Repository navigation
Expand file tree
/
Copy pathtest8.c
More file actions
1450 lines (1316 loc) · 41 KB
/
Copy pathtest8.c
File metadata and controls
1450 lines (1316 loc) · 41 KB
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
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
** 2006 June 10
**
** 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.
**
*************************************************************************
** Code for testing the virtual table interfaces. This code
** is not included in the SQLite library. It is used for automated
** testing of the SQLite library.
*/
#include "sqliteInt.h"
#if defined(INCLUDE_SQLITE_TCL_H)
# include "sqlite_tcl.h"
#else
# include "tcl.h"
#endif
#include <stdlib.h>
#include <string.h>
#ifndef SQLITE_OMIT_VIRTUALTABLE
typedef struct echo_vtab echo_vtab;
typedef struct echo_cursor echo_cursor;
/*
** The test module defined in this file uses four global Tcl variables to
** commicate with test-scripts:
**
** $::echo_module
** $::echo_module_sync_fail
** $::echo_module_begin_fail
** $::echo_module_cost
**
** The variable ::echo_module is a list. Each time one of the following
** methods is called, one or more elements are appended to the list.
** This is used for automated testing of virtual table modules.
**
** The ::echo_module_sync_fail variable is set by test scripts and read
** by code in this file. If it is set to the name of a real table in the
** the database, then all xSync operations on echo virtual tables that
** use the named table as a backing store will fail.
*/
/*
** Errors can be provoked within the following echo virtual table methods:
**
** xBestIndex xOpen xFilter xNext
** xColumn xRowid xUpdate xSync
** xBegin xRename
**
** This is done by setting the global tcl variable:
**
** echo_module_fail($method,$tbl)
**
** where $method is set to the name of the virtual table method to fail
** (i.e. "xBestIndex") and $tbl is the name of the table being echoed (not
** the name of the virtual table, the name of the underlying real table).
*/
/*
** An echo virtual-table object.
**
** echo.vtab.aIndex is an array of booleans. The nth entry is true if
** the nth column of the real table is the left-most column of an index
** (implicit or otherwise). In other words, if SQLite can optimize
** a query like "SELECT * FROM real_table WHERE col = ?".
**
** Member variable aCol[] contains copies of the column names of the real
** table.
*/
struct echo_vtab {
sqlite3_vtab base;
Tcl_Interp *interp; /* Tcl interpreter containing debug variables */
sqlite3 *db; /* Database connection */
int isPattern;
int inTransaction; /* True if within a transaction */
char *zThis; /* Name of the echo table */
char *zTableName; /* Name of the real table */
char *zLogName; /* Name of the log table */
int nCol; /* Number of columns in the real table */
int *aIndex; /* Array of size nCol. True if column has an index */
char **aCol; /* Array of size nCol. Column names */
};
/* An echo cursor object */
struct echo_cursor {
sqlite3_vtab_cursor base;
sqlite3_stmt *pStmt;
};
static int simulateVtabError(echo_vtab *p, const char *zMethod){
const char *zErr;
char zVarname[128];
zVarname[127] = '\0';
sqlite3_snprintf(127, zVarname, "echo_module_fail(%s,%s)", zMethod, p->zTableName);
zErr = Tcl_GetVar(p->interp, zVarname, TCL_GLOBAL_ONLY);
if( zErr ){
p->base.zErrMsg = sqlite3_mprintf("echo-vtab-error: %s", zErr);
}
return (zErr!=0);
}
/*
** Convert an SQL-style quoted string into a normal string by removing
** the quote characters. The conversion is done in-place. If the
** input does not begin with a quote character, then this routine
** is a no-op.
**
** Examples:
**
** "abc" becomes abc
** 'xyz' becomes xyz
** [pqr] becomes pqr
** `mno` becomes mno
*/
static void dequoteString(char *z){
int quote;
int i, j;
if( z==0 ) return;
quote = z[0];
switch( quote ){
case '\'': break;
case '"': break;
case '`': break; /* For MySQL compatibility */
case '[': quote = ']'; break; /* For MS SqlServer compatibility */
default: return;
}
for(i=1, j=0; z[i]; i++){
if( z[i]==quote ){
if( z[i+1]==quote ){
z[j++] = quote;
i++;
}else{
z[j++] = 0;
break;
}
}else{
z[j++] = z[i];
}
}
}
/*
** Retrieve the column names for the table named zTab via database
** connection db. SQLITE_OK is returned on success, or an sqlite error
** code otherwise.
**
** If successful, the number of columns is written to *pnCol. *paCol is
** set to point at sqlite3_malloc()'d space containing the array of
** nCol column names. The caller is responsible for calling sqlite3_free
** on *paCol.
*/
static int getColumnNames(
sqlite3 *db,
const char *zTab,
char ***paCol,
int *pnCol
){
char **aCol = 0;
char *zSql;
sqlite3_stmt *pStmt = 0;
int rc = SQLITE_OK;
int nCol = 0;
/* Prepare the statement "SELECT * FROM <tbl>". The column names
** of the result set of the compiled SELECT will be the same as
** the column names of table <tbl>.
*/
zSql = sqlite3_mprintf("SELECT * FROM %Q", zTab);
if( !zSql ){
rc = SQLITE_NOMEM;
goto out;
}
rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
sqlite3_free(zSql);
if( rc==SQLITE_OK ){
int ii;
int nBytes;
char *zSpace;
nCol = sqlite3_column_count(pStmt);
/* Figure out how much space to allocate for the array of column names
** (including space for the strings themselves). Then allocate it.
*/
nBytes = sizeof(char *) * nCol;
for(ii=0; ii<nCol; ii++){
const char *zName = sqlite3_column_name(pStmt, ii);
if( !zName ){
rc = SQLITE_NOMEM;
goto out;
}
nBytes += (int)strlen(zName)+1;
}
aCol = (char **)sqlite3MallocZero(nBytes);
if( !aCol ){
rc = SQLITE_NOMEM;
goto out;
}
/* Copy the column names into the allocated space and set up the
** pointers in the aCol[] array.
*/
zSpace = (char *)(&aCol[nCol]);
for(ii=0; ii<nCol; ii++){
aCol[ii] = zSpace;
sqlite3_snprintf(nBytes, zSpace, "%s", sqlite3_column_name(pStmt,ii));
zSpace += (int)strlen(zSpace) + 1;
}
assert( (zSpace-nBytes)==(char *)aCol );
}
*paCol = aCol;
*pnCol = nCol;
out:
sqlite3_finalize(pStmt);
return rc;
}
/*
** Parameter zTab is the name of a table in database db with nCol
** columns. This function allocates an array of integers nCol in
** size and populates it according to any implicit or explicit
** indices on table zTab.
**
** If successful, SQLITE_OK is returned and *paIndex set to point
** at the allocated array. Otherwise, an error code is returned.
**
** See comments associated with the member variable aIndex above
** "struct echo_vtab" for details of the contents of the array.
*/
static int getIndexArray(
sqlite3 *db, /* Database connection */
const char *zTab, /* Name of table in database db */
int nCol,
int **paIndex
){
sqlite3_stmt *pStmt = 0;
int *aIndex = 0;
int rc;
char *zSql;
/* Allocate space for the index array */
aIndex = (int *)sqlite3MallocZero(sizeof(int) * nCol);
if( !aIndex ){
rc = SQLITE_NOMEM;
goto get_index_array_out;
}
/* Compile an sqlite pragma to loop through all indices on table zTab */
zSql = sqlite3_mprintf("PRAGMA index_list(%s)", zTab);
if( !zSql ){
rc = SQLITE_NOMEM;
goto get_index_array_out;
}
rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
sqlite3_free(zSql);
/* For each index, figure out the left-most column and set the
** corresponding entry in aIndex[] to 1.
*/
while( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
const char *zIdx = (const char *)sqlite3_column_text(pStmt, 1);
sqlite3_stmt *pStmt2 = 0;
if( zIdx==0 ) continue;
zSql = sqlite3_mprintf("PRAGMA index_info(%s)", zIdx);
if( !zSql ){
rc = SQLITE_NOMEM;
goto get_index_array_out;
}
rc = sqlite3_prepare(db, zSql, -1, &pStmt2, 0);
sqlite3_free(zSql);
if( pStmt2 && sqlite3_step(pStmt2)==SQLITE_ROW ){
int cid = sqlite3_column_int(pStmt2, 1);
assert( cid>=0 && cid<nCol );
aIndex[cid] = 1;
}
if( pStmt2 ){
rc = sqlite3_finalize(pStmt2);
}
if( rc!=SQLITE_OK ){
goto get_index_array_out;
}
}
get_index_array_out:
if( pStmt ){
int rc2 = sqlite3_finalize(pStmt);
if( rc==SQLITE_OK ){
rc = rc2;
}
}
if( rc!=SQLITE_OK ){
sqlite3_free(aIndex);
aIndex = 0;
}
*paIndex = aIndex;
return rc;
}
/*
** Global Tcl variable $echo_module is a list. This routine appends
** the string element zArg to that list in interpreter interp.
*/
static void appendToEchoModule(Tcl_Interp *interp, const char *zArg){
int flags = (TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
Tcl_SetVar(interp, "echo_module", (zArg?zArg:""), flags);
}
/*
** This function is called from within the echo-modules xCreate and
** xConnect methods. The argc and argv arguments are copies of those
** passed to the calling method. This function is responsible for
** calling sqlite3_declare_vtab() to declare the schema of the virtual
** table being created or connected.
**
** If the constructor was passed just one argument, i.e.:
**
** CREATE TABLE t1 AS echo(t2);
**
** Then t2 is assumed to be the name of a *real* database table. The
** schema of the virtual table is declared by passing a copy of the
** CREATE TABLE statement for the real table to sqlite3_declare_vtab().
** Hence, the virtual table should have exactly the same column names and
** types as the real table.
*/
static int echoDeclareVtab(
echo_vtab *pVtab,
sqlite3 *db
){
int rc = SQLITE_OK;
if( pVtab->zTableName ){
sqlite3_stmt *pStmt = 0;
rc = sqlite3_prepare(db,
"SELECT sql FROM sqlite_schema WHERE type = 'table' AND name = ?",
-1, &pStmt, 0);
if( rc==SQLITE_OK ){
sqlite3_bind_text(pStmt, 1, pVtab->zTableName, -1, 0);
if( sqlite3_step(pStmt)==SQLITE_ROW ){
int rc2;
const char *zCreateTable = (const char *)sqlite3_column_text(pStmt, 0);
rc = sqlite3_declare_vtab(db, zCreateTable);
rc2 = sqlite3_finalize(pStmt);
if( rc==SQLITE_OK ){
rc = rc2;
}
} else {
rc = sqlite3_finalize(pStmt);
if( rc==SQLITE_OK ){
rc = SQLITE_ERROR;
}
}
if( rc==SQLITE_OK ){
rc = getColumnNames(db, pVtab->zTableName, &pVtab->aCol, &pVtab->nCol);
}
if( rc==SQLITE_OK ){
rc = getIndexArray(db, pVtab->zTableName, pVtab->nCol, &pVtab->aIndex);
}
}
}
return rc;
}
/*
** This function frees all runtime structures associated with the virtual
** table pVtab.
*/
static int echoDestructor(sqlite3_vtab *pVtab){
echo_vtab *p = (echo_vtab*)pVtab;
sqlite3_free(p->aIndex);
sqlite3_free(p->aCol);
sqlite3_free(p->zThis);
sqlite3_free(p->zTableName);
sqlite3_free(p->zLogName);
sqlite3_free(p);
return 0;
}
typedef struct EchoModule EchoModule;
struct EchoModule {
Tcl_Interp *interp;
sqlite3 *db;
};
/*
** This function is called to do the work of the xConnect() method -
** to allocate the required in-memory structures for a newly connected
** virtual table.
*/
static int echoConstructor(
sqlite3 *db,
void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVtab,
char **pzErr
){
int rc;
int i;
echo_vtab *pVtab;
/* Allocate the sqlite3_vtab/echo_vtab structure itself */
pVtab = sqlite3MallocZero( sizeof(*pVtab) );
if( !pVtab ){
return SQLITE_NOMEM;
}
pVtab->interp = ((EchoModule *)pAux)->interp;
pVtab->db = db;
/* Allocate echo_vtab.zThis */
pVtab->zThis = sqlite3_mprintf("%s", argv[2]);
if( !pVtab->zThis ){
echoDestructor((sqlite3_vtab *)pVtab);
return SQLITE_NOMEM;
}
/* Allocate echo_vtab.zTableName */
if( argc>3 ){
pVtab->zTableName = sqlite3_mprintf("%s", argv[3]);
dequoteString(pVtab->zTableName);
if( pVtab->zTableName && pVtab->zTableName[0]=='*' ){
char *z = sqlite3_mprintf("%s%s", argv[2], &(pVtab->zTableName[1]));
sqlite3_free(pVtab->zTableName);
pVtab->zTableName = z;
pVtab->isPattern = 1;
}
if( !pVtab->zTableName ){
echoDestructor((sqlite3_vtab *)pVtab);
return SQLITE_NOMEM;
}
}
/* Log the arguments to this function to Tcl var ::echo_module */
for(i=0; i<argc; i++){
appendToEchoModule(pVtab->interp, argv[i]);
}
/* Invoke sqlite3_declare_vtab and set up other members of the echo_vtab
** structure. If an error occurs, delete the sqlite3_vtab structure and
** return an error code.
*/
rc = echoDeclareVtab(pVtab, db);
if( rc!=SQLITE_OK ){
echoDestructor((sqlite3_vtab *)pVtab);
return rc;
}
/* Success. Set *ppVtab and return */
*ppVtab = &pVtab->base;
return SQLITE_OK;
}
/*
** Echo virtual table module xCreate method.
*/
static int echoCreate(
sqlite3 *db,
void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVtab,
char **pzErr
){
int rc = SQLITE_OK;
appendToEchoModule(((EchoModule *)pAux)->interp, "xCreate");
rc = echoConstructor(db, pAux, argc, argv, ppVtab, pzErr);
/* If there were two arguments passed to the module at the SQL level
** (i.e. "CREATE VIRTUAL TABLE tbl USING echo(arg1, arg2)"), then
** the second argument is used as a table name. Attempt to create
** such a table with a single column, "logmsg". This table will
** be used to log calls to the xUpdate method. It will be deleted
** when the virtual table is DROPed.
**
** Note: The main point of this is to test that we can drop tables
** from within an xDestroy method call.
*/
if( rc==SQLITE_OK && argc==5 ){
char *zSql;
echo_vtab *pVtab = *(echo_vtab **)ppVtab;
pVtab->zLogName = sqlite3_mprintf("%s", argv[4]);
zSql = sqlite3_mprintf("CREATE TABLE %Q(logmsg)", pVtab->zLogName);
rc = sqlite3_exec(db, zSql, 0, 0, 0);
sqlite3_free(zSql);
if( rc!=SQLITE_OK ){
*pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
}
}
if( *ppVtab && rc!=SQLITE_OK ){
echoDestructor(*ppVtab);
*ppVtab = 0;
}
if( rc==SQLITE_OK ){
(*(echo_vtab**)ppVtab)->inTransaction = 1;
}
return rc;
}
/*
** Echo virtual table module xConnect method.
*/
static int echoConnect(
sqlite3 *db,
void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVtab,
char **pzErr
){
appendToEchoModule(((EchoModule *)pAux)->interp, "xConnect");
return echoConstructor(db, pAux, argc, argv, ppVtab, pzErr);
}
/*
** Echo virtual table module xDisconnect method.
*/
static int echoDisconnect(sqlite3_vtab *pVtab){
appendToEchoModule(((echo_vtab *)pVtab)->interp, "xDisconnect");
return echoDestructor(pVtab);
}
/*
** Echo virtual table module xDestroy method.
*/
static int echoDestroy(sqlite3_vtab *pVtab){
int rc = SQLITE_OK;
echo_vtab *p = (echo_vtab *)pVtab;
appendToEchoModule(((echo_vtab *)pVtab)->interp, "xDestroy");
/* Drop the "log" table, if one exists (see echoCreate() for details) */
if( p && p->zLogName ){
char *zSql;
zSql = sqlite3_mprintf("DROP TABLE %Q", p->zLogName);
rc = sqlite3_exec(p->db, zSql, 0, 0, 0);
sqlite3_free(zSql);
}
if( rc==SQLITE_OK ){
rc = echoDestructor(pVtab);
}
return rc;
}
/*
** Echo virtual table module xOpen method.
*/
static int echoOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
echo_cursor *pCur;
if( simulateVtabError((echo_vtab *)pVTab, "xOpen") ){
return SQLITE_ERROR;
}
pCur = sqlite3MallocZero(sizeof(echo_cursor));
*ppCursor = (sqlite3_vtab_cursor *)pCur;
return (pCur ? SQLITE_OK : SQLITE_NOMEM);
}
/*
** Echo virtual table module xClose method.
*/
static int echoClose(sqlite3_vtab_cursor *cur){
int rc;
echo_cursor *pCur = (echo_cursor *)cur;
sqlite3_stmt *pStmt = pCur->pStmt;
pCur->pStmt = 0;
sqlite3_free(pCur);
rc = sqlite3_finalize(pStmt);
return rc;
}
/*
** Return non-zero if the cursor does not currently point to a valid record
** (i.e if the scan has finished), or zero otherwise.
*/
static int echoEof(sqlite3_vtab_cursor *cur){
return (((echo_cursor *)cur)->pStmt ? 0 : 1);
}
/*
** Echo virtual table module xNext method.
*/
static int echoNext(sqlite3_vtab_cursor *cur){
int rc = SQLITE_OK;
echo_cursor *pCur = (echo_cursor *)cur;
if( simulateVtabError((echo_vtab *)(cur->pVtab), "xNext") ){
return SQLITE_ERROR;
}
if( pCur->pStmt ){
rc = sqlite3_step(pCur->pStmt);
if( rc==SQLITE_ROW ){
rc = SQLITE_OK;
}else{
rc = sqlite3_finalize(pCur->pStmt);
pCur->pStmt = 0;
}
}
return rc;
}
/*
** Echo virtual table module xColumn method.
*/
static int echoColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
int iCol = i + 1;
sqlite3_stmt *pStmt = ((echo_cursor *)cur)->pStmt;
if( simulateVtabError((echo_vtab *)(cur->pVtab), "xColumn") ){
return SQLITE_ERROR;
}
if( !pStmt ){
sqlite3_result_null(ctx);
}else{
assert( sqlite3_data_count(pStmt)>iCol );
sqlite3_result_value(ctx, sqlite3_column_value(pStmt, iCol));
}
return SQLITE_OK;
}
/*
** Echo virtual table module xRowid method.
*/
static int echoRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
sqlite3_stmt *pStmt = ((echo_cursor *)cur)->pStmt;
if( simulateVtabError((echo_vtab *)(cur->pVtab), "xRowid") ){
return SQLITE_ERROR;
}
*pRowid = sqlite3_column_int64(pStmt, 0);
return SQLITE_OK;
}
/*
** Compute a simple hash of the null terminated string zString.
**
** This module uses only sqlite3_index_info.idxStr, not
** sqlite3_index_info.idxNum. So to test idxNum, when idxStr is set
** in echoBestIndex(), idxNum is set to the corresponding hash value.
** In echoFilter(), code assert()s that the supplied idxNum value is
** indeed the hash of the supplied idxStr.
*/
static int hashString(const char *zString){
u32 val = 0;
int ii;
for(ii=0; zString[ii]; ii++){
val = (val << 3) + (int)zString[ii];
}
return (int)(val&0x7fffffff);
}
/*
** Echo virtual table module xFilter method.
*/
static int echoFilter(
sqlite3_vtab_cursor *pVtabCursor,
int idxNum, const char *idxStr,
int argc, sqlite3_value **argv
){
int rc;
int i;
echo_cursor *pCur = (echo_cursor *)pVtabCursor;
echo_vtab *pVtab = (echo_vtab *)pVtabCursor->pVtab;
sqlite3 *db = pVtab->db;
if( simulateVtabError(pVtab, "xFilter") ){
return SQLITE_ERROR;
}
/* Check that idxNum matches idxStr */
assert( idxNum==hashString(idxStr) );
/* Log arguments to the ::echo_module Tcl variable */
appendToEchoModule(pVtab->interp, "xFilter");
appendToEchoModule(pVtab->interp, idxStr);
for(i=0; i<argc; i++){
appendToEchoModule(pVtab->interp, (const char*)sqlite3_value_text(argv[i]));
}
sqlite3_finalize(pCur->pStmt);
pCur->pStmt = 0;
/* Prepare the SQL statement created by echoBestIndex and bind the
** runtime parameters passed to this function to it.
*/
rc = sqlite3_prepare(db, idxStr, -1, &pCur->pStmt, 0);
assert( pCur->pStmt || rc!=SQLITE_OK );
for(i=0; rc==SQLITE_OK && i<argc; i++){
rc = sqlite3_bind_value(pCur->pStmt, i+1, argv[i]);
}
/* If everything was successful, advance to the first row of the scan */
if( rc==SQLITE_OK ){
rc = echoNext(pVtabCursor);
}
return rc;
}
/*
** A helper function used by echoUpdate() and echoBestIndex() for
** manipulating strings in concert with the sqlite3_mprintf() function.
**
** Parameter pzStr points to a pointer to a string allocated with
** sqlite3_mprintf. The second parameter, zAppend, points to another
** string. The two strings are concatenated together and *pzStr
** set to point at the result. The initial buffer pointed to by *pzStr
** is deallocated via sqlite3_free().
**
** If the third argument, doFree, is true, then sqlite3_free() is
** also called to free the buffer pointed to by zAppend.
*/
static void string_concat(char **pzStr, char *zAppend, int doFree, int *pRc){
char *zIn = *pzStr;
if( !zAppend && doFree && *pRc==SQLITE_OK ){
*pRc = SQLITE_NOMEM;
}
if( *pRc!=SQLITE_OK ){
sqlite3_free(zIn);
zIn = 0;
}else{
if( zIn ){
char *zTemp = zIn;
zIn = sqlite3_mprintf("%s%s", zIn, zAppend);
sqlite3_free(zTemp);
}else{
zIn = sqlite3_mprintf("%s", zAppend);
}
if( !zIn ){
*pRc = SQLITE_NOMEM;
}
}
*pzStr = zIn;
if( doFree ){
sqlite3_free(zAppend);
}
}
/*
** This function returns a pointer to an sqlite3_malloc()ed buffer
** containing the select-list (the thing between keywords SELECT and FROM)
** to query the underlying real table with for the scan described by
** argument pIdxInfo.
**
** If the current SQLite version is earlier than 3.10.0, this is just "*"
** (select all columns). Or, for version 3.10.0 and greater, the list of
** columns identified by the pIdxInfo->colUsed mask.
*/
static char *echoSelectList(echo_vtab *pTab, sqlite3_index_info *pIdxInfo){
char *zRet = 0;
if( sqlite3_libversion_number()<3010000 ){
zRet = sqlite3_mprintf(", *");
}else{
int i;
for(i=0; i<pTab->nCol; i++){
if( pIdxInfo->colUsed & ((sqlite3_uint64)1 << (i>=63 ? 63 : i)) ){
zRet = sqlite3_mprintf("%z, %s", zRet, pTab->aCol[i]);
}else{
zRet = sqlite3_mprintf("%z, NULL", zRet);
}
if( !zRet ) break;
}
}
return zRet;
}
/*
** The echo module implements the subset of query constraints and sort
** orders that may take advantage of SQLite indices on the underlying
** real table. For example, if the real table is declared as:
**
** CREATE TABLE real(a, b, c);
** CREATE INDEX real_index ON real(b);
**
** then the echo module handles WHERE or ORDER BY clauses that refer
** to the column "b", but not "a" or "c". If a multi-column index is
** present, only its left most column is considered.
**
** This xBestIndex method encodes the proposed search strategy as
** an SQL query on the real table underlying the virtual echo module
** table and stores the query in sqlite3_index_info.idxStr. The SQL
** statement is of the form:
**
** SELECT rowid, * FROM <real-table> ?<where-clause>? ?<order-by-clause>?
**
** where the <where-clause> and <order-by-clause> are determined
** by the contents of the structure pointed to by the pIdxInfo argument.
*/
static int echoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
int ii;
char *zQuery = 0;
char *zCol = 0;
char *zNew;
int nArg = 0;
const char *zSep = "WHERE";
echo_vtab *pVtab = (echo_vtab *)tab;
sqlite3_stmt *pStmt = 0;
Tcl_Interp *interp = pVtab->interp;
int nRow = 0;
int useIdx = 0;
int rc = SQLITE_OK;
int useCost = 0;
double cost = 0;
int isIgnoreUsable = 0;
if( Tcl_GetVar(interp, "echo_module_ignore_usable", TCL_GLOBAL_ONLY) ){
isIgnoreUsable = 1;
}
if( simulateVtabError(pVtab, "xBestIndex") ){
return SQLITE_ERROR;
}
/* Determine the number of rows in the table and store this value in local
** variable nRow. The 'estimated-cost' of the scan will be the number of
** rows in the table for a linear scan, or the log (base 2) of the
** number of rows if the proposed scan uses an index.
*/
if( Tcl_GetVar(interp, "echo_module_cost", TCL_GLOBAL_ONLY) ){
cost = atof(Tcl_GetVar(interp, "echo_module_cost", TCL_GLOBAL_ONLY));
useCost = 1;
} else {
zQuery = sqlite3_mprintf("SELECT count(*) FROM %Q", pVtab->zTableName);
if( !zQuery ){
return SQLITE_NOMEM;
}
rc = sqlite3_prepare(pVtab->db, zQuery, -1, &pStmt, 0);
sqlite3_free(zQuery);
if( rc!=SQLITE_OK ){
return rc;
}
sqlite3_step(pStmt);
nRow = sqlite3_column_int(pStmt, 0);
rc = sqlite3_finalize(pStmt);
if( rc!=SQLITE_OK ){
return rc;
}
}
zCol = echoSelectList(pVtab, pIdxInfo);
if( !zCol ) return SQLITE_NOMEM;
zQuery = sqlite3_mprintf("SELECT rowid%z FROM %Q", zCol, pVtab->zTableName);
if( !zQuery ) return SQLITE_NOMEM;
for(ii=0; ii<pIdxInfo->nConstraint; ii++){
const struct sqlite3_index_constraint *pConstraint;
struct sqlite3_index_constraint_usage *pUsage;
int iCol;
pConstraint = &pIdxInfo->aConstraint[ii];
pUsage = &pIdxInfo->aConstraintUsage[ii];
if( !isIgnoreUsable && !pConstraint->usable ) continue;
iCol = pConstraint->iColumn;
if( iCol<0 || pVtab->aIndex[iCol] ){
char *zNewCol = iCol>=0 ? pVtab->aCol[iCol] : "rowid";
char *zOp = 0;
useIdx = 1;
switch( pConstraint->op ){
case SQLITE_INDEX_CONSTRAINT_EQ:
zOp = "="; break;
case SQLITE_INDEX_CONSTRAINT_LT:
zOp = "<"; break;
case SQLITE_INDEX_CONSTRAINT_GT:
zOp = ">"; break;
case SQLITE_INDEX_CONSTRAINT_LE:
zOp = "<="; break;
case SQLITE_INDEX_CONSTRAINT_GE:
zOp = ">="; break;
case SQLITE_INDEX_CONSTRAINT_MATCH:
/* Purposely translate the MATCH operator into a LIKE, which
** will be used by the next block of code to construct a new
** query. It should also be noted here that the next block
** of code requires the first letter of this operator to be
** in upper-case to trigger the special MATCH handling (i.e.
** wrapping the bound parameter with literal '%'s).
*/
zOp = "LIKE"; break;
case SQLITE_INDEX_CONSTRAINT_LIKE:
zOp = "like"; break;
case SQLITE_INDEX_CONSTRAINT_GLOB:
zOp = "glob"; break;
case SQLITE_INDEX_CONSTRAINT_REGEXP:
zOp = "regexp"; break;
}
if( zOp ){
if( zOp[0]=='L' ){
zNew = sqlite3_mprintf(" %s %s LIKE (SELECT '%%'||?||'%%')",
zSep, zNewCol);
} else {
zNew = sqlite3_mprintf(" %s %s %s ?", zSep, zNewCol, zOp);
}
string_concat(&zQuery, zNew, 1, &rc);
zSep = "AND";
pUsage->argvIndex = ++nArg;
pUsage->omit = 1;
}
}
}
/* If there is only one term in the ORDER BY clause, and it is
** on a column that this virtual table has an index for, then consume
** the ORDER BY clause.
*/
if( pIdxInfo->nOrderBy==1 && (
pIdxInfo->aOrderBy->iColumn<0 ||
pVtab->aIndex[pIdxInfo->aOrderBy->iColumn]) ){
int iCol = pIdxInfo->aOrderBy->iColumn;
char *zNewCol = iCol>=0 ? pVtab->aCol[iCol] : "rowid";
char *zDir = pIdxInfo->aOrderBy->desc?"DESC":"ASC";
zNew = sqlite3_mprintf(" ORDER BY %s %s", zNewCol, zDir);
string_concat(&zQuery, zNew, 1, &rc);
pIdxInfo->orderByConsumed = 1;
}
appendToEchoModule(pVtab->interp, "xBestIndex");;
appendToEchoModule(pVtab->interp, zQuery);
if( !zQuery ){
return rc;
}
pIdxInfo->idxNum = hashString(zQuery);
pIdxInfo->idxStr = zQuery;
pIdxInfo->needToFreeIdxStr = 1;
if( useCost ){
pIdxInfo->estimatedCost = cost;
}else if( useIdx ){
/* Approximation of log2(nRow). */
for( ii=0; ii<(sizeof(int)*8)-1; ii++ ){
if( nRow & (1<<ii) ){
pIdxInfo->estimatedCost = (double)ii;
}
}
}else{
pIdxInfo->estimatedCost = (double)nRow;
}
return rc;
}
/*
** The xUpdate method for echo module virtual tables.
**
** apData[0] apData[1] apData[2..]
**
** INTEGER DELETE
**
** INTEGER NULL (nCol args) UPDATE (do not set rowid)
** INTEGER INTEGER (nCol args) UPDATE (with SET rowid = <arg1>)
**
** NULL NULL (nCol args) INSERT INTO (automatic rowid value)
** NULL INTEGER (nCol args) INSERT (incl. rowid value)
**
*/
int echoUpdate(
sqlite3_vtab *tab,
int nData,
sqlite3_value **apData,
sqlite_int64 *pRowid
){
echo_vtab *pVtab = (echo_vtab *)tab;
sqlite3 *db = pVtab->db;
int rc = SQLITE_OK;
sqlite3_stmt *pStmt = 0;
char *z = 0; /* SQL statement to execute */
int bindArgZero = 0; /* True to bind apData[0] to sql var no. nData */
int bindArgOne = 0; /* True to bind apData[1] to sql var no. 1 */
int i; /* Counter variable used by for loops */
assert( nData==pVtab->nCol+2 || nData==1 );
/* Ticket #3083 - make sure we always start a transaction prior to
** making any changes to a virtual table */
assert( pVtab->inTransaction );
if( simulateVtabError(pVtab, "xUpdate") ){
return SQLITE_ERROR;
}
/* If apData[0] is an integer and nData>1 then do an UPDATE */
if( nData>1 && sqlite3_value_type(apData[0])==SQLITE_INTEGER ){
char *zSep = " SET";
z = sqlite3_mprintf("UPDATE %Q", pVtab->zTableName);
if( !z ){
rc = SQLITE_NOMEM;