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Overview
Comment: | Initial check-in of the "scrub.exe" utility program prototype. Not yet fully functional. In particular, no scrubbing is done. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | scrub-backup |
Files: | files | file ages | folders |
SHA1: |
bdf2ec77d1542d4e9b68218f558710a3 |
User & Date: | drh 2016-05-05 17:15:23.301 |
Context
2016-05-05
| ||
23:09 | Finished implementation compiles, but untested. (check-in: aeb88bdf6f user: drh tags: scrub-backup) | |
17:15 | Initial check-in of the "scrub.exe" utility program prototype. Not yet fully functional. In particular, no scrubbing is done. (check-in: bdf2ec77d1 user: drh tags: scrub-backup) | |
11:53 | Renumber internal constants in the printf() implemention for a small performance improvement. (check-in: 69d11447f4 user: drh tags: trunk) | |
Changes
Changes to Makefile.in.
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584 585 586 587 588 589 590 591 592 593 594 595 596 597 | sqlite3$(TEXE): $(TOP)/src/shell.c sqlite3.c $(LTLINK) $(READLINE_FLAGS) $(SHELL_OPT) -o $@ \ $(TOP)/src/shell.c sqlite3.c \ $(LIBREADLINE) $(TLIBS) -rpath "$(libdir)" sqldiff$(TEXE): $(TOP)/tool/sqldiff.c sqlite3.c sqlite3.h $(LTLINK) -o $@ $(TOP)/tool/sqldiff.c sqlite3.c $(TLIBS) srcck1$(BEXE): $(TOP)/tool/srcck1.c $(BCC) -o srcck1$(BEXE) $(TOP)/tool/srcck1.c sourcetest: srcck1$(BEXE) sqlite3.c ./srcck1 sqlite3.c | > > > > | 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 | sqlite3$(TEXE): $(TOP)/src/shell.c sqlite3.c $(LTLINK) $(READLINE_FLAGS) $(SHELL_OPT) -o $@ \ $(TOP)/src/shell.c sqlite3.c \ $(LIBREADLINE) $(TLIBS) -rpath "$(libdir)" sqldiff$(TEXE): $(TOP)/tool/sqldiff.c sqlite3.c sqlite3.h $(LTLINK) -o $@ $(TOP)/tool/sqldiff.c sqlite3.c $(TLIBS) scrub$(TEXE): $(TOP)/ext/misc/scrub.c sqlite3.o $(LTLINK) -o $@ -I. -DSCRUB_STANDALONE \ $(TOP)/ext/misc/scrub.c sqlite3.o $(TLIBS) srcck1$(BEXE): $(TOP)/tool/srcck1.c $(BCC) -o srcck1$(BEXE) $(TOP)/tool/srcck1.c sourcetest: srcck1$(BEXE) sqlite3.c ./srcck1 sqlite3.c |
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Changes to Makefile.msc.
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1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 | $(LTLINK) $(SHELL_COMPILE_OPTS) $(READLINE_FLAGS) $(TOP)\src\shell.c $(SHELL_CORE_SRC) \ /link $(SQLITE3EXEPDB) $(LDFLAGS) $(LTLINKOPTS) $(SHELL_LINK_OPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LIBREADLINE) $(LTLIBS) $(TLIBS) # <<mark>> sqldiff.exe: $(TOP)\tool\sqldiff.c $(SQLITE3C) $(SQLITE3H) $(LTLINK) $(NO_WARN) $(TOP)\tool\sqldiff.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS) srcck1.exe: $(TOP)\tool\srcck1.c $(BCC) $(NO_WARN) -Fe$@ $(TOP)\tool\srcck1.c sourcetest: srcck1.exe sqlite3.c srcck1.exe sqlite3.c fuzzershell.exe: $(TOP)\tool\fuzzershell.c $(SQLITE3C) $(SQLITE3H) | > > > | 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 | $(LTLINK) $(SHELL_COMPILE_OPTS) $(READLINE_FLAGS) $(TOP)\src\shell.c $(SHELL_CORE_SRC) \ /link $(SQLITE3EXEPDB) $(LDFLAGS) $(LTLINKOPTS) $(SHELL_LINK_OPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LIBREADLINE) $(LTLIBS) $(TLIBS) # <<mark>> sqldiff.exe: $(TOP)\tool\sqldiff.c $(SQLITE3C) $(SQLITE3H) $(LTLINK) $(NO_WARN) $(TOP)\tool\sqldiff.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS) scrub.exe: $(TOP)\ext\misc\scrub.c $(SQLITE3C) $(SQLITE3H) $(LTLINK) $(NO_WARN) $(TOP)\ext\misc\scrub.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS) srcck1.exe: $(TOP)\tool\srcck1.c $(BCC) $(NO_WARN) -Fe$@ $(TOP)\tool\srcck1.c sourcetest: srcck1.exe sqlite3.c srcck1.exe sqlite3.c fuzzershell.exe: $(TOP)\tool\fuzzershell.c $(SQLITE3C) $(SQLITE3H) |
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Added ext/misc/scrub.c.
> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 | /* ** 2016-05-05 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ****************************************************************************** ** ** This file implements a utility function (and a utility program) that ** makes a copy of an SQLite database while simultaneously zeroing out all ** deleted content. ** ** Normally (when PRAGMA secure_delete=OFF, which is the default) when SQLite ** deletes content, it does not overwrite the deleted content but rather marks ** the region of the file that held that content as being reusable. This can ** cause deleted content to recoverable from the database file. This stale ** content is removed by the VACUUM command, but VACUUM can be expensive for ** large databases. When in PRAGMA secure_delete=ON mode, the deleted content ** is zeroed, but secure_delete=ON has overhead as well. ** ** This utility attempts to make a copy of a complete SQLite database where ** all of the deleted content is zeroed out in the copy, and it attempts to ** do so while being faster than running VACUUM. ** ** Usage: ** ** int sqlite3_scrub_backup( ** const char *zSourceFile, // Source database filename ** const char *zDestFile, // Destination database filename ** char **pzErrMsg // Write error message here ** ); ** ** Simply call the API above specifying the filename of the source database ** and the name of the backup copy. The source database must already exist ** and can be in active use. (A read lock is held during the backup.) The ** destination file should not previously exist. If the pzErrMsg parameter ** is non-NULL and if an error occurs, then an error message might be written ** into memory obtained from sqlite3_malloc() and *pzErrMsg made to point to ** that error message. But if the error is an OOM, the error might not be ** reported. The routine always returns non-zero if there is an error. ** ** If compiled with -DSCRUB_STANDALONE then a main() procedure is added and ** this file becomes a standalone program that can be run as follows: ** ** ./sqlite3scrub SOURCE DEST */ #include "sqlite3.h" #include <assert.h> #include <stdio.h> #include <stdlib.h> #include <stdarg.h> #include <string.h> typedef struct ScrubState ScrubState; typedef unsigned char u8; /* State information for a scrub-and-backup operation */ struct ScrubState { const char *zSrcFile; /* Name of the source file */ const char *zDestFile; /* Name of the destination file */ int rcErr; /* Error code */ char *zErr; /* Error message text */ sqlite3 *dbSrc; /* Source database connection */ sqlite3_file *pSrc; /* Source file handle */ sqlite3 *dbDest; /* Destination database connection */ sqlite3_file *pDest; /* Destination file handle */ unsigned int szPage; /* Page size */ unsigned int nPage; /* Number of pages */ u8 *page1; /* Content of page 1 */ }; /* Store an error message */ static void scrubBackupErr(ScrubState *p, const char *zFormat, ...){ va_list ap; sqlite3_free(p->zErr); va_start(ap, zFormat); p->zErr = sqlite3_vmprintf(zFormat, ap); va_end(ap); if( p->rcErr==0 ) p->rcErr = SQLITE_ERROR; } /* Allocate memory to hold a single page of content */ static u8 *scrubBackupAllocPage(ScrubState *p){ u8 *pPage; if( p->rcErr ) return 0; pPage = sqlite3_malloc( p->szPage ); if( pPage==0 ) p->rcErr = SQLITE_NOMEM; return pPage; } /* Read a page from the source database into memory. Use the memory ** provided by pBuf if not NULL or allocate a new page if pBuf==NULL. */ static u8 *scrubBackupRead(ScrubState *p, int pgno, u8 *pBuf){ int rc; sqlite3_int64 iOff; u8 *pOut = pBuf; if( p->rcErr ) return 0; if( pOut==0 ){ pOut = scrubBackupAllocPage(p); if( pOut==0 ) return 0; } iOff = (pgno-1)*(sqlite3_int64)p->szPage; rc = p->pSrc->pMethods->xRead(p->pSrc, pOut, p->szPage, iOff); if( rc!=SQLITE_OK ){ if( pBuf==0 ) sqlite3_free(pOut); pOut = 0; scrubBackupErr(p, "read failed for page %d", pgno); p->rcErr = SQLITE_IOERR; } return pOut; } /* Write a page to the destination database */ static void scrubBackupWrite(ScrubState *p, int pgno, u8 *pData){ int rc; sqlite3_int64 iOff; if( p->rcErr ) return; iOff = (pgno-1)*(sqlite3_int64)p->szPage; rc = p->pDest->pMethods->xWrite(p->pDest, pData, p->szPage, iOff); if( rc!=SQLITE_OK ){ scrubBackupErr(p, "write failed for page %d", pgno); p->rcErr = SQLITE_IOERR; } } /* Prepare a statement against the "db" database. */ static sqlite3_stmt *scrubBackupPrepare( ScrubState *p, /* Backup context */ sqlite3 *db, /* Database to prepare against */ const char *zSql /* SQL statement */ ){ sqlite3_stmt *pStmt; if( p->rcErr ) return 0; p->rcErr = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0); if( p->rcErr ){ scrubBackupErr(p, "SQL error \"%s\" on \"%s\"", sqlite3_errmsg(db), zSql); sqlite3_finalize(pStmt); return 0; } return pStmt; } /* Open the source database file */ static void scrubBackupOpenSrc(ScrubState *p){ sqlite3_stmt *pStmt; int rc; /* Open the source database file */ p->rcErr = sqlite3_open_v2(p->zSrcFile, &p->dbSrc, SQLITE_OPEN_READONLY | SQLITE_OPEN_URI | SQLITE_OPEN_PRIVATECACHE, 0); if( p->rcErr ){ scrubBackupErr(p, "cannot open source database: %s", sqlite3_errmsg(p->dbSrc)); return; } p->rcErr = sqlite3_exec(p->dbSrc, "BEGIN", 0, 0, 0); if( p->rcErr ){ scrubBackupErr(p, "cannot start a read transaction on the source database: %s", sqlite3_errmsg(p->dbSrc)); return; } pStmt = scrubBackupPrepare(p, p->dbSrc, "PRAGMA page_size"); if( pStmt==0 ) return; rc = sqlite3_step(pStmt); if( rc==SQLITE_ROW ){ p->szPage = sqlite3_column_int(pStmt, 0); }else{ scrubBackupErr(p, "unable to determine the page size"); } sqlite3_finalize(pStmt); if( p->rcErr ) return; pStmt = scrubBackupPrepare(p, p->dbSrc, "PRAGMA page_count"); if( pStmt==0 ) return; rc = sqlite3_step(pStmt); if( rc==SQLITE_ROW ){ p->nPage = sqlite3_column_int(pStmt, 0); }else{ scrubBackupErr(p, "unable to determine the size of the source database"); } sqlite3_finalize(pStmt); sqlite3_file_control(p->dbSrc, "main", SQLITE_FCNTL_FILE_POINTER, &p->pSrc); if( p->pSrc==0 || p->pSrc->pMethods==0 ){ scrubBackupErr(p, "cannot get the source file handle"); p->rcErr = SQLITE_ERROR; } } /* Create and open the destination file */ static void scrubBackupOpenDest(ScrubState *p){ sqlite3_stmt *pStmt; int rc; char *zSql; if( p->rcErr ) return; p->rcErr = sqlite3_open_v2(p->zDestFile, &p->dbDest, SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_URI | SQLITE_OPEN_PRIVATECACHE, 0); if( p->rcErr ){ scrubBackupErr(p, "cannot open destination database: %s", sqlite3_errmsg(p->dbDest)); return; } zSql = sqlite3_mprintf("PRAGMA page_size(%u);", p->szPage); if( zSql==0 ){ p->rcErr = SQLITE_NOMEM; return; } p->rcErr = sqlite3_exec(p->dbDest, zSql, 0, 0, 0); sqlite3_free(zSql); if( p->rcErr ){ scrubBackupErr(p, "cannot set the page size on the destination database: %s", sqlite3_errmsg(p->dbDest)); return; } sqlite3_exec(p->dbDest, "PRAGMA journal_mode=OFF;", 0, 0, 0); p->rcErr = sqlite3_exec(p->dbDest, "BEGIN EXCLUSIVE;", 0, 0, 0); if( p->rcErr ){ scrubBackupErr(p, "cannot start a write transaction on the destination database: %s", sqlite3_errmsg(p->dbDest)); return; } pStmt = scrubBackupPrepare(p, p->dbDest, "PRAGMA page_count;"); if( pStmt==0 ) return; rc = sqlite3_step(pStmt); if( rc!=SQLITE_ROW ){ scrubBackupErr(p, "cannot measure the size of the destination"); }else if( sqlite3_column_int(pStmt, 0)>1 ){ scrubBackupErr(p, "destination database is not empty - holds %d pages", sqlite3_column_int(pStmt, 0)); } sqlite3_finalize(pStmt); sqlite3_file_control(p->dbDest, "main", SQLITE_FCNTL_FILE_POINTER, &p->pDest); if( p->pDest==0 || p->pDest->pMethods==0 ){ scrubBackupErr(p, "cannot get the destination file handle"); p->rcErr = SQLITE_ERROR; } } int sqlite3_scrub_backup( const char *zSrcFile, /* Source file */ const char *zDestFile, /* Destination file */ char **pzErr /* Write error here if non-NULL */ ){ ScrubState s; unsigned int i; u8 *pBuf = 0; u8 *pData; memset(&s, 0, sizeof(s)); s.zSrcFile = zSrcFile; s.zDestFile = zDestFile; scrubBackupOpenSrc(&s); scrubBackupOpenDest(&s); pBuf = scrubBackupAllocPage(&s); for(i=1; s.rcErr==0 && i<=s.nPage; i++){ pData = scrubBackupRead(&s, i, pBuf); scrubBackupWrite(&s, i, pData); } /* Close the destination database without closing the transaction. If we ** commit, page zero will be overwritten. */ sqlite3_close(s.dbDest); sqlite3_close(s.dbSrc); sqlite3_free(s.page1); if( pzErr ){ *pzErr = s.zErr; }else{ sqlite3_free(s.zErr); } return s.rcErr; } #ifdef SCRUB_STANDALONE /* The main() routine when this utility is run as a stand-alone program */ int main(int argc, char **argv){ char *zErr = 0; int rc; if( argc!=3 ){ fprintf(stderr,"Usage: %s SOURCE DESTINATION\n", argv[0]); exit(1); } rc = sqlite3_scrub_backup(argv[1], argv[2], &zErr); if( rc==SQLITE_NOMEM ){ fprintf(stderr, "%s: out of memory\n", argv[0]); exit(1); } if( zErr ){ fprintf(stderr, "%s: %s\n", argv[0], zErr); sqlite3_free(zErr); exit(1); } return 0; } #endif |
Changes to main.mk.
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484 485 486 487 488 489 490 491 492 493 494 495 496 497 | $(TCCX) $(READLINE_FLAGS) -o sqlite3$(EXE) $(SHELL_OPT) \ $(TOP)/src/shell.c libsqlite3.a $(LIBREADLINE) $(TLIBS) $(THREADLIB) sqldiff$(EXE): $(TOP)/tool/sqldiff.c sqlite3.c sqlite3.h $(TCCX) -o sqldiff$(EXE) -DSQLITE_THREADSAFE=0 \ $(TOP)/tool/sqldiff.c sqlite3.c $(TLIBS) $(THREADLIB) srcck1$(EXE): $(TOP)/tool/srcck1.c $(BCC) -o srcck1$(EXE) $(TOP)/tool/srcck1.c sourcetest: srcck1$(EXE) sqlite3.c ./srcck1 sqlite3.c fuzzershell$(EXE): $(TOP)/tool/fuzzershell.c sqlite3.c sqlite3.h | > > > | 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 | $(TCCX) $(READLINE_FLAGS) -o sqlite3$(EXE) $(SHELL_OPT) \ $(TOP)/src/shell.c libsqlite3.a $(LIBREADLINE) $(TLIBS) $(THREADLIB) sqldiff$(EXE): $(TOP)/tool/sqldiff.c sqlite3.c sqlite3.h $(TCCX) -o sqldiff$(EXE) -DSQLITE_THREADSAFE=0 \ $(TOP)/tool/sqldiff.c sqlite3.c $(TLIBS) $(THREADLIB) scrub$(EXE): $(TOP)/ext/misc/scrub.c sqlite3.o $(TCC) -I. -DSCRUB_STANDALONE -o scrub$(EXE) $(TOP)/ext/misc/scrub.c sqlite3.o $(THREADLIB) srcck1$(EXE): $(TOP)/tool/srcck1.c $(BCC) -o srcck1$(EXE) $(TOP)/tool/srcck1.c sourcetest: srcck1$(EXE) sqlite3.c ./srcck1 sqlite3.c fuzzershell$(EXE): $(TOP)/tool/fuzzershell.c sqlite3.c sqlite3.h |
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