1 /*
2  * contrib/intarray/_int_bool.c
3  */
4 #include "postgres.h"
5 
6 #include "_int.h"
7 #include "miscadmin.h"
8 #include "utils/builtins.h"
9 
10 PG_FUNCTION_INFO_V1(bqarr_in);
11 PG_FUNCTION_INFO_V1(bqarr_out);
12 PG_FUNCTION_INFO_V1(boolop);
13 PG_FUNCTION_INFO_V1(rboolop);
14 PG_FUNCTION_INFO_V1(querytree);
15 
16 
17 /* parser's states */
18 #define WAITOPERAND 1
19 #define WAITENDOPERAND	2
20 #define WAITOPERATOR	3
21 
22 /*
23  * node of query tree, also used
24  * for storing polish notation in parser
25  */
26 typedef struct NODE
27 {
28 	int32		type;
29 	int32		val;
30 	struct NODE *next;
31 } NODE;
32 
33 typedef struct
34 {
35 	char	   *buf;
36 	int32		state;
37 	int32		count;
38 	/* reverse polish notation in list (for temporary usage) */
39 	NODE	   *str;
40 	/* number in str */
41 	int32		num;
42 } WORKSTATE;
43 
44 /*
45  * get token from query string
46  */
47 static int32
48 gettoken(WORKSTATE *state, int32 *val)
49 {
50 	char		nnn[16];
51 	int			innn;
52 
53 	*val = 0;					/* default result */
54 
55 	innn = 0;
56 	while (1)
57 	{
58 		if (innn >= sizeof(nnn))
59 			return ERR;			/* buffer overrun => syntax error */
60 		switch (state->state)
61 		{
62 			case WAITOPERAND:
63 				innn = 0;
64 				if ((*(state->buf) >= '0' && *(state->buf) <= '9') ||
65 					*(state->buf) == '-')
66 				{
67 					state->state = WAITENDOPERAND;
68 					nnn[innn++] = *(state->buf);
69 				}
70 				else if (*(state->buf) == '!')
71 				{
72 					(state->buf)++;
73 					*val = (int32) '!';
74 					return OPR;
75 				}
76 				else if (*(state->buf) == '(')
77 				{
78 					state->count++;
79 					(state->buf)++;
80 					return OPEN;
81 				}
82 				else if (*(state->buf) != ' ')
83 					return ERR;
84 				break;
85 			case WAITENDOPERAND:
86 				if (*(state->buf) >= '0' && *(state->buf) <= '9')
87 				{
88 					nnn[innn++] = *(state->buf);
89 				}
90 				else
91 				{
92 					long		lval;
93 
94 					nnn[innn] = '\0';
95 					errno = 0;
96 					lval = strtol(nnn, NULL, 0);
97 					*val = (int32) lval;
98 					if (errno != 0 || (long) *val != lval)
99 						return ERR;
100 					state->state = WAITOPERATOR;
101 					return (state->count && *(state->buf) == '\0')
102 						? ERR : VAL;
103 				}
104 				break;
105 			case WAITOPERATOR:
106 				if (*(state->buf) == '&' || *(state->buf) == '|')
107 				{
108 					state->state = WAITOPERAND;
109 					*val = (int32) *(state->buf);
110 					(state->buf)++;
111 					return OPR;
112 				}
113 				else if (*(state->buf) == ')')
114 				{
115 					(state->buf)++;
116 					state->count--;
117 					return (state->count < 0) ? ERR : CLOSE;
118 				}
119 				else if (*(state->buf) == '\0')
120 					return (state->count) ? ERR : END;
121 				else if (*(state->buf) != ' ')
122 					return ERR;
123 				break;
124 			default:
125 				return ERR;
126 				break;
127 		}
128 		(state->buf)++;
129 	}
130 }
131 
132 /*
133  * push new one in polish notation reverse view
134  */
135 static void
136 pushquery(WORKSTATE *state, int32 type, int32 val)
137 {
138 	NODE	   *tmp = (NODE *) palloc(sizeof(NODE));
139 
140 	tmp->type = type;
141 	tmp->val = val;
142 	tmp->next = state->str;
143 	state->str = tmp;
144 	state->num++;
145 }
146 
147 #define STACKDEPTH	16
148 
149 /*
150  * make polish notation of query
151  */
152 static int32
153 makepol(WORKSTATE *state)
154 {
155 	int32		val,
156 				type;
157 	int32		stack[STACKDEPTH];
158 	int32		lenstack = 0;
159 
160 	/* since this function recurses, it could be driven to stack overflow */
161 	check_stack_depth();
162 
163 	while ((type = gettoken(state, &val)) != END)
164 	{
165 		switch (type)
166 		{
167 			case VAL:
168 				pushquery(state, type, val);
169 				while (lenstack && (stack[lenstack - 1] == (int32) '&' ||
170 									stack[lenstack - 1] == (int32) '!'))
171 				{
172 					lenstack--;
173 					pushquery(state, OPR, stack[lenstack]);
174 				}
175 				break;
176 			case OPR:
177 				if (lenstack && val == (int32) '|')
178 					pushquery(state, OPR, val);
179 				else
180 				{
181 					if (lenstack == STACKDEPTH)
182 						ereport(ERROR,
183 								(errcode(ERRCODE_STATEMENT_TOO_COMPLEX),
184 								 errmsg("statement too complex")));
185 					stack[lenstack] = val;
186 					lenstack++;
187 				}
188 				break;
189 			case OPEN:
190 				if (makepol(state) == ERR)
191 					return ERR;
192 				while (lenstack && (stack[lenstack - 1] == (int32) '&' ||
193 									stack[lenstack - 1] == (int32) '!'))
194 				{
195 					lenstack--;
196 					pushquery(state, OPR, stack[lenstack]);
197 				}
198 				break;
199 			case CLOSE:
200 				while (lenstack)
201 				{
202 					lenstack--;
203 					pushquery(state, OPR, stack[lenstack]);
204 				};
205 				return END;
206 				break;
207 			case ERR:
208 			default:
209 				ereport(ERROR,
210 						(errcode(ERRCODE_SYNTAX_ERROR),
211 						 errmsg("syntax error")));
212 				return ERR;
213 
214 		}
215 	}
216 
217 	while (lenstack)
218 	{
219 		lenstack--;
220 		pushquery(state, OPR, stack[lenstack]);
221 	};
222 	return END;
223 }
224 
225 typedef struct
226 {
227 	int32	   *arrb;
228 	int32	   *arre;
229 } CHKVAL;
230 
231 /*
232  * is there value 'val' in (sorted) array or not ?
233  */
234 static bool
235 checkcondition_arr(void *checkval, ITEM *item, void *options)
236 {
237 	int32	   *StopLow = ((CHKVAL *) checkval)->arrb;
238 	int32	   *StopHigh = ((CHKVAL *) checkval)->arre;
239 	int32	   *StopMiddle;
240 
241 	/* Loop invariant: StopLow <= val < StopHigh */
242 
243 	while (StopLow < StopHigh)
244 	{
245 		StopMiddle = StopLow + (StopHigh - StopLow) / 2;
246 		if (*StopMiddle == item->val)
247 			return true;
248 		else if (*StopMiddle < item->val)
249 			StopLow = StopMiddle + 1;
250 		else
251 			StopHigh = StopMiddle;
252 	}
253 	return false;
254 }
255 
256 static bool
257 checkcondition_bit(void *checkval, ITEM *item, void *siglen)
258 {
259 	return GETBIT(checkval, HASHVAL(item->val, (int) (intptr_t) siglen));
260 }
261 
262 /*
263  * evaluate boolean expression, using chkcond() to test the primitive cases
264  */
265 static bool
266 execute(ITEM *curitem, void *checkval, void *options, bool calcnot,
267 		bool (*chkcond) (void *checkval, ITEM *item, void *options))
268 {
269 	/* since this function recurses, it could be driven to stack overflow */
270 	check_stack_depth();
271 
272 	if (curitem->type == VAL)
273 		return (*chkcond) (checkval, curitem, options);
274 	else if (curitem->val == (int32) '!')
275 	{
276 		return calcnot ?
277 			((execute(curitem - 1, checkval, options, calcnot, chkcond)) ? false : true)
278 			: true;
279 	}
280 	else if (curitem->val == (int32) '&')
281 	{
282 		if (execute(curitem + curitem->left, checkval, options, calcnot, chkcond))
283 			return execute(curitem - 1, checkval, options, calcnot, chkcond);
284 		else
285 			return false;
286 	}
287 	else
288 	{							/* |-operator */
289 		if (execute(curitem + curitem->left, checkval, options, calcnot, chkcond))
290 			return true;
291 		else
292 			return execute(curitem - 1, checkval, options, calcnot, chkcond);
293 	}
294 }
295 
296 /*
297  * signconsistent & execconsistent called by *_consistent
298  */
299 bool
300 signconsistent(QUERYTYPE *query, BITVECP sign, int siglen, bool calcnot)
301 {
302 	return execute(GETQUERY(query) + query->size - 1,
303 				   (void *) sign, (void *) (intptr_t) siglen, calcnot,
304 				   checkcondition_bit);
305 }
306 
307 /* Array must be sorted! */
308 bool
309 execconsistent(QUERYTYPE *query, ArrayType *array, bool calcnot)
310 {
311 	CHKVAL		chkval;
312 
313 	CHECKARRVALID(array);
314 	chkval.arrb = ARRPTR(array);
315 	chkval.arre = chkval.arrb + ARRNELEMS(array);
316 	return execute(GETQUERY(query) + query->size - 1,
317 				   (void *) &chkval, NULL, calcnot,
318 				   checkcondition_arr);
319 }
320 
321 typedef struct
322 {
323 	ITEM	   *first;
324 	bool	   *mapped_check;
325 } GinChkVal;
326 
327 static bool
328 checkcondition_gin(void *checkval, ITEM *item, void *options)
329 {
330 	GinChkVal  *gcv = (GinChkVal *) checkval;
331 
332 	return gcv->mapped_check[item - gcv->first];
333 }
334 
335 bool
336 gin_bool_consistent(QUERYTYPE *query, bool *check)
337 {
338 	GinChkVal	gcv;
339 	ITEM	   *items = GETQUERY(query);
340 	int			i,
341 				j = 0;
342 
343 	if (query->size <= 0)
344 		return false;
345 
346 	/*
347 	 * Set up data for checkcondition_gin.  This must agree with the query
348 	 * extraction code in ginint4_queryextract.
349 	 */
350 	gcv.first = items;
351 	gcv.mapped_check = (bool *) palloc(sizeof(bool) * query->size);
352 	for (i = 0; i < query->size; i++)
353 	{
354 		if (items[i].type == VAL)
355 			gcv.mapped_check[i] = check[j++];
356 	}
357 
358 	return execute(GETQUERY(query) + query->size - 1,
359 				   (void *) &gcv, NULL, true,
360 				   checkcondition_gin);
361 }
362 
363 static bool
364 contains_required_value(ITEM *curitem)
365 {
366 	/* since this function recurses, it could be driven to stack overflow */
367 	check_stack_depth();
368 
369 	if (curitem->type == VAL)
370 		return true;
371 	else if (curitem->val == (int32) '!')
372 	{
373 		/*
374 		 * Assume anything under a NOT is non-required.  For some cases with
375 		 * nested NOTs, we could prove there's a required value, but it seems
376 		 * unlikely to be worth the trouble.
377 		 */
378 		return false;
379 	}
380 	else if (curitem->val == (int32) '&')
381 	{
382 		/* If either side has a required value, we're good */
383 		if (contains_required_value(curitem + curitem->left))
384 			return true;
385 		else
386 			return contains_required_value(curitem - 1);
387 	}
388 	else
389 	{							/* |-operator */
390 		/* Both sides must have required values */
391 		if (contains_required_value(curitem + curitem->left))
392 			return contains_required_value(curitem - 1);
393 		else
394 			return false;
395 	}
396 }
397 
398 bool
399 query_has_required_values(QUERYTYPE *query)
400 {
401 	if (query->size <= 0)
402 		return false;
403 	return contains_required_value(GETQUERY(query) + query->size - 1);
404 }
405 
406 /*
407  * boolean operations
408  */
409 Datum
410 rboolop(PG_FUNCTION_ARGS)
411 {
412 	/* just reverse the operands */
413 	return DirectFunctionCall2(boolop,
414 							   PG_GETARG_DATUM(1),
415 							   PG_GETARG_DATUM(0));
416 }
417 
418 Datum
419 boolop(PG_FUNCTION_ARGS)
420 {
421 	ArrayType  *val = PG_GETARG_ARRAYTYPE_P_COPY(0);
422 	QUERYTYPE  *query = PG_GETARG_QUERYTYPE_P(1);
423 	CHKVAL		chkval;
424 	bool		result;
425 
426 	CHECKARRVALID(val);
427 	PREPAREARR(val);
428 	chkval.arrb = ARRPTR(val);
429 	chkval.arre = chkval.arrb + ARRNELEMS(val);
430 	result = execute(GETQUERY(query) + query->size - 1,
431 					 &chkval, NULL, true,
432 					 checkcondition_arr);
433 	pfree(val);
434 
435 	PG_FREE_IF_COPY(query, 1);
436 	PG_RETURN_BOOL(result);
437 }
438 
439 static void
440 findoprnd(ITEM *ptr, int32 *pos)
441 {
442 	/* since this function recurses, it could be driven to stack overflow. */
443 	check_stack_depth();
444 
445 #ifdef BS_DEBUG
446 	elog(DEBUG3, (ptr[*pos].type == OPR) ?
447 		 "%d  %c" : "%d  %d", *pos, ptr[*pos].val);
448 #endif
449 	if (ptr[*pos].type == VAL)
450 	{
451 		ptr[*pos].left = 0;
452 		(*pos)--;
453 	}
454 	else if (ptr[*pos].val == (int32) '!')
455 	{
456 		ptr[*pos].left = -1;
457 		(*pos)--;
458 		findoprnd(ptr, pos);
459 	}
460 	else
461 	{
462 		ITEM	   *curitem = &ptr[*pos];
463 		int32		tmp = *pos;
464 
465 		(*pos)--;
466 		findoprnd(ptr, pos);
467 		curitem->left = *pos - tmp;
468 		findoprnd(ptr, pos);
469 	}
470 }
471 
472 
473 /*
474  * input
475  */
476 Datum
477 bqarr_in(PG_FUNCTION_ARGS)
478 {
479 	char	   *buf = (char *) PG_GETARG_POINTER(0);
480 	WORKSTATE	state;
481 	int32		i;
482 	QUERYTYPE  *query;
483 	int32		commonlen;
484 	ITEM	   *ptr;
485 	NODE	   *tmp;
486 	int32		pos = 0;
487 
488 #ifdef BS_DEBUG
489 	StringInfoData pbuf;
490 #endif
491 
492 	state.buf = buf;
493 	state.state = WAITOPERAND;
494 	state.count = 0;
495 	state.num = 0;
496 	state.str = NULL;
497 
498 	/* make polish notation (postfix, but in reverse order) */
499 	makepol(&state);
500 	if (!state.num)
501 		ereport(ERROR,
502 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
503 				 errmsg("empty query")));
504 
505 	if (state.num > QUERYTYPEMAXITEMS)
506 		ereport(ERROR,
507 				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
508 				 errmsg("number of query items (%d) exceeds the maximum allowed (%d)",
509 						state.num, (int) QUERYTYPEMAXITEMS)));
510 	commonlen = COMPUTESIZE(state.num);
511 
512 	query = (QUERYTYPE *) palloc(commonlen);
513 	SET_VARSIZE(query, commonlen);
514 	query->size = state.num;
515 	ptr = GETQUERY(query);
516 
517 	for (i = state.num - 1; i >= 0; i--)
518 	{
519 		ptr[i].type = state.str->type;
520 		ptr[i].val = state.str->val;
521 		tmp = state.str->next;
522 		pfree(state.str);
523 		state.str = tmp;
524 	}
525 
526 	pos = query->size - 1;
527 	findoprnd(ptr, &pos);
528 #ifdef BS_DEBUG
529 	initStringInfo(&pbuf);
530 	for (i = 0; i < query->size; i++)
531 	{
532 		if (ptr[i].type == OPR)
533 			appendStringInfo(&pbuf, "%c(%d) ", ptr[i].val, ptr[i].left);
534 		else
535 			appendStringInfo(&pbuf, "%d ", ptr[i].val);
536 	}
537 	elog(DEBUG3, "POR: %s", pbuf.data);
538 	pfree(pbuf.data);
539 #endif
540 
541 	PG_RETURN_POINTER(query);
542 }
543 
544 
545 /*
546  * out function
547  */
548 typedef struct
549 {
550 	ITEM	   *curpol;
551 	char	   *buf;
552 	char	   *cur;
553 	int32		buflen;
554 } INFIX;
555 
556 #define RESIZEBUF(inf,addsize) while( ( (inf)->cur - (inf)->buf ) + (addsize) + 1 >= (inf)->buflen ) { \
557 	int32 len = inf->cur - inf->buf; \
558 	inf->buflen *= 2; \
559 	inf->buf = (char*) repalloc( (void*)inf->buf, inf->buflen ); \
560 	inf->cur = inf->buf + len; \
561 }
562 
563 static void
564 infix(INFIX *in, bool first)
565 {
566 	/* since this function recurses, it could be driven to stack overflow. */
567 	check_stack_depth();
568 
569 	if (in->curpol->type == VAL)
570 	{
571 		RESIZEBUF(in, 11);
572 		sprintf(in->cur, "%d", in->curpol->val);
573 		in->cur = strchr(in->cur, '\0');
574 		in->curpol--;
575 	}
576 	else if (in->curpol->val == (int32) '!')
577 	{
578 		bool		isopr = false;
579 
580 		RESIZEBUF(in, 1);
581 		*(in->cur) = '!';
582 		in->cur++;
583 		*(in->cur) = '\0';
584 		in->curpol--;
585 		if (in->curpol->type == OPR)
586 		{
587 			isopr = true;
588 			RESIZEBUF(in, 2);
589 			sprintf(in->cur, "( ");
590 			in->cur = strchr(in->cur, '\0');
591 		}
592 		infix(in, isopr);
593 		if (isopr)
594 		{
595 			RESIZEBUF(in, 2);
596 			sprintf(in->cur, " )");
597 			in->cur = strchr(in->cur, '\0');
598 		}
599 	}
600 	else
601 	{
602 		int32		op = in->curpol->val;
603 		INFIX		nrm;
604 
605 		in->curpol--;
606 		if (op == (int32) '|' && !first)
607 		{
608 			RESIZEBUF(in, 2);
609 			sprintf(in->cur, "( ");
610 			in->cur = strchr(in->cur, '\0');
611 		}
612 
613 		nrm.curpol = in->curpol;
614 		nrm.buflen = 16;
615 		nrm.cur = nrm.buf = (char *) palloc(sizeof(char) * nrm.buflen);
616 
617 		/* get right operand */
618 		infix(&nrm, false);
619 
620 		/* get & print left operand */
621 		in->curpol = nrm.curpol;
622 		infix(in, false);
623 
624 		/* print operator & right operand */
625 		RESIZEBUF(in, 3 + (nrm.cur - nrm.buf));
626 		sprintf(in->cur, " %c %s", op, nrm.buf);
627 		in->cur = strchr(in->cur, '\0');
628 		pfree(nrm.buf);
629 
630 		if (op == (int32) '|' && !first)
631 		{
632 			RESIZEBUF(in, 2);
633 			sprintf(in->cur, " )");
634 			in->cur = strchr(in->cur, '\0');
635 		}
636 	}
637 }
638 
639 
640 Datum
641 bqarr_out(PG_FUNCTION_ARGS)
642 {
643 	QUERYTYPE  *query = PG_GETARG_QUERYTYPE_P(0);
644 	INFIX		nrm;
645 
646 	if (query->size == 0)
647 		ereport(ERROR,
648 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
649 				 errmsg("empty query")));
650 
651 	nrm.curpol = GETQUERY(query) + query->size - 1;
652 	nrm.buflen = 32;
653 	nrm.cur = nrm.buf = (char *) palloc(sizeof(char) * nrm.buflen);
654 	*(nrm.cur) = '\0';
655 	infix(&nrm, true);
656 
657 	PG_FREE_IF_COPY(query, 0);
658 	PG_RETURN_POINTER(nrm.buf);
659 }
660 
661 
662 /* Useless old "debugging" function for a fundamentally wrong algorithm */
663 Datum
664 querytree(PG_FUNCTION_ARGS)
665 {
666 	elog(ERROR, "querytree is no longer implemented");
667 	PG_RETURN_NULL();
668 }
669