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1 : /*-------------------------------------------------------------------------
2 : *
3 : * nodes.h
4 : * Definitions for tagged nodes.
5 : *
6 : *
7 : * Portions Copyright (c) 1996-2024, 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 : *
58 : * - no_copy: Does not support copyObject() at all.
59 : *
60 : * - no_equal: Does not support equal() at all.
61 : *
62 : * - no_copy_equal: Shorthand for both no_copy and no_equal.
63 : *
64 : * - no_query_jumble: Does not support JumbleQuery() at all.
65 : *
66 : * - no_read: Does not support nodeRead() at all.
67 : *
68 : * - nodetag_only: Does not support copyObject(), equal(), jumbleQuery()
69 : * outNode() or nodeRead().
70 : *
71 : * - special_read_write: Has special treatment in outNode() and nodeRead().
72 : *
73 : * - nodetag_number(VALUE): assign the specified nodetag number instead of
74 : * an auto-generated number. Typically this would only be used in stable
75 : * branches, to give a newly-added node type a number without breaking ABI
76 : * by changing the numbers of existing node types.
77 : *
78 : * Node types can be supertypes of other types whether or not they are marked
79 : * abstract: if a node struct appears as the first field of another struct
80 : * type, then it is the supertype of that type. The no_copy, no_equal,
81 : * no_query_jumble and no_read node attributes are automatically inherited
82 : * from the supertype. (Notice that nodetag_only does not inherit, so it's
83 : * not quite equivalent to a combination of other attributes.)
84 : *
85 : * Valid node field attributes:
86 : *
87 : * - array_size(OTHERFIELD): This field is a dynamically allocated array with
88 : * size indicated by the mentioned other field. The other field is either a
89 : * scalar or a list, in which case the length of the list is used.
90 : *
91 : * - copy_as(VALUE): In copyObject(), replace the field's value with VALUE.
92 : *
93 : * - copy_as_scalar: In copyObject(), copy the field as a scalar value
94 : * (e.g. a pointer) even if it is a node-type pointer.
95 : *
96 : * - equal_as_scalar: In equal(), compare the field as a scalar value
97 : * even if it is a node-type pointer.
98 : *
99 : * - equal_ignore: Ignore the field for equality.
100 : *
101 : * - equal_ignore_if_zero: Ignore the field for equality if it is zero.
102 : * (Otherwise, compare normally.)
103 : *
104 : * - query_jumble_ignore: Ignore the field for the query jumbling. Note
105 : * that typmod and collation information are usually irrelevant for the
106 : * query jumbling.
107 : *
108 : * - query_jumble_location: Mark the field as a location to track. This is
109 : * only allowed for integer fields that include "location" in their name.
110 : *
111 : * - read_as(VALUE): In nodeRead(), replace the field's value with VALUE.
112 : *
113 : * - read_write_ignore: Ignore the field for read/write. This is only allowed
114 : * if the node type is marked no_read or read_as() is also specified.
115 : *
116 : * - write_only_relids, write_only_nondefault_pathtarget, write_only_req_outer:
117 : * Special handling for Path struct; see there.
118 : *
119 : */
120 : #define pg_node_attr(...)
121 :
122 : /*
123 : * The first field of a node of any type is guaranteed to be the NodeTag.
124 : * Hence the type of any node can be gotten by casting it to Node. Declaring
125 : * a variable to be of Node * (instead of void *) can also facilitate
126 : * debugging.
127 : */
128 : typedef struct Node
129 : {
130 : NodeTag type;
131 : } Node;
132 :
133 : #define nodeTag(nodeptr) (((const Node*)(nodeptr))->type)
134 :
135 : /*
136 : * newNode -
137 : * create a new node of the specified size and tag the node with the
138 : * specified tag.
139 : *
140 : * !WARNING!: Avoid using newNode directly. You should be using the
141 : * macro makeNode. eg. to create a Query node, use makeNode(Query)
142 : */
143 : static inline Node *
144 230766174 : newNode(size_t size, NodeTag tag)
145 : {
146 : Node *result;
147 :
148 : Assert(size >= sizeof(Node)); /* need the tag, at least */
149 230766174 : result = (Node *) palloc0(size);
150 230766174 : result->type = tag;
151 :
152 230766174 : return result;
153 : }
154 :
155 : #define makeNode(_type_) ((_type_ *) newNode(sizeof(_type_),T_##_type_))
156 : #define NodeSetTag(nodeptr,t) (((Node*)(nodeptr))->type = (t))
157 :
158 : #define IsA(nodeptr,_type_) (nodeTag(nodeptr) == T_##_type_)
159 :
160 : /*
161 : * castNode(type, ptr) casts ptr to "type *", and if assertions are enabled,
162 : * verifies that the node has the appropriate type (using its nodeTag()).
163 : *
164 : * Use an inline function when assertions are enabled, to avoid multiple
165 : * evaluations of the ptr argument (which could e.g. be a function call).
166 : */
167 : #ifdef USE_ASSERT_CHECKING
168 : static inline Node *
169 : castNodeImpl(NodeTag type, void *ptr)
170 : {
171 : Assert(ptr == NULL || nodeTag(ptr) == type);
172 : return (Node *) ptr;
173 : }
174 : #define castNode(_type_, nodeptr) ((_type_ *) castNodeImpl(T_##_type_, nodeptr))
175 : #else
176 : #define castNode(_type_, nodeptr) ((_type_ *) (nodeptr))
177 : #endif /* USE_ASSERT_CHECKING */
178 :
179 :
180 : /* ----------------------------------------------------------------
181 : * extern declarations follow
182 : * ----------------------------------------------------------------
183 : */
184 :
185 : /*
186 : * nodes/{outfuncs.c,print.c}
187 : */
188 : struct Bitmapset; /* not to include bitmapset.h here */
189 : struct StringInfoData; /* not to include stringinfo.h here */
190 :
191 : extern void outNode(struct StringInfoData *str, const void *obj);
192 : extern void outToken(struct StringInfoData *str, const char *s);
193 : extern void outBitmapset(struct StringInfoData *str,
194 : const struct Bitmapset *bms);
195 : extern void outDatum(struct StringInfoData *str, uintptr_t value,
196 : int typlen, bool typbyval);
197 : extern char *nodeToString(const void *obj);
198 : extern char *nodeToStringWithLocations(const void *obj);
199 : extern char *bmsToString(const struct Bitmapset *bms);
200 :
201 : /*
202 : * nodes/{readfuncs.c,read.c}
203 : */
204 : extern void *stringToNode(const char *str);
205 : #ifdef WRITE_READ_PARSE_PLAN_TREES
206 : extern void *stringToNodeWithLocations(const char *str);
207 : #endif
208 : extern struct Bitmapset *readBitmapset(void);
209 : extern uintptr_t readDatum(bool typbyval);
210 : extern bool *readBoolCols(int numCols);
211 : extern int *readIntCols(int numCols);
212 : extern Oid *readOidCols(int numCols);
213 : extern int16 *readAttrNumberCols(int numCols);
214 :
215 : /*
216 : * nodes/copyfuncs.c
217 : */
218 : extern void *copyObjectImpl(const void *from);
219 :
220 : /* cast result back to argument type, if supported by compiler */
221 : #ifdef HAVE_TYPEOF
222 : #define copyObject(obj) ((typeof(obj)) copyObjectImpl(obj))
223 : #else
224 : #define copyObject(obj) copyObjectImpl(obj)
225 : #endif
226 :
227 : /*
228 : * nodes/equalfuncs.c
229 : */
230 : extern bool equal(const void *a, const void *b);
231 :
232 :
233 : /*
234 : * Typedef for parse location. This is just an int, but this way
235 : * gen_node_support.pl knows which fields should get special treatment for
236 : * location values.
237 : *
238 : * -1 is used for unknown.
239 : */
240 : typedef int ParseLoc;
241 :
242 : /*
243 : * Typedefs for identifying qualifier selectivities, plan costs, and row
244 : * counts as such. These are just plain "double"s, but declaring a variable
245 : * as Selectivity, Cost, or Cardinality makes the intent more obvious.
246 : *
247 : * These could have gone into plannodes.h or some such, but many files
248 : * depend on them...
249 : */
250 : typedef double Selectivity; /* fraction of tuples a qualifier will pass */
251 : typedef double Cost; /* execution cost (in page-access units) */
252 : typedef double Cardinality; /* (estimated) number of rows or other integer
253 : * count */
254 :
255 :
256 : /*
257 : * CmdType -
258 : * enums for type of operation represented by a Query or PlannedStmt
259 : *
260 : * This is needed in both parsenodes.h and plannodes.h, so put it here...
261 : */
262 : typedef enum CmdType
263 : {
264 : CMD_UNKNOWN,
265 : CMD_SELECT, /* select stmt */
266 : CMD_UPDATE, /* update stmt */
267 : CMD_INSERT, /* insert stmt */
268 : CMD_DELETE, /* delete stmt */
269 : CMD_MERGE, /* merge stmt */
270 : CMD_UTILITY, /* cmds like create, destroy, copy, vacuum,
271 : * etc. */
272 : CMD_NOTHING, /* dummy command for instead nothing rules
273 : * with qual */
274 : } CmdType;
275 :
276 :
277 : /*
278 : * JoinType -
279 : * enums for types of relation joins
280 : *
281 : * JoinType determines the exact semantics of joining two relations using
282 : * a matching qualification. For example, it tells what to do with a tuple
283 : * that has no match in the other relation.
284 : *
285 : * This is needed in both parsenodes.h and plannodes.h, so put it here...
286 : */
287 : typedef enum JoinType
288 : {
289 : /*
290 : * The canonical kinds of joins according to the SQL JOIN syntax. Only
291 : * these codes can appear in parser output (e.g., JoinExpr nodes).
292 : */
293 : JOIN_INNER, /* matching tuple pairs only */
294 : JOIN_LEFT, /* pairs + unmatched LHS tuples */
295 : JOIN_FULL, /* pairs + unmatched LHS + unmatched RHS */
296 : JOIN_RIGHT, /* pairs + unmatched RHS tuples */
297 :
298 : /*
299 : * Semijoins and anti-semijoins (as defined in relational theory) do not
300 : * appear in the SQL JOIN syntax, but there are standard idioms for
301 : * representing them (e.g., using EXISTS). The planner recognizes these
302 : * cases and converts them to joins. So the planner and executor must
303 : * support these codes. NOTE: in JOIN_SEMI output, it is unspecified
304 : * which matching RHS row is joined to. In JOIN_ANTI output, the row is
305 : * guaranteed to be null-extended.
306 : */
307 : JOIN_SEMI, /* 1 copy of each LHS row that has match(es) */
308 : JOIN_ANTI, /* 1 copy of each LHS row that has no match */
309 : JOIN_RIGHT_ANTI, /* 1 copy of each RHS row that has no match */
310 :
311 : /*
312 : * These codes are used internally in the planner, but are not supported
313 : * by the executor (nor, indeed, by most of the planner).
314 : */
315 : JOIN_UNIQUE_OUTER, /* LHS path must be made unique */
316 : JOIN_UNIQUE_INNER, /* RHS path must be made unique */
317 :
318 : /*
319 : * We might need additional join types someday.
320 : */
321 : } JoinType;
322 :
323 : /*
324 : * OUTER joins are those for which pushed-down quals must behave differently
325 : * from the join's own quals. This is in fact everything except INNER and
326 : * SEMI joins. However, this macro must also exclude the JOIN_UNIQUE symbols
327 : * since those are temporary proxies for what will eventually be an INNER
328 : * join.
329 : *
330 : * Note: semijoins are a hybrid case, but we choose to treat them as not
331 : * being outer joins. This is okay principally because the SQL syntax makes
332 : * it impossible to have a pushed-down qual that refers to the inner relation
333 : * of a semijoin; so there is no strong need to distinguish join quals from
334 : * pushed-down quals. This is convenient because for almost all purposes,
335 : * quals attached to a semijoin can be treated the same as innerjoin quals.
336 : */
337 : #define IS_OUTER_JOIN(jointype) \
338 : (((1 << (jointype)) & \
339 : ((1 << JOIN_LEFT) | \
340 : (1 << JOIN_FULL) | \
341 : (1 << JOIN_RIGHT) | \
342 : (1 << JOIN_ANTI) | \
343 : (1 << JOIN_RIGHT_ANTI))) != 0)
344 :
345 : /*
346 : * AggStrategy -
347 : * overall execution strategies for Agg plan nodes
348 : *
349 : * This is needed in both pathnodes.h and plannodes.h, so put it here...
350 : */
351 : typedef enum AggStrategy
352 : {
353 : AGG_PLAIN, /* simple agg across all input rows */
354 : AGG_SORTED, /* grouped agg, input must be sorted */
355 : AGG_HASHED, /* grouped agg, use internal hashtable */
356 : AGG_MIXED, /* grouped agg, hash and sort both used */
357 : } AggStrategy;
358 :
359 : /*
360 : * AggSplit -
361 : * splitting (partial aggregation) modes for Agg plan nodes
362 : *
363 : * This is needed in both pathnodes.h and plannodes.h, so put it here...
364 : */
365 :
366 : /* Primitive options supported by nodeAgg.c: */
367 : #define AGGSPLITOP_COMBINE 0x01 /* substitute combinefn for transfn */
368 : #define AGGSPLITOP_SKIPFINAL 0x02 /* skip finalfn, return state as-is */
369 : #define AGGSPLITOP_SERIALIZE 0x04 /* apply serialfn to output */
370 : #define AGGSPLITOP_DESERIALIZE 0x08 /* apply deserialfn to input */
371 :
372 : /* Supported operating modes (i.e., useful combinations of these options): */
373 : typedef enum AggSplit
374 : {
375 : /* Basic, non-split aggregation: */
376 : AGGSPLIT_SIMPLE = 0,
377 : /* Initial phase of partial aggregation, with serialization: */
378 : AGGSPLIT_INITIAL_SERIAL = AGGSPLITOP_SKIPFINAL | AGGSPLITOP_SERIALIZE,
379 : /* Final phase of partial aggregation, with deserialization: */
380 : AGGSPLIT_FINAL_DESERIAL = AGGSPLITOP_COMBINE | AGGSPLITOP_DESERIALIZE,
381 : } AggSplit;
382 :
383 : /* Test whether an AggSplit value selects each primitive option: */
384 : #define DO_AGGSPLIT_COMBINE(as) (((as) & AGGSPLITOP_COMBINE) != 0)
385 : #define DO_AGGSPLIT_SKIPFINAL(as) (((as) & AGGSPLITOP_SKIPFINAL) != 0)
386 : #define DO_AGGSPLIT_SERIALIZE(as) (((as) & AGGSPLITOP_SERIALIZE) != 0)
387 : #define DO_AGGSPLIT_DESERIALIZE(as) (((as) & AGGSPLITOP_DESERIALIZE) != 0)
388 :
389 : /*
390 : * SetOpCmd and SetOpStrategy -
391 : * overall semantics and execution strategies for SetOp plan nodes
392 : *
393 : * This is needed in both pathnodes.h and plannodes.h, so put it here...
394 : */
395 : typedef enum SetOpCmd
396 : {
397 : SETOPCMD_INTERSECT,
398 : SETOPCMD_INTERSECT_ALL,
399 : SETOPCMD_EXCEPT,
400 : SETOPCMD_EXCEPT_ALL,
401 : } SetOpCmd;
402 :
403 : typedef enum SetOpStrategy
404 : {
405 : SETOP_SORTED, /* input must be sorted */
406 : SETOP_HASHED, /* use internal hashtable */
407 : } SetOpStrategy;
408 :
409 : /*
410 : * OnConflictAction -
411 : * "ON CONFLICT" clause type of query
412 : *
413 : * This is needed in both parsenodes.h and plannodes.h, so put it here...
414 : */
415 : typedef enum OnConflictAction
416 : {
417 : ONCONFLICT_NONE, /* No "ON CONFLICT" clause */
418 : ONCONFLICT_NOTHING, /* ON CONFLICT ... DO NOTHING */
419 : ONCONFLICT_UPDATE, /* ON CONFLICT ... DO UPDATE */
420 : } OnConflictAction;
421 :
422 : /*
423 : * LimitOption -
424 : * LIMIT option of query
425 : *
426 : * This is needed in both parsenodes.h and plannodes.h, so put it here...
427 : */
428 : typedef enum LimitOption
429 : {
430 : LIMIT_OPTION_COUNT, /* FETCH FIRST... ONLY */
431 : LIMIT_OPTION_WITH_TIES, /* FETCH FIRST... WITH TIES */
432 : } LimitOption;
433 :
434 : #endif /* NODES_H */
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