xref: /sqlite-3.40.0/src/test_tclvar.c (revision 7aa3ebee)
1 /*
2 ** 2006 June 13
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 ** The emphasis of this file is a virtual table that provides
17 ** access to TCL variables.
18 */
19 #include "sqliteInt.h"
20 #include "tcl.h"
21 #include <stdlib.h>
22 #include <string.h>
23 
24 #ifndef SQLITE_OMIT_VIRTUALTABLE
25 
26 /*
27 ** Characters that make up the idxStr created by xBestIndex for xFilter.
28 */
29 #define TCLVAR_NAME_EQ      'e'
30 #define TCLVAR_NAME_MATCH   'm'
31 #define TCLVAR_VALUE_GLOB   'g'
32 #define TCLVAR_VALUE_REGEXP 'r'
33 #define TCLVAR_VALUE_LIKE   'l'
34 
35 typedef struct tclvar_vtab tclvar_vtab;
36 typedef struct tclvar_cursor tclvar_cursor;
37 
38 /*
39 ** A tclvar virtual-table object
40 */
41 struct tclvar_vtab {
42   sqlite3_vtab base;
43   Tcl_Interp *interp;
44 };
45 
46 /* A tclvar cursor object */
47 struct tclvar_cursor {
48   sqlite3_vtab_cursor base;
49 
50   Tcl_Obj *pList1;     /* Result of [info vars ?pattern?] */
51   Tcl_Obj *pList2;     /* Result of [array names [lindex $pList1 $i1]] */
52   int i1;              /* Current item in pList1 */
53   int i2;              /* Current item (if any) in pList2 */
54 };
55 
56 /* Methods for the tclvar module */
57 static int tclvarConnect(
58   sqlite3 *db,
59   void *pAux,
60   int argc, const char *const*argv,
61   sqlite3_vtab **ppVtab,
62   char **pzErr
63 ){
64   tclvar_vtab *pVtab;
65   static const char zSchema[] =
66      "CREATE TABLE whatever(name TEXT, arrayname TEXT, value TEXT)";
67   pVtab = sqlite3MallocZero( sizeof(*pVtab) );
68   if( pVtab==0 ) return SQLITE_NOMEM;
69   *ppVtab = &pVtab->base;
70   pVtab->interp = (Tcl_Interp *)pAux;
71   sqlite3_declare_vtab(db, zSchema);
72   return SQLITE_OK;
73 }
74 /* Note that for this virtual table, the xCreate and xConnect
75 ** methods are identical. */
76 
77 static int tclvarDisconnect(sqlite3_vtab *pVtab){
78   sqlite3_free(pVtab);
79   return SQLITE_OK;
80 }
81 /* The xDisconnect and xDestroy methods are also the same */
82 
83 /*
84 ** Open a new tclvar cursor.
85 */
86 static int tclvarOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
87   tclvar_cursor *pCur;
88   pCur = sqlite3MallocZero(sizeof(tclvar_cursor));
89   *ppCursor = &pCur->base;
90   return SQLITE_OK;
91 }
92 
93 /*
94 ** Close a tclvar cursor.
95 */
96 static int tclvarClose(sqlite3_vtab_cursor *cur){
97   tclvar_cursor *pCur = (tclvar_cursor *)cur;
98   if( pCur->pList1 ){
99     Tcl_DecrRefCount(pCur->pList1);
100   }
101   if( pCur->pList2 ){
102     Tcl_DecrRefCount(pCur->pList2);
103   }
104   sqlite3_free(pCur);
105   return SQLITE_OK;
106 }
107 
108 /*
109 ** Returns 1 if data is ready, or 0 if not.
110 */
111 static int next2(Tcl_Interp *interp, tclvar_cursor *pCur, Tcl_Obj *pObj){
112   Tcl_Obj *p;
113 
114   if( pObj ){
115     if( !pCur->pList2 ){
116       p = Tcl_NewStringObj("array names", -1);
117       Tcl_IncrRefCount(p);
118       Tcl_ListObjAppendElement(0, p, pObj);
119       Tcl_EvalObjEx(interp, p, TCL_EVAL_GLOBAL);
120       Tcl_DecrRefCount(p);
121       pCur->pList2 = Tcl_GetObjResult(interp);
122       Tcl_IncrRefCount(pCur->pList2);
123       assert( pCur->i2==0 );
124     }else{
125       int n = 0;
126       pCur->i2++;
127       Tcl_ListObjLength(0, pCur->pList2, &n);
128       if( pCur->i2>=n ){
129         Tcl_DecrRefCount(pCur->pList2);
130         pCur->pList2 = 0;
131         pCur->i2 = 0;
132         return 0;
133       }
134     }
135   }
136 
137   return 1;
138 }
139 
140 static int tclvarNext(sqlite3_vtab_cursor *cur){
141   Tcl_Obj *pObj;
142   int n = 0;
143   int ok = 0;
144 
145   tclvar_cursor *pCur = (tclvar_cursor *)cur;
146   Tcl_Interp *interp = ((tclvar_vtab *)(cur->pVtab))->interp;
147 
148   Tcl_ListObjLength(0, pCur->pList1, &n);
149   while( !ok && pCur->i1<n ){
150     Tcl_ListObjIndex(0, pCur->pList1, pCur->i1, &pObj);
151     ok = next2(interp, pCur, pObj);
152     if( !ok ){
153       pCur->i1++;
154     }
155   }
156 
157   return 0;
158 }
159 
160 static int tclvarFilter(
161   sqlite3_vtab_cursor *pVtabCursor,
162   int idxNum, const char *idxStr,
163   int argc, sqlite3_value **argv
164 ){
165   tclvar_cursor *pCur = (tclvar_cursor *)pVtabCursor;
166   Tcl_Interp *interp = ((tclvar_vtab *)(pVtabCursor->pVtab))->interp;
167   Tcl_Obj *p = Tcl_NewStringObj("tclvar_filter_cmd", -1);
168 
169   const char *zEq = "";
170   const char *zMatch = "";
171   const char *zGlob = "";
172   const char *zRegexp = "";
173   const char *zLike = "";
174   int i;
175 
176   for(i=0; idxStr[i]; i++){
177     switch( idxStr[i] ){
178       case TCLVAR_NAME_EQ:
179         zEq = (const char*)sqlite3_value_text(argv[i]);
180         break;
181       case TCLVAR_NAME_MATCH:
182         zMatch = (const char*)sqlite3_value_text(argv[i]);
183         break;
184       case TCLVAR_VALUE_GLOB:
185         zGlob = (const char*)sqlite3_value_text(argv[i]);
186         break;
187       case TCLVAR_VALUE_REGEXP:
188         zRegexp = (const char*)sqlite3_value_text(argv[i]);
189         break;
190       case TCLVAR_VALUE_LIKE:
191         zLike = (const char*)sqlite3_value_text(argv[i]);
192         break;
193       default:
194         assert( 0 );
195     }
196   }
197 
198   Tcl_IncrRefCount(p);
199   Tcl_ListObjAppendElement(0, p, Tcl_NewStringObj(zEq, -1));
200   Tcl_ListObjAppendElement(0, p, Tcl_NewStringObj(zMatch, -1));
201   Tcl_ListObjAppendElement(0, p, Tcl_NewStringObj(zGlob, -1));
202   Tcl_ListObjAppendElement(0, p, Tcl_NewStringObj(zRegexp, -1));
203   Tcl_ListObjAppendElement(0, p, Tcl_NewStringObj(zLike, -1));
204 
205   Tcl_EvalObjEx(interp, p, TCL_EVAL_GLOBAL);
206   if( pCur->pList1 ){
207     Tcl_DecrRefCount(pCur->pList1);
208   }
209   if( pCur->pList2 ){
210     Tcl_DecrRefCount(pCur->pList2);
211     pCur->pList2 = 0;
212   }
213   pCur->i1 = 0;
214   pCur->i2 = 0;
215   pCur->pList1 = Tcl_GetObjResult(interp);
216   Tcl_IncrRefCount(pCur->pList1);
217 
218   Tcl_DecrRefCount(p);
219   return tclvarNext(pVtabCursor);
220 }
221 
222 static int tclvarColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
223   Tcl_Obj *p1;
224   Tcl_Obj *p2;
225   const char *z1;
226   const char *z2 = "";
227   tclvar_cursor *pCur = (tclvar_cursor*)cur;
228   Tcl_Interp *interp = ((tclvar_vtab *)cur->pVtab)->interp;
229 
230   Tcl_ListObjIndex(interp, pCur->pList1, pCur->i1, &p1);
231   Tcl_ListObjIndex(interp, pCur->pList2, pCur->i2, &p2);
232   z1 = Tcl_GetString(p1);
233   if( p2 ){
234     z2 = Tcl_GetString(p2);
235   }
236   switch (i) {
237     case 0: {
238       sqlite3_result_text(ctx, z1, -1, SQLITE_TRANSIENT);
239       break;
240     }
241     case 1: {
242       sqlite3_result_text(ctx, z2, -1, SQLITE_TRANSIENT);
243       break;
244     }
245     case 2: {
246       Tcl_Obj *pVal = Tcl_GetVar2Ex(interp, z1, *z2?z2:0, TCL_GLOBAL_ONLY);
247       sqlite3_result_text(ctx, Tcl_GetString(pVal), -1, SQLITE_TRANSIENT);
248       break;
249     }
250   }
251   return SQLITE_OK;
252 }
253 
254 static int tclvarRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
255   *pRowid = 0;
256   return SQLITE_OK;
257 }
258 
259 static int tclvarEof(sqlite3_vtab_cursor *cur){
260   tclvar_cursor *pCur = (tclvar_cursor*)cur;
261   return (pCur->pList2?0:1);
262 }
263 
264 /*
265 ** If nul-terminated string zStr does not already contain the character
266 ** passed as the second argument, append it and return 0. Or, if there is
267 ** already an instance of x in zStr, do nothing return 1;
268 **
269 ** There is guaranteed to be enough room in the buffer pointed to by zStr
270 ** for the new character and nul-terminator.
271 */
272 static int tclvarAddToIdxstr(char *zStr, char x){
273   int i;
274   for(i=0; zStr[i]; i++){
275     if( zStr[i]==x ) return 1;
276   }
277   zStr[i] = x;
278   zStr[i+1] = '\0';
279   return 0;
280 }
281 
282 /*
283 ** Return true if variable $::tclvar_set_omit exists and is set to true.
284 ** False otherwise.
285 */
286 static int tclvarSetOmit(Tcl_Interp *interp){
287   int rc;
288   int res = 0;
289   Tcl_Obj *pRes;
290   rc = Tcl_Eval(interp,
291     "expr {[info exists ::tclvar_set_omit] && $::tclvar_set_omit}"
292   );
293   if( rc==TCL_OK ){
294     pRes = Tcl_GetObjResult(interp);
295     rc = Tcl_GetBooleanFromObj(0, pRes, &res);
296   }
297   return (rc==TCL_OK && res);
298 }
299 
300 /*
301 ** The xBestIndex() method. This virtual table supports the following
302 ** operators:
303 **
304 **     name = ?                    (omit flag clear)
305 **     name MATCH ?                (omit flag set)
306 **     value GLOB ?                (omit flag set iff $::tclvar_set_omit)
307 **     value REGEXP ?              (omit flag set iff $::tclvar_set_omit)
308 **     value LIKE ?                (omit flag set iff $::tclvar_set_omit)
309 **
310 ** For each constraint present, the corresponding TCLVAR_XXX character is
311 ** appended to the idxStr value.
312 */
313 static int tclvarBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
314   tclvar_vtab *pTab = (tclvar_vtab*)tab;
315   int ii;
316   char *zStr = sqlite3_malloc(32);
317   int iStr = 0;
318 
319   if( zStr==0 ) return SQLITE_NOMEM;
320   zStr[0] = '\0';
321 
322   for(ii=0; ii<pIdxInfo->nConstraint; ii++){
323     struct sqlite3_index_constraint const *pCons = &pIdxInfo->aConstraint[ii];
324     struct sqlite3_index_constraint_usage *pUsage;
325 
326     pUsage = &pIdxInfo->aConstraintUsage[ii];
327     if( pCons->usable ){
328       /* name = ? */
329       if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ && pCons->iColumn==0 ){
330         if( 0==tclvarAddToIdxstr(zStr, TCLVAR_NAME_EQ) ){
331           pUsage->argvIndex = ++iStr;
332           pUsage->omit = 0;
333         }
334       }
335 
336       /* name MATCH ? */
337       if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH && pCons->iColumn==0 ){
338         if( 0==tclvarAddToIdxstr(zStr, TCLVAR_NAME_MATCH) ){
339           pUsage->argvIndex = ++iStr;
340           pUsage->omit = 1;
341         }
342       }
343 
344       /* value GLOB ? */
345       if( pCons->op==SQLITE_INDEX_CONSTRAINT_GLOB && pCons->iColumn==2 ){
346         if( 0==tclvarAddToIdxstr(zStr, TCLVAR_VALUE_GLOB) ){
347           pUsage->argvIndex = ++iStr;
348           pUsage->omit = tclvarSetOmit(pTab->interp);
349         }
350       }
351 
352       /* value REGEXP ? */
353       if( pCons->op==SQLITE_INDEX_CONSTRAINT_REGEXP && pCons->iColumn==2 ){
354         if( 0==tclvarAddToIdxstr(zStr, TCLVAR_VALUE_REGEXP) ){
355           pUsage->argvIndex = ++iStr;
356           pUsage->omit = tclvarSetOmit(pTab->interp);
357         }
358       }
359 
360       /* value LIKE ? */
361       if( pCons->op==SQLITE_INDEX_CONSTRAINT_LIKE && pCons->iColumn==2 ){
362         if( 0==tclvarAddToIdxstr(zStr, TCLVAR_VALUE_LIKE) ){
363           pUsage->argvIndex = ++iStr;
364           pUsage->omit = tclvarSetOmit(pTab->interp);
365         }
366       }
367     }
368   }
369   pIdxInfo->idxStr = zStr;
370   pIdxInfo->needToFreeIdxStr = 1;
371 
372   return SQLITE_OK;
373 }
374 
375 /*
376 ** A virtual table module that provides read-only access to a
377 ** Tcl global variable namespace.
378 */
379 static sqlite3_module tclvarModule = {
380   0,                         /* iVersion */
381   tclvarConnect,
382   tclvarConnect,
383   tclvarBestIndex,
384   tclvarDisconnect,
385   tclvarDisconnect,
386   tclvarOpen,                  /* xOpen - open a cursor */
387   tclvarClose,                 /* xClose - close a cursor */
388   tclvarFilter,                /* xFilter - configure scan constraints */
389   tclvarNext,                  /* xNext - advance a cursor */
390   tclvarEof,                   /* xEof - check for end of scan */
391   tclvarColumn,                /* xColumn - read data */
392   tclvarRowid,                 /* xRowid - read data */
393   0,                           /* xUpdate */
394   0,                           /* xBegin */
395   0,                           /* xSync */
396   0,                           /* xCommit */
397   0,                           /* xRollback */
398   0,                           /* xFindMethod */
399   0,                           /* xRename */
400 };
401 
402 /*
403 ** Decode a pointer to an sqlite3 object.
404 */
405 extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
406 
407 /*
408 ** Register the echo virtual table module.
409 */
410 static int register_tclvar_module(
411   ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
412   Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
413   int objc,              /* Number of arguments */
414   Tcl_Obj *CONST objv[]  /* Command arguments */
415 ){
416   int rc = TCL_OK;
417   sqlite3 *db;
418   if( objc!=2 ){
419     Tcl_WrongNumArgs(interp, 1, objv, "DB");
420     return TCL_ERROR;
421   }
422   if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
423 #ifndef SQLITE_OMIT_VIRTUALTABLE
424   sqlite3_create_module(db, "tclvar", &tclvarModule, (void*)interp);
425   rc = Tcl_Eval(interp,
426       "proc like {pattern str} {\n"
427       "  set p [string map {% * _ ?} $pattern]\n"
428       "  string match $p $str\n"
429       "}\n"
430       "proc tclvar_filter_cmd {eq match glob regexp like} {\n"
431       "  set res {}\n"
432       "  set pattern $eq\n"
433       "  if {$pattern=={}} { set pattern $match }\n"
434       "  if {$pattern=={}} { set pattern * }\n"
435       "  foreach v [uplevel #0 info vars $pattern] {\n"
436       "    if {($glob=={} || [string match $glob [uplevel #0 set $v]])\n"
437       "     && ($like=={} || [like $like [uplevel #0 set $v]])\n"
438       "     && ($regexp=={} || [regexp $regexp [uplevel #0 set $v]])\n"
439       "    } {\n"
440       "      lappend res $v\n"
441       "    }\n"
442       "  }\n"
443       "  set res\n"
444       "}\n"
445   );
446 #endif
447   return rc;
448 }
449 
450 #endif
451 
452 
453 /*
454 ** Register commands with the TCL interpreter.
455 */
456 int Sqlitetesttclvar_Init(Tcl_Interp *interp){
457 #ifndef SQLITE_OMIT_VIRTUALTABLE
458   static struct {
459      char *zName;
460      Tcl_ObjCmdProc *xProc;
461      void *clientData;
462   } aObjCmd[] = {
463      { "register_tclvar_module",   register_tclvar_module, 0 },
464   };
465   int i;
466   for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
467     Tcl_CreateObjCommand(interp, aObjCmd[i].zName,
468         aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
469   }
470 #endif
471   return TCL_OK;
472 }
473