSectorSize;
 501   }else{
 502     g.iSectorSize = 512;
 503   }
 504 }
 505
 506 void devsym_unregister(){
 507   sqlite3_vfs_unregister(&devsym_vfs);
 508   sqlite3_vfs_unregister(&writecrash_vfs);
 509   g.pVfs = 0;
 510   g.iDeviceChar = 0;
 511   g.iSectorSize = 0;
 512 }
 513
 514 void devsym_crash_on_write(int nWrite){
 515   if( g.pVfs==0 ){
 516     g.pVfs = sqlite3_vfs_find(0);
 517     devsym_vfs.szOsFile += g.pVfs->szOsFile;
 518     writecrash_vfs.szOsFile += g.pVfs->szOsFile;
 519     sqlite3_vfs_register(&devsym_vfs, 0);
 520     sqlite3_vfs_register(&writecrash_vfs, 0);
 521   }
 522   g.nWriteCrash = nWrite;
 523 }
 524
 525 #endif