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1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * pg_list.h
4 : : * interface for PostgreSQL generic list package
5 : : *
6 : : * Once upon a time, parts of Postgres were written in Lisp and used real
7 : : * cons-cell lists for major data structures. When that code was rewritten
8 : : * in C, we initially had a faithful emulation of cons-cell lists, which
9 : : * unsurprisingly was a performance bottleneck. A couple of major rewrites
10 : : * later, these data structures are actually simple expansible arrays;
11 : : * but the "List" name and a lot of the notation survives.
12 : : *
13 : : * One important concession to the original implementation is that an empty
14 : : * list is always represented by a null pointer (preferentially written NIL).
15 : : * Non-empty lists have a header, which will not be relocated as long as the
16 : : * list remains non-empty, and an expansible data array.
17 : : *
18 : : * We support four types of lists:
19 : : *
20 : : * T_List: lists of pointers
21 : : * (in practice usually pointers to Nodes, but not always;
22 : : * declared as "void *" to minimize casting annoyances)
23 : : * T_IntList: lists of integers
24 : : * T_OidList: lists of Oids
25 : : * T_XidList: lists of TransactionIds
26 : : * (the XidList infrastructure is less complete than the other cases)
27 : : *
28 : : * (At the moment, ints, Oids, and XIDs are the same size, but they may not
29 : : * always be so; be careful to use the appropriate list type for your data.)
30 : : *
31 : : *
32 : : * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
33 : : * Portions Copyright (c) 1994, Regents of the University of California
34 : : *
35 : : * src/include/nodes/pg_list.h
36 : : *
37 : : *-------------------------------------------------------------------------
38 : : */
39 : : #ifndef PG_LIST_H
40 : : #define PG_LIST_H
41 : :
42 : : #include "nodes/nodes.h"
43 : :
44 : :
45 : : typedef union ListCell
46 : : {
47 : : void *ptr_value;
48 : : int int_value;
49 : : Oid oid_value;
50 : : TransactionId xid_value;
51 : : } ListCell;
52 : :
53 : : typedef struct List
54 : : {
55 : : NodeTag type; /* T_List, T_IntList, T_OidList, or T_XidList */
56 : : int length; /* number of elements currently present */
57 : : int max_length; /* allocated length of elements[] */
58 : : ListCell *elements; /* re-allocatable array of cells */
59 : : /* We may allocate some cells along with the List header: */
60 : : ListCell initial_elements[FLEXIBLE_ARRAY_MEMBER];
61 : : /* If elements == initial_elements, it's not a separate allocation */
62 : : } List;
63 : :
64 : : /*
65 : : * The *only* valid representation of an empty list is NIL; in other
66 : : * words, a non-NIL list is guaranteed to have length >= 1.
67 : : */
68 : : #define NIL ((List *) NULL)
69 : :
70 : : /*
71 : : * State structs for various looping macros below.
72 : : */
73 : : typedef struct ForEachState
74 : : {
75 : : const List *l; /* list we're looping through */
76 : : int i; /* current element index */
77 : : } ForEachState;
78 : :
79 : : typedef struct ForBothState
80 : : {
81 : : const List *l1; /* lists we're looping through */
82 : : const List *l2;
83 : : int i; /* common element index */
84 : : } ForBothState;
85 : :
86 : : typedef struct ForBothCellState
87 : : {
88 : : const List *l1; /* lists we're looping through */
89 : : const List *l2;
90 : : int i1; /* current element indexes */
91 : : int i2;
92 : : } ForBothCellState;
93 : :
94 : : typedef struct ForThreeState
95 : : {
96 : : const List *l1; /* lists we're looping through */
97 : : const List *l2;
98 : : const List *l3;
99 : : int i; /* common element index */
100 : : } ForThreeState;
101 : :
102 : : typedef struct ForFourState
103 : : {
104 : : const List *l1; /* lists we're looping through */
105 : : const List *l2;
106 : : const List *l3;
107 : : const List *l4;
108 : : int i; /* common element index */
109 : : } ForFourState;
110 : :
111 : : typedef struct ForFiveState
112 : : {
113 : : const List *l1; /* lists we're looping through */
114 : : const List *l2;
115 : : const List *l3;
116 : : const List *l4;
117 : : const List *l5;
118 : : int i; /* common element index */
119 : : } ForFiveState;
120 : :
121 : : /*
122 : : * These routines are small enough, and used often enough, to justify being
123 : : * inline.
124 : : */
125 : :
126 : : /* Fetch address of list's first cell; NULL if empty list */
127 : : static inline ListCell *
4512 peter_e@gmx.net 128 :CBC 14784248 : list_head(const List *l)
129 : : {
1735 tgl@sss.pgh.pa.us 130 [ + + ]: 14784248 : return l ? &l->elements[0] : NULL;
131 : : }
132 : :
133 : : /* Fetch address of list's last cell; NULL if empty list */
134 : : static inline ListCell *
135 : : list_tail(const List *l)
136 : : {
137 : : return l ? &l->elements[l->length - 1] : NULL;
138 : : }
139 : :
140 : : /* Fetch address of list's second cell, if it has one, else NULL */
141 : : static inline ListCell *
142 : 67538 : list_second_cell(const List *l)
143 : : {
144 [ + - + + ]: 67538 : if (l && l->length >= 2)
145 : 65154 : return &l->elements[1];
146 : : else
147 : 2384 : return NULL;
148 : : }
149 : :
150 : : /* Fetch list's length */
151 : : static inline int
4512 peter_e@gmx.net 152 : 43553091 : list_length(const List *l)
153 : : {
7263 neilc@samurai.com 154 [ + + ]: 43553091 : return l ? l->length : 0;
155 : : }
156 : :
157 : : /*
158 : : * Macros to access the data values within List cells.
159 : : *
160 : : * Note that with the exception of the "xxx_node" macros, these are
161 : : * lvalues and can be assigned to.
162 : : *
163 : : * NB: There is an unfortunate legacy from a previous incarnation of
164 : : * the List API: the macro lfirst() was used to mean "the data in this
165 : : * cons cell". To avoid changing every usage of lfirst(), that meaning
166 : : * has been kept. As a result, lfirst() takes a ListCell and returns
167 : : * the data it contains; to get the data in the first cell of a
168 : : * List, use linitial(). Worse, lsecond() is more closely related to
169 : : * linitial() than lfirst(): given a List, lsecond() returns the data
170 : : * in the second list cell.
171 : : */
172 : : #define lfirst(lc) ((lc)->ptr_value)
173 : : #define lfirst_int(lc) ((lc)->int_value)
174 : : #define lfirst_oid(lc) ((lc)->oid_value)
175 : : #define lfirst_xid(lc) ((lc)->xid_value)
176 : : #define lfirst_node(type,lc) castNode(type, lfirst(lc))
177 : :
178 : : #define linitial(l) lfirst(list_nth_cell(l, 0))
179 : : #define linitial_int(l) lfirst_int(list_nth_cell(l, 0))
180 : : #define linitial_oid(l) lfirst_oid(list_nth_cell(l, 0))
181 : : #define linitial_node(type,l) castNode(type, linitial(l))
182 : :
183 : : #define lsecond(l) lfirst(list_nth_cell(l, 1))
184 : : #define lsecond_int(l) lfirst_int(list_nth_cell(l, 1))
185 : : #define lsecond_oid(l) lfirst_oid(list_nth_cell(l, 1))
186 : : #define lsecond_node(type,l) castNode(type, lsecond(l))
187 : :
188 : : #define lthird(l) lfirst(list_nth_cell(l, 2))
189 : : #define lthird_int(l) lfirst_int(list_nth_cell(l, 2))
190 : : #define lthird_oid(l) lfirst_oid(list_nth_cell(l, 2))
191 : : #define lthird_node(type,l) castNode(type, lthird(l))
192 : :
193 : : #define lfourth(l) lfirst(list_nth_cell(l, 3))
194 : : #define lfourth_int(l) lfirst_int(list_nth_cell(l, 3))
195 : : #define lfourth_oid(l) lfirst_oid(list_nth_cell(l, 3))
196 : : #define lfourth_node(type,l) castNode(type, lfourth(l))
197 : :
198 : : #define llast(l) lfirst(list_last_cell(l))
199 : : #define llast_int(l) lfirst_int(list_last_cell(l))
200 : : #define llast_oid(l) lfirst_oid(list_last_cell(l))
201 : : #define llast_xid(l) lfirst_xid(list_last_cell(l))
202 : : #define llast_node(type,l) castNode(type, llast(l))
203 : :
204 : : /*
205 : : * Convenience macros for building fixed-length lists
206 : : */
207 : : #define list_make_ptr_cell(v) ((ListCell) {.ptr_value = (v)})
208 : : #define list_make_int_cell(v) ((ListCell) {.int_value = (v)})
209 : : #define list_make_oid_cell(v) ((ListCell) {.oid_value = (v)})
210 : : #define list_make_xid_cell(v) ((ListCell) {.xid_value = (v)})
211 : :
212 : : #define list_make1(x1) \
213 : : list_make1_impl(T_List, list_make_ptr_cell(x1))
214 : : #define list_make2(x1,x2) \
215 : : list_make2_impl(T_List, list_make_ptr_cell(x1), list_make_ptr_cell(x2))
216 : : #define list_make3(x1,x2,x3) \
217 : : list_make3_impl(T_List, list_make_ptr_cell(x1), list_make_ptr_cell(x2), \
218 : : list_make_ptr_cell(x3))
219 : : #define list_make4(x1,x2,x3,x4) \
220 : : list_make4_impl(T_List, list_make_ptr_cell(x1), list_make_ptr_cell(x2), \
221 : : list_make_ptr_cell(x3), list_make_ptr_cell(x4))
222 : : #define list_make5(x1,x2,x3,x4,x5) \
223 : : list_make5_impl(T_List, list_make_ptr_cell(x1), list_make_ptr_cell(x2), \
224 : : list_make_ptr_cell(x3), list_make_ptr_cell(x4), \
225 : : list_make_ptr_cell(x5))
226 : :
227 : : #define list_make1_int(x1) \
228 : : list_make1_impl(T_IntList, list_make_int_cell(x1))
229 : : #define list_make2_int(x1,x2) \
230 : : list_make2_impl(T_IntList, list_make_int_cell(x1), list_make_int_cell(x2))
231 : : #define list_make3_int(x1,x2,x3) \
232 : : list_make3_impl(T_IntList, list_make_int_cell(x1), list_make_int_cell(x2), \
233 : : list_make_int_cell(x3))
234 : : #define list_make4_int(x1,x2,x3,x4) \
235 : : list_make4_impl(T_IntList, list_make_int_cell(x1), list_make_int_cell(x2), \
236 : : list_make_int_cell(x3), list_make_int_cell(x4))
237 : : #define list_make5_int(x1,x2,x3,x4,x5) \
238 : : list_make5_impl(T_IntList, list_make_int_cell(x1), list_make_int_cell(x2), \
239 : : list_make_int_cell(x3), list_make_int_cell(x4), \
240 : : list_make_int_cell(x5))
241 : :
242 : : #define list_make1_oid(x1) \
243 : : list_make1_impl(T_OidList, list_make_oid_cell(x1))
244 : : #define list_make2_oid(x1,x2) \
245 : : list_make2_impl(T_OidList, list_make_oid_cell(x1), list_make_oid_cell(x2))
246 : : #define list_make3_oid(x1,x2,x3) \
247 : : list_make3_impl(T_OidList, list_make_oid_cell(x1), list_make_oid_cell(x2), \
248 : : list_make_oid_cell(x3))
249 : : #define list_make4_oid(x1,x2,x3,x4) \
250 : : list_make4_impl(T_OidList, list_make_oid_cell(x1), list_make_oid_cell(x2), \
251 : : list_make_oid_cell(x3), list_make_oid_cell(x4))
252 : : #define list_make5_oid(x1,x2,x3,x4,x5) \
253 : : list_make5_impl(T_OidList, list_make_oid_cell(x1), list_make_oid_cell(x2), \
254 : : list_make_oid_cell(x3), list_make_oid_cell(x4), \
255 : : list_make_oid_cell(x5))
256 : :
257 : : #define list_make1_xid(x1) \
258 : : list_make1_impl(T_XidList, list_make_xid_cell(x1))
259 : : #define list_make2_xid(x1,x2) \
260 : : list_make2_impl(T_XidList, list_make_xid_cell(x1), list_make_xid_cell(x2))
261 : : #define list_make3_xid(x1,x2,x3) \
262 : : list_make3_impl(T_XidList, list_make_xid_cell(x1), list_make_xid_cell(x2), \
263 : : list_make_xid_cell(x3))
264 : : #define list_make4_xid(x1,x2,x3,x4) \
265 : : list_make4_impl(T_XidList, list_make_xid_cell(x1), list_make_xid_cell(x2), \
266 : : list_make_xid_cell(x3), list_make_xid_cell(x4))
267 : : #define list_make5_xid(x1,x2,x3,x4,x5) \
268 : : list_make5_impl(T_XidList, list_make_xid_cell(x1), list_make_xid_cell(x2), \
269 : : list_make_xid_cell(x3), list_make_xid_cell(x4), \
270 : : list_make_xid_cell(x5))
271 : :
272 : : /*
273 : : * Locate the n'th cell (counting from 0) of the list.
274 : : * It is an assertion failure if there is no such cell.
275 : : */
276 : : static inline ListCell *
1735 tgl@sss.pgh.pa.us 277 : 32215425 : list_nth_cell(const List *list, int n)
278 : : {
279 [ - + ]: 32215425 : Assert(list != NIL);
280 [ + - - + ]: 32215425 : Assert(n >= 0 && n < list->length);
281 : 32215425 : return &list->elements[n];
282 : : }
283 : :
284 : : /*
285 : : * Return the last cell in a non-NIL List.
286 : : */
287 : : static inline ListCell *
1294 drowley@postgresql.o 288 : 44640471 : list_last_cell(const List *list)
289 : : {
290 [ - + ]: 44640471 : Assert(list != NIL);
291 : 44640471 : return &list->elements[list->length - 1];
292 : : }
293 : :
294 : : /*
295 : : * Return the pointer value contained in the n'th element of the
296 : : * specified list. (List elements begin at 0.)
297 : : */
298 : : static inline void *
1735 tgl@sss.pgh.pa.us 299 : 11998606 : list_nth(const List *list, int n)
300 : : {
301 [ - + ]: 11998606 : Assert(IsA(list, List));
302 : 11998606 : return lfirst(list_nth_cell(list, n));
303 : : }
304 : :
305 : : /*
306 : : * Return the integer value contained in the n'th element of the
307 : : * specified list.
308 : : */
309 : : static inline int
310 : 6132 : list_nth_int(const List *list, int n)
311 : : {
312 [ - + ]: 6132 : Assert(IsA(list, IntList));
313 : 6132 : return lfirst_int(list_nth_cell(list, n));
314 : : }
315 : :
316 : : /*
317 : : * Return the OID value contained in the n'th element of the specified
318 : : * list.
319 : : */
320 : : static inline Oid
321 : 7258 : list_nth_oid(const List *list, int n)
322 : : {
323 [ - + ]: 7258 : Assert(IsA(list, OidList));
324 : 7258 : return lfirst_oid(list_nth_cell(list, n));
325 : : }
326 : :
327 : : #define list_nth_node(type,list,n) castNode(type, list_nth(list, n))
328 : :
329 : : /*
330 : : * Get the given ListCell's index (from 0) in the given List.
331 : : */
332 : : static inline int
333 : 101850 : list_cell_number(const List *l, const ListCell *c)
334 : : {
335 [ + - - + ]: 101850 : Assert(c >= &l->elements[0] && c < &l->elements[l->length]);
336 : 101850 : return c - l->elements;
337 : : }
338 : :
339 : : /*
340 : : * Get the address of the next cell after "c" within list "l", or NULL if none.
341 : : */
342 : : static inline ListCell *
343 : 5283389 : lnext(const List *l, const ListCell *c)
344 : : {
345 [ + - - + ]: 5283389 : Assert(c >= &l->elements[0] && c < &l->elements[l->length]);
346 : 5283389 : c++;
347 [ + + ]: 5283389 : if (c < &l->elements[l->length])
348 : 3102331 : return (ListCell *) c;
349 : : else
350 : 2181058 : return NULL;
351 : : }
352 : :
353 : : /*
354 : : * foreach -
355 : : * a convenience macro for looping through a list
356 : : *
357 : : * "cell" must be the name of a "ListCell *" variable; it's made to point
358 : : * to each List element in turn. "cell" will be NULL after normal exit from
359 : : * the loop, but an early "break" will leave it pointing at the current
360 : : * List element.
361 : : *
362 : : * Beware of changing the List object while the loop is iterating.
363 : : * The current semantics are that we examine successive list indices in
364 : : * each iteration, so that insertion or deletion of list elements could
365 : : * cause elements to be re-visited or skipped unexpectedly. Previous
366 : : * implementations of foreach() behaved differently. However, it's safe
367 : : * to append elements to the List (or in general, insert them after the
368 : : * current element); such new elements are guaranteed to be visited.
369 : : * Also, the current element of the List can be deleted, if you use
370 : : * foreach_delete_current() to do so. BUT: either of these actions will
371 : : * invalidate the "cell" pointer for the remainder of the current iteration.
372 : : */
373 : : #define foreach(cell, lst) \
374 : : for (ForEachState cell##__state = {(lst), 0}; \
375 : : (cell##__state.l != NIL && \
376 : : cell##__state.i < cell##__state.l->length) ? \
377 : : (cell = &cell##__state.l->elements[cell##__state.i], true) : \
378 : : (cell = NULL, false); \
379 : : cell##__state.i++)
380 : :
381 : : /*
382 : : * foreach_delete_current -
383 : : * delete the current list element from the List associated with a
384 : : * surrounding foreach() or foreach_*() loop, returning the new List
385 : : * pointer; pass the name of the iterator variable.
386 : : *
387 : : * This is similar to list_delete_cell(), but it also adjusts the loop's state
388 : : * so that no list elements will be missed. Do not delete elements from an
389 : : * active foreach or foreach_* loop's list in any other way!
390 : : */
391 : : #define foreach_delete_current(lst, var_or_cell) \
392 : : ((List *) (var_or_cell##__state.l = list_delete_nth_cell(lst, var_or_cell##__state.i--)))
393 : :
394 : : /*
395 : : * foreach_current_index -
396 : : * get the zero-based list index of a surrounding foreach() or foreach_*()
397 : : * loop's current element; pass the name of the iterator variable.
398 : : *
399 : : * Beware of using this after foreach_delete_current(); the value will be
400 : : * out of sync for the rest of the current loop iteration. Anyway, since
401 : : * you just deleted the current element, the value is pretty meaningless.
402 : : */
403 : : #define foreach_current_index(var_or_cell) (var_or_cell##__state.i)
404 : :
405 : : /*
406 : : * for_each_from -
407 : : * Like foreach(), but start from the N'th (zero-based) list element,
408 : : * not necessarily the first one.
409 : : *
410 : : * It's okay for N to exceed the list length, but not for it to be negative.
411 : : *
412 : : * The caveats for foreach() apply equally here.
413 : : */
414 : : #define for_each_from(cell, lst, N) \
415 : : for (ForEachState cell##__state = for_each_from_setup(lst, N); \
416 : : (cell##__state.l != NIL && \
417 : : cell##__state.i < cell##__state.l->length) ? \
418 : : (cell = &cell##__state.l->elements[cell##__state.i], true) : \
419 : : (cell = NULL, false); \
420 : : cell##__state.i++)
421 : :
422 : : static inline ForEachState
1294 423 : 306660 : for_each_from_setup(const List *lst, int N)
424 : : {
425 : 306660 : ForEachState r = {lst, N};
426 : :
427 [ - + ]: 306660 : Assert(N >= 0);
428 : 306660 : return r;
429 : : }
430 : :
431 : : /*
432 : : * for_each_cell -
433 : : * a convenience macro which loops through a list starting from a
434 : : * specified cell
435 : : *
436 : : * The caveats for foreach() apply equally here.
437 : : */
438 : : #define for_each_cell(cell, lst, initcell) \
439 : : for (ForEachState cell##__state = for_each_cell_setup(lst, initcell); \
440 : : (cell##__state.l != NIL && \
441 : : cell##__state.i < cell##__state.l->length) ? \
442 : : (cell = &cell##__state.l->elements[cell##__state.i], true) : \
443 : : (cell = NULL, false); \
444 : : cell##__state.i++)
445 : :
446 : : static inline ForEachState
447 : 101191 : for_each_cell_setup(const List *lst, const ListCell *initcell)
448 : : {
1735 449 : 202382 : ForEachState r = {lst,
450 [ + + ]: 101191 : initcell ? list_cell_number(lst, initcell) : list_length(lst)};
451 : :
452 : 101191 : return r;
453 : : }
454 : :
455 : : /*
456 : : * Convenience macros that loop through a list without needing a separate
457 : : * "ListCell *" variable. Instead, the macros declare a locally-scoped loop
458 : : * variable with the provided name and the appropriate type.
459 : : *
460 : : * Since the variable is scoped to the loop, it's not possible to detect an
461 : : * early break by checking its value after the loop completes, as is common
462 : : * practice. If you need to do this, you can either use foreach() instead or
463 : : * manually track early breaks with a separate variable declared outside of the
464 : : * loop.
465 : : *
466 : : * Note that the caveats described in the comment above the foreach() macro
467 : : * also apply to these convenience macros.
468 : : */
469 : : #define foreach_ptr(type, var, lst) foreach_internal(type, *, var, lst, lfirst)
470 : : #define foreach_int(var, lst) foreach_internal(int, , var, lst, lfirst_int)
471 : : #define foreach_oid(var, lst) foreach_internal(Oid, , var, lst, lfirst_oid)
472 : : #define foreach_xid(var, lst) foreach_internal(TransactionId, , var, lst, lfirst_xid)
473 : :
474 : : /*
475 : : * The internal implementation of the above macros. Do not use directly.
476 : : *
477 : : * This macro actually generates two loops in order to declare two variables of
478 : : * different types. The outer loop only iterates once, so we expect optimizing
479 : : * compilers will unroll it, thereby optimizing it away.
480 : : */
481 : : #define foreach_internal(type, pointer, var, lst, func) \
482 : : for (type pointer var = 0, pointer var##__outerloop = (type pointer) 1; \
483 : : var##__outerloop; \
484 : : var##__outerloop = 0) \
485 : : for (ForEachState var##__state = {(lst), 0}; \
486 : : (var##__state.l != NIL && \
487 : : var##__state.i < var##__state.l->length && \
488 : : (var = func(&var##__state.l->elements[var##__state.i]), true)); \
489 : : var##__state.i++)
490 : :
491 : : /*
492 : : * foreach_node -
493 : : * The same as foreach_ptr, but asserts that the element is of the specified
494 : : * node type.
495 : : */
496 : : #define foreach_node(type, var, lst) \
497 : : for (type * var = 0, *var##__outerloop = (type *) 1; \
498 : : var##__outerloop; \
499 : : var##__outerloop = 0) \
500 : : for (ForEachState var##__state = {(lst), 0}; \
501 : : (var##__state.l != NIL && \
502 : : var##__state.i < var##__state.l->length && \
503 : : (var = lfirst_node(type, &var##__state.l->elements[var##__state.i]), true)); \
504 : : var##__state.i++)
505 : :
506 : : /*
507 : : * forboth -
508 : : * a convenience macro for advancing through two linked lists
509 : : * simultaneously. This macro loops through both lists at the same
510 : : * time, stopping when either list runs out of elements. Depending
511 : : * on the requirements of the call site, it may also be wise to
512 : : * assert that the lengths of the two lists are equal. (But, if they
513 : : * are not, some callers rely on the ending cell values being separately
514 : : * NULL or non-NULL as defined here; don't try to optimize that.)
515 : : *
516 : : * The caveats for foreach() apply equally here.
517 : : */
518 : : #define forboth(cell1, list1, cell2, list2) \
519 : : for (ForBothState cell1##__state = {(list1), (list2), 0}; \
520 : : multi_for_advance_cell(cell1, cell1##__state, l1, i), \
521 : : multi_for_advance_cell(cell2, cell1##__state, l2, i), \
522 : : (cell1 != NULL && cell2 != NULL); \
523 : : cell1##__state.i++)
524 : :
525 : : #define multi_for_advance_cell(cell, state, l, i) \
526 : : (cell = (state.l != NIL && state.i < state.l->length) ? \
527 : : &state.l->elements[state.i] : NULL)
528 : :
529 : : /*
530 : : * for_both_cell -
531 : : * a convenience macro which loops through two lists starting from the
532 : : * specified cells of each. This macro loops through both lists at the same
533 : : * time, stopping when either list runs out of elements. Depending on the
534 : : * requirements of the call site, it may also be wise to assert that the
535 : : * lengths of the two lists are equal, and initcell1 and initcell2 are at
536 : : * the same position in the respective lists.
537 : : *
538 : : * The caveats for foreach() apply equally here.
539 : : */
540 : : #define for_both_cell(cell1, list1, initcell1, cell2, list2, initcell2) \
541 : : for (ForBothCellState cell1##__state = \
542 : : for_both_cell_setup(list1, initcell1, list2, initcell2); \
543 : : multi_for_advance_cell(cell1, cell1##__state, l1, i1), \
544 : : multi_for_advance_cell(cell2, cell1##__state, l2, i2), \
545 : : (cell1 != NULL && cell2 != NULL); \
546 : : cell1##__state.i1++, cell1##__state.i2++)
547 : :
548 : : static inline ForBothCellState
1294 549 : 2022 : for_both_cell_setup(const List *list1, const ListCell *initcell1,
550 : : const List *list2, const ListCell *initcell2)
551 : : {
1735 552 : 6066 : ForBothCellState r = {list1, list2,
553 [ + - ]: 2022 : initcell1 ? list_cell_number(list1, initcell1) : list_length(list1),
554 [ + - ]: 2022 : initcell2 ? list_cell_number(list2, initcell2) : list_length(list2)};
555 : :
556 : 2022 : return r;
557 : : }
558 : :
559 : : /*
560 : : * forthree -
561 : : * the same for three lists
562 : : */
563 : : #define forthree(cell1, list1, cell2, list2, cell3, list3) \
564 : : for (ForThreeState cell1##__state = {(list1), (list2), (list3), 0}; \
565 : : multi_for_advance_cell(cell1, cell1##__state, l1, i), \
566 : : multi_for_advance_cell(cell2, cell1##__state, l2, i), \
567 : : multi_for_advance_cell(cell3, cell1##__state, l3, i), \
568 : : (cell1 != NULL && cell2 != NULL && cell3 != NULL); \
569 : : cell1##__state.i++)
570 : :
571 : : /*
572 : : * forfour -
573 : : * the same for four lists
574 : : */
575 : : #define forfour(cell1, list1, cell2, list2, cell3, list3, cell4, list4) \
576 : : for (ForFourState cell1##__state = {(list1), (list2), (list3), (list4), 0}; \
577 : : multi_for_advance_cell(cell1, cell1##__state, l1, i), \
578 : : multi_for_advance_cell(cell2, cell1##__state, l2, i), \
579 : : multi_for_advance_cell(cell3, cell1##__state, l3, i), \
580 : : multi_for_advance_cell(cell4, cell1##__state, l4, i), \
581 : : (cell1 != NULL && cell2 != NULL && cell3 != NULL && cell4 != NULL); \
582 : : cell1##__state.i++)
583 : :
584 : : /*
585 : : * forfive -
586 : : * the same for five lists
587 : : */
588 : : #define forfive(cell1, list1, cell2, list2, cell3, list3, cell4, list4, cell5, list5) \
589 : : for (ForFiveState cell1##__state = {(list1), (list2), (list3), (list4), (list5), 0}; \
590 : : multi_for_advance_cell(cell1, cell1##__state, l1, i), \
591 : : multi_for_advance_cell(cell2, cell1##__state, l2, i), \
592 : : multi_for_advance_cell(cell3, cell1##__state, l3, i), \
593 : : multi_for_advance_cell(cell4, cell1##__state, l4, i), \
594 : : multi_for_advance_cell(cell5, cell1##__state, l5, i), \
595 : : (cell1 != NULL && cell2 != NULL && cell3 != NULL && \
596 : : cell4 != NULL && cell5 != NULL); \
597 : : cell1##__state.i++)
598 : :
599 : : /* Functions in src/backend/nodes/list.c */
600 : :
601 : : extern List *list_make1_impl(NodeTag t, ListCell datum1);
602 : : extern List *list_make2_impl(NodeTag t, ListCell datum1, ListCell datum2);
603 : : extern List *list_make3_impl(NodeTag t, ListCell datum1, ListCell datum2,
604 : : ListCell datum3);
605 : : extern List *list_make4_impl(NodeTag t, ListCell datum1, ListCell datum2,
606 : : ListCell datum3, ListCell datum4);
607 : : extern List *list_make5_impl(NodeTag t, ListCell datum1, ListCell datum2,
608 : : ListCell datum3, ListCell datum4,
609 : : ListCell datum5);
610 : :
611 : : extern pg_nodiscard List *lappend(List *list, void *datum);
612 : : extern pg_nodiscard List *lappend_int(List *list, int datum);
613 : : extern pg_nodiscard List *lappend_oid(List *list, Oid datum);
614 : : extern pg_nodiscard List *lappend_xid(List *list, TransactionId datum);
615 : :
616 : : extern pg_nodiscard List *list_insert_nth(List *list, int pos, void *datum);
617 : : extern pg_nodiscard List *list_insert_nth_int(List *list, int pos, int datum);
618 : : extern pg_nodiscard List *list_insert_nth_oid(List *list, int pos, Oid datum);
619 : :
620 : : extern pg_nodiscard List *lcons(void *datum, List *list);
621 : : extern pg_nodiscard List *lcons_int(int datum, List *list);
622 : : extern pg_nodiscard List *lcons_oid(Oid datum, List *list);
623 : :
624 : : extern pg_nodiscard List *list_concat(List *list1, const List *list2);
625 : : extern pg_nodiscard List *list_concat_copy(const List *list1, const List *list2);
626 : :
627 : : extern pg_nodiscard List *list_truncate(List *list, int new_size);
628 : :
629 : : extern bool list_member(const List *list, const void *datum);
630 : : extern bool list_member_ptr(const List *list, const void *datum);
631 : : extern bool list_member_int(const List *list, int datum);
632 : : extern bool list_member_oid(const List *list, Oid datum);
633 : : extern bool list_member_xid(const List *list, TransactionId datum);
634 : :
635 : : extern pg_nodiscard List *list_delete(List *list, void *datum);
636 : : extern pg_nodiscard List *list_delete_ptr(List *list, void *datum);
637 : : extern pg_nodiscard List *list_delete_int(List *list, int datum);
638 : : extern pg_nodiscard List *list_delete_oid(List *list, Oid datum);
639 : : extern pg_nodiscard List *list_delete_first(List *list);
640 : : extern pg_nodiscard List *list_delete_last(List *list);
641 : : extern pg_nodiscard List *list_delete_first_n(List *list, int n);
642 : : extern pg_nodiscard List *list_delete_nth_cell(List *list, int n);
643 : : extern pg_nodiscard List *list_delete_cell(List *list, ListCell *cell);
644 : :
645 : : extern List *list_union(const List *list1, const List *list2);
646 : : extern List *list_union_ptr(const List *list1, const List *list2);
647 : : extern List *list_union_int(const List *list1, const List *list2);
648 : : extern List *list_union_oid(const List *list1, const List *list2);
649 : :
650 : : extern List *list_intersection(const List *list1, const List *list2);
651 : : extern List *list_intersection_int(const List *list1, const List *list2);
652 : :
653 : : /* currently, there's no need for list_intersection_ptr etc */
654 : :
655 : : extern List *list_difference(const List *list1, const List *list2);
656 : : extern List *list_difference_ptr(const List *list1, const List *list2);
657 : : extern List *list_difference_int(const List *list1, const List *list2);
658 : : extern List *list_difference_oid(const List *list1, const List *list2);
659 : :
660 : : extern pg_nodiscard List *list_append_unique(List *list, void *datum);
661 : : extern pg_nodiscard List *list_append_unique_ptr(List *list, void *datum);
662 : : extern pg_nodiscard List *list_append_unique_int(List *list, int datum);
663 : : extern pg_nodiscard List *list_append_unique_oid(List *list, Oid datum);
664 : :
665 : : extern pg_nodiscard List *list_concat_unique(List *list1, const List *list2);
666 : : extern pg_nodiscard List *list_concat_unique_ptr(List *list1, const List *list2);
667 : : extern pg_nodiscard List *list_concat_unique_int(List *list1, const List *list2);
668 : : extern pg_nodiscard List *list_concat_unique_oid(List *list1, const List *list2);
669 : :
670 : : extern void list_deduplicate_oid(List *list);
671 : :
672 : : extern void list_free(List *list);
673 : : extern void list_free_deep(List *list);
674 : :
675 : : extern pg_nodiscard List *list_copy(const List *oldlist);
676 : : extern pg_nodiscard List *list_copy_head(const List *oldlist, int len);
677 : : extern pg_nodiscard List *list_copy_tail(const List *oldlist, int nskip);
678 : : extern pg_nodiscard List *list_copy_deep(const List *oldlist);
679 : :
680 : : typedef int (*list_sort_comparator) (const ListCell *a, const ListCell *b);
681 : : extern void list_sort(List *list, list_sort_comparator cmp);
682 : :
683 : : extern int list_int_cmp(const ListCell *p1, const ListCell *p2);
684 : : extern int list_oid_cmp(const ListCell *p1, const ListCell *p2);
685 : :
686 : : #endif /* PG_LIST_H */
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