Branch data Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * htup_details.h
4 : : * POSTGRES heap tuple header definitions.
5 : : *
6 : : *
7 : : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
8 : : * Portions Copyright (c) 1994, Regents of the University of California
9 : : *
10 : : * src/include/access/htup_details.h
11 : : *
12 : : *-------------------------------------------------------------------------
13 : : */
14 : : #ifndef HTUP_DETAILS_H
15 : : #define HTUP_DETAILS_H
16 : :
17 : : #include "access/htup.h"
18 : : #include "access/transam.h"
19 : : #include "access/tupdesc.h"
20 : : #include "access/tupmacs.h"
21 : : #include "storage/bufpage.h"
22 : : #include "varatt.h"
23 : :
24 : : /*
25 : : * MaxTupleAttributeNumber limits the number of (user) columns in a tuple.
26 : : * The key limit on this value is that the size of the fixed overhead for
27 : : * a tuple, plus the size of the null-values bitmap (at 1 bit per column),
28 : : * plus MAXALIGN alignment, must fit into t_hoff which is uint8. On most
29 : : * machines the upper limit without making t_hoff wider would be a little
30 : : * over 1700. We use round numbers here and for MaxHeapAttributeNumber
31 : : * so that alterations in HeapTupleHeaderData layout won't change the
32 : : * supported max number of columns.
33 : : */
34 : : #define MaxTupleAttributeNumber 1664 /* 8 * 208 */
35 : :
36 : : /*
37 : : * MaxHeapAttributeNumber limits the number of (user) columns in a table.
38 : : * This should be somewhat less than MaxTupleAttributeNumber. It must be
39 : : * at least one less, else we will fail to do UPDATEs on a maximal-width
40 : : * table (because UPDATE has to form working tuples that include CTID).
41 : : * In practice we want some additional daylight so that we can gracefully
42 : : * support operations that add hidden "resjunk" columns, for example
43 : : * SELECT * FROM wide_table ORDER BY foo, bar, baz.
44 : : * In any case, depending on column data types you will likely be running
45 : : * into the disk-block-based limit on overall tuple size if you have more
46 : : * than a thousand or so columns. TOAST won't help.
47 : : */
48 : : #define MaxHeapAttributeNumber 1600 /* 8 * 200 */
49 : :
50 : : /*
51 : : * Heap tuple header. To avoid wasting space, the fields should be
52 : : * laid out in such a way as to avoid structure padding.
53 : : *
54 : : * Datums of composite types (row types) share the same general structure
55 : : * as on-disk tuples, so that the same routines can be used to build and
56 : : * examine them. However the requirements are slightly different: a Datum
57 : : * does not need any transaction visibility information, and it does need
58 : : * a length word and some embedded type information. We can achieve this
59 : : * by overlaying the xmin/cmin/xmax/cmax/xvac fields of a heap tuple
60 : : * with the fields needed in the Datum case. Typically, all tuples built
61 : : * in-memory will be initialized with the Datum fields; but when a tuple is
62 : : * about to be inserted in a table, the transaction fields will be filled,
63 : : * overwriting the datum fields.
64 : : *
65 : : * The overall structure of a heap tuple looks like:
66 : : * fixed fields (HeapTupleHeaderData struct)
67 : : * nulls bitmap (if HEAP_HASNULL is set in t_infomask)
68 : : * alignment padding (as needed to make user data MAXALIGN'd)
69 : : * object ID (if HEAP_HASOID_OLD is set in t_infomask, not created
70 : : * anymore)
71 : : * user data fields
72 : : *
73 : : * We store five "virtual" fields Xmin, Cmin, Xmax, Cmax, and Xvac in three
74 : : * physical fields. Xmin and Xmax are always really stored, but Cmin, Cmax
75 : : * and Xvac share a field. This works because we know that Cmin and Cmax
76 : : * are only interesting for the lifetime of the inserting and deleting
77 : : * transaction respectively. If a tuple is inserted and deleted in the same
78 : : * transaction, we store a "combo" command id that can be mapped to the real
79 : : * cmin and cmax, but only by use of local state within the originating
80 : : * backend. See combocid.c for more details. Meanwhile, Xvac is only set by
81 : : * old-style VACUUM FULL, which does not have any command sub-structure and so
82 : : * does not need either Cmin or Cmax. (This requires that old-style VACUUM
83 : : * FULL never try to move a tuple whose Cmin or Cmax is still interesting,
84 : : * ie, an insert-in-progress or delete-in-progress tuple.)
85 : : *
86 : : * A word about t_ctid: whenever a new tuple is stored on disk, its t_ctid
87 : : * is initialized with its own TID (location). If the tuple is ever updated,
88 : : * its t_ctid is changed to point to the replacement version of the tuple. Or
89 : : * if the tuple is moved from one partition to another, due to an update of
90 : : * the partition key, t_ctid is set to a special value to indicate that
91 : : * (see ItemPointerSetMovedPartitions). Thus, a tuple is the latest version
92 : : * of its row iff XMAX is invalid or
93 : : * t_ctid points to itself (in which case, if XMAX is valid, the tuple is
94 : : * either locked or deleted). One can follow the chain of t_ctid links
95 : : * to find the newest version of the row, unless it was moved to a different
96 : : * partition. Beware however that VACUUM might
97 : : * erase the pointed-to (newer) tuple before erasing the pointing (older)
98 : : * tuple. Hence, when following a t_ctid link, it is necessary to check
99 : : * to see if the referenced slot is empty or contains an unrelated tuple.
100 : : * Check that the referenced tuple has XMIN equal to the referencing tuple's
101 : : * XMAX to verify that it is actually the descendant version and not an
102 : : * unrelated tuple stored into a slot recently freed by VACUUM. If either
103 : : * check fails, one may assume that there is no live descendant version.
104 : : *
105 : : * t_ctid is sometimes used to store a speculative insertion token, instead
106 : : * of a real TID. A speculative token is set on a tuple that's being
107 : : * inserted, until the inserter is sure that it wants to go ahead with the
108 : : * insertion. Hence a token should only be seen on a tuple with an XMAX
109 : : * that's still in-progress, or invalid/aborted. The token is replaced with
110 : : * the tuple's real TID when the insertion is confirmed. One should never
111 : : * see a speculative insertion token while following a chain of t_ctid links,
112 : : * because they are not used on updates, only insertions.
113 : : *
114 : : * Following the fixed header fields, the nulls bitmap is stored (beginning
115 : : * at t_bits). The bitmap is *not* stored if t_infomask shows that there
116 : : * are no nulls in the tuple. If an OID field is present (as indicated by
117 : : * t_infomask), then it is stored just before the user data, which begins at
118 : : * the offset shown by t_hoff. Note that t_hoff must be a multiple of
119 : : * MAXALIGN.
120 : : */
121 : :
122 : : typedef struct HeapTupleFields
123 : : {
124 : : TransactionId t_xmin; /* inserting xact ID */
125 : : TransactionId t_xmax; /* deleting or locking xact ID */
126 : :
127 : : union
128 : : {
129 : : CommandId t_cid; /* inserting or deleting command ID, or both */
130 : : TransactionId t_xvac; /* old-style VACUUM FULL xact ID */
131 : : } t_field3;
132 : : } HeapTupleFields;
133 : :
134 : : typedef struct DatumTupleFields
135 : : {
136 : : int32 datum_len_; /* varlena header (do not touch directly!) */
137 : :
138 : : /* ---
139 : : * If datum_typeid == RECORDOID, datum_typmod is either the identifier of
140 : : * the blessed TupleDesc or -1 if not blessed.
141 : : *
142 : : * If the tuple is of an identified row type, but has been created before
143 : : * versioning was introduced, -1 is stored.
144 : : *
145 : : * If the tuple is versioned (see HeapTupleHeaderIsVersionedDatum()):
146 : : * - datum_typmod contains the lower 32 bits of the version
147 : : * - the high 32 bits of the version are stored in t_ctid
148 : : *
149 : : * For more about versioning see src/backend/catalog/README.attver.md
150 : : * ---
151 : : */
152 : : int32 datum_typmod;
153 : :
154 : : Oid datum_typeid; /* composite type OID, or RECORDOID */
155 : :
156 : : /*
157 : : * datum_typeid cannot be a domain over composite, only plain composite,
158 : : * even if the datum is meant as a value of a domain-over-composite type.
159 : : * This is in line with the general principle that CoerceToDomain does not
160 : : * change the physical representation of the base type value.
161 : : *
162 : : * Note: field ordering is chosen with thought that Oid might someday
163 : : * widen to 64 bits.
164 : : */
165 : : } DatumTupleFields;
166 : :
167 : : struct HeapTupleHeaderData
168 : : {
169 : : union
170 : : {
171 : : HeapTupleFields t_heap;
172 : : DatumTupleFields t_datum;
173 : : } t_choice;
174 : :
175 : : /*
176 : : * Current TID of this or newer tuple.
177 : : *
178 : : * During speculative insertions, a speculative insertion token is stored
179 : : * instead.
180 : : *
181 : : * If the tuple is a versioned datum tuple, ip_posid is set to
182 : : * VersionedDatumOffsetNumber and the high 32 bits of the version number
183 : : * are stored in ip_blkid. The low 32 bits are stored in datum_typmod,
184 : : * see also the comment there.
185 : : */
186 : : ItemPointerData t_ctid;
187 : :
188 : : /* Fields below here must match MinimalTupleData! */
189 : :
190 : : #define FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK2 2
191 : : uint16 t_infomask2; /* number of attributes + various flags */
192 : :
193 : : #define FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK 3
194 : : uint16 t_infomask; /* various flag bits, see below */
195 : :
196 : : #define FIELDNO_HEAPTUPLEHEADERDATA_HOFF 4
197 : : uint8 t_hoff; /* sizeof header incl. bitmap, padding */
198 : :
199 : : /* ^ - 23 bytes - ^ */
200 : :
201 : : #define FIELDNO_HEAPTUPLEHEADERDATA_BITS 5
202 : : uint8 t_bits[FLEXIBLE_ARRAY_MEMBER]; /* bitmap of NULLs */
203 : :
204 : : /* MORE DATA FOLLOWS AT END OF STRUCT */
205 : : };
206 : :
207 : : /* typedef appears in htup.h */
208 : :
209 : : #define SizeofHeapTupleHeader offsetof(HeapTupleHeaderData, t_bits)
210 : :
211 : : /*
212 : : * information stored in t_infomask:
213 : : */
214 : : #define HEAP_HASNULL 0x0001 /* has null attribute(s) */
215 : : #define HEAP_HASVARWIDTH 0x0002 /* has variable-width attribute(s) */
216 : : #define HEAP_HASEXTERNAL 0x0004 /* has external stored attribute(s) */
217 : : #define HEAP_HASOID_OLD 0x0008 /* has an object-id field */
218 : : #define HEAP_XMAX_KEYSHR_LOCK 0x0010 /* xmax is a key-shared locker */
219 : : #define HEAP_COMBOCID 0x0020 /* t_cid is a combo CID */
220 : : #define HEAP_XMAX_EXCL_LOCK 0x0040 /* xmax is exclusive locker */
221 : : #define HEAP_XMAX_LOCK_ONLY 0x0080 /* xmax, if valid, is only a locker */
222 : :
223 : : /* xmax is a shared locker */
224 : : #define HEAP_XMAX_SHR_LOCK (HEAP_XMAX_EXCL_LOCK | HEAP_XMAX_KEYSHR_LOCK)
225 : :
226 : : #define HEAP_LOCK_MASK (HEAP_XMAX_SHR_LOCK | HEAP_XMAX_EXCL_LOCK | \
227 : : HEAP_XMAX_KEYSHR_LOCK)
228 : : #define HEAP_XMIN_COMMITTED 0x0100 /* t_xmin committed */
229 : : #define HEAP_XMIN_INVALID 0x0200 /* t_xmin invalid/aborted */
230 : : #define HEAP_XMIN_FROZEN (HEAP_XMIN_COMMITTED|HEAP_XMIN_INVALID)
231 : : #define HEAP_XMAX_COMMITTED 0x0400 /* t_xmax committed */
232 : : #define HEAP_XMAX_INVALID 0x0800 /* t_xmax invalid/aborted */
233 : : #define HEAP_XMAX_IS_MULTI 0x1000 /* t_xmax is a MultiXactId */
234 : : #define HEAP_UPDATED 0x2000 /* this is UPDATEd version of row */
235 : : #define HEAP_MOVED_OFF 0x4000 /* moved to another place by pre-9.0
236 : : * VACUUM FULL; kept for binary
237 : : * upgrade support */
238 : : #define HEAP_MOVED_IN 0x8000 /* moved from another place by pre-9.0
239 : : * VACUUM FULL; kept for binary
240 : : * upgrade support */
241 : : #define HEAP_MOVED (HEAP_MOVED_OFF | HEAP_MOVED_IN)
242 : :
243 : : #define HEAP_XACT_MASK 0xFFF0 /* visibility-related bits */
244 : :
245 : : /*
246 : : * Marks a tuple as a composite datum, i.e. t_choice.t_datum is valid. This
247 : : * combination of bits never occurs in a heap tuple in a page (xmax can't be
248 : : * committed and invalid), and as both bits are part of HEAP_XACT_MASK,
249 : : * inserting the tuple into a heap clears it.
250 : : */
251 : : #define HEAP_IS_DATUM (HEAP_XMAX_COMMITTED | HEAP_XMAX_INVALID)
252 : :
253 : : /*
254 : : * A tuple is only locked (i.e. not updated by its Xmax) if the
255 : : * HEAP_XMAX_LOCK_ONLY bit is set; or, for pg_upgrade's sake, if the Xmax is
256 : : * not a multi and the EXCL_LOCK bit is set.
257 : : *
258 : : * See also HeapTupleHeaderIsOnlyLocked, which also checks for a possible
259 : : * aborted updater transaction.
260 : : */
261 : : static inline bool
262 : 31449820 : HEAP_XMAX_IS_LOCKED_ONLY(uint16 infomask)
263 : : {
264 [ + + ]: 60652169 : return (infomask & HEAP_XMAX_LOCK_ONLY) ||
265 [ - + ]: 29202349 : (infomask & (HEAP_XMAX_IS_MULTI | HEAP_LOCK_MASK)) == HEAP_XMAX_EXCL_LOCK;
266 : : }
267 : :
268 : : /*
269 : : * A tuple that has HEAP_XMAX_IS_MULTI and HEAP_XMAX_LOCK_ONLY but neither of
270 : : * HEAP_XMAX_EXCL_LOCK and HEAP_XMAX_KEYSHR_LOCK must come from a tuple that was
271 : : * share-locked in 9.2 or earlier and then pg_upgrade'd.
272 : : *
273 : : * In 9.2 and prior, HEAP_XMAX_IS_MULTI was only set when there were multiple
274 : : * FOR SHARE lockers of that tuple. That set HEAP_XMAX_LOCK_ONLY (with a
275 : : * different name back then) but neither of HEAP_XMAX_EXCL_LOCK and
276 : : * HEAP_XMAX_KEYSHR_LOCK. That combination is no longer possible in 9.3 and
277 : : * up, so if we see that combination we know for certain that the tuple was
278 : : * locked in an earlier release; since all such lockers are gone (they cannot
279 : : * survive through pg_upgrade), such tuples can safely be considered not
280 : : * locked.
281 : : *
282 : : * We must not resolve such multixacts locally, because the result would be
283 : : * bogus, regardless of where they stand with respect to the current valid
284 : : * multixact range.
285 : : */
286 : : static inline bool
287 : 186552 : HEAP_LOCKED_UPGRADED(uint16 infomask)
288 : : {
289 : : return
290 : 336841 : (infomask & HEAP_XMAX_IS_MULTI) != 0 &&
291 [ + + + + ]: 332470 : (infomask & HEAP_XMAX_LOCK_ONLY) != 0 &&
292 [ - + ]: 145918 : (infomask & (HEAP_XMAX_EXCL_LOCK | HEAP_XMAX_KEYSHR_LOCK)) == 0;
293 : : }
294 : :
295 : : /*
296 : : * Use these to test whether a particular lock is applied to a tuple
297 : : */
298 : : static inline bool
299 : 99972 : HEAP_XMAX_IS_SHR_LOCKED(uint16 infomask)
300 : : {
301 : 99972 : return (infomask & HEAP_LOCK_MASK) == HEAP_XMAX_SHR_LOCK;
302 : : }
303 : :
304 : : static inline bool
305 : 106774 : HEAP_XMAX_IS_EXCL_LOCKED(uint16 infomask)
306 : : {
307 : 106774 : return (infomask & HEAP_LOCK_MASK) == HEAP_XMAX_EXCL_LOCK;
308 : : }
309 : :
310 : : static inline bool
311 : 105922 : HEAP_XMAX_IS_KEYSHR_LOCKED(uint16 infomask)
312 : : {
313 : 105922 : return (infomask & HEAP_LOCK_MASK) == HEAP_XMAX_KEYSHR_LOCK;
314 : : }
315 : :
316 : : /* turn these all off when Xmax is to change */
317 : : #define HEAP_XMAX_BITS (HEAP_XMAX_COMMITTED | HEAP_XMAX_INVALID | \
318 : : HEAP_XMAX_IS_MULTI | HEAP_LOCK_MASK | HEAP_XMAX_LOCK_ONLY)
319 : :
320 : : /*
321 : : * information stored in t_infomask2:
322 : : */
323 : : #define HEAP_NATTS_MASK 0x07FF /* 11 bits for number of attributes */
324 : : /* bits 0x1800 are available */
325 : : #define HEAP_KEYS_UPDATED 0x2000 /* tuple was updated and key cols
326 : : * modified, or tuple deleted */
327 : : #define HEAP_HOT_UPDATED 0x4000 /* tuple was HOT-updated */
328 : : #define HEAP_ONLY_TUPLE 0x8000 /* this is heap-only tuple */
329 : :
330 : : #define HEAP2_XACT_MASK 0xE000 /* visibility-related bits */
331 : :
332 : : /*
333 : : * HEAP_TUPLE_HAS_MATCH is a temporary flag used during hash joins. It is
334 : : * only used in tuples that are in the hash table, and those don't need
335 : : * any visibility information, so we can overlay it on a visibility flag
336 : : * instead of using up a dedicated bit.
337 : : */
338 : : #define HEAP_TUPLE_HAS_MATCH HEAP_ONLY_TUPLE /* tuple has a join match */
339 : :
340 : : /*
341 : : * HeapTupleHeader accessor functions
342 : : */
343 : :
344 : : static bool HeapTupleHeaderXminFrozen(const HeapTupleHeaderData *tup);
345 : :
346 : : /*
347 : : * HeapTupleHeaderGetRawXmin returns the "raw" xmin field, which is the xid
348 : : * originally used to insert the tuple. However, the tuple might actually
349 : : * be frozen (via HeapTupleHeaderSetXminFrozen) in which case the tuple's xmin
350 : : * is visible to every snapshot. Prior to PostgreSQL 9.4, we actually changed
351 : : * the xmin to FrozenTransactionId, and that value may still be encountered
352 : : * on disk.
353 : : */
354 : : static inline TransactionId
355 : 206513012 : HeapTupleHeaderGetRawXmin(const HeapTupleHeaderData *tup)
356 : : {
357 : 206513012 : return tup->t_choice.t_heap.t_xmin;
358 : : }
359 : :
360 : : static inline TransactionId
361 : 71555997 : HeapTupleHeaderGetXmin(const HeapTupleHeaderData *tup)
362 : : {
363 : 71555997 : return HeapTupleHeaderXminFrozen(tup) ?
364 [ + + ]: 71555997 : FrozenTransactionId : HeapTupleHeaderGetRawXmin(tup);
365 : : }
366 : :
367 : : static inline void
368 : 18106852 : HeapTupleHeaderSetXmin(HeapTupleHeaderData *tup, TransactionId xid)
369 : : {
370 : 18106852 : tup->t_choice.t_heap.t_xmin = xid;
371 : 18106852 : }
372 : :
373 : : static inline bool
374 : 187564204 : HeapTupleHeaderXminCommitted(const HeapTupleHeaderData *tup)
375 : : {
376 : 187564204 : return (tup->t_infomask & HEAP_XMIN_COMMITTED) != 0;
377 : : }
378 : :
379 : : static inline bool
380 : 49546859 : HeapTupleHeaderXminInvalid(const HeapTupleHeaderData *tup) \
381 : : {
382 : 49546859 : return (tup->t_infomask & (HEAP_XMIN_COMMITTED | HEAP_XMIN_INVALID)) ==
383 : : HEAP_XMIN_INVALID;
384 : : }
385 : :
386 : : static inline bool
387 : 376943435 : HeapTupleHeaderXminFrozen(const HeapTupleHeaderData *tup)
388 : : {
389 : 376943435 : return (tup->t_infomask & HEAP_XMIN_FROZEN) == HEAP_XMIN_FROZEN;
390 : : }
391 : :
392 : : static inline void
393 : 104151 : HeapTupleHeaderSetXminFrozen(HeapTupleHeaderData *tup)
394 : : {
395 : : Assert(!HeapTupleHeaderXminInvalid(tup));
396 : 104151 : tup->t_infomask |= HEAP_XMIN_FROZEN;
397 : 104151 : }
398 : :
399 : : static inline TransactionId
400 : 88994125 : HeapTupleHeaderGetRawXmax(const HeapTupleHeaderData *tup)
401 : : {
402 : 88994125 : return tup->t_choice.t_heap.t_xmax;
403 : : }
404 : :
405 : : static inline void
406 : 25562864 : HeapTupleHeaderSetXmax(HeapTupleHeaderData *tup, TransactionId xid)
407 : : {
408 : 25562864 : tup->t_choice.t_heap.t_xmax = xid;
409 : 25562864 : }
410 : :
411 : : #ifndef FRONTEND
412 : : /*
413 : : * HeapTupleHeaderGetRawXmax gets you the raw Xmax field. To find out the Xid
414 : : * that updated a tuple, you might need to resolve the MultiXactId if certain
415 : : * bits are set. HeapTupleHeaderGetUpdateXid checks those bits and takes care
416 : : * to resolve the MultiXactId if necessary. This might involve multixact I/O,
417 : : * so it should only be used if absolutely necessary.
418 : : */
419 : : static inline TransactionId
420 : 12545319 : HeapTupleHeaderGetUpdateXid(const HeapTupleHeaderData *tup)
421 : : {
422 [ + + ]: 12545319 : if (!((tup)->t_infomask & HEAP_XMAX_INVALID) &&
423 [ + + ]: 11835433 : ((tup)->t_infomask & HEAP_XMAX_IS_MULTI) &&
424 [ + + ]: 76749 : !((tup)->t_infomask & HEAP_XMAX_LOCK_ONLY))
425 : 76709 : return HeapTupleGetUpdateXid(tup);
426 : : else
427 : 12468610 : return HeapTupleHeaderGetRawXmax(tup);
428 : : }
429 : : #endif /* FRONTEND */
430 : :
431 : : /*
432 : : * HeapTupleHeaderGetRawCommandId will give you what's in the header whether
433 : : * it is useful or not. Most code should use HeapTupleHeaderGetCmin or
434 : : * HeapTupleHeaderGetCmax instead, but note that those Assert that you can
435 : : * get a legitimate result, ie you are in the originating transaction!
436 : : */
437 : : static inline CommandId
438 : 20016677 : HeapTupleHeaderGetRawCommandId(const HeapTupleHeaderData *tup)
439 : : {
440 : 20016677 : return tup->t_choice.t_heap.t_field3.t_cid;
441 : : }
442 : :
443 : : /* SetCmin is reasonably simple since we never need a combo CID */
444 : : static inline void
445 : 18055342 : HeapTupleHeaderSetCmin(HeapTupleHeaderData *tup, CommandId cid)
446 : : {
447 : : Assert(!(tup->t_infomask & HEAP_MOVED));
448 : 18055342 : tup->t_choice.t_heap.t_field3.t_cid = cid;
449 : 18055342 : tup->t_infomask &= ~HEAP_COMBOCID;
450 : 18055342 : }
451 : :
452 : : /* SetCmax must be used after HeapTupleHeaderAdjustCmax; see combocid.c */
453 : : static inline void
454 : 7035358 : HeapTupleHeaderSetCmax(HeapTupleHeaderData *tup, CommandId cid, bool iscombo)
455 : : {
456 : : Assert(!((tup)->t_infomask & HEAP_MOVED));
457 : 7035358 : tup->t_choice.t_heap.t_field3.t_cid = cid;
458 [ + + ]: 7035358 : if (iscombo)
459 : 250955 : tup->t_infomask |= HEAP_COMBOCID;
460 : : else
461 : 6784403 : tup->t_infomask &= ~HEAP_COMBOCID;
462 : 7035358 : }
463 : :
464 : : static inline TransactionId
465 : 17193995 : HeapTupleHeaderGetXvac(const HeapTupleHeaderData *tup)
466 : : {
467 [ - + ]: 17193995 : if (tup->t_infomask & HEAP_MOVED)
468 : 0 : return tup->t_choice.t_heap.t_field3.t_xvac;
469 : : else
470 : 17193995 : return InvalidTransactionId;
471 : : }
472 : :
473 : : static inline void
474 : 0 : HeapTupleHeaderSetXvac(HeapTupleHeaderData *tup, TransactionId xid)
475 : : {
476 : : Assert(tup->t_infomask & HEAP_MOVED);
477 : 0 : tup->t_choice.t_heap.t_field3.t_xvac = xid;
478 : 0 : }
479 : :
480 : : StaticAssertDecl(MaxOffsetNumber < SpecTokenOffsetNumber,
481 : : "invalid speculative token constant");
482 : :
483 : : static inline bool
484 : 229254150 : HeapTupleHeaderIsSpeculative(const HeapTupleHeaderData *tup)
485 : : {
486 : 229254150 : return ItemPointerGetOffsetNumberNoCheck(&tup->t_ctid) == SpecTokenOffsetNumber;
487 : : }
488 : :
489 : : static inline BlockNumber
490 : 2 : HeapTupleHeaderGetSpeculativeToken(const HeapTupleHeaderData *tup)
491 : : {
492 : : Assert(HeapTupleHeaderIsSpeculative(tup));
493 : 2 : return ItemPointerGetBlockNumber(&tup->t_ctid);
494 : : }
495 : :
496 : : static inline void
497 : 2279 : HeapTupleHeaderSetSpeculativeToken(HeapTupleHeaderData *tup, BlockNumber token)
498 : : {
499 : 2279 : ItemPointerSet(&tup->t_ctid, token, SpecTokenOffsetNumber);
500 : 2279 : }
501 : :
502 : : static inline bool
503 : 17176 : HeapTupleHeaderIndicatesMovedPartitions(const HeapTupleHeaderData *tup)
504 : : {
505 : 17176 : return ItemPointerIndicatesMovedPartitions(&tup->t_ctid);
506 : : }
507 : :
508 : : static inline void
509 : 780 : HeapTupleHeaderSetMovedPartitions(HeapTupleHeaderData *tup)
510 : : {
511 : 780 : ItemPointerSetMovedPartitions(&tup->t_ctid);
512 : 780 : }
513 : :
514 : : /*
515 : : * Is the tuple a datum tuple, i.e. are the t_choice.t_datum fields valid?
516 : : *
517 : : * Datum tuples created before HEAP_IS_DATUM was introduced (e.g. pg_upgrade'd
518 : : * ones, or ones from an older minor version) are not marked as such on-disk,
519 : : * but DatumGetHeapTupleHeader() returns a marked copy whenever such a Datum is
520 : : * converted to a HeapTupleHeader. DatumGetHeapTupleHeader() is expected to be
521 : : * called at least once in the path towards tuple deformation.
522 : : *
523 : : * See also HeapTupleHeaderReallyIsDatum().
524 : : */
525 : : static inline bool
526 : 201325065 : HeapTupleHeaderIsDatum(const HeapTupleHeaderData *tup)
527 : : {
528 : 201325065 : return (tup->t_infomask & HEAP_IS_DATUM) == HEAP_IS_DATUM;
529 : : }
530 : :
531 : : static inline void
532 : 19214008 : HeapTupleHeaderSetDatum(HeapTupleHeaderData *tup)
533 : : {
534 : 19214008 : tup->t_infomask |= HEAP_IS_DATUM;
535 : 19214008 : }
536 : :
537 : : static inline void
538 : 47013 : HeapTupleHeaderClearDatum(HeapTupleHeaderData *tup)
539 : : {
540 : : /* otherwise we might clear transactionally relevant bits */
541 : : Assert(HeapTupleHeaderIsDatum(tup));
542 : 47013 : tup->t_infomask &= ~HEAP_IS_DATUM;
543 : 47013 : }
544 : :
545 : : static inline uint32
546 : 1747275 : HeapTupleHeaderGetDatumLength(const HeapTupleHeaderData *tup)
547 : : {
548 : 1747275 : return VARSIZE(tup);
549 : : }
550 : :
551 : : static inline void
552 : 19213964 : HeapTupleHeaderSetDatumLength(HeapTupleHeaderData *tup, uint32 len)
553 : : {
554 : 19213964 : SET_VARSIZE(tup, len);
555 : 19213964 : }
556 : :
557 : : static inline Oid
558 : 7414658 : HeapTupleHeaderGetTypeId(const HeapTupleHeaderData *tup)
559 : : {
560 : 7414658 : return tup->t_choice.t_datum.datum_typeid;
561 : : }
562 : :
563 : : static inline void
564 : 19213964 : HeapTupleHeaderSetTypeId(HeapTupleHeaderData *tup, Oid datum_typeid)
565 : : {
566 : 19213964 : tup->t_choice.t_datum.datum_typeid = datum_typeid;
567 : 19213964 : }
568 : :
569 : : static inline int32
570 : 2840957 : HeapTupleHeaderGetTypMod(const HeapTupleHeaderData *tup)
571 : : {
572 : : /*
573 : : * If the tuple is versioned (only happens for !RECORDOID), datum_typmod
574 : : * carries part of the version. We don't want callers to have to care
575 : : * about that, so we return the traditional -1 in that case.
576 : : *
577 : : * As this is a static inline, extensions compiled with the old definition
578 : : * will return the version, but based on an inspection of extensions
579 : : * that's ok. Almost all just call lookup_rowtype_tupdesc(), which ignores
580 : : * typmod for !RECORDOID cases. The one other case (Citus) is never
581 : : * generated by its own planner for !RECORDOID.
582 : : */
583 [ + + ]: 2840957 : if (HeapTupleHeaderGetTypeId(tup) != RECORDOID)
584 : 1198170 : return -1;
585 : 1642787 : return tup->t_choice.t_datum.datum_typmod;
586 : : }
587 : :
588 : : static inline void
589 : 14170058 : HeapTupleHeaderSetTypMod(HeapTupleHeaderData *tup, int32 typmod)
590 : : {
591 : 14170058 : tup->t_choice.t_datum.datum_typmod = typmod;
592 : 14170058 : }
593 : :
594 : : /*
595 : : * Is this really a datum tuple?
596 : : *
597 : : * postgres_fdw has historically overwritten xmin/xmax/cmin/ctid, several
598 : : * out-of-tree extensions have copied that pattern. That clears the length,
599 : : * typmod, ... of a datum tuple. Because those extensions were written before
600 : : * versioned datums were a thing, they are not calling
601 : : * HeapTupleHeaderClearDatum(), resulting in the possibility of getting here
602 : : * with partially overwritten version information.
603 : : *
604 : : * We can detect this by checking if the length of the datum has been zeroed
605 : : * out. No real datum tuple can have a zero length, so this does not weaken
606 : : * protections.
607 : : *
608 : : * Other FDWs overwrite just t_ctid, which makes the datum unversioned (a real
609 : : * TID's ip_posid is never VersionedDatumOffsetNumber), which will cause
610 : : * HeapTupleHeaderIsVersionedDatum() to return false.
611 : : *
612 : : * It's typically OK to not check a "falsely marked" datum tuple, because
613 : : * other protections, e.g. locking of foreign tables against DDL, should
614 : : * protect until the tuple is converted to a "real" datum tuple.
615 : : *
616 : : * NB: This should only be used when relying on the length/typeid/typmod. For
617 : : * other cases, e.g. whether HEAP_IS_DATUM is to be cleared,
618 : : * HeapTupleHeaderIsDatum() needs to be used.
619 : : */
620 : : static inline bool
621 : 1187820 : HeapTupleHeaderReallyIsDatum(const HeapTupleHeaderData *tup)
622 : : {
623 [ + + + + ]: 1187820 : return HeapTupleHeaderIsDatum(tup) && tup->t_choice.t_datum.datum_len_ != 0;
624 : : }
625 : :
626 : : /*
627 : : * Is the tuple a versioned datum tuple?
628 : : *
629 : : * RECORDOID datums are never versioned. Neither are datums whose t_ctid has
630 : : * been overwritten, e.g. by FDWs storing a real TID there.
631 : : */
632 : : static inline bool
633 : 194770489 : HeapTupleHeaderIsVersionedDatum(const HeapTupleHeaderData *tup)
634 : : {
635 [ + + + + ]: 199663755 : return HeapTupleHeaderIsDatum(tup) &&
636 : 4893266 : ItemPointerGetOffsetNumberNoCheck(&tup->t_ctid) == VersionedDatumOffsetNumber;
637 : : }
638 : :
639 : : static inline void
640 : 5043973 : HeapTupleHeaderSetVersion(HeapTupleHeaderData *tup, XLogRecPtr version)
641 : : {
642 : 5043973 : uint32 version_high = (uint32) (version >> 32);
643 : 5043973 : uint32 version_low = (uint32) (version);
644 : :
645 : : Assert(HeapTupleHeaderIsDatum(tup));
646 : :
647 : : /* set the version */
648 : 5043973 : tup->t_choice.t_datum.datum_typmod = version_low;
649 : 5043973 : ItemPointerSetBlockNumber(&tup->t_ctid, version_high);
650 : :
651 : : /* mark as versioned */
652 : 5043973 : ItemPointerSetOffsetNumber(&tup->t_ctid, VersionedDatumOffsetNumber);
653 : 5043973 : }
654 : :
655 : : static inline XLogRecPtr
656 : 1002665 : HeapTupleHeaderGetVersion(const HeapTupleHeaderData *tup)
657 : : {
658 : : XLogRecPtr version;
659 : : uint32 version_low;
660 : : uint32 version_high;
661 : :
662 : : Assert(HeapTupleHeaderIsVersionedDatum(tup));
663 : :
664 : 1002665 : version_low = tup->t_choice.t_datum.datum_typmod;
665 : 1002665 : version_high = ItemPointerGetBlockNumberNoCheck(&tup->t_ctid);
666 : :
667 : 1002665 : version = ((uint64) version_high) << 32 | version_low;
668 : :
669 : 1002665 : return version;
670 : : }
671 : :
672 : : /*
673 : : * Note that we stop considering a tuple HOT-updated as soon as it is known
674 : : * aborted or the would-be updating transaction is known aborted. For best
675 : : * efficiency, check tuple visibility before using this function, so that the
676 : : * INVALID bits will be as up to date as possible.
677 : : */
678 : : static inline bool
679 : 27011869 : HeapTupleHeaderIsHotUpdated(const HeapTupleHeaderData *tup)
680 : : {
681 : : return
682 : 28860771 : (tup->t_infomask2 & HEAP_HOT_UPDATED) != 0 &&
683 [ + + + + ]: 28860763 : (tup->t_infomask & HEAP_XMAX_INVALID) == 0 &&
684 [ + + ]: 1848894 : !HeapTupleHeaderXminInvalid(tup);
685 : : }
686 : :
687 : : static inline void
688 : 214324 : HeapTupleHeaderSetHotUpdated(HeapTupleHeaderData *tup)
689 : : {
690 : 214324 : tup->t_infomask2 |= HEAP_HOT_UPDATED;
691 : 214324 : }
692 : :
693 : : static inline void
694 : 6980086 : HeapTupleHeaderClearHotUpdated(HeapTupleHeaderData *tup)
695 : : {
696 : 6980086 : tup->t_infomask2 &= ~HEAP_HOT_UPDATED;
697 : 6980086 : }
698 : :
699 : : static inline bool
700 : 85469500 : HeapTupleHeaderIsHeapOnly(const HeapTupleHeaderData *tup) \
701 : : {
702 : 85469500 : return (tup->t_infomask2 & HEAP_ONLY_TUPLE) != 0;
703 : : }
704 : :
705 : : static inline void
706 : 347584 : HeapTupleHeaderSetHeapOnly(HeapTupleHeaderData *tup)
707 : : {
708 : 347584 : tup->t_infomask2 |= HEAP_ONLY_TUPLE;
709 : 347584 : }
710 : :
711 : : static inline void
712 : 4458618 : HeapTupleHeaderClearHeapOnly(HeapTupleHeaderData *tup)
713 : : {
714 : 4458618 : tup->t_infomask2 &= ~HEAP_ONLY_TUPLE;
715 : 4458618 : }
716 : :
717 : : /*
718 : : * These are used with both HeapTuple and MinimalTuple, so they must be
719 : : * macros.
720 : : */
721 : :
722 : : #define HeapTupleHeaderGetNatts(tup) \
723 : : ((tup)->t_infomask2 & HEAP_NATTS_MASK)
724 : :
725 : : #define HeapTupleHeaderSetNatts(tup, natts) \
726 : : ( \
727 : : (tup)->t_infomask2 = ((tup)->t_infomask2 & ~HEAP_NATTS_MASK) | (natts) \
728 : : )
729 : :
730 : : #define HeapTupleHeaderHasExternal(tup) \
731 : : (((tup)->t_infomask & HEAP_HASEXTERNAL) != 0)
732 : :
733 : :
734 : : /*
735 : : * BITMAPLEN(NATTS) -
736 : : * Computes size of null bitmap given number of data columns.
737 : : */
738 : : static inline int
739 : 34331931 : BITMAPLEN(int NATTS)
740 : : {
741 : 34331931 : return (NATTS + 7) / 8;
742 : : }
743 : :
744 : : /*
745 : : * MaxHeapTupleSize is the maximum allowed size of a heap tuple, including
746 : : * header and MAXALIGN alignment padding. Basically it's BLCKSZ minus the
747 : : * other stuff that has to be on a disk page. Since heap pages use no
748 : : * "special space", there's no deduction for that.
749 : : *
750 : : * NOTE: we allow for the ItemId that must point to the tuple, ensuring that
751 : : * an otherwise-empty page can indeed hold a tuple of this size. Because
752 : : * ItemIds and tuples have different alignment requirements, don't assume that
753 : : * you can, say, fit 2 tuples of size MaxHeapTupleSize/2 on the same page.
754 : : */
755 : : #define MaxHeapTupleSize (BLCKSZ - MAXALIGN(SizeOfPageHeaderData + sizeof(ItemIdData)))
756 : : #define MinHeapTupleSize MAXALIGN(SizeofHeapTupleHeader)
757 : :
758 : : /*
759 : : * MaxHeapTuplesPerPage is an upper bound on the number of tuples that can
760 : : * fit on one heap page. (Note that indexes could have more, because they
761 : : * use a smaller tuple header.) We arrive at the divisor because each tuple
762 : : * must be maxaligned, and it must have an associated line pointer.
763 : : *
764 : : * Note: with HOT, there could theoretically be more line pointers (not actual
765 : : * tuples) than this on a heap page. However we constrain the number of line
766 : : * pointers to this anyway, to avoid excessive line-pointer bloat and not
767 : : * require increases in the size of work arrays.
768 : : */
769 : : #define MaxHeapTuplesPerPage \
770 : : ((int) ((BLCKSZ - SizeOfPageHeaderData) / \
771 : : (MAXALIGN(SizeofHeapTupleHeader) + sizeof(ItemIdData))))
772 : :
773 : : /*
774 : : * MaxAttrSize is a somewhat arbitrary upper limit on the declared size of
775 : : * data fields of char(n) and similar types. It need not have anything
776 : : * directly to do with the *actual* upper limit of varlena values, which
777 : : * is currently 1Gb (see TOAST structures in varatt.h). I've set it
778 : : * at 10Mb which seems like a reasonable number --- tgl 8/6/00.
779 : : */
780 : : #define MaxAttrSize (10 * 1024 * 1024)
781 : :
782 : :
783 : : /*
784 : : * MinimalTuple is an alternative representation that is used for transient
785 : : * tuples inside the executor, in places where transaction status information
786 : : * is not required, the tuple rowtype is known, and shaving off a few bytes
787 : : * is worthwhile because we need to store many tuples. The representation
788 : : * is chosen so that tuple access routines can work with either full or
789 : : * minimal tuples via a HeapTupleData pointer structure. The access routines
790 : : * see no difference, except that they must not access the transaction status
791 : : * or t_ctid fields because those aren't there.
792 : : *
793 : : * For the most part, MinimalTuples should be accessed via TupleTableSlot
794 : : * routines. These routines will prevent access to the "system columns"
795 : : * and thereby prevent accidental use of the nonexistent fields.
796 : : *
797 : : * MinimalTupleData contains a length word, some padding, and fields matching
798 : : * HeapTupleHeaderData beginning with t_infomask2. The padding is chosen so
799 : : * that offsetof(t_infomask2) is the same modulo MAXIMUM_ALIGNOF in both
800 : : * structs. This makes data alignment rules equivalent in both cases.
801 : : *
802 : : * When a minimal tuple is accessed via a HeapTupleData pointer, t_data is
803 : : * set to point MINIMAL_TUPLE_OFFSET bytes before the actual start of the
804 : : * minimal tuple --- that is, where a full tuple matching the minimal tuple's
805 : : * data would start. This trick is what makes the structs seem equivalent.
806 : : *
807 : : * Note that t_hoff is computed the same as in a full tuple, hence it includes
808 : : * the MINIMAL_TUPLE_OFFSET distance. t_len does not include that, however.
809 : : *
810 : : * MINIMAL_TUPLE_DATA_OFFSET is the offset to the first useful (non-pad) data
811 : : * other than the length word. tuplesort.c and tuplestore.c use this to avoid
812 : : * writing the padding to disk.
813 : : */
814 : : #define MINIMAL_TUPLE_OFFSET \
815 : : ((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) / MAXIMUM_ALIGNOF * MAXIMUM_ALIGNOF)
816 : : #define MINIMAL_TUPLE_PADDING \
817 : : ((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) % MAXIMUM_ALIGNOF)
818 : : #define MINIMAL_TUPLE_DATA_OFFSET \
819 : : offsetof(MinimalTupleData, t_infomask2)
820 : :
821 : : struct MinimalTupleData
822 : : {
823 : : uint32 t_len; /* actual length of minimal tuple */
824 : :
825 : : char mt_padding[MINIMAL_TUPLE_PADDING];
826 : :
827 : : /* Fields below here must match HeapTupleHeaderData! */
828 : :
829 : : uint16 t_infomask2; /* number of attributes + various flags */
830 : :
831 : : uint16 t_infomask; /* various flag bits, see below */
832 : :
833 : : uint8 t_hoff; /* sizeof header incl. bitmap, padding */
834 : :
835 : : /* ^ - 23 bytes - ^ */
836 : :
837 : : uint8 t_bits[FLEXIBLE_ARRAY_MEMBER]; /* bitmap of NULLs */
838 : :
839 : : /* MORE DATA FOLLOWS AT END OF STRUCT */
840 : : };
841 : :
842 : : /* typedef appears in htup.h */
843 : :
844 : : #define SizeofMinimalTupleHeader offsetof(MinimalTupleData, t_bits)
845 : :
846 : : /*
847 : : * MinimalTuple accessor functions
848 : : */
849 : :
850 : : static inline bool
851 : 9252633 : HeapTupleHeaderHasMatch(const MinimalTupleData *tup)
852 : : {
853 : 9252633 : return (tup->t_infomask2 & HEAP_TUPLE_HAS_MATCH) != 0;
854 : : }
855 : :
856 : : static inline void
857 : 3986946 : HeapTupleHeaderSetMatch(MinimalTupleData *tup)
858 : : {
859 : 3986946 : tup->t_infomask2 |= HEAP_TUPLE_HAS_MATCH;
860 : 3986946 : }
861 : :
862 : : static inline void
863 : 7653766 : HeapTupleHeaderClearMatch(MinimalTupleData *tup)
864 : : {
865 : 7653766 : tup->t_infomask2 &= ~HEAP_TUPLE_HAS_MATCH;
866 : 7653766 : }
867 : :
868 : :
869 : : /*
870 : : * GETSTRUCT - given a HeapTuple pointer, return address of the user data
871 : : */
872 : : static inline void *
873 : 97076701 : GETSTRUCT(const HeapTupleData *tuple)
874 : : {
875 : 97076701 : return ((char *) (tuple->t_data) + tuple->t_data->t_hoff);
876 : : }
877 : :
878 : : /*
879 : : * Accessor functions to be used with HeapTuple pointers.
880 : : */
881 : :
882 : : static inline bool
883 : 481565603 : HeapTupleHasNulls(const HeapTupleData *tuple)
884 : : {
885 : 481565603 : return (tuple->t_data->t_infomask & HEAP_HASNULL) != 0;
886 : : }
887 : :
888 : : static inline bool
889 : 206897499 : HeapTupleNoNulls(const HeapTupleData *tuple)
890 : : {
891 : 206897499 : return !HeapTupleHasNulls(tuple);
892 : : }
893 : :
894 : : static inline bool
895 : 138259040 : HeapTupleHasVarWidth(const HeapTupleData *tuple)
896 : : {
897 : 138259040 : return (tuple->t_data->t_infomask & HEAP_HASVARWIDTH) != 0;
898 : : }
899 : :
900 : : static inline bool
901 : : HeapTupleAllFixed(const HeapTupleData *tuple)
902 : : {
903 : : return !HeapTupleHasVarWidth(tuple);
904 : : }
905 : :
906 : : static inline bool
907 : 24707185 : HeapTupleHasExternal(const HeapTupleData *tuple)
908 : : {
909 : 24707185 : return (tuple->t_data->t_infomask & HEAP_HASEXTERNAL) != 0;
910 : : }
911 : :
912 : : static inline bool
913 : 10208101 : HeapTupleIsHotUpdated(const HeapTupleData *tuple)
914 : : {
915 : 10208101 : return HeapTupleHeaderIsHotUpdated(tuple->t_data);
916 : : }
917 : :
918 : : static inline void
919 : 173792 : HeapTupleSetHotUpdated(const HeapTupleData *tuple)
920 : : {
921 : 173792 : HeapTupleHeaderSetHotUpdated(tuple->t_data);
922 : 173792 : }
923 : :
924 : : static inline void
925 : 4442328 : HeapTupleClearHotUpdated(const HeapTupleData *tuple)
926 : : {
927 : 4442328 : HeapTupleHeaderClearHotUpdated(tuple->t_data);
928 : 4442328 : }
929 : :
930 : : static inline bool
931 : 45394188 : HeapTupleIsHeapOnly(const HeapTupleData *tuple)
932 : : {
933 : 45394188 : return HeapTupleHeaderIsHeapOnly(tuple->t_data);
934 : : }
935 : :
936 : : static inline void
937 : 347584 : HeapTupleSetHeapOnly(const HeapTupleData *tuple)
938 : : {
939 : 347584 : HeapTupleHeaderSetHeapOnly(tuple->t_data);
940 : 347584 : }
941 : :
942 : : static inline void
943 : 4458618 : HeapTupleClearHeapOnly(const HeapTupleData *tuple)
944 : : {
945 : 4458618 : HeapTupleHeaderClearHeapOnly(tuple->t_data);
946 : 4458618 : }
947 : :
948 : : /* GUC variable, in common/heaptuple.c */
949 : : extern PGDLLIMPORT int composite_type_mismatch;
950 : :
951 : : /* possible values for composite_type_mismatch */
952 : : typedef enum CompositeTypeMismatchOptions
953 : : {
954 : : COMPOSITE_TYPE_MISMATCH_ERROR,
955 : : COMPOSITE_TYPE_MISMATCH_WARN,
956 : : COMPOSITE_TYPE_MISMATCH_DISABLED,
957 : : } CompositeTypeMismatchOptions;
958 : :
959 : : /* prototypes for functions in common/heaptuple.c */
960 : : extern Size heap_compute_data_size(TupleDesc tupleDesc,
961 : : const Datum *values, const bool *isnull,
962 : : bool allow_huge);
963 : :
964 : : extern void heap_fill_tuple(TupleDesc tupleDesc,
965 : : const Datum *values, const bool *isnull,
966 : : char *data, Size data_size,
967 : : uint16 *infomask, uint8 *bit);
968 : : extern void heap_tuple_set_datum(HeapTupleHeader tup, TupleDesc tupleDesc, uint32 len);
969 : : extern void heap_datum_update_type(HeapTupleHeader tup, TupleDesc tupleDesc);
970 : : extern bool heap_attisnull(HeapTuple tup, int attnum, TupleDesc tupleDesc);
971 : : extern Datum nocachegetattr(HeapTuple tup, int attnum,
972 : : TupleDesc tupleDesc);
973 : : extern Datum heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
974 : : bool *isnull);
975 : : extern Datum getmissingattr(TupleDesc tupleDesc,
976 : : int attnum, bool *isnull);
977 : : extern HeapTuple heap_copytuple(HeapTuple tuple);
978 : : extern void heap_copytuple_with_tuple(HeapTuple src, HeapTuple dest);
979 : : extern Datum heap_copy_tuple_as_datum(HeapTuple tuple, TupleDesc tupleDesc);
980 : : extern HeapTuple heap_form_tuple(TupleDesc tupleDescriptor,
981 : : const Datum *values, const bool *isnull);
982 : : extern HeapTuple heap_modify_tuple(HeapTuple tuple,
983 : : TupleDesc tupleDesc,
984 : : const Datum *replValues,
985 : : const bool *replIsnull,
986 : : const bool *doReplace);
987 : : extern HeapTuple heap_modify_tuple_by_cols(HeapTuple tuple,
988 : : TupleDesc tupleDesc,
989 : : int nCols,
990 : : const int *replCols,
991 : : const Datum *replValues,
992 : : const bool *replIsnull);
993 : : extern void heap_datum_check(HeapTupleHeader tup, TupleDesc tupleDesc);
994 : : extern void heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
995 : : Datum *values, bool *isnull);
996 : : extern void heap_freetuple(HeapTuple htup);
997 : : extern MinimalTuple heap_form_minimal_tuple(TupleDesc tupleDescriptor,
998 : : const Datum *values, const bool *isnull,
999 : : Size extra);
1000 : : extern void heap_free_minimal_tuple(MinimalTuple mtup);
1001 : : extern MinimalTuple heap_copy_minimal_tuple(MinimalTuple mtup, Size extra);
1002 : : extern HeapTuple heap_tuple_from_minimal_tuple(MinimalTuple mtup);
1003 : : extern MinimalTuple minimal_tuple_from_heap_tuple(HeapTuple htup, Size extra);
1004 : : extern size_t varsize_any(void *p);
1005 : : extern HeapTuple heap_expand_tuple(HeapTuple sourceTuple, TupleDesc tupleDesc);
1006 : : extern MinimalTuple minimal_expand_tuple(HeapTuple sourceTuple, TupleDesc tupleDesc);
1007 : :
1008 : : #ifndef FRONTEND
1009 : : /*
1010 : : * fastgetattr
1011 : : * Fetch a user attribute's value as a Datum (might be either a
1012 : : * value, or a pointer into the data area of the tuple).
1013 : : *
1014 : : * This must not be used when a system attribute might be requested.
1015 : : * Furthermore, the passed attnum MUST be valid. Use heap_getattr()
1016 : : * instead, if in doubt.
1017 : : *
1018 : : * This gets called many times, so we macro the cacheable and NULL
1019 : : * lookups, and call nocachegetattr() for the rest.
1020 : : */
1021 : : static inline Datum
1022 : 200024623 : fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
1023 : : {
1024 : : Assert(attnum > 0);
1025 : :
1026 : : /*
1027 : : * NB: Right now this does not call heap_datum_check(). The reasoning is
1028 : : * that
1029 : : *
1030 : : * a) fastgetattr() is used in quite performance sensitive paths like
1031 : : * catcache, adding code bloat to it would not be great
1032 : : *
1033 : : * b) The requirement that the caller already have validated attnum
1034 : : * (without that we'd run off the end of the attribute array!), basically
1035 : : * means it can only be used where the caller is sure that the type isn't
1036 : : * evolving.
1037 : : *
1038 : : * c) fastgetattr() is called from heap_getattr(), so we would often check
1039 : : * twice.
1040 : : *
1041 : : * I think that's the right decision. An investigation of extensions found
1042 : : * only two users ("rum" and "storage_engine") and both of them use
1043 : : * fastgetattr() on tables that can't be altered by non-superusers.
1044 : : *
1045 : : * While it might seem we should just assert that this is not used for
1046 : : * datum tuples, we can't - fastgetattr() is often called on a modified
1047 : : * copy of the tuple, and those are marked as datum tuples, so this would
1048 : : * spuriously trigger all the time :(.
1049 : : */
1050 : :
1051 : 200024623 : *isnull = false;
1052 [ + + ]: 200024623 : if (HeapTupleNoNulls(tup))
1053 : : {
1054 : : CompactAttribute *att;
1055 : :
1056 : 82963707 : att = TupleDescCompactAttr(tupleDesc, attnum - 1);
1057 [ + + ]: 82963707 : if (att->attcacheoff >= 0)
1058 : 46365319 : return fetchatt(att, (char *) tup->t_data + tup->t_data->t_hoff +
1059 : : att->attcacheoff);
1060 : : else
1061 : 36598388 : return nocachegetattr(tup, attnum, tupleDesc);
1062 : : }
1063 : : else
1064 : : {
1065 [ + + ]: 117060916 : if (att_isnull(attnum - 1, tup->t_data->t_bits))
1066 : : {
1067 : 15085621 : *isnull = true;
1068 : 15085621 : return (Datum) 0;
1069 : : }
1070 : : else
1071 : 101975295 : return nocachegetattr(tup, attnum, tupleDesc);
1072 : : }
1073 : : }
1074 : :
1075 : : /*
1076 : : * heap_getattr
1077 : : * Extract an attribute of a heap tuple and return it as a Datum.
1078 : : * This works for either system or user attributes. The given attnum
1079 : : * is properly range-checked.
1080 : : *
1081 : : * If the field in question has a NULL value, we return a zero Datum
1082 : : * and set *isnull == true. Otherwise, we set *isnull == false.
1083 : : *
1084 : : * <tup> is the pointer to the heap tuple. <attnum> is the attribute
1085 : : * number of the column (field) caller wants. <tupleDesc> is a
1086 : : * pointer to the structure describing the row and all its fields.
1087 : : *
1088 : : */
1089 : : static inline Datum
1090 : 187402237 : heap_getattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
1091 : : {
1092 : : /*
1093 : : * It's a bit sad to have an external function call here, but we shouldn't
1094 : : * use it in too many speed critical paths anymore. Separately, the
1095 : : * function looks like it's getting too complicated to be worth inlining.
1096 : : */
1097 [ + + ]: 187402237 : if (HeapTupleHeaderIsVersionedDatum(tup->t_data))
1098 : 1005139 : heap_datum_check(tup->t_data, tupleDesc);
1099 : :
1100 [ + - ]: 187402220 : if (attnum > 0)
1101 : : {
1102 [ + + ]: 187402220 : if (attnum > (int) HeapTupleHeaderGetNatts(tup->t_data))
1103 : 249 : return getmissingattr(tupleDesc, attnum, isnull);
1104 : : else
1105 : 187401971 : return fastgetattr(tup, attnum, tupleDesc, isnull);
1106 : : }
1107 : : else
1108 : 0 : return heap_getsysattr(tup, attnum, tupleDesc, isnull);
1109 : : }
1110 : : #endif /* FRONTEND */
1111 : :
1112 : : #endif /* HTUP_DETAILS_H */
|
