diff options
Diffstat (limited to 'src/include/access/htup.h')
| -rw-r--r-- | src/include/access/htup.h | 632 |
1 files changed, 3 insertions, 629 deletions
diff --git a/src/include/access/htup.h b/src/include/access/htup.h index 74cad2bb2b..53b711046c 100644 --- a/src/include/access/htup.h +++ b/src/include/access/htup.h @@ -14,470 +14,15 @@ #ifndef HTUP_H #define HTUP_H -#include "access/tupdesc.h" -#include "access/tupmacs.h" -#include "storage/bufpage.h" #include "storage/itemptr.h" -#include "storage/relfilenode.h" -/* - * MaxTupleAttributeNumber limits the number of (user) columns in a tuple. - * The key limit on this value is that the size of the fixed overhead for - * a tuple, plus the size of the null-values bitmap (at 1 bit per column), - * plus MAXALIGN alignment, must fit into t_hoff which is uint8. On most - * machines the upper limit without making t_hoff wider would be a little - * over 1700. We use round numbers here and for MaxHeapAttributeNumber - * so that alterations in HeapTupleHeaderData layout won't change the - * supported max number of columns. - */ -#define MaxTupleAttributeNumber 1664 /* 8 * 208 */ - -/* - * MaxHeapAttributeNumber limits the number of (user) columns in a table. - * This should be somewhat less than MaxTupleAttributeNumber. It must be - * at least one less, else we will fail to do UPDATEs on a maximal-width - * table (because UPDATE has to form working tuples that include CTID). - * In practice we want some additional daylight so that we can gracefully - * support operations that add hidden "resjunk" columns, for example - * SELECT * FROM wide_table ORDER BY foo, bar, baz. - * In any case, depending on column data types you will likely be running - * into the disk-block-based limit on overall tuple size if you have more - * than a thousand or so columns. TOAST won't help. - */ -#define MaxHeapAttributeNumber 1600 /* 8 * 200 */ - -/* - * Heap tuple header. To avoid wasting space, the fields should be - * laid out in such a way as to avoid structure padding. - * - * Datums of composite types (row types) share the same general structure - * as on-disk tuples, so that the same routines can be used to build and - * examine them. However the requirements are slightly different: a Datum - * does not need any transaction visibility information, and it does need - * a length word and some embedded type information. We can achieve this - * by overlaying the xmin/cmin/xmax/cmax/xvac fields of a heap tuple - * with the fields needed in the Datum case. Typically, all tuples built - * in-memory will be initialized with the Datum fields; but when a tuple is - * about to be inserted in a table, the transaction fields will be filled, - * overwriting the datum fields. - * - * The overall structure of a heap tuple looks like: - * fixed fields (HeapTupleHeaderData struct) - * nulls bitmap (if HEAP_HASNULL is set in t_infomask) - * alignment padding (as needed to make user data MAXALIGN'd) - * object ID (if HEAP_HASOID is set in t_infomask) - * user data fields - * - * We store five "virtual" fields Xmin, Cmin, Xmax, Cmax, and Xvac in three - * physical fields. Xmin and Xmax are always really stored, but Cmin, Cmax - * and Xvac share a field. This works because we know that Cmin and Cmax - * are only interesting for the lifetime of the inserting and deleting - * transaction respectively. If a tuple is inserted and deleted in the same - * transaction, we store a "combo" command id that can be mapped to the real - * cmin and cmax, but only by use of local state within the originating - * backend. See combocid.c for more details. Meanwhile, Xvac is only set by - * old-style VACUUM FULL, which does not have any command sub-structure and so - * does not need either Cmin or Cmax. (This requires that old-style VACUUM - * FULL never try to move a tuple whose Cmin or Cmax is still interesting, - * ie, an insert-in-progress or delete-in-progress tuple.) - * - * A word about t_ctid: whenever a new tuple is stored on disk, its t_ctid - * is initialized with its own TID (location). If the tuple is ever updated, - * its t_ctid is changed to point to the replacement version of the tuple. - * Thus, a tuple is the latest version of its row iff XMAX is invalid or - * t_ctid points to itself (in which case, if XMAX is valid, the tuple is - * either locked or deleted). One can follow the chain of t_ctid links - * to find the newest version of the row. Beware however that VACUUM might - * erase the pointed-to (newer) tuple before erasing the pointing (older) - * tuple. Hence, when following a t_ctid link, it is necessary to check - * to see if the referenced slot is empty or contains an unrelated tuple. - * Check that the referenced tuple has XMIN equal to the referencing tuple's - * XMAX to verify that it is actually the descendant version and not an - * unrelated tuple stored into a slot recently freed by VACUUM. If either - * check fails, one may assume that there is no live descendant version. - * - * Following the fixed header fields, the nulls bitmap is stored (beginning - * at t_bits). The bitmap is *not* stored if t_infomask shows that there - * are no nulls in the tuple. If an OID field is present (as indicated by - * t_infomask), then it is stored just before the user data, which begins at - * the offset shown by t_hoff. Note that t_hoff must be a multiple of - * MAXALIGN. - */ - -typedef struct HeapTupleFields -{ - TransactionId t_xmin; /* inserting xact ID */ - TransactionId t_xmax; /* deleting or locking xact ID */ - - union - { - CommandId t_cid; /* inserting or deleting command ID, or both */ - TransactionId t_xvac; /* old-style VACUUM FULL xact ID */ - } t_field3; -} HeapTupleFields; - -typedef struct DatumTupleFields -{ - int32 datum_len_; /* varlena header (do not touch directly!) */ +/* typedefs and forward declarations for structs defined in htup.h */ - int32 datum_typmod; /* -1, or identifier of a record type */ - - Oid datum_typeid; /* composite type OID, or RECORDOID */ - - /* - * Note: field ordering is chosen with thought that Oid might someday - * widen to 64 bits. - */ -} DatumTupleFields; - -typedef struct HeapTupleHeaderData -{ - union - { - HeapTupleFields t_heap; - DatumTupleFields t_datum; - } t_choice; - - ItemPointerData t_ctid; /* current TID of this or newer tuple */ - - /* Fields below here must match MinimalTupleData! */ - - uint16 t_infomask2; /* number of attributes + various flags */ - - uint16 t_infomask; /* various flag bits, see below */ - - uint8 t_hoff; /* sizeof header incl. bitmap, padding */ - - /* ^ - 23 bytes - ^ */ - - bits8 t_bits[1]; /* bitmap of NULLs -- VARIABLE LENGTH */ - - /* MORE DATA FOLLOWS AT END OF STRUCT */ -} HeapTupleHeaderData; +typedef struct HeapTupleHeaderData HeapTupleHeaderData; typedef HeapTupleHeaderData *HeapTupleHeader; -/* - * information stored in t_infomask: - */ -#define HEAP_HASNULL 0x0001 /* has null attribute(s) */ -#define HEAP_HASVARWIDTH 0x0002 /* has variable-width attribute(s) */ -#define HEAP_HASEXTERNAL 0x0004 /* has external stored attribute(s) */ -#define HEAP_HASOID 0x0008 /* has an object-id field */ -/* bit 0x0010 is available */ -#define HEAP_COMBOCID 0x0020 /* t_cid is a combo cid */ -#define HEAP_XMAX_EXCL_LOCK 0x0040 /* xmax is exclusive locker */ -#define HEAP_XMAX_SHARED_LOCK 0x0080 /* xmax is shared locker */ -/* if either LOCK bit is set, xmax hasn't deleted the tuple, only locked it */ -#define HEAP_IS_LOCKED (HEAP_XMAX_EXCL_LOCK | HEAP_XMAX_SHARED_LOCK) -#define HEAP_XMIN_COMMITTED 0x0100 /* t_xmin committed */ -#define HEAP_XMIN_INVALID 0x0200 /* t_xmin invalid/aborted */ -#define HEAP_XMAX_COMMITTED 0x0400 /* t_xmax committed */ -#define HEAP_XMAX_INVALID 0x0800 /* t_xmax invalid/aborted */ -#define HEAP_XMAX_IS_MULTI 0x1000 /* t_xmax is a MultiXactId */ -#define HEAP_UPDATED 0x2000 /* this is UPDATEd version of row */ -#define HEAP_MOVED_OFF 0x4000 /* moved to another place by pre-9.0 - * VACUUM FULL; kept for binary - * upgrade support */ -#define HEAP_MOVED_IN 0x8000 /* moved from another place by pre-9.0 - * VACUUM FULL; kept for binary - * upgrade support */ -#define HEAP_MOVED (HEAP_MOVED_OFF | HEAP_MOVED_IN) - -#define HEAP_XACT_MASK 0xFFE0 /* visibility-related bits */ - -/* - * information stored in t_infomask2: - */ -#define HEAP_NATTS_MASK 0x07FF /* 11 bits for number of attributes */ -/* bits 0x3800 are available */ -#define HEAP_HOT_UPDATED 0x4000 /* tuple was HOT-updated */ -#define HEAP_ONLY_TUPLE 0x8000 /* this is heap-only tuple */ - -#define HEAP2_XACT_MASK 0xC000 /* visibility-related bits */ - -/* - * HEAP_TUPLE_HAS_MATCH is a temporary flag used during hash joins. It is - * only used in tuples that are in the hash table, and those don't need - * any visibility information, so we can overlay it on a visibility flag - * instead of using up a dedicated bit. - */ -#define HEAP_TUPLE_HAS_MATCH HEAP_ONLY_TUPLE /* tuple has a join match */ - -/* - * HeapTupleHeader accessor macros - * - * Note: beware of multiple evaluations of "tup" argument. But the Set - * macros evaluate their other argument only once. - */ - -#define HeapTupleHeaderGetXmin(tup) \ -( \ - (tup)->t_choice.t_heap.t_xmin \ -) - -#define HeapTupleHeaderSetXmin(tup, xid) \ -( \ - (tup)->t_choice.t_heap.t_xmin = (xid) \ -) - -#define HeapTupleHeaderGetXmax(tup) \ -( \ - (tup)->t_choice.t_heap.t_xmax \ -) - -#define HeapTupleHeaderSetXmax(tup, xid) \ -( \ - (tup)->t_choice.t_heap.t_xmax = (xid) \ -) - -/* - * HeapTupleHeaderGetRawCommandId will give you what's in the header whether - * it is useful or not. Most code should use HeapTupleHeaderGetCmin or - * HeapTupleHeaderGetCmax instead, but note that those Assert that you can - * get a legitimate result, ie you are in the originating transaction! - */ -#define HeapTupleHeaderGetRawCommandId(tup) \ -( \ - (tup)->t_choice.t_heap.t_field3.t_cid \ -) - -/* SetCmin is reasonably simple since we never need a combo CID */ -#define HeapTupleHeaderSetCmin(tup, cid) \ -do { \ - Assert(!((tup)->t_infomask & HEAP_MOVED)); \ - (tup)->t_choice.t_heap.t_field3.t_cid = (cid); \ - (tup)->t_infomask &= ~HEAP_COMBOCID; \ -} while (0) - -/* SetCmax must be used after HeapTupleHeaderAdjustCmax; see combocid.c */ -#define HeapTupleHeaderSetCmax(tup, cid, iscombo) \ -do { \ - Assert(!((tup)->t_infomask & HEAP_MOVED)); \ - (tup)->t_choice.t_heap.t_field3.t_cid = (cid); \ - if (iscombo) \ - (tup)->t_infomask |= HEAP_COMBOCID; \ - else \ - (tup)->t_infomask &= ~HEAP_COMBOCID; \ -} while (0) - -#define HeapTupleHeaderGetXvac(tup) \ -( \ - ((tup)->t_infomask & HEAP_MOVED) ? \ - (tup)->t_choice.t_heap.t_field3.t_xvac \ - : \ - InvalidTransactionId \ -) - -#define HeapTupleHeaderSetXvac(tup, xid) \ -do { \ - Assert((tup)->t_infomask & HEAP_MOVED); \ - (tup)->t_choice.t_heap.t_field3.t_xvac = (xid); \ -} while (0) - -#define HeapTupleHeaderGetDatumLength(tup) \ - VARSIZE(tup) - -#define HeapTupleHeaderSetDatumLength(tup, len) \ - SET_VARSIZE(tup, len) - -#define HeapTupleHeaderGetTypeId(tup) \ -( \ - (tup)->t_choice.t_datum.datum_typeid \ -) - -#define HeapTupleHeaderSetTypeId(tup, typeid) \ -( \ - (tup)->t_choice.t_datum.datum_typeid = (typeid) \ -) - -#define HeapTupleHeaderGetTypMod(tup) \ -( \ - (tup)->t_choice.t_datum.datum_typmod \ -) - -#define HeapTupleHeaderSetTypMod(tup, typmod) \ -( \ - (tup)->t_choice.t_datum.datum_typmod = (typmod) \ -) - -#define HeapTupleHeaderGetOid(tup) \ -( \ - ((tup)->t_infomask & HEAP_HASOID) ? \ - *((Oid *) ((char *)(tup) + (tup)->t_hoff - sizeof(Oid))) \ - : \ - InvalidOid \ -) - -#define HeapTupleHeaderSetOid(tup, oid) \ -do { \ - Assert((tup)->t_infomask & HEAP_HASOID); \ - *((Oid *) ((char *)(tup) + (tup)->t_hoff - sizeof(Oid))) = (oid); \ -} while (0) - -/* - * Note that we stop considering a tuple HOT-updated as soon as it is known - * aborted or the would-be updating transaction is known aborted. For best - * efficiency, check tuple visibility before using this macro, so that the - * INVALID bits will be as up to date as possible. - */ -#define HeapTupleHeaderIsHotUpdated(tup) \ -( \ - ((tup)->t_infomask2 & HEAP_HOT_UPDATED) != 0 && \ - ((tup)->t_infomask & (HEAP_XMIN_INVALID | HEAP_XMAX_INVALID)) == 0 \ -) - -#define HeapTupleHeaderSetHotUpdated(tup) \ -( \ - (tup)->t_infomask2 |= HEAP_HOT_UPDATED \ -) - -#define HeapTupleHeaderClearHotUpdated(tup) \ -( \ - (tup)->t_infomask2 &= ~HEAP_HOT_UPDATED \ -) - -#define HeapTupleHeaderIsHeapOnly(tup) \ -( \ - (tup)->t_infomask2 & HEAP_ONLY_TUPLE \ -) - -#define HeapTupleHeaderSetHeapOnly(tup) \ -( \ - (tup)->t_infomask2 |= HEAP_ONLY_TUPLE \ -) - -#define HeapTupleHeaderClearHeapOnly(tup) \ -( \ - (tup)->t_infomask2 &= ~HEAP_ONLY_TUPLE \ -) - -#define HeapTupleHeaderHasMatch(tup) \ -( \ - (tup)->t_infomask2 & HEAP_TUPLE_HAS_MATCH \ -) - -#define HeapTupleHeaderSetMatch(tup) \ -( \ - (tup)->t_infomask2 |= HEAP_TUPLE_HAS_MATCH \ -) - -#define HeapTupleHeaderClearMatch(tup) \ -( \ - (tup)->t_infomask2 &= ~HEAP_TUPLE_HAS_MATCH \ -) - -#define HeapTupleHeaderGetNatts(tup) \ - ((tup)->t_infomask2 & HEAP_NATTS_MASK) - -#define HeapTupleHeaderSetNatts(tup, natts) \ -( \ - (tup)->t_infomask2 = ((tup)->t_infomask2 & ~HEAP_NATTS_MASK) | (natts) \ -) - - -/* - * BITMAPLEN(NATTS) - - * Computes size of null bitmap given number of data columns. - */ -#define BITMAPLEN(NATTS) (((int)(NATTS) + 7) / 8) - -/* - * MaxHeapTupleSize is the maximum allowed size of a heap tuple, including - * header and MAXALIGN alignment padding. Basically it's BLCKSZ minus the - * other stuff that has to be on a disk page. Since heap pages use no - * "special space", there's no deduction for that. - * - * NOTE: we allow for the ItemId that must point to the tuple, ensuring that - * an otherwise-empty page can indeed hold a tuple of this size. Because - * ItemIds and tuples have different alignment requirements, don't assume that - * you can, say, fit 2 tuples of size MaxHeapTupleSize/2 on the same page. - */ -#define MaxHeapTupleSize (BLCKSZ - MAXALIGN(SizeOfPageHeaderData + sizeof(ItemIdData))) - -/* - * MaxHeapTuplesPerPage is an upper bound on the number of tuples that can - * fit on one heap page. (Note that indexes could have more, because they - * use a smaller tuple header.) We arrive at the divisor because each tuple - * must be maxaligned, and it must have an associated item pointer. - * - * Note: with HOT, there could theoretically be more line pointers (not actual - * tuples) than this on a heap page. However we constrain the number of line - * pointers to this anyway, to avoid excessive line-pointer bloat and not - * require increases in the size of work arrays. - */ -#define MaxHeapTuplesPerPage \ - ((int) ((BLCKSZ - SizeOfPageHeaderData) / \ - (MAXALIGN(offsetof(HeapTupleHeaderData, t_bits)) + sizeof(ItemIdData)))) - -/* - * MaxAttrSize is a somewhat arbitrary upper limit on the declared size of - * data fields of char(n) and similar types. It need not have anything - * directly to do with the *actual* upper limit of varlena values, which - * is currently 1Gb (see TOAST structures in postgres.h). I've set it - * at 10Mb which seems like a reasonable number --- tgl 8/6/00. - */ -#define MaxAttrSize (10 * 1024 * 1024) - - -/* - * MinimalTuple is an alternative representation that is used for transient - * tuples inside the executor, in places where transaction status information - * is not required, the tuple rowtype is known, and shaving off a few bytes - * is worthwhile because we need to store many tuples. The representation - * is chosen so that tuple access routines can work with either full or - * minimal tuples via a HeapTupleData pointer structure. The access routines - * see no difference, except that they must not access the transaction status - * or t_ctid fields because those aren't there. - * - * For the most part, MinimalTuples should be accessed via TupleTableSlot - * routines. These routines will prevent access to the "system columns" - * and thereby prevent accidental use of the nonexistent fields. - * - * MinimalTupleData contains a length word, some padding, and fields matching - * HeapTupleHeaderData beginning with t_infomask2. The padding is chosen so - * that offsetof(t_infomask2) is the same modulo MAXIMUM_ALIGNOF in both - * structs. This makes data alignment rules equivalent in both cases. - * - * When a minimal tuple is accessed via a HeapTupleData pointer, t_data is - * set to point MINIMAL_TUPLE_OFFSET bytes before the actual start of the - * minimal tuple --- that is, where a full tuple matching the minimal tuple's - * data would start. This trick is what makes the structs seem equivalent. - * - * Note that t_hoff is computed the same as in a full tuple, hence it includes - * the MINIMAL_TUPLE_OFFSET distance. t_len does not include that, however. - * - * MINIMAL_TUPLE_DATA_OFFSET is the offset to the first useful (non-pad) data - * other than the length word. tuplesort.c and tuplestore.c use this to avoid - * writing the padding to disk. - */ -#define MINIMAL_TUPLE_OFFSET \ - ((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) / MAXIMUM_ALIGNOF * MAXIMUM_ALIGNOF) -#define MINIMAL_TUPLE_PADDING \ - ((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) % MAXIMUM_ALIGNOF) -#define MINIMAL_TUPLE_DATA_OFFSET \ - offsetof(MinimalTupleData, t_infomask2) - -typedef struct MinimalTupleData -{ - uint32 t_len; /* actual length of minimal tuple */ - - char mt_padding[MINIMAL_TUPLE_PADDING]; - - /* Fields below here must match HeapTupleHeaderData! */ - - uint16 t_infomask2; /* number of attributes + various flags */ - - uint16 t_infomask; /* various flag bits, see below */ - - uint8 t_hoff; /* sizeof header incl. bitmap, padding */ - - /* ^ - 23 bytes - ^ */ - - bits8 t_bits[1]; /* bitmap of NULLs -- VARIABLE LENGTH */ - - /* MORE DATA FOLLOWS AT END OF STRUCT */ -} MinimalTupleData; +typedef struct MinimalTupleData MinimalTupleData; typedef MinimalTupleData *MinimalTuple; @@ -527,56 +72,10 @@ typedef HeapTupleData *HeapTuple; #define HEAPTUPLESIZE MAXALIGN(sizeof(HeapTupleData)) /* - * GETSTRUCT - given a HeapTuple pointer, return address of the user data - */ -#define GETSTRUCT(TUP) ((char *) ((TUP)->t_data) + (TUP)->t_data->t_hoff) - -/* * Accessor macros to be used with HeapTuple pointers. */ #define HeapTupleIsValid(tuple) PointerIsValid(tuple) -#define HeapTupleHasNulls(tuple) \ - (((tuple)->t_data->t_infomask & HEAP_HASNULL) != 0) - -#define HeapTupleNoNulls(tuple) \ - (!((tuple)->t_data->t_infomask & HEAP_HASNULL)) - -#define HeapTupleHasVarWidth(tuple) \ - (((tuple)->t_data->t_infomask & HEAP_HASVARWIDTH) != 0) - -#define HeapTupleAllFixed(tuple) \ - (!((tuple)->t_data->t_infomask & HEAP_HASVARWIDTH)) - -#define HeapTupleHasExternal(tuple) \ - (((tuple)->t_data->t_infomask & HEAP_HASEXTERNAL) != 0) - -#define HeapTupleIsHotUpdated(tuple) \ - HeapTupleHeaderIsHotUpdated((tuple)->t_data) - -#define HeapTupleSetHotUpdated(tuple) \ - HeapTupleHeaderSetHotUpdated((tuple)->t_data) - -#define HeapTupleClearHotUpdated(tuple) \ - HeapTupleHeaderClearHotUpdated((tuple)->t_data) - -#define HeapTupleIsHeapOnly(tuple) \ - HeapTupleHeaderIsHeapOnly((tuple)->t_data) - -#define HeapTupleSetHeapOnly(tuple) \ - HeapTupleHeaderSetHeapOnly((tuple)->t_data) - -#define HeapTupleClearHeapOnly(tuple) \ - HeapTupleHeaderClearHeapOnly((tuple)->t_data) - -#define HeapTupleGetOid(tuple) \ - HeapTupleHeaderGetOid((tuple)->t_data) - -#define HeapTupleSetOid(tuple, oid) \ - HeapTupleHeaderSetOid((tuple)->t_data, (oid)) - - - /* HeapTupleHeader functions implemented in utils/time/combocid.c */ extern CommandId HeapTupleHeaderGetCmin(HeapTupleHeader tup); extern CommandId HeapTupleHeaderGetCmax(HeapTupleHeader tup); @@ -584,129 +83,4 @@ extern void HeapTupleHeaderAdjustCmax(HeapTupleHeader tup, CommandId *cmax, bool *iscombo); -/* ---------------- - * fastgetattr - * - * Fetch a user attribute's value as a Datum (might be either a - * value, or a pointer into the data area of the tuple). - * - * This must not be used when a system attribute might be requested. - * Furthermore, the passed attnum MUST be valid. Use heap_getattr() - * instead, if in doubt. - * - * This gets called many times, so we macro the cacheable and NULL - * lookups, and call nocachegetattr() for the rest. - * ---------------- - */ - -#if !defined(DISABLE_COMPLEX_MACRO) - -#define fastgetattr(tup, attnum, tupleDesc, isnull) \ -( \ - AssertMacro((attnum) > 0), \ - (*(isnull) = false), \ - HeapTupleNoNulls(tup) ? \ - ( \ - (tupleDesc)->attrs[(attnum)-1]->attcacheoff >= 0 ? \ - ( \ - fetchatt((tupleDesc)->attrs[(attnum)-1], \ - (char *) (tup)->t_data + (tup)->t_data->t_hoff + \ - (tupleDesc)->attrs[(attnum)-1]->attcacheoff) \ - ) \ - : \ - nocachegetattr((tup), (attnum), (tupleDesc)) \ - ) \ - : \ - ( \ - att_isnull((attnum)-1, (tup)->t_data->t_bits) ? \ - ( \ - (*(isnull) = true), \ - (Datum)NULL \ - ) \ - : \ - ( \ - nocachegetattr((tup), (attnum), (tupleDesc)) \ - ) \ - ) \ -) -#else /* defined(DISABLE_COMPLEX_MACRO) */ - -extern Datum fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, - bool *isnull); -#endif /* defined(DISABLE_COMPLEX_MACRO) */ - - -/* ---------------- - * heap_getattr - * - * Extract an attribute of a heap tuple and return it as a Datum. - * This works for either system or user attributes. The given attnum - * is properly range-checked. - * - * If the field in question has a NULL value, we return a zero Datum - * and set *isnull == true. Otherwise, we set *isnull == false. - * - * <tup> is the pointer to the heap tuple. <attnum> is the attribute - * number of the column (field) caller wants. <tupleDesc> is a - * pointer to the structure describing the row and all its fields. - * ---------------- - */ -#define heap_getattr(tup, attnum, tupleDesc, isnull) \ - ( \ - ((attnum) > 0) ? \ - ( \ - ((attnum) > (int) HeapTupleHeaderGetNatts((tup)->t_data)) ? \ - ( \ - (*(isnull) = true), \ - (Datum)NULL \ - ) \ - : \ - fastgetattr((tup), (attnum), (tupleDesc), (isnull)) \ - ) \ - : \ - heap_getsysattr((tup), (attnum), (tupleDesc), (isnull)) \ - ) - -/* prototypes for functions in common/heaptuple.c */ -extern Size heap_compute_data_size(TupleDesc tupleDesc, - Datum *values, bool *isnull); -extern void heap_fill_tuple(TupleDesc tupleDesc, - Datum *values, bool *isnull, - char *data, Size data_size, - uint16 *infomask, bits8 *bit); -extern bool heap_attisnull(HeapTuple tup, int attnum); -extern Datum nocachegetattr(HeapTuple tup, int attnum, - TupleDesc att); -extern Datum heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, - bool *isnull); -extern HeapTuple heap_copytuple(HeapTuple tuple); -extern void heap_copytuple_with_tuple(HeapTuple src, HeapTuple dest); -extern HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, - Datum *values, bool *isnull); -extern HeapTuple heap_modify_tuple(HeapTuple tuple, - TupleDesc tupleDesc, - Datum *replValues, - bool *replIsnull, - bool *doReplace); -extern void heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc, - Datum *values, bool *isnull); - -/* these three are deprecated versions of the three above: */ -extern HeapTuple heap_formtuple(TupleDesc tupleDescriptor, - Datum *values, char *nulls); -extern HeapTuple heap_modifytuple(HeapTuple tuple, - TupleDesc tupleDesc, - Datum *replValues, - char *replNulls, - char *replActions); -extern void heap_deformtuple(HeapTuple tuple, TupleDesc tupleDesc, - Datum *values, char *nulls); -extern void heap_freetuple(HeapTuple htup); -extern MinimalTuple heap_form_minimal_tuple(TupleDesc tupleDescriptor, - Datum *values, bool *isnull); -extern void heap_free_minimal_tuple(MinimalTuple mtup); -extern MinimalTuple heap_copy_minimal_tuple(MinimalTuple mtup); -extern HeapTuple heap_tuple_from_minimal_tuple(MinimalTuple mtup); -extern MinimalTuple minimal_tuple_from_heap_tuple(HeapTuple htup); - #endif /* HTUP_H */ |