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1 : /*-------------------------------------------------------------------------
2 : *
3 : * nodes.h
4 : * Definitions for tagged nodes.
5 : *
6 : *
7 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
8 : * Portions Copyright (c) 1994, Regents of the University of California
9 : *
10 : * src/include/nodes/nodes.h
11 : *
12 : *-------------------------------------------------------------------------
13 : */
14 : #ifndef NODES_H
15 : #define NODES_H
16 :
17 : /*
18 : * The first field of every node is NodeTag. Each node created (with makeNode)
19 : * will have one of the following tags as the value of its first field.
20 : *
21 : * Note that inserting or deleting node types changes the numbers of other
22 : * node types later in the list. This is no problem during development, since
23 : * the node numbers are never stored on disk. But don't do it in a released
24 : * branch, because that would represent an ABI break for extensions.
25 : */
26 : typedef enum NodeTag
27 : {
28 : T_Invalid = 0,
29 :
30 : #include "nodes/nodetags.h"
31 : } NodeTag;
32 :
33 : /*
34 : * pg_node_attr() - Used in node definitions to set extra information for
35 : * gen_node_support.pl
36 : *
37 : * Attributes can be attached to a node as a whole (place the attribute
38 : * specification on the first line after the struct's opening brace)
39 : * or to a specific field (place it at the end of that field's line). The
40 : * argument is a comma-separated list of attributes. Unrecognized attributes
41 : * cause an error.
42 : *
43 : * Valid node attributes:
44 : *
45 : * - abstract: Abstract types are types that cannot be instantiated but that
46 : * can be supertypes of other types. We track their fields, so that
47 : * subtypes can use them, but we don't emit a node tag, so you can't
48 : * instantiate them.
49 : *
50 : * - custom_copy_equal: Has custom implementations in copyfuncs.c and
51 : * equalfuncs.c.
52 : *
53 : * - custom_read_write: Has custom implementations in outfuncs.c and
54 : * readfuncs.c.
55 : *
56 : * - custom_query_jumble: Has custom implementation in queryjumblefuncs.c.
57 : * Also available as a node field attribute.
58 : *
59 : * - no_copy: Does not support copyObject() at all.
60 : *
61 : * - no_equal: Does not support equal() at all.
62 : *
63 : * - no_copy_equal: Shorthand for both no_copy and no_equal.
64 : *
65 : * - no_query_jumble: Does not support JumbleQuery() at all.
66 : *
67 : * - no_read: Does not support nodeRead() at all.
68 : *
69 : * - nodetag_only: Does not support copyObject(), equal(), jumbleQuery()
70 : * outNode() or nodeRead().
71 : *
72 : * - special_read_write: Has special treatment in outNode() and nodeRead().
73 : *
74 : * - nodetag_number(VALUE): assign the specified nodetag number instead of
75 : * an auto-generated number. Typically this would only be used in stable
76 : * branches, to give a newly-added node type a number without breaking ABI
77 : * by changing the numbers of existing node types.
78 : *
79 : * Node types can be supertypes of other types whether or not they are marked
80 : * abstract: if a node struct appears as the first field of another struct
81 : * type, then it is the supertype of that type. The no_copy, no_equal,
82 : * no_query_jumble and no_read node attributes are automatically inherited
83 : * from the supertype. (Notice that nodetag_only does not inherit, so it's
84 : * not quite equivalent to a combination of other attributes.)
85 : *
86 : * Valid node field attributes:
87 : *
88 : * - array_size(OTHERFIELD): This field is a dynamically allocated array with
89 : * size indicated by the mentioned other field. The other field is either a
90 : * scalar or a list, in which case the length of the list is used.
91 : *
92 : * - copy_as(VALUE): In copyObject(), replace the field's value with VALUE.
93 : *
94 : * - copy_as_scalar: In copyObject(), copy the field as a scalar value
95 : * (e.g. a pointer) even if it is a node-type pointer.
96 : *
97 : * - equal_as_scalar: In equal(), compare the field as a scalar value
98 : * even if it is a node-type pointer.
99 : *
100 : * - equal_ignore: Ignore the field for equality.
101 : *
102 : * - equal_ignore_if_zero: Ignore the field for equality if it is zero.
103 : * (Otherwise, compare normally.)
104 : *
105 : * - custom_query_jumble: Has custom implementation in queryjumblefuncs.c
106 : * for the field of a node. Also available as a node attribute.
107 : *
108 : * - query_jumble_ignore: Ignore the field for the query jumbling. Note
109 : * that typmod and collation information are usually irrelevant for the
110 : * query jumbling.
111 : *
112 : * - query_jumble_squash: Squash multiple values during query jumbling.
113 : *
114 : * - query_jumble_location: Mark the field as a location to track. This is
115 : * only allowed for integer fields that include "location" in their name.
116 : *
117 : * - read_as(VALUE): In nodeRead(), replace the field's value with VALUE.
118 : *
119 : * - read_write_ignore: Ignore the field for read/write. This is only allowed
120 : * if the node type is marked no_read or read_as() is also specified.
121 : *
122 : * - write_only_relids, write_only_nondefault_pathtarget, write_only_req_outer:
123 : * Special handling for Path struct; see there.
124 : *
125 : */
126 : #define pg_node_attr(...)
127 :
128 : /*
129 : * The first field of a node of any type is guaranteed to be the NodeTag.
130 : * Hence the type of any node can be gotten by casting it to Node. Declaring
131 : * a variable to be of Node * (instead of void *) can also facilitate
132 : * debugging.
133 : */
134 : typedef struct Node
135 : {
136 : NodeTag type;
137 : } Node;
138 :
139 : #define nodeTag(nodeptr) (((const Node*)(nodeptr))->type)
140 :
141 : /*
142 : * newNode -
143 : * create a new node of the specified size and tag the node with the
144 : * specified tag.
145 : *
146 : * !WARNING!: Avoid using newNode directly. You should be using the
147 : * macro makeNode. eg. to create a Query node, use makeNode(Query)
148 : */
149 : static inline Node *
150 262380268 : newNode(size_t size, NodeTag tag)
151 : {
152 : Node *result;
153 :
154 : Assert(size >= sizeof(Node)); /* need the tag, at least */
155 262380268 : result = (Node *) palloc0(size);
156 262380268 : result->type = tag;
157 :
158 262380268 : return result;
159 : }
160 :
161 : #define makeNode(_type_) ((_type_ *) newNode(sizeof(_type_),T_##_type_))
162 : #define NodeSetTag(nodeptr,t) (((Node*)(nodeptr))->type = (t))
163 :
164 : #define IsA(nodeptr,_type_) (nodeTag(nodeptr) == T_##_type_)
165 :
166 : /*
167 : * castNode(type, ptr) casts ptr to "type *", and if assertions are enabled,
168 : * verifies that the node has the appropriate type (using its nodeTag()).
169 : *
170 : * Use an inline function when assertions are enabled, to avoid multiple
171 : * evaluations of the ptr argument (which could e.g. be a function call).
172 : */
173 : #ifdef USE_ASSERT_CHECKING
174 : static inline Node *
175 : castNodeImpl(NodeTag type, void *ptr)
176 : {
177 : Assert(ptr == NULL || nodeTag(ptr) == type);
178 : return (Node *) ptr;
179 : }
180 : #define castNode(_type_, nodeptr) ((_type_ *) castNodeImpl(T_##_type_, nodeptr))
181 : #else
182 : #define castNode(_type_, nodeptr) ((_type_ *) (nodeptr))
183 : #endif /* USE_ASSERT_CHECKING */
184 :
185 :
186 : /* ----------------------------------------------------------------
187 : * extern declarations follow
188 : * ----------------------------------------------------------------
189 : */
190 :
191 : /*
192 : * nodes/{outfuncs.c,print.c}
193 : */
194 : struct Bitmapset; /* not to include bitmapset.h here */
195 : struct StringInfoData; /* not to include stringinfo.h here */
196 :
197 : extern void outNode(struct StringInfoData *str, const void *obj);
198 : extern void outToken(struct StringInfoData *str, const char *s);
199 : extern void outBitmapset(struct StringInfoData *str,
200 : const struct Bitmapset *bms);
201 : extern void outDatum(struct StringInfoData *str, uintptr_t value,
202 : int typlen, bool typbyval);
203 : extern char *nodeToString(const void *obj);
204 : extern char *nodeToStringWithLocations(const void *obj);
205 : extern char *bmsToString(const struct Bitmapset *bms);
206 :
207 : /*
208 : * nodes/{readfuncs.c,read.c}
209 : */
210 : extern void *stringToNode(const char *str);
211 : #ifdef DEBUG_NODE_TESTS_ENABLED
212 : extern void *stringToNodeWithLocations(const char *str);
213 : #endif
214 : extern struct Bitmapset *readBitmapset(void);
215 : extern uintptr_t readDatum(bool typbyval);
216 : extern bool *readBoolCols(int numCols);
217 : extern int *readIntCols(int numCols);
218 : extern Oid *readOidCols(int numCols);
219 : extern int16 *readAttrNumberCols(int numCols);
220 :
221 : /*
222 : * nodes/copyfuncs.c
223 : */
224 : extern void *copyObjectImpl(const void *from);
225 :
226 : /* cast result back to argument type, if supported by compiler */
227 : #ifdef HAVE_TYPEOF
228 : #define copyObject(obj) ((typeof(obj)) copyObjectImpl(obj))
229 : #else
230 : #define copyObject(obj) copyObjectImpl(obj)
231 : #endif
232 :
233 : /*
234 : * nodes/equalfuncs.c
235 : */
236 : extern bool equal(const void *a, const void *b);
237 :
238 :
239 : /*
240 : * Typedef for parse location. This is just an int, but this way
241 : * gen_node_support.pl knows which fields should get special treatment for
242 : * location values.
243 : *
244 : * -1 is used for unknown.
245 : */
246 : typedef int ParseLoc;
247 :
248 : /*
249 : * Typedefs for identifying qualifier selectivities, plan costs, and row
250 : * counts as such. These are just plain "double"s, but declaring a variable
251 : * as Selectivity, Cost, or Cardinality makes the intent more obvious.
252 : *
253 : * These could have gone into plannodes.h or some such, but many files
254 : * depend on them...
255 : */
256 : typedef double Selectivity; /* fraction of tuples a qualifier will pass */
257 : typedef double Cost; /* execution cost (in page-access units) */
258 : typedef double Cardinality; /* (estimated) number of rows or other integer
259 : * count */
260 :
261 :
262 : /*
263 : * CmdType -
264 : * enums for type of operation represented by a Query or PlannedStmt
265 : *
266 : * This is needed in both parsenodes.h and plannodes.h, so put it here...
267 : */
268 : typedef enum CmdType
269 : {
270 : CMD_UNKNOWN,
271 : CMD_SELECT, /* select stmt */
272 : CMD_UPDATE, /* update stmt */
273 : CMD_INSERT, /* insert stmt */
274 : CMD_DELETE, /* delete stmt */
275 : CMD_MERGE, /* merge stmt */
276 : CMD_UTILITY, /* cmds like create, destroy, copy, vacuum,
277 : * etc. */
278 : CMD_NOTHING, /* dummy command for instead nothing rules
279 : * with qual */
280 : } CmdType;
281 :
282 :
283 : /*
284 : * JoinType -
285 : * enums for types of relation joins
286 : *
287 : * JoinType determines the exact semantics of joining two relations using
288 : * a matching qualification. For example, it tells what to do with a tuple
289 : * that has no match in the other relation.
290 : *
291 : * This is needed in both parsenodes.h and plannodes.h, so put it here...
292 : */
293 : typedef enum JoinType
294 : {
295 : /*
296 : * The canonical kinds of joins according to the SQL JOIN syntax. Only
297 : * these codes can appear in parser output (e.g., JoinExpr nodes).
298 : */
299 : JOIN_INNER, /* matching tuple pairs only */
300 : JOIN_LEFT, /* pairs + unmatched LHS tuples */
301 : JOIN_FULL, /* pairs + unmatched LHS + unmatched RHS */
302 : JOIN_RIGHT, /* pairs + unmatched RHS tuples */
303 :
304 : /*
305 : * Semijoins and anti-semijoins (as defined in relational theory) do not
306 : * appear in the SQL JOIN syntax, but there are standard idioms for
307 : * representing them (e.g., using EXISTS). The planner recognizes these
308 : * cases and converts them to joins. So the planner and executor must
309 : * support these codes. NOTE: in JOIN_SEMI output, it is unspecified
310 : * which matching RHS row is joined to. In JOIN_ANTI output, the row is
311 : * guaranteed to be null-extended.
312 : */
313 : JOIN_SEMI, /* 1 copy of each LHS row that has match(es) */
314 : JOIN_ANTI, /* 1 copy of each LHS row that has no match */
315 : JOIN_RIGHT_SEMI, /* 1 copy of each RHS row that has match(es) */
316 : JOIN_RIGHT_ANTI, /* 1 copy of each RHS row that has no match */
317 :
318 : /*
319 : * These codes are used internally in the planner, but are not supported
320 : * by the executor (nor, indeed, by most of the planner).
321 : */
322 : JOIN_UNIQUE_OUTER, /* LHS path must be made unique */
323 : JOIN_UNIQUE_INNER, /* RHS path must be made unique */
324 :
325 : /*
326 : * We might need additional join types someday.
327 : */
328 : } JoinType;
329 :
330 : /*
331 : * OUTER joins are those for which pushed-down quals must behave differently
332 : * from the join's own quals. This is in fact everything except INNER, SEMI
333 : * and RIGHT_SEMI joins. However, this macro must also exclude the
334 : * JOIN_UNIQUE symbols since those are temporary proxies for what will
335 : * eventually be an INNER join.
336 : *
337 : * Note: semijoins are a hybrid case, but we choose to treat them as not
338 : * being outer joins. This is okay principally because the SQL syntax makes
339 : * it impossible to have a pushed-down qual that refers to the inner relation
340 : * of a semijoin; so there is no strong need to distinguish join quals from
341 : * pushed-down quals. This is convenient because for almost all purposes,
342 : * quals attached to a semijoin can be treated the same as innerjoin quals.
343 : */
344 : #define IS_OUTER_JOIN(jointype) \
345 : (((1 << (jointype)) & \
346 : ((1 << JOIN_LEFT) | \
347 : (1 << JOIN_FULL) | \
348 : (1 << JOIN_RIGHT) | \
349 : (1 << JOIN_ANTI) | \
350 : (1 << JOIN_RIGHT_ANTI))) != 0)
351 :
352 : /*
353 : * AggStrategy -
354 : * overall execution strategies for Agg plan nodes
355 : *
356 : * This is needed in both pathnodes.h and plannodes.h, so put it here...
357 : */
358 : typedef enum AggStrategy
359 : {
360 : AGG_PLAIN, /* simple agg across all input rows */
361 : AGG_SORTED, /* grouped agg, input must be sorted */
362 : AGG_HASHED, /* grouped agg, use internal hashtable */
363 : AGG_MIXED, /* grouped agg, hash and sort both used */
364 : } AggStrategy;
365 :
366 : /*
367 : * AggSplit -
368 : * splitting (partial aggregation) modes for Agg plan nodes
369 : *
370 : * This is needed in both pathnodes.h and plannodes.h, so put it here...
371 : */
372 :
373 : /* Primitive options supported by nodeAgg.c: */
374 : #define AGGSPLITOP_COMBINE 0x01 /* substitute combinefn for transfn */
375 : #define AGGSPLITOP_SKIPFINAL 0x02 /* skip finalfn, return state as-is */
376 : #define AGGSPLITOP_SERIALIZE 0x04 /* apply serialfn to output */
377 : #define AGGSPLITOP_DESERIALIZE 0x08 /* apply deserialfn to input */
378 :
379 : /* Supported operating modes (i.e., useful combinations of these options): */
380 : typedef enum AggSplit
381 : {
382 : /* Basic, non-split aggregation: */
383 : AGGSPLIT_SIMPLE = 0,
384 : /* Initial phase of partial aggregation, with serialization: */
385 : AGGSPLIT_INITIAL_SERIAL = AGGSPLITOP_SKIPFINAL | AGGSPLITOP_SERIALIZE,
386 : /* Final phase of partial aggregation, with deserialization: */
387 : AGGSPLIT_FINAL_DESERIAL = AGGSPLITOP_COMBINE | AGGSPLITOP_DESERIALIZE,
388 : } AggSplit;
389 :
390 : /* Test whether an AggSplit value selects each primitive option: */
391 : #define DO_AGGSPLIT_COMBINE(as) (((as) & AGGSPLITOP_COMBINE) != 0)
392 : #define DO_AGGSPLIT_SKIPFINAL(as) (((as) & AGGSPLITOP_SKIPFINAL) != 0)
393 : #define DO_AGGSPLIT_SERIALIZE(as) (((as) & AGGSPLITOP_SERIALIZE) != 0)
394 : #define DO_AGGSPLIT_DESERIALIZE(as) (((as) & AGGSPLITOP_DESERIALIZE) != 0)
395 :
396 : /*
397 : * SetOpCmd and SetOpStrategy -
398 : * overall semantics and execution strategies for SetOp plan nodes
399 : *
400 : * This is needed in both pathnodes.h and plannodes.h, so put it here...
401 : */
402 : typedef enum SetOpCmd
403 : {
404 : SETOPCMD_INTERSECT,
405 : SETOPCMD_INTERSECT_ALL,
406 : SETOPCMD_EXCEPT,
407 : SETOPCMD_EXCEPT_ALL,
408 : } SetOpCmd;
409 :
410 : typedef enum SetOpStrategy
411 : {
412 : SETOP_SORTED, /* input must be sorted */
413 : SETOP_HASHED, /* use internal hashtable */
414 : } SetOpStrategy;
415 :
416 : /*
417 : * OnConflictAction -
418 : * "ON CONFLICT" clause type of query
419 : *
420 : * This is needed in both parsenodes.h and plannodes.h, so put it here...
421 : */
422 : typedef enum OnConflictAction
423 : {
424 : ONCONFLICT_NONE, /* No "ON CONFLICT" clause */
425 : ONCONFLICT_NOTHING, /* ON CONFLICT ... DO NOTHING */
426 : ONCONFLICT_UPDATE, /* ON CONFLICT ... DO UPDATE */
427 : } OnConflictAction;
428 :
429 : /*
430 : * LimitOption -
431 : * LIMIT option of query
432 : *
433 : * This is needed in both parsenodes.h and plannodes.h, so put it here...
434 : */
435 : typedef enum LimitOption
436 : {
437 : LIMIT_OPTION_COUNT, /* FETCH FIRST... ONLY */
438 : LIMIT_OPTION_WITH_TIES, /* FETCH FIRST... WITH TIES */
439 : } LimitOption;
440 :
441 : #endif /* NODES_H */
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