Kaido Kert | 25902c6 | 2024-06-17 17:10:28 -0700 | [diff] [blame^] | 1 | /* |
| 2 | ** 2016-05-27 |
| 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 the implementation of an SQLite vfs shim that |
| 14 | ** tracks I/O. Access to the accumulated status counts is provided using |
| 15 | ** an eponymous virtual table. |
| 16 | */ |
| 17 | #include <sqlite3ext.h> |
| 18 | SQLITE_EXTENSION_INIT1 |
| 19 | |
| 20 | /* |
| 21 | ** This module contains code for a wrapper VFS that cause stats for |
| 22 | ** most VFS calls to be recorded. |
| 23 | ** |
| 24 | ** To use this module, first compile it as a loadable extension. See |
| 25 | ** https://www.sqlite.org/loadext.html#build for compilations instructions. |
| 26 | ** |
| 27 | ** After compliing, load this extension, then open database connections to be |
| 28 | ** measured. Query usages status using the vfsstat virtual table: |
| 29 | ** |
| 30 | ** SELECT * FROM vfsstat; |
| 31 | ** |
| 32 | ** Reset counters using UPDATE statements against vfsstat: |
| 33 | ** |
| 34 | ** UPDATE vfsstat SET count=0; |
| 35 | ** |
| 36 | ** EXAMPLE SCRIPT: |
| 37 | ** |
| 38 | ** .load ./vfsstat |
| 39 | ** .open test.db |
| 40 | ** DROP TABLE IF EXISTS t1; |
| 41 | ** CREATE TABLE t1(x,y); |
| 42 | ** INSERT INTO t1 VALUES(123, randomblob(5000)); |
| 43 | ** CREATE INDEX t1x ON t1(x); |
| 44 | ** DROP TABLE t1; |
| 45 | ** VACUUM; |
| 46 | ** SELECT * FROM vfsstat WHERE count>0; |
| 47 | ** |
| 48 | ** LIMITATIONS: |
| 49 | ** |
| 50 | ** This module increments counters without using mutex protection. So if |
| 51 | ** two or more threads try to use this module at the same time, race conditions |
| 52 | ** may occur which mess up the counts. This is harmless, other than giving |
| 53 | ** incorrect statistics. |
| 54 | */ |
| 55 | #include <string.h> |
| 56 | #include <stdlib.h> |
| 57 | #include <assert.h> |
| 58 | |
| 59 | /* |
| 60 | ** File types |
| 61 | */ |
| 62 | #define VFSSTAT_MAIN 0 /* Main database file */ |
| 63 | #define VFSSTAT_JOURNAL 1 /* Rollback journal */ |
| 64 | #define VFSSTAT_WAL 2 /* Write-ahead log file */ |
| 65 | #define VFSSTAT_MASTERJRNL 3 /* Master journal */ |
| 66 | #define VFSSTAT_SUBJRNL 4 /* Subjournal */ |
| 67 | #define VFSSTAT_TEMPDB 5 /* TEMP database */ |
| 68 | #define VFSSTAT_TEMPJRNL 6 /* Journal for TEMP database */ |
| 69 | #define VFSSTAT_TRANSIENT 7 /* Transient database */ |
| 70 | #define VFSSTAT_ANY 8 /* Unspecified file type */ |
| 71 | #define VFSSTAT_nFile 9 /* This many file types */ |
| 72 | |
| 73 | /* Names of the file types. These are allowed values for the |
| 74 | ** first column of the vfsstat virtual table. |
| 75 | */ |
| 76 | static const char *azFile[] = { |
| 77 | "database", "journal", "wal", "master-journal", "sub-journal", |
| 78 | "temp-database", "temp-journal", "transient-db", "*" |
| 79 | }; |
| 80 | |
| 81 | /* |
| 82 | ** Stat types |
| 83 | */ |
| 84 | #define VFSSTAT_BYTESIN 0 /* Bytes read in */ |
| 85 | #define VFSSTAT_BYTESOUT 1 /* Bytes written out */ |
| 86 | #define VFSSTAT_READ 2 /* Read requests */ |
| 87 | #define VFSSTAT_WRITE 3 /* Write requests */ |
| 88 | #define VFSSTAT_SYNC 4 /* Syncs */ |
| 89 | #define VFSSTAT_OPEN 5 /* File opens */ |
| 90 | #define VFSSTAT_LOCK 6 /* Lock requests */ |
| 91 | #define VFSSTAT_ACCESS 0 /* xAccess calls. filetype==ANY only */ |
| 92 | #define VFSSTAT_DELETE 1 /* xDelete calls. filetype==ANY only */ |
| 93 | #define VFSSTAT_FULLPATH 2 /* xFullPathname calls. ANY only */ |
| 94 | #define VFSSTAT_RANDOM 3 /* xRandomness calls. ANY only */ |
| 95 | #define VFSSTAT_SLEEP 4 /* xSleep calls. ANY only */ |
| 96 | #define VFSSTAT_CURTIME 5 /* xCurrentTime calls. ANY only */ |
| 97 | #define VFSSTAT_nStat 7 /* This many stat types */ |
| 98 | |
| 99 | |
| 100 | /* Names for the second column of the vfsstat virtual table for all |
| 101 | ** cases except when the first column is "*" or VFSSTAT_ANY. */ |
| 102 | static const char *azStat[] = { |
| 103 | "bytes-in", "bytes-out", "read", "write", "sync", "open", "lock", |
| 104 | }; |
| 105 | static const char *azStatAny[] = { |
| 106 | "access", "delete", "fullpathname", "randomness", "sleep", "currenttimestamp", |
| 107 | "not-used" |
| 108 | }; |
| 109 | |
| 110 | /* Total number of counters */ |
| 111 | #define VFSSTAT_MXCNT (VFSSTAT_nStat*VFSSTAT_nFile) |
| 112 | |
| 113 | /* |
| 114 | ** Performance stats are collected in an instance of the following |
| 115 | ** global array. |
| 116 | */ |
| 117 | static sqlite3_uint64 aVfsCnt[VFSSTAT_MXCNT]; |
| 118 | |
| 119 | /* |
| 120 | ** Access to a specific counter |
| 121 | */ |
| 122 | #define STATCNT(filetype,stat) (aVfsCnt[(filetype)*VFSSTAT_nStat+(stat)]) |
| 123 | |
| 124 | /* |
| 125 | ** Forward declaration of objects used by this utility |
| 126 | */ |
| 127 | typedef struct VStatVfs VStatVfs; |
| 128 | typedef struct VStatFile VStatFile; |
| 129 | |
| 130 | /* An instance of the VFS */ |
| 131 | struct VStatVfs { |
| 132 | sqlite3_vfs base; /* VFS methods */ |
| 133 | sqlite3_vfs *pVfs; /* Parent VFS */ |
| 134 | }; |
| 135 | |
| 136 | /* An open file */ |
| 137 | struct VStatFile { |
| 138 | sqlite3_file base; /* IO methods */ |
| 139 | sqlite3_file *pReal; /* Underlying file handle */ |
| 140 | unsigned char eFiletype; /* What type of file is this */ |
| 141 | }; |
| 142 | |
| 143 | #define REALVFS(p) (((VStatVfs*)(p))->pVfs) |
| 144 | |
| 145 | /* |
| 146 | ** Methods for VStatFile |
| 147 | */ |
| 148 | static int vstatClose(sqlite3_file*); |
| 149 | static int vstatRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); |
| 150 | static int vstatWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst); |
| 151 | static int vstatTruncate(sqlite3_file*, sqlite3_int64 size); |
| 152 | static int vstatSync(sqlite3_file*, int flags); |
| 153 | static int vstatFileSize(sqlite3_file*, sqlite3_int64 *pSize); |
| 154 | static int vstatLock(sqlite3_file*, int); |
| 155 | static int vstatUnlock(sqlite3_file*, int); |
| 156 | static int vstatCheckReservedLock(sqlite3_file*, int *pResOut); |
| 157 | static int vstatFileControl(sqlite3_file*, int op, void *pArg); |
| 158 | static int vstatSectorSize(sqlite3_file*); |
| 159 | static int vstatDeviceCharacteristics(sqlite3_file*); |
| 160 | static int vstatShmMap(sqlite3_file*, int iPg, int pgsz, int, void volatile**); |
| 161 | static int vstatShmLock(sqlite3_file*, int offset, int n, int flags); |
| 162 | static void vstatShmBarrier(sqlite3_file*); |
| 163 | static int vstatShmUnmap(sqlite3_file*, int deleteFlag); |
| 164 | static int vstatFetch(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); |
| 165 | static int vstatUnfetch(sqlite3_file*, sqlite3_int64 iOfst, void *p); |
| 166 | |
| 167 | /* |
| 168 | ** Methods for VStatVfs |
| 169 | */ |
| 170 | static int vstatOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *); |
| 171 | static int vstatDelete(sqlite3_vfs*, const char *zName, int syncDir); |
| 172 | static int vstatAccess(sqlite3_vfs*, const char *zName, int flags, int *); |
| 173 | static int vstatFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut); |
| 174 | static void *vstatDlOpen(sqlite3_vfs*, const char *zFilename); |
| 175 | static void vstatDlError(sqlite3_vfs*, int nByte, char *zErrMsg); |
| 176 | static void (*vstatDlSym(sqlite3_vfs *pVfs, void *p, const char*zSym))(void); |
| 177 | static void vstatDlClose(sqlite3_vfs*, void*); |
| 178 | static int vstatRandomness(sqlite3_vfs*, int nByte, char *zOut); |
| 179 | static int vstatSleep(sqlite3_vfs*, int microseconds); |
| 180 | static int vstatCurrentTime(sqlite3_vfs*, double*); |
| 181 | static int vstatGetLastError(sqlite3_vfs*, int, char *); |
| 182 | static int vstatCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*); |
| 183 | |
| 184 | static VStatVfs vstat_vfs = { |
| 185 | { |
| 186 | 2, /* iVersion */ |
| 187 | 0, /* szOsFile (set by register_vstat()) */ |
| 188 | 1024, /* mxPathname */ |
| 189 | 0, /* pNext */ |
| 190 | "vfslog", /* zName */ |
| 191 | 0, /* pAppData */ |
| 192 | vstatOpen, /* xOpen */ |
| 193 | vstatDelete, /* xDelete */ |
| 194 | vstatAccess, /* xAccess */ |
| 195 | vstatFullPathname, /* xFullPathname */ |
| 196 | vstatDlOpen, /* xDlOpen */ |
| 197 | vstatDlError, /* xDlError */ |
| 198 | vstatDlSym, /* xDlSym */ |
| 199 | vstatDlClose, /* xDlClose */ |
| 200 | vstatRandomness, /* xRandomness */ |
| 201 | vstatSleep, /* xSleep */ |
| 202 | vstatCurrentTime, /* xCurrentTime */ |
| 203 | vstatGetLastError, /* xGetLastError */ |
| 204 | vstatCurrentTimeInt64 /* xCurrentTimeInt64 */ |
| 205 | }, |
| 206 | 0 |
| 207 | }; |
| 208 | |
| 209 | static const sqlite3_io_methods vstat_io_methods = { |
| 210 | 3, /* iVersion */ |
| 211 | vstatClose, /* xClose */ |
| 212 | vstatRead, /* xRead */ |
| 213 | vstatWrite, /* xWrite */ |
| 214 | vstatTruncate, /* xTruncate */ |
| 215 | vstatSync, /* xSync */ |
| 216 | vstatFileSize, /* xFileSize */ |
| 217 | vstatLock, /* xLock */ |
| 218 | vstatUnlock, /* xUnlock */ |
| 219 | vstatCheckReservedLock, /* xCheckReservedLock */ |
| 220 | vstatFileControl, /* xFileControl */ |
| 221 | vstatSectorSize, /* xSectorSize */ |
| 222 | vstatDeviceCharacteristics, /* xDeviceCharacteristics */ |
| 223 | vstatShmMap, /* xShmMap */ |
| 224 | vstatShmLock, /* xShmLock */ |
| 225 | vstatShmBarrier, /* xShmBarrier */ |
| 226 | vstatShmUnmap, /* xShmUnmap */ |
| 227 | vstatFetch, /* xFetch */ |
| 228 | vstatUnfetch /* xUnfetch */ |
| 229 | }; |
| 230 | |
| 231 | |
| 232 | |
| 233 | /* |
| 234 | ** Close an vstat-file. |
| 235 | */ |
| 236 | static int vstatClose(sqlite3_file *pFile){ |
| 237 | VStatFile *p = (VStatFile *)pFile; |
| 238 | int rc = SQLITE_OK; |
| 239 | |
| 240 | if( p->pReal->pMethods ){ |
| 241 | rc = p->pReal->pMethods->xClose(p->pReal); |
| 242 | } |
| 243 | return rc; |
| 244 | } |
| 245 | |
| 246 | |
| 247 | /* |
| 248 | ** Read data from an vstat-file. |
| 249 | */ |
| 250 | static int vstatRead( |
| 251 | sqlite3_file *pFile, |
| 252 | void *zBuf, |
| 253 | int iAmt, |
| 254 | sqlite_int64 iOfst |
| 255 | ){ |
| 256 | int rc; |
| 257 | VStatFile *p = (VStatFile *)pFile; |
| 258 | |
| 259 | rc = p->pReal->pMethods->xRead(p->pReal, zBuf, iAmt, iOfst); |
| 260 | STATCNT(p->eFiletype,VFSSTAT_READ)++; |
| 261 | if( rc==SQLITE_OK ){ |
| 262 | STATCNT(p->eFiletype,VFSSTAT_BYTESIN) += iAmt; |
| 263 | } |
| 264 | return rc; |
| 265 | } |
| 266 | |
| 267 | /* |
| 268 | ** Write data to an vstat-file. |
| 269 | */ |
| 270 | static int vstatWrite( |
| 271 | sqlite3_file *pFile, |
| 272 | const void *z, |
| 273 | int iAmt, |
| 274 | sqlite_int64 iOfst |
| 275 | ){ |
| 276 | int rc; |
| 277 | VStatFile *p = (VStatFile *)pFile; |
| 278 | |
| 279 | rc = p->pReal->pMethods->xWrite(p->pReal, z, iAmt, iOfst); |
| 280 | STATCNT(p->eFiletype,VFSSTAT_WRITE)++; |
| 281 | if( rc==SQLITE_OK ){ |
| 282 | STATCNT(p->eFiletype,VFSSTAT_BYTESOUT) += iAmt; |
| 283 | } |
| 284 | return rc; |
| 285 | } |
| 286 | |
| 287 | /* |
| 288 | ** Truncate an vstat-file. |
| 289 | */ |
| 290 | static int vstatTruncate(sqlite3_file *pFile, sqlite_int64 size){ |
| 291 | int rc; |
| 292 | VStatFile *p = (VStatFile *)pFile; |
| 293 | rc = p->pReal->pMethods->xTruncate(p->pReal, size); |
| 294 | return rc; |
| 295 | } |
| 296 | |
| 297 | /* |
| 298 | ** Sync an vstat-file. |
| 299 | */ |
| 300 | static int vstatSync(sqlite3_file *pFile, int flags){ |
| 301 | int rc; |
| 302 | VStatFile *p = (VStatFile *)pFile; |
| 303 | rc = p->pReal->pMethods->xSync(p->pReal, flags); |
| 304 | STATCNT(p->eFiletype,VFSSTAT_SYNC)++; |
| 305 | return rc; |
| 306 | } |
| 307 | |
| 308 | /* |
| 309 | ** Return the current file-size of an vstat-file. |
| 310 | */ |
| 311 | static int vstatFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){ |
| 312 | int rc; |
| 313 | VStatFile *p = (VStatFile *)pFile; |
| 314 | rc = p->pReal->pMethods->xFileSize(p->pReal, pSize); |
| 315 | return rc; |
| 316 | } |
| 317 | |
| 318 | /* |
| 319 | ** Lock an vstat-file. |
| 320 | */ |
| 321 | static int vstatLock(sqlite3_file *pFile, int eLock){ |
| 322 | int rc; |
| 323 | VStatFile *p = (VStatFile *)pFile; |
| 324 | rc = p->pReal->pMethods->xLock(p->pReal, eLock); |
| 325 | STATCNT(p->eFiletype,VFSSTAT_LOCK)++; |
| 326 | return rc; |
| 327 | } |
| 328 | |
| 329 | /* |
| 330 | ** Unlock an vstat-file. |
| 331 | */ |
| 332 | static int vstatUnlock(sqlite3_file *pFile, int eLock){ |
| 333 | int rc; |
| 334 | VStatFile *p = (VStatFile *)pFile; |
| 335 | rc = p->pReal->pMethods->xUnlock(p->pReal, eLock); |
| 336 | STATCNT(p->eFiletype,VFSSTAT_LOCK)++; |
| 337 | return rc; |
| 338 | } |
| 339 | |
| 340 | /* |
| 341 | ** Check if another file-handle holds a RESERVED lock on an vstat-file. |
| 342 | */ |
| 343 | static int vstatCheckReservedLock(sqlite3_file *pFile, int *pResOut){ |
| 344 | int rc; |
| 345 | VStatFile *p = (VStatFile *)pFile; |
| 346 | rc = p->pReal->pMethods->xCheckReservedLock(p->pReal, pResOut); |
| 347 | STATCNT(p->eFiletype,VFSSTAT_LOCK)++; |
| 348 | return rc; |
| 349 | } |
| 350 | |
| 351 | /* |
| 352 | ** File control method. For custom operations on an vstat-file. |
| 353 | */ |
| 354 | static int vstatFileControl(sqlite3_file *pFile, int op, void *pArg){ |
| 355 | VStatFile *p = (VStatFile *)pFile; |
| 356 | int rc; |
| 357 | rc = p->pReal->pMethods->xFileControl(p->pReal, op, pArg); |
| 358 | if( op==SQLITE_FCNTL_VFSNAME && rc==SQLITE_OK ){ |
| 359 | *(char**)pArg = sqlite3_mprintf("vstat/%z", *(char**)pArg); |
| 360 | } |
| 361 | return rc; |
| 362 | } |
| 363 | |
| 364 | /* |
| 365 | ** Return the sector-size in bytes for an vstat-file. |
| 366 | */ |
| 367 | static int vstatSectorSize(sqlite3_file *pFile){ |
| 368 | int rc; |
| 369 | VStatFile *p = (VStatFile *)pFile; |
| 370 | rc = p->pReal->pMethods->xSectorSize(p->pReal); |
| 371 | return rc; |
| 372 | } |
| 373 | |
| 374 | /* |
| 375 | ** Return the device characteristic flags supported by an vstat-file. |
| 376 | */ |
| 377 | static int vstatDeviceCharacteristics(sqlite3_file *pFile){ |
| 378 | int rc; |
| 379 | VStatFile *p = (VStatFile *)pFile; |
| 380 | rc = p->pReal->pMethods->xDeviceCharacteristics(p->pReal); |
| 381 | return rc; |
| 382 | } |
| 383 | |
| 384 | /* Create a shared memory file mapping */ |
| 385 | static int vstatShmMap( |
| 386 | sqlite3_file *pFile, |
| 387 | int iPg, |
| 388 | int pgsz, |
| 389 | int bExtend, |
| 390 | void volatile **pp |
| 391 | ){ |
| 392 | VStatFile *p = (VStatFile *)pFile; |
| 393 | return p->pReal->pMethods->xShmMap(p->pReal, iPg, pgsz, bExtend, pp); |
| 394 | } |
| 395 | |
| 396 | /* Perform locking on a shared-memory segment */ |
| 397 | static int vstatShmLock(sqlite3_file *pFile, int offset, int n, int flags){ |
| 398 | VStatFile *p = (VStatFile *)pFile; |
| 399 | return p->pReal->pMethods->xShmLock(p->pReal, offset, n, flags); |
| 400 | } |
| 401 | |
| 402 | /* Memory barrier operation on shared memory */ |
| 403 | static void vstatShmBarrier(sqlite3_file *pFile){ |
| 404 | VStatFile *p = (VStatFile *)pFile; |
| 405 | p->pReal->pMethods->xShmBarrier(p->pReal); |
| 406 | } |
| 407 | |
| 408 | /* Unmap a shared memory segment */ |
| 409 | static int vstatShmUnmap(sqlite3_file *pFile, int deleteFlag){ |
| 410 | VStatFile *p = (VStatFile *)pFile; |
| 411 | return p->pReal->pMethods->xShmUnmap(p->pReal, deleteFlag); |
| 412 | } |
| 413 | |
| 414 | /* Fetch a page of a memory-mapped file */ |
| 415 | static int vstatFetch( |
| 416 | sqlite3_file *pFile, |
| 417 | sqlite3_int64 iOfst, |
| 418 | int iAmt, |
| 419 | void **pp |
| 420 | ){ |
| 421 | VStatFile *p = (VStatFile *)pFile; |
| 422 | return p->pReal->pMethods->xFetch(p->pReal, iOfst, iAmt, pp); |
| 423 | } |
| 424 | |
| 425 | /* Release a memory-mapped page */ |
| 426 | static int vstatUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){ |
| 427 | VStatFile *p = (VStatFile *)pFile; |
| 428 | return p->pReal->pMethods->xUnfetch(p->pReal, iOfst, pPage); |
| 429 | } |
| 430 | |
| 431 | /* |
| 432 | ** Open an vstat file handle. |
| 433 | */ |
| 434 | static int vstatOpen( |
| 435 | sqlite3_vfs *pVfs, |
| 436 | const char *zName, |
| 437 | sqlite3_file *pFile, |
| 438 | int flags, |
| 439 | int *pOutFlags |
| 440 | ){ |
| 441 | int rc; |
| 442 | VStatFile *p = (VStatFile*)pFile; |
| 443 | |
| 444 | p->pReal = (sqlite3_file*)&p[1]; |
| 445 | rc = REALVFS(pVfs)->xOpen(REALVFS(pVfs), zName, p->pReal, flags, pOutFlags); |
| 446 | if( flags & SQLITE_OPEN_MAIN_DB ){ |
| 447 | p->eFiletype = VFSSTAT_MAIN; |
| 448 | }else if( flags & SQLITE_OPEN_MAIN_JOURNAL ){ |
| 449 | p->eFiletype = VFSSTAT_JOURNAL; |
| 450 | }else if( flags & SQLITE_OPEN_WAL ){ |
| 451 | p->eFiletype = VFSSTAT_WAL; |
| 452 | }else if( flags & SQLITE_OPEN_MASTER_JOURNAL ){ |
| 453 | p->eFiletype = VFSSTAT_MASTERJRNL; |
| 454 | }else if( flags & SQLITE_OPEN_SUBJOURNAL ){ |
| 455 | p->eFiletype = VFSSTAT_SUBJRNL; |
| 456 | }else if( flags & SQLITE_OPEN_TEMP_DB ){ |
| 457 | p->eFiletype = VFSSTAT_TEMPDB; |
| 458 | }else if( flags & SQLITE_OPEN_TEMP_JOURNAL ){ |
| 459 | p->eFiletype = VFSSTAT_TEMPJRNL; |
| 460 | }else{ |
| 461 | p->eFiletype = VFSSTAT_TRANSIENT; |
| 462 | } |
| 463 | STATCNT(p->eFiletype,VFSSTAT_OPEN)++; |
| 464 | pFile->pMethods = rc ? 0 : &vstat_io_methods; |
| 465 | return rc; |
| 466 | } |
| 467 | |
| 468 | /* |
| 469 | ** Delete the file located at zPath. If the dirSync argument is true, |
| 470 | ** ensure the file-system modifications are synced to disk before |
| 471 | ** returning. |
| 472 | */ |
| 473 | static int vstatDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){ |
| 474 | int rc; |
| 475 | rc = REALVFS(pVfs)->xDelete(REALVFS(pVfs), zPath, dirSync); |
| 476 | STATCNT(VFSSTAT_ANY,VFSSTAT_DELETE)++; |
| 477 | return rc; |
| 478 | } |
| 479 | |
| 480 | /* |
| 481 | ** Test for access permissions. Return true if the requested permission |
| 482 | ** is available, or false otherwise. |
| 483 | */ |
| 484 | static int vstatAccess( |
| 485 | sqlite3_vfs *pVfs, |
| 486 | const char *zPath, |
| 487 | int flags, |
| 488 | int *pResOut |
| 489 | ){ |
| 490 | int rc; |
| 491 | rc = REALVFS(pVfs)->xAccess(REALVFS(pVfs), zPath, flags, pResOut); |
| 492 | STATCNT(VFSSTAT_ANY,VFSSTAT_ACCESS)++; |
| 493 | return rc; |
| 494 | } |
| 495 | |
| 496 | /* |
| 497 | ** Populate buffer zOut with the full canonical pathname corresponding |
| 498 | ** to the pathname in zPath. zOut is guaranteed to point to a buffer |
| 499 | ** of at least (INST_MAX_PATHNAME+1) bytes. |
| 500 | */ |
| 501 | static int vstatFullPathname( |
| 502 | sqlite3_vfs *pVfs, |
| 503 | const char *zPath, |
| 504 | int nOut, |
| 505 | char *zOut |
| 506 | ){ |
| 507 | STATCNT(VFSSTAT_ANY,VFSSTAT_FULLPATH)++; |
| 508 | return REALVFS(pVfs)->xFullPathname(REALVFS(pVfs), zPath, nOut, zOut); |
| 509 | } |
| 510 | |
| 511 | /* |
| 512 | ** Open the dynamic library located at zPath and return a handle. |
| 513 | */ |
| 514 | static void *vstatDlOpen(sqlite3_vfs *pVfs, const char *zPath){ |
| 515 | return REALVFS(pVfs)->xDlOpen(REALVFS(pVfs), zPath); |
| 516 | } |
| 517 | |
| 518 | /* |
| 519 | ** Populate the buffer zErrMsg (size nByte bytes) with a human readable |
| 520 | ** utf-8 string describing the most recent error encountered associated |
| 521 | ** with dynamic libraries. |
| 522 | */ |
| 523 | static void vstatDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){ |
| 524 | REALVFS(pVfs)->xDlError(REALVFS(pVfs), nByte, zErrMsg); |
| 525 | } |
| 526 | |
| 527 | /* |
| 528 | ** Return a pointer to the symbol zSymbol in the dynamic library pHandle. |
| 529 | */ |
| 530 | static void (*vstatDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){ |
| 531 | return REALVFS(pVfs)->xDlSym(REALVFS(pVfs), p, zSym); |
| 532 | } |
| 533 | |
| 534 | /* |
| 535 | ** Close the dynamic library handle pHandle. |
| 536 | */ |
| 537 | static void vstatDlClose(sqlite3_vfs *pVfs, void *pHandle){ |
| 538 | REALVFS(pVfs)->xDlClose(REALVFS(pVfs), pHandle); |
| 539 | } |
| 540 | |
| 541 | /* |
| 542 | ** Populate the buffer pointed to by zBufOut with nByte bytes of |
| 543 | ** random data. |
| 544 | */ |
| 545 | static int vstatRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){ |
| 546 | STATCNT(VFSSTAT_ANY,VFSSTAT_RANDOM)++; |
| 547 | return REALVFS(pVfs)->xRandomness(REALVFS(pVfs), nByte, zBufOut); |
| 548 | } |
| 549 | |
| 550 | /* |
| 551 | ** Sleep for nMicro microseconds. Return the number of microseconds |
| 552 | ** actually slept. |
| 553 | */ |
| 554 | static int vstatSleep(sqlite3_vfs *pVfs, int nMicro){ |
| 555 | STATCNT(VFSSTAT_ANY,VFSSTAT_SLEEP)++; |
| 556 | return REALVFS(pVfs)->xSleep(REALVFS(pVfs), nMicro); |
| 557 | } |
| 558 | |
| 559 | /* |
| 560 | ** Return the current time as a Julian Day number in *pTimeOut. |
| 561 | */ |
| 562 | static int vstatCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){ |
| 563 | STATCNT(VFSSTAT_ANY,VFSSTAT_CURTIME)++; |
| 564 | return REALVFS(pVfs)->xCurrentTime(REALVFS(pVfs), pTimeOut); |
| 565 | } |
| 566 | |
| 567 | static int vstatGetLastError(sqlite3_vfs *pVfs, int a, char *b){ |
| 568 | return REALVFS(pVfs)->xGetLastError(REALVFS(pVfs), a, b); |
| 569 | } |
| 570 | static int vstatCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){ |
| 571 | STATCNT(VFSSTAT_ANY,VFSSTAT_CURTIME)++; |
| 572 | return REALVFS(pVfs)->xCurrentTimeInt64(REALVFS(pVfs), p); |
| 573 | } |
| 574 | |
| 575 | /* |
| 576 | ** A virtual table for accessing the stats collected by this VFS shim |
| 577 | */ |
| 578 | static int vstattabConnect(sqlite3*, void*, int, const char*const*, |
| 579 | sqlite3_vtab**,char**); |
| 580 | static int vstattabBestIndex(sqlite3_vtab*,sqlite3_index_info*); |
| 581 | static int vstattabDisconnect(sqlite3_vtab*); |
| 582 | static int vstattabOpen(sqlite3_vtab*, sqlite3_vtab_cursor**); |
| 583 | static int vstattabClose(sqlite3_vtab_cursor*); |
| 584 | static int vstattabFilter(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, |
| 585 | int argc, sqlite3_value **argv); |
| 586 | static int vstattabNext(sqlite3_vtab_cursor*); |
| 587 | static int vstattabEof(sqlite3_vtab_cursor*); |
| 588 | static int vstattabColumn(sqlite3_vtab_cursor*,sqlite3_context*,int); |
| 589 | static int vstattabRowid(sqlite3_vtab_cursor*,sqlite3_int64*); |
| 590 | static int vstattabUpdate(sqlite3_vtab*,int,sqlite3_value**,sqlite3_int64*); |
| 591 | |
| 592 | /* A cursor for the vfsstat virtual table */ |
| 593 | typedef struct VfsStatCursor { |
| 594 | sqlite3_vtab_cursor base; /* Base class. Must be first */ |
| 595 | int i; /* Pointing to this aVfsCnt[] value */ |
| 596 | } VfsStatCursor; |
| 597 | |
| 598 | |
| 599 | static int vstattabConnect( |
| 600 | sqlite3 *db, |
| 601 | void *pAux, |
| 602 | int argc, const char *const*argv, |
| 603 | sqlite3_vtab **ppVtab, |
| 604 | char **pzErr |
| 605 | ){ |
| 606 | sqlite3_vtab *pNew; |
| 607 | int rc; |
| 608 | |
| 609 | /* Column numbers */ |
| 610 | #define VSTAT_COLUMN_FILE 0 |
| 611 | #define VSTAT_COLUMN_STAT 1 |
| 612 | #define VSTAT_COLUMN_COUNT 2 |
| 613 | |
| 614 | rc = sqlite3_declare_vtab(db,"CREATE TABLE x(file,stat,count)"); |
| 615 | if( rc==SQLITE_OK ){ |
| 616 | pNew = *ppVtab = sqlite3_malloc( sizeof(*pNew) ); |
| 617 | if( pNew==0 ) return SQLITE_NOMEM; |
| 618 | memset(pNew, 0, sizeof(*pNew)); |
| 619 | } |
| 620 | return rc; |
| 621 | } |
| 622 | |
| 623 | /* |
| 624 | ** This method is the destructor for vstat table object. |
| 625 | */ |
| 626 | static int vstattabDisconnect(sqlite3_vtab *pVtab){ |
| 627 | sqlite3_free(pVtab); |
| 628 | return SQLITE_OK; |
| 629 | } |
| 630 | |
| 631 | /* |
| 632 | ** Constructor for a new vstat table cursor object. |
| 633 | */ |
| 634 | static int vstattabOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){ |
| 635 | VfsStatCursor *pCur; |
| 636 | pCur = sqlite3_malloc( sizeof(*pCur) ); |
| 637 | if( pCur==0 ) return SQLITE_NOMEM; |
| 638 | memset(pCur, 0, sizeof(*pCur)); |
| 639 | *ppCursor = &pCur->base; |
| 640 | return SQLITE_OK; |
| 641 | } |
| 642 | |
| 643 | |
| 644 | /* |
| 645 | ** Destructor for a VfsStatCursor. |
| 646 | */ |
| 647 | static int vstattabClose(sqlite3_vtab_cursor *cur){ |
| 648 | sqlite3_free(cur); |
| 649 | return SQLITE_OK; |
| 650 | } |
| 651 | |
| 652 | |
| 653 | /* |
| 654 | ** Advance a VfsStatCursor to its next row of output. |
| 655 | */ |
| 656 | static int vstattabNext(sqlite3_vtab_cursor *cur){ |
| 657 | ((VfsStatCursor*)cur)->i++; |
| 658 | return SQLITE_OK; |
| 659 | } |
| 660 | |
| 661 | /* |
| 662 | ** Return values of columns for the row at which the VfsStatCursor |
| 663 | ** is currently pointing. |
| 664 | */ |
| 665 | static int vstattabColumn( |
| 666 | sqlite3_vtab_cursor *cur, /* The cursor */ |
| 667 | sqlite3_context *ctx, /* First argument to sqlite3_result_...() */ |
| 668 | int i /* Which column to return */ |
| 669 | ){ |
| 670 | VfsStatCursor *pCur = (VfsStatCursor*)cur; |
| 671 | switch( i ){ |
| 672 | case VSTAT_COLUMN_FILE: { |
| 673 | sqlite3_result_text(ctx, azFile[pCur->i/VFSSTAT_nStat], -1, SQLITE_STATIC); |
| 674 | break; |
| 675 | } |
| 676 | case VSTAT_COLUMN_STAT: { |
| 677 | const char **az; |
| 678 | az = (pCur->i/VFSSTAT_nStat)==VFSSTAT_ANY ? azStatAny : azStat; |
| 679 | sqlite3_result_text(ctx, az[pCur->i%VFSSTAT_nStat], -1, SQLITE_STATIC); |
| 680 | break; |
| 681 | } |
| 682 | case VSTAT_COLUMN_COUNT: { |
| 683 | sqlite3_result_int64(ctx, aVfsCnt[pCur->i]); |
| 684 | break; |
| 685 | } |
| 686 | } |
| 687 | return SQLITE_OK; |
| 688 | } |
| 689 | |
| 690 | /* |
| 691 | ** Return the rowid for the current row. |
| 692 | */ |
| 693 | static int vstattabRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ |
| 694 | VfsStatCursor *pCur = (VfsStatCursor*)cur; |
| 695 | *pRowid = pCur->i; |
| 696 | return SQLITE_OK; |
| 697 | } |
| 698 | |
| 699 | /* |
| 700 | ** Return TRUE if the cursor has been moved off of the last |
| 701 | ** row of output. |
| 702 | */ |
| 703 | static int vstattabEof(sqlite3_vtab_cursor *cur){ |
| 704 | VfsStatCursor *pCur = (VfsStatCursor*)cur; |
| 705 | return pCur->i >= VFSSTAT_MXCNT; |
| 706 | } |
| 707 | |
| 708 | /* |
| 709 | ** Only a full table scan is supported. So xFilter simply rewinds to |
| 710 | ** the beginning. |
| 711 | */ |
| 712 | static int vstattabFilter( |
| 713 | sqlite3_vtab_cursor *pVtabCursor, |
| 714 | int idxNum, const char *idxStr, |
| 715 | int argc, sqlite3_value **argv |
| 716 | ){ |
| 717 | VfsStatCursor *pCur = (VfsStatCursor*)pVtabCursor; |
| 718 | pCur->i = 0; |
| 719 | return SQLITE_OK; |
| 720 | } |
| 721 | |
| 722 | /* |
| 723 | ** Only a forwards full table scan is supported. xBestIndex is a no-op. |
| 724 | */ |
| 725 | static int vstattabBestIndex( |
| 726 | sqlite3_vtab *tab, |
| 727 | sqlite3_index_info *pIdxInfo |
| 728 | ){ |
| 729 | return SQLITE_OK; |
| 730 | } |
| 731 | |
| 732 | /* |
| 733 | ** Any VSTAT_COLUMN_COUNT can be changed to a positive integer. |
| 734 | ** No deletions or insertions are allowed. No changes to other |
| 735 | ** columns are allowed. |
| 736 | */ |
| 737 | static int vstattabUpdate( |
| 738 | sqlite3_vtab *tab, |
| 739 | int argc, sqlite3_value **argv, |
| 740 | sqlite3_int64 *pRowid |
| 741 | ){ |
| 742 | sqlite3_int64 iRowid, x; |
| 743 | if( argc==1 ) return SQLITE_ERROR; |
| 744 | if( sqlite3_value_type(argv[0])!=SQLITE_INTEGER ) return SQLITE_ERROR; |
| 745 | iRowid = sqlite3_value_int64(argv[0]); |
| 746 | if( iRowid!=sqlite3_value_int64(argv[1]) ) return SQLITE_ERROR; |
| 747 | if( iRowid<0 || iRowid>=VFSSTAT_MXCNT ) return SQLITE_ERROR; |
| 748 | if( sqlite3_value_type(argv[VSTAT_COLUMN_COUNT+2])!=SQLITE_INTEGER ){ |
| 749 | return SQLITE_ERROR; |
| 750 | } |
| 751 | x = sqlite3_value_int64(argv[VSTAT_COLUMN_COUNT+2]); |
| 752 | if( x<0 ) return SQLITE_ERROR; |
| 753 | aVfsCnt[iRowid] = x; |
| 754 | return SQLITE_OK; |
| 755 | } |
| 756 | |
| 757 | static sqlite3_module VfsStatModule = { |
| 758 | 0, /* iVersion */ |
| 759 | 0, /* xCreate */ |
| 760 | vstattabConnect, /* xConnect */ |
| 761 | vstattabBestIndex, /* xBestIndex */ |
| 762 | vstattabDisconnect, /* xDisconnect */ |
| 763 | 0, /* xDestroy */ |
| 764 | vstattabOpen, /* xOpen - open a cursor */ |
| 765 | vstattabClose, /* xClose - close a cursor */ |
| 766 | vstattabFilter, /* xFilter - configure scan constraints */ |
| 767 | vstattabNext, /* xNext - advance a cursor */ |
| 768 | vstattabEof, /* xEof - check for end of scan */ |
| 769 | vstattabColumn, /* xColumn - read data */ |
| 770 | vstattabRowid, /* xRowid - read data */ |
| 771 | vstattabUpdate, /* xUpdate */ |
| 772 | 0, /* xBegin */ |
| 773 | 0, /* xSync */ |
| 774 | 0, /* xCommit */ |
| 775 | 0, /* xRollback */ |
| 776 | 0, /* xFindMethod */ |
| 777 | 0, /* xRename */ |
| 778 | }; |
| 779 | |
| 780 | /* |
| 781 | ** This routine is an sqlite3_auto_extension() callback, invoked to register |
| 782 | ** the vfsstat virtual table for all new database connections. |
| 783 | */ |
| 784 | static int vstatRegister( |
| 785 | sqlite3 *db, |
| 786 | char **pzErrMsg, |
| 787 | const sqlite3_api_routines *pThunk |
| 788 | ){ |
| 789 | return sqlite3_create_module(db, "vfsstat", &VfsStatModule, 0); |
| 790 | } |
| 791 | |
| 792 | #ifdef _WIN32 |
| 793 | __declspec(dllexport) |
| 794 | #endif |
| 795 | /* |
| 796 | ** This routine is called when the extension is loaded. |
| 797 | ** |
| 798 | ** Register the new VFS. Make arrangement to register the virtual table |
| 799 | ** for each new database connection. |
| 800 | */ |
| 801 | int sqlite3_vfsstat_init( |
| 802 | sqlite3 *db, |
| 803 | char **pzErrMsg, |
| 804 | const sqlite3_api_routines *pApi |
| 805 | ){ |
| 806 | int rc = SQLITE_OK; |
| 807 | SQLITE_EXTENSION_INIT2(pApi); |
| 808 | vstat_vfs.pVfs = sqlite3_vfs_find(0); |
| 809 | if( vstat_vfs.pVfs==0 ) return SQLITE_ERROR; |
| 810 | vstat_vfs.base.szOsFile = sizeof(VStatFile) + vstat_vfs.pVfs->szOsFile; |
| 811 | rc = sqlite3_vfs_register(&vstat_vfs.base, 1); |
| 812 | if( rc==SQLITE_OK ){ |
| 813 | rc = vstatRegister(db, pzErrMsg, pApi); |
| 814 | if( rc==SQLITE_OK ){ |
| 815 | rc = sqlite3_auto_extension((void(*)(void))vstatRegister); |
| 816 | } |
| 817 | } |
| 818 | if( rc==SQLITE_OK ) rc = SQLITE_OK_LOAD_PERMANENTLY; |
| 819 | return rc; |
| 820 | } |