1 /* 2 ** 2006 June 10 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 ** Code for testing the virtual table interfaces. This code 13 ** is not included in the SQLite library. It is used for automated 14 ** testing of the SQLite library. 15 */ 16 #include "sqliteInt.h" 17 #if defined(INCLUDE_SQLITE_TCL_H) 18 # include "sqlite_tcl.h" 19 #else 20 # include "tcl.h" 21 #endif 22 #include <stdlib.h> 23 #include <string.h> 24 25 #ifndef SQLITE_OMIT_VIRTUALTABLE 26 27 typedef struct echo_vtab echo_vtab; 28 typedef struct echo_cursor echo_cursor; 29 30 /* 31 ** The test module defined in this file uses four global Tcl variables to 32 ** commicate with test-scripts: 33 ** 34 ** $::echo_module 35 ** $::echo_module_sync_fail 36 ** $::echo_module_begin_fail 37 ** $::echo_module_cost 38 ** 39 ** The variable ::echo_module is a list. Each time one of the following 40 ** methods is called, one or more elements are appended to the list. 41 ** This is used for automated testing of virtual table modules. 42 ** 43 ** The ::echo_module_sync_fail variable is set by test scripts and read 44 ** by code in this file. If it is set to the name of a real table in the 45 ** the database, then all xSync operations on echo virtual tables that 46 ** use the named table as a backing store will fail. 47 */ 48 49 /* 50 ** Errors can be provoked within the following echo virtual table methods: 51 ** 52 ** xBestIndex xOpen xFilter xNext 53 ** xColumn xRowid xUpdate xSync 54 ** xBegin xRename 55 ** 56 ** This is done by setting the global tcl variable: 57 ** 58 ** echo_module_fail($method,$tbl) 59 ** 60 ** where $method is set to the name of the virtual table method to fail 61 ** (i.e. "xBestIndex") and $tbl is the name of the table being echoed (not 62 ** the name of the virtual table, the name of the underlying real table). 63 */ 64 65 /* 66 ** An echo virtual-table object. 67 ** 68 ** echo.vtab.aIndex is an array of booleans. The nth entry is true if 69 ** the nth column of the real table is the left-most column of an index 70 ** (implicit or otherwise). In other words, if SQLite can optimize 71 ** a query like "SELECT * FROM real_table WHERE col = ?". 72 ** 73 ** Member variable aCol[] contains copies of the column names of the real 74 ** table. 75 */ 76 struct echo_vtab { 77 sqlite3_vtab base; 78 Tcl_Interp *interp; /* Tcl interpreter containing debug variables */ 79 sqlite3 *db; /* Database connection */ 80 81 int isPattern; 82 int inTransaction; /* True if within a transaction */ 83 char *zThis; /* Name of the echo table */ 84 char *zTableName; /* Name of the real table */ 85 char *zLogName; /* Name of the log table */ 86 int nCol; /* Number of columns in the real table */ 87 int *aIndex; /* Array of size nCol. True if column has an index */ 88 char **aCol; /* Array of size nCol. Column names */ 89 }; 90 91 /* An echo cursor object */ 92 struct echo_cursor { 93 sqlite3_vtab_cursor base; 94 sqlite3_stmt *pStmt; 95 }; 96 97 static int simulateVtabError(echo_vtab *p, const char *zMethod){ 98 const char *zErr; 99 char zVarname[128]; 100 zVarname[127] = '\0'; 101 sqlite3_snprintf(127, zVarname, "echo_module_fail(%s,%s)", zMethod, p->zTableName); 102 zErr = Tcl_GetVar(p->interp, zVarname, TCL_GLOBAL_ONLY); 103 if( zErr ){ 104 p->base.zErrMsg = sqlite3_mprintf("echo-vtab-error: %s", zErr); 105 } 106 return (zErr!=0); 107 } 108 109 /* 110 ** Convert an SQL-style quoted string into a normal string by removing 111 ** the quote characters. The conversion is done in-place. If the 112 ** input does not begin with a quote character, then this routine 113 ** is a no-op. 114 ** 115 ** Examples: 116 ** 117 ** "abc" becomes abc 118 ** 'xyz' becomes xyz 119 ** [pqr] becomes pqr 120 ** `mno` becomes mno 121 */ 122 static void dequoteString(char *z){ 123 int quote; 124 int i, j; 125 if( z==0 ) return; 126 quote = z[0]; 127 switch( quote ){ 128 case '\'': break; 129 case '"': break; 130 case '`': break; /* For MySQL compatibility */ 131 case '[': quote = ']'; break; /* For MS SqlServer compatibility */ 132 default: return; 133 } 134 for(i=1, j=0; z[i]; i++){ 135 if( z[i]==quote ){ 136 if( z[i+1]==quote ){ 137 z[j++] = quote; 138 i++; 139 }else{ 140 z[j++] = 0; 141 break; 142 } 143 }else{ 144 z[j++] = z[i]; 145 } 146 } 147 } 148 149 /* 150 ** Retrieve the column names for the table named zTab via database 151 ** connection db. SQLITE_OK is returned on success, or an sqlite error 152 ** code otherwise. 153 ** 154 ** If successful, the number of columns is written to *pnCol. *paCol is 155 ** set to point at sqlite3_malloc()'d space containing the array of 156 ** nCol column names. The caller is responsible for calling sqlite3_free 157 ** on *paCol. 158 */ 159 static int getColumnNames( 160 sqlite3 *db, 161 const char *zTab, 162 char ***paCol, 163 int *pnCol 164 ){ 165 char **aCol = 0; 166 char *zSql; 167 sqlite3_stmt *pStmt = 0; 168 int rc = SQLITE_OK; 169 int nCol = 0; 170 171 /* Prepare the statement "SELECT * FROM <tbl>". The column names 172 ** of the result set of the compiled SELECT will be the same as 173 ** the column names of table <tbl>. 174 */ 175 zSql = sqlite3_mprintf("SELECT * FROM %Q", zTab); 176 if( !zSql ){ 177 rc = SQLITE_NOMEM; 178 goto out; 179 } 180 rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0); 181 sqlite3_free(zSql); 182 183 if( rc==SQLITE_OK ){ 184 int ii; 185 int nBytes; 186 char *zSpace; 187 nCol = sqlite3_column_count(pStmt); 188 189 /* Figure out how much space to allocate for the array of column names 190 ** (including space for the strings themselves). Then allocate it. 191 */ 192 nBytes = sizeof(char *) * nCol; 193 for(ii=0; ii<nCol; ii++){ 194 const char *zName = sqlite3_column_name(pStmt, ii); 195 if( !zName ){ 196 rc = SQLITE_NOMEM; 197 goto out; 198 } 199 nBytes += (int)strlen(zName)+1; 200 } 201 aCol = (char **)sqlite3MallocZero(nBytes); 202 if( !aCol ){ 203 rc = SQLITE_NOMEM; 204 goto out; 205 } 206 207 /* Copy the column names into the allocated space and set up the 208 ** pointers in the aCol[] array. 209 */ 210 zSpace = (char *)(&aCol[nCol]); 211 for(ii=0; ii<nCol; ii++){ 212 aCol[ii] = zSpace; 213 sqlite3_snprintf(nBytes, zSpace, "%s", sqlite3_column_name(pStmt,ii)); 214 zSpace += (int)strlen(zSpace) + 1; 215 } 216 assert( (zSpace-nBytes)==(char *)aCol ); 217 } 218 219 *paCol = aCol; 220 *pnCol = nCol; 221 222 out: 223 sqlite3_finalize(pStmt); 224 return rc; 225 } 226 227 /* 228 ** Parameter zTab is the name of a table in database db with nCol 229 ** columns. This function allocates an array of integers nCol in 230 ** size and populates it according to any implicit or explicit 231 ** indices on table zTab. 232 ** 233 ** If successful, SQLITE_OK is returned and *paIndex set to point 234 ** at the allocated array. Otherwise, an error code is returned. 235 ** 236 ** See comments associated with the member variable aIndex above 237 ** "struct echo_vtab" for details of the contents of the array. 238 */ 239 static int getIndexArray( 240 sqlite3 *db, /* Database connection */ 241 const char *zTab, /* Name of table in database db */ 242 int nCol, 243 int **paIndex 244 ){ 245 sqlite3_stmt *pStmt = 0; 246 int *aIndex = 0; 247 int rc; 248 char *zSql; 249 250 /* Allocate space for the index array */ 251 aIndex = (int *)sqlite3MallocZero(sizeof(int) * nCol); 252 if( !aIndex ){ 253 rc = SQLITE_NOMEM; 254 goto get_index_array_out; 255 } 256 257 /* Compile an sqlite pragma to loop through all indices on table zTab */ 258 zSql = sqlite3_mprintf("PRAGMA index_list(%s)", zTab); 259 if( !zSql ){ 260 rc = SQLITE_NOMEM; 261 goto get_index_array_out; 262 } 263 rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0); 264 sqlite3_free(zSql); 265 266 /* For each index, figure out the left-most column and set the 267 ** corresponding entry in aIndex[] to 1. 268 */ 269 while( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){ 270 const char *zIdx = (const char *)sqlite3_column_text(pStmt, 1); 271 sqlite3_stmt *pStmt2 = 0; 272 if( zIdx==0 ) continue; 273 zSql = sqlite3_mprintf("PRAGMA index_info(%s)", zIdx); 274 if( !zSql ){ 275 rc = SQLITE_NOMEM; 276 goto get_index_array_out; 277 } 278 rc = sqlite3_prepare(db, zSql, -1, &pStmt2, 0); 279 sqlite3_free(zSql); 280 if( pStmt2 && sqlite3_step(pStmt2)==SQLITE_ROW ){ 281 int cid = sqlite3_column_int(pStmt2, 1); 282 assert( cid>=0 && cid<nCol ); 283 aIndex[cid] = 1; 284 } 285 if( pStmt2 ){ 286 rc = sqlite3_finalize(pStmt2); 287 } 288 if( rc!=SQLITE_OK ){ 289 goto get_index_array_out; 290 } 291 } 292 293 294 get_index_array_out: 295 if( pStmt ){ 296 int rc2 = sqlite3_finalize(pStmt); 297 if( rc==SQLITE_OK ){ 298 rc = rc2; 299 } 300 } 301 if( rc!=SQLITE_OK ){ 302 sqlite3_free(aIndex); 303 aIndex = 0; 304 } 305 *paIndex = aIndex; 306 return rc; 307 } 308 309 /* 310 ** Global Tcl variable $echo_module is a list. This routine appends 311 ** the string element zArg to that list in interpreter interp. 312 */ 313 static void appendToEchoModule(Tcl_Interp *interp, const char *zArg){ 314 int flags = (TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY); 315 Tcl_SetVar(interp, "echo_module", (zArg?zArg:""), flags); 316 } 317 318 /* 319 ** This function is called from within the echo-modules xCreate and 320 ** xConnect methods. The argc and argv arguments are copies of those 321 ** passed to the calling method. This function is responsible for 322 ** calling sqlite3_declare_vtab() to declare the schema of the virtual 323 ** table being created or connected. 324 ** 325 ** If the constructor was passed just one argument, i.e.: 326 ** 327 ** CREATE TABLE t1 AS echo(t2); 328 ** 329 ** Then t2 is assumed to be the name of a *real* database table. The 330 ** schema of the virtual table is declared by passing a copy of the 331 ** CREATE TABLE statement for the real table to sqlite3_declare_vtab(). 332 ** Hence, the virtual table should have exactly the same column names and 333 ** types as the real table. 334 */ 335 static int echoDeclareVtab( 336 echo_vtab *pVtab, 337 sqlite3 *db 338 ){ 339 int rc = SQLITE_OK; 340 341 if( pVtab->zTableName ){ 342 sqlite3_stmt *pStmt = 0; 343 rc = sqlite3_prepare(db, 344 "SELECT sql FROM sqlite_master WHERE type = 'table' AND name = ?", 345 -1, &pStmt, 0); 346 if( rc==SQLITE_OK ){ 347 sqlite3_bind_text(pStmt, 1, pVtab->zTableName, -1, 0); 348 if( sqlite3_step(pStmt)==SQLITE_ROW ){ 349 int rc2; 350 const char *zCreateTable = (const char *)sqlite3_column_text(pStmt, 0); 351 rc = sqlite3_declare_vtab(db, zCreateTable); 352 rc2 = sqlite3_finalize(pStmt); 353 if( rc==SQLITE_OK ){ 354 rc = rc2; 355 } 356 } else { 357 rc = sqlite3_finalize(pStmt); 358 if( rc==SQLITE_OK ){ 359 rc = SQLITE_ERROR; 360 } 361 } 362 if( rc==SQLITE_OK ){ 363 rc = getColumnNames(db, pVtab->zTableName, &pVtab->aCol, &pVtab->nCol); 364 } 365 if( rc==SQLITE_OK ){ 366 rc = getIndexArray(db, pVtab->zTableName, pVtab->nCol, &pVtab->aIndex); 367 } 368 } 369 } 370 371 return rc; 372 } 373 374 /* 375 ** This function frees all runtime structures associated with the virtual 376 ** table pVtab. 377 */ 378 static int echoDestructor(sqlite3_vtab *pVtab){ 379 echo_vtab *p = (echo_vtab*)pVtab; 380 sqlite3_free(p->aIndex); 381 sqlite3_free(p->aCol); 382 sqlite3_free(p->zThis); 383 sqlite3_free(p->zTableName); 384 sqlite3_free(p->zLogName); 385 sqlite3_free(p); 386 return 0; 387 } 388 389 typedef struct EchoModule EchoModule; 390 struct EchoModule { 391 Tcl_Interp *interp; 392 }; 393 394 /* 395 ** This function is called to do the work of the xConnect() method - 396 ** to allocate the required in-memory structures for a newly connected 397 ** virtual table. 398 */ 399 static int echoConstructor( 400 sqlite3 *db, 401 void *pAux, 402 int argc, const char *const*argv, 403 sqlite3_vtab **ppVtab, 404 char **pzErr 405 ){ 406 int rc; 407 int i; 408 echo_vtab *pVtab; 409 410 /* Allocate the sqlite3_vtab/echo_vtab structure itself */ 411 pVtab = sqlite3MallocZero( sizeof(*pVtab) ); 412 if( !pVtab ){ 413 return SQLITE_NOMEM; 414 } 415 pVtab->interp = ((EchoModule *)pAux)->interp; 416 pVtab->db = db; 417 418 /* Allocate echo_vtab.zThis */ 419 pVtab->zThis = sqlite3_mprintf("%s", argv[2]); 420 if( !pVtab->zThis ){ 421 echoDestructor((sqlite3_vtab *)pVtab); 422 return SQLITE_NOMEM; 423 } 424 425 /* Allocate echo_vtab.zTableName */ 426 if( argc>3 ){ 427 pVtab->zTableName = sqlite3_mprintf("%s", argv[3]); 428 dequoteString(pVtab->zTableName); 429 if( pVtab->zTableName && pVtab->zTableName[0]=='*' ){ 430 char *z = sqlite3_mprintf("%s%s", argv[2], &(pVtab->zTableName[1])); 431 sqlite3_free(pVtab->zTableName); 432 pVtab->zTableName = z; 433 pVtab->isPattern = 1; 434 } 435 if( !pVtab->zTableName ){ 436 echoDestructor((sqlite3_vtab *)pVtab); 437 return SQLITE_NOMEM; 438 } 439 } 440 441 /* Log the arguments to this function to Tcl var ::echo_module */ 442 for(i=0; i<argc; i++){ 443 appendToEchoModule(pVtab->interp, argv[i]); 444 } 445 446 /* Invoke sqlite3_declare_vtab and set up other members of the echo_vtab 447 ** structure. If an error occurs, delete the sqlite3_vtab structure and 448 ** return an error code. 449 */ 450 rc = echoDeclareVtab(pVtab, db); 451 if( rc!=SQLITE_OK ){ 452 echoDestructor((sqlite3_vtab *)pVtab); 453 return rc; 454 } 455 456 /* Success. Set *ppVtab and return */ 457 *ppVtab = &pVtab->base; 458 return SQLITE_OK; 459 } 460 461 /* 462 ** Echo virtual table module xCreate method. 463 */ 464 static int echoCreate( 465 sqlite3 *db, 466 void *pAux, 467 int argc, const char *const*argv, 468 sqlite3_vtab **ppVtab, 469 char **pzErr 470 ){ 471 int rc = SQLITE_OK; 472 appendToEchoModule(((EchoModule *)pAux)->interp, "xCreate"); 473 rc = echoConstructor(db, pAux, argc, argv, ppVtab, pzErr); 474 475 /* If there were two arguments passed to the module at the SQL level 476 ** (i.e. "CREATE VIRTUAL TABLE tbl USING echo(arg1, arg2)"), then 477 ** the second argument is used as a table name. Attempt to create 478 ** such a table with a single column, "logmsg". This table will 479 ** be used to log calls to the xUpdate method. It will be deleted 480 ** when the virtual table is DROPed. 481 ** 482 ** Note: The main point of this is to test that we can drop tables 483 ** from within an xDestroy method call. 484 */ 485 if( rc==SQLITE_OK && argc==5 ){ 486 char *zSql; 487 echo_vtab *pVtab = *(echo_vtab **)ppVtab; 488 pVtab->zLogName = sqlite3_mprintf("%s", argv[4]); 489 zSql = sqlite3_mprintf("CREATE TABLE %Q(logmsg)", pVtab->zLogName); 490 rc = sqlite3_exec(db, zSql, 0, 0, 0); 491 sqlite3_free(zSql); 492 if( rc!=SQLITE_OK ){ 493 *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db)); 494 } 495 } 496 497 if( *ppVtab && rc!=SQLITE_OK ){ 498 echoDestructor(*ppVtab); 499 *ppVtab = 0; 500 } 501 502 if( rc==SQLITE_OK ){ 503 (*(echo_vtab**)ppVtab)->inTransaction = 1; 504 } 505 506 return rc; 507 } 508 509 /* 510 ** Echo virtual table module xConnect method. 511 */ 512 static int echoConnect( 513 sqlite3 *db, 514 void *pAux, 515 int argc, const char *const*argv, 516 sqlite3_vtab **ppVtab, 517 char **pzErr 518 ){ 519 appendToEchoModule(((EchoModule *)pAux)->interp, "xConnect"); 520 return echoConstructor(db, pAux, argc, argv, ppVtab, pzErr); 521 } 522 523 /* 524 ** Echo virtual table module xDisconnect method. 525 */ 526 static int echoDisconnect(sqlite3_vtab *pVtab){ 527 appendToEchoModule(((echo_vtab *)pVtab)->interp, "xDisconnect"); 528 return echoDestructor(pVtab); 529 } 530 531 /* 532 ** Echo virtual table module xDestroy method. 533 */ 534 static int echoDestroy(sqlite3_vtab *pVtab){ 535 int rc = SQLITE_OK; 536 echo_vtab *p = (echo_vtab *)pVtab; 537 appendToEchoModule(((echo_vtab *)pVtab)->interp, "xDestroy"); 538 539 /* Drop the "log" table, if one exists (see echoCreate() for details) */ 540 if( p && p->zLogName ){ 541 char *zSql; 542 zSql = sqlite3_mprintf("DROP TABLE %Q", p->zLogName); 543 rc = sqlite3_exec(p->db, zSql, 0, 0, 0); 544 sqlite3_free(zSql); 545 } 546 547 if( rc==SQLITE_OK ){ 548 rc = echoDestructor(pVtab); 549 } 550 return rc; 551 } 552 553 /* 554 ** Echo virtual table module xOpen method. 555 */ 556 static int echoOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){ 557 echo_cursor *pCur; 558 if( simulateVtabError((echo_vtab *)pVTab, "xOpen") ){ 559 return SQLITE_ERROR; 560 } 561 pCur = sqlite3MallocZero(sizeof(echo_cursor)); 562 *ppCursor = (sqlite3_vtab_cursor *)pCur; 563 return (pCur ? SQLITE_OK : SQLITE_NOMEM); 564 } 565 566 /* 567 ** Echo virtual table module xClose method. 568 */ 569 static int echoClose(sqlite3_vtab_cursor *cur){ 570 int rc; 571 echo_cursor *pCur = (echo_cursor *)cur; 572 sqlite3_stmt *pStmt = pCur->pStmt; 573 pCur->pStmt = 0; 574 sqlite3_free(pCur); 575 rc = sqlite3_finalize(pStmt); 576 return rc; 577 } 578 579 /* 580 ** Return non-zero if the cursor does not currently point to a valid record 581 ** (i.e if the scan has finished), or zero otherwise. 582 */ 583 static int echoEof(sqlite3_vtab_cursor *cur){ 584 return (((echo_cursor *)cur)->pStmt ? 0 : 1); 585 } 586 587 /* 588 ** Echo virtual table module xNext method. 589 */ 590 static int echoNext(sqlite3_vtab_cursor *cur){ 591 int rc = SQLITE_OK; 592 echo_cursor *pCur = (echo_cursor *)cur; 593 594 if( simulateVtabError((echo_vtab *)(cur->pVtab), "xNext") ){ 595 return SQLITE_ERROR; 596 } 597 598 if( pCur->pStmt ){ 599 rc = sqlite3_step(pCur->pStmt); 600 if( rc==SQLITE_ROW ){ 601 rc = SQLITE_OK; 602 }else{ 603 rc = sqlite3_finalize(pCur->pStmt); 604 pCur->pStmt = 0; 605 } 606 } 607 608 return rc; 609 } 610 611 /* 612 ** Echo virtual table module xColumn method. 613 */ 614 static int echoColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){ 615 int iCol = i + 1; 616 sqlite3_stmt *pStmt = ((echo_cursor *)cur)->pStmt; 617 618 if( simulateVtabError((echo_vtab *)(cur->pVtab), "xColumn") ){ 619 return SQLITE_ERROR; 620 } 621 622 if( !pStmt ){ 623 sqlite3_result_null(ctx); 624 }else{ 625 assert( sqlite3_data_count(pStmt)>iCol ); 626 sqlite3_result_value(ctx, sqlite3_column_value(pStmt, iCol)); 627 } 628 return SQLITE_OK; 629 } 630 631 /* 632 ** Echo virtual table module xRowid method. 633 */ 634 static int echoRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ 635 sqlite3_stmt *pStmt = ((echo_cursor *)cur)->pStmt; 636 637 if( simulateVtabError((echo_vtab *)(cur->pVtab), "xRowid") ){ 638 return SQLITE_ERROR; 639 } 640 641 *pRowid = sqlite3_column_int64(pStmt, 0); 642 return SQLITE_OK; 643 } 644 645 /* 646 ** Compute a simple hash of the null terminated string zString. 647 ** 648 ** This module uses only sqlite3_index_info.idxStr, not 649 ** sqlite3_index_info.idxNum. So to test idxNum, when idxStr is set 650 ** in echoBestIndex(), idxNum is set to the corresponding hash value. 651 ** In echoFilter(), code assert()s that the supplied idxNum value is 652 ** indeed the hash of the supplied idxStr. 653 */ 654 static int hashString(const char *zString){ 655 u32 val = 0; 656 int ii; 657 for(ii=0; zString[ii]; ii++){ 658 val = (val << 3) + (int)zString[ii]; 659 } 660 return (int)(val&0x7fffffff); 661 } 662 663 /* 664 ** Echo virtual table module xFilter method. 665 */ 666 static int echoFilter( 667 sqlite3_vtab_cursor *pVtabCursor, 668 int idxNum, const char *idxStr, 669 int argc, sqlite3_value **argv 670 ){ 671 int rc; 672 int i; 673 674 echo_cursor *pCur = (echo_cursor *)pVtabCursor; 675 echo_vtab *pVtab = (echo_vtab *)pVtabCursor->pVtab; 676 sqlite3 *db = pVtab->db; 677 678 if( simulateVtabError(pVtab, "xFilter") ){ 679 return SQLITE_ERROR; 680 } 681 682 /* Check that idxNum matches idxStr */ 683 assert( idxNum==hashString(idxStr) ); 684 685 /* Log arguments to the ::echo_module Tcl variable */ 686 appendToEchoModule(pVtab->interp, "xFilter"); 687 appendToEchoModule(pVtab->interp, idxStr); 688 for(i=0; i<argc; i++){ 689 appendToEchoModule(pVtab->interp, (const char*)sqlite3_value_text(argv[i])); 690 } 691 692 sqlite3_finalize(pCur->pStmt); 693 pCur->pStmt = 0; 694 695 /* Prepare the SQL statement created by echoBestIndex and bind the 696 ** runtime parameters passed to this function to it. 697 */ 698 rc = sqlite3_prepare(db, idxStr, -1, &pCur->pStmt, 0); 699 assert( pCur->pStmt || rc!=SQLITE_OK ); 700 for(i=0; rc==SQLITE_OK && i<argc; i++){ 701 rc = sqlite3_bind_value(pCur->pStmt, i+1, argv[i]); 702 } 703 704 /* If everything was successful, advance to the first row of the scan */ 705 if( rc==SQLITE_OK ){ 706 rc = echoNext(pVtabCursor); 707 } 708 709 return rc; 710 } 711 712 713 /* 714 ** A helper function used by echoUpdate() and echoBestIndex() for 715 ** manipulating strings in concert with the sqlite3_mprintf() function. 716 ** 717 ** Parameter pzStr points to a pointer to a string allocated with 718 ** sqlite3_mprintf. The second parameter, zAppend, points to another 719 ** string. The two strings are concatenated together and *pzStr 720 ** set to point at the result. The initial buffer pointed to by *pzStr 721 ** is deallocated via sqlite3_free(). 722 ** 723 ** If the third argument, doFree, is true, then sqlite3_free() is 724 ** also called to free the buffer pointed to by zAppend. 725 */ 726 static void string_concat(char **pzStr, char *zAppend, int doFree, int *pRc){ 727 char *zIn = *pzStr; 728 if( !zAppend && doFree && *pRc==SQLITE_OK ){ 729 *pRc = SQLITE_NOMEM; 730 } 731 if( *pRc!=SQLITE_OK ){ 732 sqlite3_free(zIn); 733 zIn = 0; 734 }else{ 735 if( zIn ){ 736 char *zTemp = zIn; 737 zIn = sqlite3_mprintf("%s%s", zIn, zAppend); 738 sqlite3_free(zTemp); 739 }else{ 740 zIn = sqlite3_mprintf("%s", zAppend); 741 } 742 if( !zIn ){ 743 *pRc = SQLITE_NOMEM; 744 } 745 } 746 *pzStr = zIn; 747 if( doFree ){ 748 sqlite3_free(zAppend); 749 } 750 } 751 752 /* 753 ** This function returns a pointer to an sqlite3_malloc()ed buffer 754 ** containing the select-list (the thing between keywords SELECT and FROM) 755 ** to query the underlying real table with for the scan described by 756 ** argument pIdxInfo. 757 ** 758 ** If the current SQLite version is earlier than 3.10.0, this is just "*" 759 ** (select all columns). Or, for version 3.10.0 and greater, the list of 760 ** columns identified by the pIdxInfo->colUsed mask. 761 */ 762 static char *echoSelectList(echo_vtab *pTab, sqlite3_index_info *pIdxInfo){ 763 char *zRet = 0; 764 if( sqlite3_libversion_number()<3010000 ){ 765 zRet = sqlite3_mprintf(", *"); 766 }else{ 767 int i; 768 for(i=0; i<pTab->nCol; i++){ 769 if( pIdxInfo->colUsed & ((sqlite3_uint64)1 << (i>=63 ? 63 : i)) ){ 770 zRet = sqlite3_mprintf("%z, %s", zRet, pTab->aCol[i]); 771 }else{ 772 zRet = sqlite3_mprintf("%z, NULL", zRet); 773 } 774 if( !zRet ) break; 775 } 776 } 777 return zRet; 778 } 779 780 /* 781 ** The echo module implements the subset of query constraints and sort 782 ** orders that may take advantage of SQLite indices on the underlying 783 ** real table. For example, if the real table is declared as: 784 ** 785 ** CREATE TABLE real(a, b, c); 786 ** CREATE INDEX real_index ON real(b); 787 ** 788 ** then the echo module handles WHERE or ORDER BY clauses that refer 789 ** to the column "b", but not "a" or "c". If a multi-column index is 790 ** present, only its left most column is considered. 791 ** 792 ** This xBestIndex method encodes the proposed search strategy as 793 ** an SQL query on the real table underlying the virtual echo module 794 ** table and stores the query in sqlite3_index_info.idxStr. The SQL 795 ** statement is of the form: 796 ** 797 ** SELECT rowid, * FROM <real-table> ?<where-clause>? ?<order-by-clause>? 798 ** 799 ** where the <where-clause> and <order-by-clause> are determined 800 ** by the contents of the structure pointed to by the pIdxInfo argument. 801 */ 802 static int echoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){ 803 int ii; 804 char *zQuery = 0; 805 char *zCol = 0; 806 char *zNew; 807 int nArg = 0; 808 const char *zSep = "WHERE"; 809 echo_vtab *pVtab = (echo_vtab *)tab; 810 sqlite3_stmt *pStmt = 0; 811 Tcl_Interp *interp = pVtab->interp; 812 813 int nRow = 0; 814 int useIdx = 0; 815 int rc = SQLITE_OK; 816 int useCost = 0; 817 double cost = 0; 818 int isIgnoreUsable = 0; 819 if( Tcl_GetVar(interp, "echo_module_ignore_usable", TCL_GLOBAL_ONLY) ){ 820 isIgnoreUsable = 1; 821 } 822 823 if( simulateVtabError(pVtab, "xBestIndex") ){ 824 return SQLITE_ERROR; 825 } 826 827 /* Determine the number of rows in the table and store this value in local 828 ** variable nRow. The 'estimated-cost' of the scan will be the number of 829 ** rows in the table for a linear scan, or the log (base 2) of the 830 ** number of rows if the proposed scan uses an index. 831 */ 832 if( Tcl_GetVar(interp, "echo_module_cost", TCL_GLOBAL_ONLY) ){ 833 cost = atof(Tcl_GetVar(interp, "echo_module_cost", TCL_GLOBAL_ONLY)); 834 useCost = 1; 835 } else { 836 zQuery = sqlite3_mprintf("SELECT count(*) FROM %Q", pVtab->zTableName); 837 if( !zQuery ){ 838 return SQLITE_NOMEM; 839 } 840 rc = sqlite3_prepare(pVtab->db, zQuery, -1, &pStmt, 0); 841 sqlite3_free(zQuery); 842 if( rc!=SQLITE_OK ){ 843 return rc; 844 } 845 sqlite3_step(pStmt); 846 nRow = sqlite3_column_int(pStmt, 0); 847 rc = sqlite3_finalize(pStmt); 848 if( rc!=SQLITE_OK ){ 849 return rc; 850 } 851 } 852 853 zCol = echoSelectList(pVtab, pIdxInfo); 854 if( !zCol ) return SQLITE_NOMEM; 855 zQuery = sqlite3_mprintf("SELECT rowid%z FROM %Q", zCol, pVtab->zTableName); 856 if( !zQuery ) return SQLITE_NOMEM; 857 858 for(ii=0; ii<pIdxInfo->nConstraint; ii++){ 859 const struct sqlite3_index_constraint *pConstraint; 860 struct sqlite3_index_constraint_usage *pUsage; 861 int iCol; 862 863 pConstraint = &pIdxInfo->aConstraint[ii]; 864 pUsage = &pIdxInfo->aConstraintUsage[ii]; 865 866 if( !isIgnoreUsable && !pConstraint->usable ) continue; 867 868 iCol = pConstraint->iColumn; 869 if( iCol<0 || pVtab->aIndex[iCol] ){ 870 char *zNewCol = iCol>=0 ? pVtab->aCol[iCol] : "rowid"; 871 char *zOp = 0; 872 useIdx = 1; 873 switch( pConstraint->op ){ 874 case SQLITE_INDEX_CONSTRAINT_EQ: 875 zOp = "="; break; 876 case SQLITE_INDEX_CONSTRAINT_LT: 877 zOp = "<"; break; 878 case SQLITE_INDEX_CONSTRAINT_GT: 879 zOp = ">"; break; 880 case SQLITE_INDEX_CONSTRAINT_LE: 881 zOp = "<="; break; 882 case SQLITE_INDEX_CONSTRAINT_GE: 883 zOp = ">="; break; 884 case SQLITE_INDEX_CONSTRAINT_MATCH: 885 /* Purposely translate the MATCH operator into a LIKE, which 886 ** will be used by the next block of code to construct a new 887 ** query. It should also be noted here that the next block 888 ** of code requires the first letter of this operator to be 889 ** in upper-case to trigger the special MATCH handling (i.e. 890 ** wrapping the bound parameter with literal '%'s). 891 */ 892 zOp = "LIKE"; break; 893 case SQLITE_INDEX_CONSTRAINT_LIKE: 894 zOp = "like"; break; 895 case SQLITE_INDEX_CONSTRAINT_GLOB: 896 zOp = "glob"; break; 897 case SQLITE_INDEX_CONSTRAINT_REGEXP: 898 zOp = "regexp"; break; 899 } 900 if( zOp ){ 901 if( zOp[0]=='L' ){ 902 zNew = sqlite3_mprintf(" %s %s LIKE (SELECT '%%'||?||'%%')", 903 zSep, zNewCol); 904 } else { 905 zNew = sqlite3_mprintf(" %s %s %s ?", zSep, zNewCol, zOp); 906 } 907 string_concat(&zQuery, zNew, 1, &rc); 908 zSep = "AND"; 909 pUsage->argvIndex = ++nArg; 910 pUsage->omit = 1; 911 } 912 } 913 } 914 915 /* If there is only one term in the ORDER BY clause, and it is 916 ** on a column that this virtual table has an index for, then consume 917 ** the ORDER BY clause. 918 */ 919 if( pIdxInfo->nOrderBy==1 && ( 920 pIdxInfo->aOrderBy->iColumn<0 || 921 pVtab->aIndex[pIdxInfo->aOrderBy->iColumn]) ){ 922 int iCol = pIdxInfo->aOrderBy->iColumn; 923 char *zNewCol = iCol>=0 ? pVtab->aCol[iCol] : "rowid"; 924 char *zDir = pIdxInfo->aOrderBy->desc?"DESC":"ASC"; 925 zNew = sqlite3_mprintf(" ORDER BY %s %s", zNewCol, zDir); 926 string_concat(&zQuery, zNew, 1, &rc); 927 pIdxInfo->orderByConsumed = 1; 928 } 929 930 appendToEchoModule(pVtab->interp, "xBestIndex");; 931 appendToEchoModule(pVtab->interp, zQuery); 932 933 if( !zQuery ){ 934 return rc; 935 } 936 pIdxInfo->idxNum = hashString(zQuery); 937 pIdxInfo->idxStr = zQuery; 938 pIdxInfo->needToFreeIdxStr = 1; 939 if( useCost ){ 940 pIdxInfo->estimatedCost = cost; 941 }else if( useIdx ){ 942 /* Approximation of log2(nRow). */ 943 for( ii=0; ii<(sizeof(int)*8)-1; ii++ ){ 944 if( nRow & (1<<ii) ){ 945 pIdxInfo->estimatedCost = (double)ii; 946 } 947 } 948 }else{ 949 pIdxInfo->estimatedCost = (double)nRow; 950 } 951 return rc; 952 } 953 954 /* 955 ** The xUpdate method for echo module virtual tables. 956 ** 957 ** apData[0] apData[1] apData[2..] 958 ** 959 ** INTEGER DELETE 960 ** 961 ** INTEGER NULL (nCol args) UPDATE (do not set rowid) 962 ** INTEGER INTEGER (nCol args) UPDATE (with SET rowid = <arg1>) 963 ** 964 ** NULL NULL (nCol args) INSERT INTO (automatic rowid value) 965 ** NULL INTEGER (nCol args) INSERT (incl. rowid value) 966 ** 967 */ 968 int echoUpdate( 969 sqlite3_vtab *tab, 970 int nData, 971 sqlite3_value **apData, 972 sqlite_int64 *pRowid 973 ){ 974 echo_vtab *pVtab = (echo_vtab *)tab; 975 sqlite3 *db = pVtab->db; 976 int rc = SQLITE_OK; 977 978 sqlite3_stmt *pStmt = 0; 979 char *z = 0; /* SQL statement to execute */ 980 int bindArgZero = 0; /* True to bind apData[0] to sql var no. nData */ 981 int bindArgOne = 0; /* True to bind apData[1] to sql var no. 1 */ 982 int i; /* Counter variable used by for loops */ 983 984 assert( nData==pVtab->nCol+2 || nData==1 ); 985 986 /* Ticket #3083 - make sure we always start a transaction prior to 987 ** making any changes to a virtual table */ 988 assert( pVtab->inTransaction ); 989 990 if( simulateVtabError(pVtab, "xUpdate") ){ 991 return SQLITE_ERROR; 992 } 993 994 /* If apData[0] is an integer and nData>1 then do an UPDATE */ 995 if( nData>1 && sqlite3_value_type(apData[0])==SQLITE_INTEGER ){ 996 char *zSep = " SET"; 997 z = sqlite3_mprintf("UPDATE %Q", pVtab->zTableName); 998 if( !z ){ 999 rc = SQLITE_NOMEM; 1000 } 1001 1002 bindArgOne = (apData[1] && sqlite3_value_type(apData[1])==SQLITE_INTEGER); 1003 bindArgZero = 1; 1004 1005 if( bindArgOne ){ 1006 string_concat(&z, " SET rowid=?1 ", 0, &rc); 1007 zSep = ","; 1008 } 1009 for(i=2; i<nData; i++){ 1010 if( apData[i]==0 ) continue; 1011 string_concat(&z, sqlite3_mprintf( 1012 "%s %Q=?%d", zSep, pVtab->aCol[i-2], i), 1, &rc); 1013 zSep = ","; 1014 } 1015 string_concat(&z, sqlite3_mprintf(" WHERE rowid=?%d", nData), 1, &rc); 1016 } 1017 1018 /* If apData[0] is an integer and nData==1 then do a DELETE */ 1019 else if( nData==1 && sqlite3_value_type(apData[0])==SQLITE_INTEGER ){ 1020 z = sqlite3_mprintf("DELETE FROM %Q WHERE rowid = ?1", pVtab->zTableName); 1021 if( !z ){ 1022 rc = SQLITE_NOMEM; 1023 } 1024 bindArgZero = 1; 1025 } 1026 1027 /* If the first argument is NULL and there are more than two args, INSERT */ 1028 else if( nData>2 && sqlite3_value_type(apData[0])==SQLITE_NULL ){ 1029 int ii; 1030 char *zInsert = 0; 1031 char *zValues = 0; 1032 1033 zInsert = sqlite3_mprintf("INSERT INTO %Q (", pVtab->zTableName); 1034 if( !zInsert ){ 1035 rc = SQLITE_NOMEM; 1036 } 1037 if( sqlite3_value_type(apData[1])==SQLITE_INTEGER ){ 1038 bindArgOne = 1; 1039 zValues = sqlite3_mprintf("?"); 1040 string_concat(&zInsert, "rowid", 0, &rc); 1041 } 1042 1043 assert((pVtab->nCol+2)==nData); 1044 for(ii=2; ii<nData; ii++){ 1045 string_concat(&zInsert, 1046 sqlite3_mprintf("%s%Q", zValues?", ":"", pVtab->aCol[ii-2]), 1, &rc); 1047 string_concat(&zValues, 1048 sqlite3_mprintf("%s?%d", zValues?", ":"", ii), 1, &rc); 1049 } 1050 1051 string_concat(&z, zInsert, 1, &rc); 1052 string_concat(&z, ") VALUES(", 0, &rc); 1053 string_concat(&z, zValues, 1, &rc); 1054 string_concat(&z, ")", 0, &rc); 1055 } 1056 1057 /* Anything else is an error */ 1058 else{ 1059 assert(0); 1060 return SQLITE_ERROR; 1061 } 1062 1063 if( rc==SQLITE_OK ){ 1064 rc = sqlite3_prepare(db, z, -1, &pStmt, 0); 1065 } 1066 assert( rc!=SQLITE_OK || pStmt ); 1067 sqlite3_free(z); 1068 if( rc==SQLITE_OK ) { 1069 if( bindArgZero ){ 1070 sqlite3_bind_value(pStmt, nData, apData[0]); 1071 } 1072 if( bindArgOne ){ 1073 sqlite3_bind_value(pStmt, 1, apData[1]); 1074 } 1075 for(i=2; i<nData && rc==SQLITE_OK; i++){ 1076 if( apData[i] ) rc = sqlite3_bind_value(pStmt, i, apData[i]); 1077 } 1078 if( rc==SQLITE_OK ){ 1079 sqlite3_step(pStmt); 1080 rc = sqlite3_finalize(pStmt); 1081 }else{ 1082 sqlite3_finalize(pStmt); 1083 } 1084 } 1085 1086 if( pRowid && rc==SQLITE_OK ){ 1087 *pRowid = sqlite3_last_insert_rowid(db); 1088 } 1089 if( rc!=SQLITE_OK ){ 1090 tab->zErrMsg = sqlite3_mprintf("echo-vtab-error: %s", sqlite3_errmsg(db)); 1091 } 1092 1093 return rc; 1094 } 1095 1096 /* 1097 ** xBegin, xSync, xCommit and xRollback callbacks for echo module 1098 ** virtual tables. Do nothing other than add the name of the callback 1099 ** to the $::echo_module Tcl variable. 1100 */ 1101 static int echoTransactionCall(sqlite3_vtab *tab, const char *zCall){ 1102 char *z; 1103 echo_vtab *pVtab = (echo_vtab *)tab; 1104 z = sqlite3_mprintf("echo(%s)", pVtab->zTableName); 1105 if( z==0 ) return SQLITE_NOMEM; 1106 appendToEchoModule(pVtab->interp, zCall); 1107 appendToEchoModule(pVtab->interp, z); 1108 sqlite3_free(z); 1109 return SQLITE_OK; 1110 } 1111 static int echoBegin(sqlite3_vtab *tab){ 1112 int rc; 1113 echo_vtab *pVtab = (echo_vtab *)tab; 1114 Tcl_Interp *interp = pVtab->interp; 1115 const char *zVal; 1116 1117 /* Ticket #3083 - do not start a transaction if we are already in 1118 ** a transaction */ 1119 assert( !pVtab->inTransaction ); 1120 1121 if( simulateVtabError(pVtab, "xBegin") ){ 1122 return SQLITE_ERROR; 1123 } 1124 1125 rc = echoTransactionCall(tab, "xBegin"); 1126 1127 if( rc==SQLITE_OK ){ 1128 /* Check if the $::echo_module_begin_fail variable is defined. If it is, 1129 ** and it is set to the name of the real table underlying this virtual 1130 ** echo module table, then cause this xSync operation to fail. 1131 */ 1132 zVal = Tcl_GetVar(interp, "echo_module_begin_fail", TCL_GLOBAL_ONLY); 1133 if( zVal && 0==strcmp(zVal, pVtab->zTableName) ){ 1134 rc = SQLITE_ERROR; 1135 } 1136 } 1137 if( rc==SQLITE_OK ){ 1138 pVtab->inTransaction = 1; 1139 } 1140 return rc; 1141 } 1142 static int echoSync(sqlite3_vtab *tab){ 1143 int rc; 1144 echo_vtab *pVtab = (echo_vtab *)tab; 1145 Tcl_Interp *interp = pVtab->interp; 1146 const char *zVal; 1147 1148 /* Ticket #3083 - Only call xSync if we have previously started a 1149 ** transaction */ 1150 assert( pVtab->inTransaction ); 1151 1152 if( simulateVtabError(pVtab, "xSync") ){ 1153 return SQLITE_ERROR; 1154 } 1155 1156 rc = echoTransactionCall(tab, "xSync"); 1157 1158 if( rc==SQLITE_OK ){ 1159 /* Check if the $::echo_module_sync_fail variable is defined. If it is, 1160 ** and it is set to the name of the real table underlying this virtual 1161 ** echo module table, then cause this xSync operation to fail. 1162 */ 1163 zVal = Tcl_GetVar(interp, "echo_module_sync_fail", TCL_GLOBAL_ONLY); 1164 if( zVal && 0==strcmp(zVal, pVtab->zTableName) ){ 1165 rc = -1; 1166 } 1167 } 1168 return rc; 1169 } 1170 static int echoCommit(sqlite3_vtab *tab){ 1171 echo_vtab *pVtab = (echo_vtab*)tab; 1172 int rc; 1173 1174 /* Ticket #3083 - Only call xCommit if we have previously started 1175 ** a transaction */ 1176 assert( pVtab->inTransaction ); 1177 1178 if( simulateVtabError(pVtab, "xCommit") ){ 1179 return SQLITE_ERROR; 1180 } 1181 1182 sqlite3BeginBenignMalloc(); 1183 rc = echoTransactionCall(tab, "xCommit"); 1184 sqlite3EndBenignMalloc(); 1185 pVtab->inTransaction = 0; 1186 return rc; 1187 } 1188 static int echoRollback(sqlite3_vtab *tab){ 1189 int rc; 1190 echo_vtab *pVtab = (echo_vtab*)tab; 1191 1192 /* Ticket #3083 - Only call xRollback if we have previously started 1193 ** a transaction */ 1194 assert( pVtab->inTransaction ); 1195 1196 rc = echoTransactionCall(tab, "xRollback"); 1197 pVtab->inTransaction = 0; 1198 return rc; 1199 } 1200 1201 /* 1202 ** Implementation of "GLOB" function on the echo module. Pass 1203 ** all arguments to the ::echo_glob_overload procedure of TCL 1204 ** and return the result of that procedure as a string. 1205 */ 1206 static void overloadedGlobFunction( 1207 sqlite3_context *pContext, 1208 int nArg, 1209 sqlite3_value **apArg 1210 ){ 1211 Tcl_Interp *interp = sqlite3_user_data(pContext); 1212 Tcl_DString str; 1213 int i; 1214 int rc; 1215 Tcl_DStringInit(&str); 1216 Tcl_DStringAppendElement(&str, "::echo_glob_overload"); 1217 for(i=0; i<nArg; i++){ 1218 Tcl_DStringAppendElement(&str, (char*)sqlite3_value_text(apArg[i])); 1219 } 1220 rc = Tcl_Eval(interp, Tcl_DStringValue(&str)); 1221 Tcl_DStringFree(&str); 1222 if( rc ){ 1223 sqlite3_result_error(pContext, Tcl_GetStringResult(interp), -1); 1224 }else{ 1225 sqlite3_result_text(pContext, Tcl_GetStringResult(interp), 1226 -1, SQLITE_TRANSIENT); 1227 } 1228 Tcl_ResetResult(interp); 1229 } 1230 1231 /* 1232 ** This is the xFindFunction implementation for the echo module. 1233 ** SQLite calls this routine when the first argument of a function 1234 ** is a column of an echo virtual table. This routine can optionally 1235 ** override the implementation of that function. It will choose to 1236 ** do so if the function is named "glob", and a TCL command named 1237 ** ::echo_glob_overload exists. 1238 */ 1239 static int echoFindFunction( 1240 sqlite3_vtab *vtab, 1241 int nArg, 1242 const char *zFuncName, 1243 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 1244 void **ppArg 1245 ){ 1246 echo_vtab *pVtab = (echo_vtab *)vtab; 1247 Tcl_Interp *interp = pVtab->interp; 1248 Tcl_CmdInfo info; 1249 if( strcmp(zFuncName,"glob")!=0 ){ 1250 return 0; 1251 } 1252 if( Tcl_GetCommandInfo(interp, "::echo_glob_overload", &info)==0 ){ 1253 return 0; 1254 } 1255 *pxFunc = overloadedGlobFunction; 1256 *ppArg = interp; 1257 return 1; 1258 } 1259 1260 static int echoRename(sqlite3_vtab *vtab, const char *zNewName){ 1261 int rc = SQLITE_OK; 1262 echo_vtab *p = (echo_vtab *)vtab; 1263 1264 if( simulateVtabError(p, "xRename") ){ 1265 return SQLITE_ERROR; 1266 } 1267 1268 if( p->isPattern ){ 1269 int nThis = (int)strlen(p->zThis); 1270 char *zSql = sqlite3_mprintf("ALTER TABLE %s RENAME TO %s%s", 1271 p->zTableName, zNewName, &p->zTableName[nThis] 1272 ); 1273 rc = sqlite3_exec(p->db, zSql, 0, 0, 0); 1274 sqlite3_free(zSql); 1275 } 1276 1277 return rc; 1278 } 1279 1280 static int echoSavepoint(sqlite3_vtab *pVTab, int iSavepoint){ 1281 assert( pVTab ); 1282 return SQLITE_OK; 1283 } 1284 1285 static int echoRelease(sqlite3_vtab *pVTab, int iSavepoint){ 1286 assert( pVTab ); 1287 return SQLITE_OK; 1288 } 1289 1290 static int echoRollbackTo(sqlite3_vtab *pVTab, int iSavepoint){ 1291 assert( pVTab ); 1292 return SQLITE_OK; 1293 } 1294 1295 /* 1296 ** A virtual table module that merely "echos" the contents of another 1297 ** table (like an SQL VIEW). 1298 */ 1299 static sqlite3_module echoModule = { 1300 1, /* iVersion */ 1301 echoCreate, 1302 echoConnect, 1303 echoBestIndex, 1304 echoDisconnect, 1305 echoDestroy, 1306 echoOpen, /* xOpen - open a cursor */ 1307 echoClose, /* xClose - close a cursor */ 1308 echoFilter, /* xFilter - configure scan constraints */ 1309 echoNext, /* xNext - advance a cursor */ 1310 echoEof, /* xEof */ 1311 echoColumn, /* xColumn - read data */ 1312 echoRowid, /* xRowid - read data */ 1313 echoUpdate, /* xUpdate - write data */ 1314 echoBegin, /* xBegin - begin transaction */ 1315 echoSync, /* xSync - sync transaction */ 1316 echoCommit, /* xCommit - commit transaction */ 1317 echoRollback, /* xRollback - rollback transaction */ 1318 echoFindFunction, /* xFindFunction - function overloading */ 1319 echoRename /* xRename - rename the table */ 1320 }; 1321 1322 static sqlite3_module echoModuleV2 = { 1323 2, /* iVersion */ 1324 echoCreate, 1325 echoConnect, 1326 echoBestIndex, 1327 echoDisconnect, 1328 echoDestroy, 1329 echoOpen, /* xOpen - open a cursor */ 1330 echoClose, /* xClose - close a cursor */ 1331 echoFilter, /* xFilter - configure scan constraints */ 1332 echoNext, /* xNext - advance a cursor */ 1333 echoEof, /* xEof */ 1334 echoColumn, /* xColumn - read data */ 1335 echoRowid, /* xRowid - read data */ 1336 echoUpdate, /* xUpdate - write data */ 1337 echoBegin, /* xBegin - begin transaction */ 1338 echoSync, /* xSync - sync transaction */ 1339 echoCommit, /* xCommit - commit transaction */ 1340 echoRollback, /* xRollback - rollback transaction */ 1341 echoFindFunction, /* xFindFunction - function overloading */ 1342 echoRename, /* xRename - rename the table */ 1343 echoSavepoint, 1344 echoRelease, 1345 echoRollbackTo 1346 }; 1347 1348 /* 1349 ** Decode a pointer to an sqlite3 object. 1350 */ 1351 extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb); 1352 extern const char *sqlite3ErrName(int); 1353 1354 static void moduleDestroy(void *p){ 1355 sqlite3_free(p); 1356 } 1357 1358 /* 1359 ** Register the echo virtual table module. 1360 */ 1361 static int SQLITE_TCLAPI register_echo_module( 1362 ClientData clientData, /* Pointer to sqlite3_enable_XXX function */ 1363 Tcl_Interp *interp, /* The TCL interpreter that invoked this command */ 1364 int objc, /* Number of arguments */ 1365 Tcl_Obj *CONST objv[] /* Command arguments */ 1366 ){ 1367 int rc; 1368 sqlite3 *db; 1369 EchoModule *pMod; 1370 if( objc!=2 ){ 1371 Tcl_WrongNumArgs(interp, 1, objv, "DB"); 1372 return TCL_ERROR; 1373 } 1374 if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR; 1375 1376 /* Virtual table module "echo" */ 1377 pMod = sqlite3_malloc(sizeof(EchoModule)); 1378 pMod->interp = interp; 1379 rc = sqlite3_create_module_v2( 1380 db, "echo", &echoModule, (void*)pMod, moduleDestroy 1381 ); 1382 1383 /* Virtual table module "echo_v2" */ 1384 if( rc==SQLITE_OK ){ 1385 pMod = sqlite3_malloc(sizeof(EchoModule)); 1386 pMod->interp = interp; 1387 rc = sqlite3_create_module_v2(db, "echo_v2", 1388 &echoModuleV2, (void*)pMod, moduleDestroy 1389 ); 1390 } 1391 1392 Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC); 1393 return TCL_OK; 1394 } 1395 1396 /* 1397 ** Tcl interface to sqlite3_declare_vtab, invoked as follows from Tcl: 1398 ** 1399 ** sqlite3_declare_vtab DB SQL 1400 */ 1401 static int SQLITE_TCLAPI declare_vtab( 1402 ClientData clientData, /* Pointer to sqlite3_enable_XXX function */ 1403 Tcl_Interp *interp, /* The TCL interpreter that invoked this command */ 1404 int objc, /* Number of arguments */ 1405 Tcl_Obj *CONST objv[] /* Command arguments */ 1406 ){ 1407 sqlite3 *db; 1408 int rc; 1409 if( objc!=3 ){ 1410 Tcl_WrongNumArgs(interp, 1, objv, "DB SQL"); 1411 return TCL_ERROR; 1412 } 1413 if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR; 1414 rc = sqlite3_declare_vtab(db, Tcl_GetString(objv[2])); 1415 if( rc!=SQLITE_OK ){ 1416 Tcl_SetResult(interp, (char *)sqlite3_errmsg(db), TCL_VOLATILE); 1417 return TCL_ERROR; 1418 } 1419 return TCL_OK; 1420 } 1421 1422 #endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */ 1423 1424 /* 1425 ** Register commands with the TCL interpreter. 1426 */ 1427 int Sqlitetest8_Init(Tcl_Interp *interp){ 1428 #ifndef SQLITE_OMIT_VIRTUALTABLE 1429 static struct { 1430 char *zName; 1431 Tcl_ObjCmdProc *xProc; 1432 void *clientData; 1433 } aObjCmd[] = { 1434 { "register_echo_module", register_echo_module, 0 }, 1435 { "sqlite3_declare_vtab", declare_vtab, 0 }, 1436 }; 1437 int i; 1438 for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){ 1439 Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 1440 aObjCmd[i].xProc, aObjCmd[i].clientData, 0); 1441 } 1442 #endif 1443 return TCL_OK; 1444 } 1445