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Data Structures | Macros | Typedefs | Functions
itup.h File Reference
#include "access/tupdesc.h"
#include "access/tupmacs.h"
#include "storage/bufpage.h"
#include "storage/itemptr.h"
Include dependency graph for itup.h:
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Data Structures

struct   IndexTupleData
 
struct   IndexAttributeBitMapData
 

Macros

#define  INDEX_SIZE_MASK   0x1FFF
 
#define  INDEX_AM_RESERVED_BIT
 
#define  INDEX_VAR_MASK   0x4000
 
#define  INDEX_NULL_MASK   0x8000
 
#define  MaxIndexTuplesPerPage
 

Typedefs

typedef struct IndexTupleData  IndexTupleData
 
typedef IndexTupleData *  IndexTuple
 
typedef struct IndexAttributeBitMapData  IndexAttributeBitMapData
 
typedef IndexAttributeBitMapData *  IndexAttributeBitMap
 

Functions

static Size  IndexTupleSize (const IndexTupleData *itup)
 
static bool  IndexTupleHasNulls (const IndexTupleData *itup)
 
static bool  IndexTupleHasVarwidths (const IndexTupleData *itup)
 
IndexTuple  index_form_tuple (TupleDesc tupleDescriptor, const Datum *values, const bool *isnull)
 
IndexTuple  index_form_tuple_context (TupleDesc tupleDescriptor, const Datum *values, const bool *isnull, MemoryContext context)
 
Datum  nocache_index_getattr (IndexTuple tup, int attnum, TupleDesc tupleDesc)
 
void  index_deform_tuple (IndexTuple tup, TupleDesc tupleDescriptor, Datum *values, bool *isnull)
 
void  index_deform_tuple_internal (TupleDesc tupleDescriptor, Datum *values, bool *isnull, char *tp, bits8 *bp, int hasnulls)
 
IndexTuple  CopyIndexTuple (IndexTuple source)
 
IndexTuple  index_truncate_tuple (TupleDesc sourceDescriptor, IndexTuple source, int leavenatts)
 
static Size  IndexInfoFindDataOffset (unsigned short t_info)
 
static Datum  index_getattr (IndexTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
 

Macro Definition Documentation

◆ INDEX_AM_RESERVED_BIT

#define INDEX_AM_RESERVED_BIT
Value:
0x2000 /* reserved for index-AM specific
* usage */

Definition at line 66 of file itup.h.

◆ INDEX_NULL_MASK

#define INDEX_NULL_MASK   0x8000

Definition at line 68 of file itup.h.

◆ INDEX_SIZE_MASK

#define INDEX_SIZE_MASK   0x1FFF

Definition at line 65 of file itup.h.

◆ INDEX_VAR_MASK

#define INDEX_VAR_MASK   0x4000

Definition at line 67 of file itup.h.

◆ MaxIndexTuplesPerPage

#define MaxIndexTuplesPerPage
Value:
((int) ((BLCKSZ - SizeOfPageHeaderData) / \
(MAXALIGN(sizeof(IndexTupleData) + 1) + sizeof(ItemIdData))))
#define SizeOfPageHeaderData
Definition: bufpage.h:217
#define MAXALIGN(LEN)
Definition: c.h:810
struct ItemIdData ItemIdData

Definition at line 181 of file itup.h.

Typedef Documentation

◆ IndexAttributeBitMap

typedef IndexAttributeBitMapData* IndexAttributeBitMap

Definition at line 60 of file itup.h.

◆ IndexAttributeBitMapData

typedef struct IndexAttributeBitMapData IndexAttributeBitMapData

◆ IndexTuple

typedef IndexTupleData* IndexTuple

Definition at line 53 of file itup.h.

◆ IndexTupleData

typedef struct IndexTupleData IndexTupleData

Function Documentation

◆ CopyIndexTuple()

IndexTuple CopyIndexTuple ( IndexTuple  source )

Definition at line 547 of file indextuple.c.

548{
549 IndexTuple result;
550 Size size;
551
552 size = IndexTupleSize(source);
553 result = (IndexTuple) palloc(size);
554 memcpy(result, source, size);
555 return result;
556}
size_t Size
Definition: c.h:610
IndexTupleData * IndexTuple
Definition: itup.h:53
static Size IndexTupleSize(const IndexTupleData *itup)
Definition: itup.h:71
void * palloc(Size size)
Definition: mcxt.c:1365
static rewind_source * source
Definition: pg_rewind.c:89

References IndexTupleSize(), palloc(), and source.

Referenced by _bt_buildadd(), _bt_insert_parent(), _bt_insertonpg(), _bt_load(), _bt_newlevel(), _bt_pagedel(), _bt_swap_posting(), _hash_splitbucket(), _hash_squeezebucket(), btree_xlog_insert(), btree_xlog_split(), gin_check_parent_keys_consistency(), gin_refind_parent(), gistformdownlink(), and index_truncate_tuple().

◆ index_deform_tuple()

void index_deform_tuple ( IndexTuple  tup,
TupleDesc  tupleDescriptor,
Datum *  values,
bool *  isnull 
)

Definition at line 456 of file indextuple.c.

458{
459 char *tp; /* ptr to tuple data */
460 bits8 *bp; /* ptr to null bitmap in tuple */
461
462 /* XXX "knows" t_bits are just after fixed tuple header! */
463 bp = (bits8 *) ((char *) tup + sizeof(IndexTupleData));
464
465 tp = (char *) tup + IndexInfoFindDataOffset(tup->t_info);
466
467 index_deform_tuple_internal(tupleDescriptor, values, isnull,
468 tp, bp, IndexTupleHasNulls(tup));
469}
static Datum values[MAXATTR]
Definition: bootstrap.c:153
uint8 bits8
Definition: c.h:545
void index_deform_tuple_internal(TupleDesc tupleDescriptor, Datum *values, bool *isnull, char *tp, bits8 *bp, int hasnulls)
Definition: indextuple.c:479
static bool IndexTupleHasNulls(const IndexTupleData *itup)
Definition: itup.h:77
struct IndexTupleData IndexTupleData
static Size IndexInfoFindDataOffset(unsigned short t_info)
Definition: itup.h:112
unsigned short t_info
Definition: itup.h:49

References index_deform_tuple_internal(), IndexInfoFindDataOffset(), IndexTupleHasNulls(), IndexTupleData::t_info, and values.

Referenced by _bt_check_unique(), comparetup_index_btree_tiebreak(), get_actual_variable_endpoint(), gist_page_items(), index_truncate_tuple(), and StoreIndexTuple().

◆ index_deform_tuple_internal()

void index_deform_tuple_internal ( TupleDesc  tupleDescriptor,
Datum *  values,
bool *  isnull,
char *  tp,
bits8 *  bp,
int  hasnulls 
)

Definition at line 479 of file indextuple.c.

482{
483 int natts = tupleDescriptor->natts; /* number of atts to extract */
484 int attnum;
485 int off = 0; /* offset in tuple data */
486 bool slow = false; /* can we use/set attcacheoff? */
487
488 /* Assert to protect callers who allocate fixed-size arrays */
489 Assert(natts <= INDEX_MAX_KEYS);
490
491 for (attnum = 0; attnum < natts; attnum++)
492 {
493 CompactAttribute *thisatt = TupleDescCompactAttr(tupleDescriptor, attnum);
494
495 if (hasnulls && att_isnull(attnum, bp))
496 {
497 values[attnum] = (Datum) 0;
498 isnull[attnum] = true;
499 slow = true; /* can't use attcacheoff anymore */
500 continue;
501 }
502
503 isnull[attnum] = false;
504
505 if (!slow && thisatt->attcacheoff >= 0)
506 off = thisatt->attcacheoff;
507 else if (thisatt->attlen == -1)
508 {
509 /*
510 * We can only cache the offset for a varlena attribute if the
511 * offset is already suitably aligned, so that there would be no
512 * pad bytes in any case: then the offset will be valid for either
513 * an aligned or unaligned value.
514 */
515 if (!slow &&
516 off == att_nominal_alignby(off, thisatt->attalignby))
517 thisatt->attcacheoff = off;
518 else
519 {
520 off = att_pointer_alignby(off, thisatt->attalignby, -1,
521 tp + off);
522 slow = true;
523 }
524 }
525 else
526 {
527 /* not varlena, so safe to use att_nominal_alignby */
528 off = att_nominal_alignby(off, thisatt->attalignby);
529
530 if (!slow)
531 thisatt->attcacheoff = off;
532 }
533
534 values[attnum] = fetchatt(thisatt, tp + off);
535
536 off = att_addlength_pointer(off, thisatt->attlen, tp + off);
537
538 if (thisatt->attlen <= 0)
539 slow = true; /* can't use attcacheoff anymore */
540 }
541}
Assert(PointerIsAligned(start, uint64))
int16 attnum
Definition: pg_attribute.h:74
#define INDEX_MAX_KEYS
uint64_t Datum
Definition: postgres.h:70
uint8 attalignby
Definition: tupdesc.h:80
int16 attlen
Definition: tupdesc.h:71
int32 attcacheoff
Definition: tupdesc.h:70
int natts
Definition: tupdesc.h:137
static CompactAttribute * TupleDescCompactAttr(TupleDesc tupdesc, int i)
Definition: tupdesc.h:175
#define att_nominal_alignby(cur_offset, attalignby)
Definition: tupmacs.h:160
static bool att_isnull(int ATT, const bits8 *BITS)
Definition: tupmacs.h:26
#define att_addlength_pointer(cur_offset, attlen, attptr)
Definition: tupmacs.h:180
#define att_pointer_alignby(cur_offset, attalignby, attlen, attptr)
Definition: tupmacs.h:124
#define fetchatt(A, T)
Definition: tupmacs.h:44

References Assert(), att_addlength_pointer, att_isnull(), att_nominal_alignby, att_pointer_alignby, CompactAttribute::attalignby, CompactAttribute::attcacheoff, CompactAttribute::attlen, attnum, fetchatt, INDEX_MAX_KEYS, TupleDescData::natts, TupleDescCompactAttr(), and values.

Referenced by index_deform_tuple(), and spgDeformLeafTuple().

◆ index_form_tuple()

IndexTuple index_form_tuple ( TupleDesc  tupleDescriptor,
const Datum *  values,
const bool *  isnull 
)

Definition at line 44 of file indextuple.c.

47{
48 return index_form_tuple_context(tupleDescriptor, values, isnull,
50}
IndexTuple index_form_tuple_context(TupleDesc tupleDescriptor, const Datum *values, const bool *isnull, MemoryContext context)
Definition: indextuple.c:65
MemoryContext CurrentMemoryContext
Definition: mcxt.c:160

References CurrentMemoryContext, index_form_tuple_context(), and values.

Referenced by bt_normalize_tuple(), bt_tuple_present_callback(), btinsert(), GinFormTuple(), gistFormTuple(), hashbuildCallback(), hashinsert(), and index_truncate_tuple().

◆ index_form_tuple_context()

IndexTuple index_form_tuple_context ( TupleDesc  tupleDescriptor,
const Datum *  values,
const bool *  isnull,
MemoryContext  context 
)

Definition at line 65 of file indextuple.c.

69{
70 char *tp; /* tuple pointer */
71 IndexTuple tuple; /* return tuple */
72 Size size,
73 data_size,
74 hoff;
75 int i;
76 unsigned short infomask = 0;
77 bool hasnull = false;
78 uint16 tupmask = 0;
79 int numberOfAttributes = tupleDescriptor->natts;
80
81#ifdef TOAST_INDEX_HACK
82 Datum untoasted_values[INDEX_MAX_KEYS] = {0};
83 bool untoasted_free[INDEX_MAX_KEYS] = {0};
84#endif
85
86 if (numberOfAttributes > INDEX_MAX_KEYS)
88 (errcode(ERRCODE_TOO_MANY_COLUMNS),
89 errmsg("number of index columns (%d) exceeds limit (%d)",
90 numberOfAttributes, INDEX_MAX_KEYS)));
91
92#ifdef TOAST_INDEX_HACK
93 for (i = 0; i < numberOfAttributes; i++)
94 {
95 Form_pg_attribute att = TupleDescAttr(tupleDescriptor, i);
96
97 untoasted_values[i] = values[i];
98 untoasted_free[i] = false;
99
100 /* Do nothing if value is NULL or not of varlena type */
101 if (isnull[i] || att->attlen != -1)
102 continue;
103
104 /*
105 * If value is stored EXTERNAL, must fetch it so we are not depending
106 * on outside storage. This should be improved someday.
107 */
109 {
110 untoasted_values[i] =
113 untoasted_free[i] = true;
114 }
115
116 /*
117 * If value is above size target, and is of a compressible datatype,
118 * try to compress it in-line.
119 */
120 if (!VARATT_IS_EXTENDED(DatumGetPointer(untoasted_values[i])) &&
121 VARSIZE(DatumGetPointer(untoasted_values[i])) > TOAST_INDEX_TARGET &&
122 (att->attstorage == TYPSTORAGE_EXTENDED ||
123 att->attstorage == TYPSTORAGE_MAIN))
124 {
125 Datum cvalue;
126
127 cvalue = toast_compress_datum(untoasted_values[i],
128 att->attcompression);
129
130 if (DatumGetPointer(cvalue) != NULL)
131 {
132 /* successful compression */
133 if (untoasted_free[i])
134 pfree(DatumGetPointer(untoasted_values[i]));
135 untoasted_values[i] = cvalue;
136 untoasted_free[i] = true;
137 }
138 }
139 }
140#endif
141
142 for (i = 0; i < numberOfAttributes; i++)
143 {
144 if (isnull[i])
145 {
146 hasnull = true;
147 break;
148 }
149 }
150
151 if (hasnull)
152 infomask |= INDEX_NULL_MASK;
153
154 hoff = IndexInfoFindDataOffset(infomask);
155#ifdef TOAST_INDEX_HACK
156 data_size = heap_compute_data_size(tupleDescriptor,
157 untoasted_values, isnull);
158#else
159 data_size = heap_compute_data_size(tupleDescriptor,
160 values, isnull);
161#endif
162 size = hoff + data_size;
163 size = MAXALIGN(size); /* be conservative */
164
165 tp = (char *) MemoryContextAllocZero(context, size);
166 tuple = (IndexTuple) tp;
167
168 heap_fill_tuple(tupleDescriptor,
169#ifdef TOAST_INDEX_HACK
170 untoasted_values,
171#else
172 values,
173#endif
174 isnull,
175 (char *) tp + hoff,
176 data_size,
177 &tupmask,
178 (hasnull ? (bits8 *) tp + sizeof(IndexTupleData) : NULL));
179
180#ifdef TOAST_INDEX_HACK
181 for (i = 0; i < numberOfAttributes; i++)
182 {
183 if (untoasted_free[i])
184 pfree(DatumGetPointer(untoasted_values[i]));
185 }
186#endif
187
188 /*
189 * We do this because heap_fill_tuple wants to initialize a "tupmask"
190 * which is used for HeapTuples, but we want an indextuple infomask. The
191 * only relevant info is the "has variable attributes" field. We have
192 * already set the hasnull bit above.
193 */
194 if (tupmask & HEAP_HASVARWIDTH)
195 infomask |= INDEX_VAR_MASK;
196
197 /* Also assert we got rid of external attributes */
198#ifdef TOAST_INDEX_HACK
199 Assert((tupmask & HEAP_HASEXTERNAL) == 0);
200#endif
201
202 /*
203 * Here we make sure that the size will fit in the field reserved for it
204 * in t_info.
205 */
206 if ((size & INDEX_SIZE_MASK) != size)
208 (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
209 errmsg("index row requires %zu bytes, maximum size is %zu",
210 size, (Size) INDEX_SIZE_MASK)));
211
212 infomask |= size;
213
214 /*
215 * initialize metadata
216 */
217 tuple->t_info = infomask;
218 return tuple;
219}
uint16_t uint16
Definition: c.h:537
struct varlena * detoast_external_attr(struct varlena *attr)
Definition: detoast.c:45
int errcode(int sqlerrcode)
Definition: elog.c:854
int errmsg(const char *fmt,...)
Definition: elog.c:1071
#define ERROR
Definition: elog.h:39
#define ereport(elevel,...)
Definition: elog.h:150
#define TOAST_INDEX_TARGET
Definition: heaptoast.h:68
Size heap_compute_data_size(TupleDesc tupleDesc, const Datum *values, const bool *isnull)
Definition: heaptuple.c:219
void heap_fill_tuple(TupleDesc tupleDesc, const Datum *values, const bool *isnull, char *data, Size data_size, uint16 *infomask, bits8 *bit)
Definition: heaptuple.c:401
#define HEAP_HASVARWIDTH
Definition: htup_details.h:191
#define HEAP_HASEXTERNAL
Definition: htup_details.h:192
#define TOAST_INDEX_HACK
Definition: indextuple.c:29
i
int i
Definition: isn.c:77
#define INDEX_VAR_MASK
Definition: itup.h:67
#define INDEX_NULL_MASK
Definition: itup.h:68
#define INDEX_SIZE_MASK
Definition: itup.h:65
void * MemoryContextAllocZero(MemoryContext context, Size size)
Definition: mcxt.c:1263
void pfree(void *pointer)
Definition: mcxt.c:1594
FormData_pg_attribute * Form_pg_attribute
Definition: pg_attribute.h:202
static Datum PointerGetDatum(const void *X)
Definition: postgres.h:332
static Pointer DatumGetPointer(Datum X)
Definition: postgres.h:322
Definition: c.h:692
Datum toast_compress_datum(Datum value, char cmethod)
static FormData_pg_attribute * TupleDescAttr(TupleDesc tupdesc, int i)
Definition: tupdesc.h:160
static bool VARATT_IS_EXTENDED(const void *PTR)
Definition: varatt.h:410
static bool VARATT_IS_EXTERNAL(const void *PTR)
Definition: varatt.h:354
static Size VARSIZE(const void *PTR)
Definition: varatt.h:298

References Assert(), DatumGetPointer(), detoast_external_attr(), ereport, errcode(), errmsg(), ERROR, heap_compute_data_size(), heap_fill_tuple(), HEAP_HASEXTERNAL, HEAP_HASVARWIDTH, i, INDEX_MAX_KEYS, INDEX_NULL_MASK, INDEX_SIZE_MASK, INDEX_VAR_MASK, IndexInfoFindDataOffset(), MAXALIGN, MemoryContextAllocZero(), TupleDescData::natts, pfree(), PointerGetDatum(), IndexTupleData::t_info, toast_compress_datum(), TOAST_INDEX_HACK, TOAST_INDEX_TARGET, TupleDescAttr(), values, VARATT_IS_EXTENDED(), VARATT_IS_EXTERNAL(), and VARSIZE().

Referenced by index_form_tuple(), and tuplesort_putindextuplevalues().

◆ index_getattr()

static Datum index_getattr ( IndexTuple  tup,
int  attnum,
TupleDesc  tupleDesc,
bool *  isnull 
)
inlinestatic

Definition at line 131 of file itup.h.

133{
134 Assert(isnull);
135 Assert(attnum > 0);
136
137 *isnull = false;
138
139 if (!IndexTupleHasNulls(tup))
140 {
141 CompactAttribute *attr = TupleDescCompactAttr(tupleDesc, attnum - 1);
142
143 if (attr->attcacheoff >= 0)
144 {
145 return fetchatt(attr,
146 (char *) tup + IndexInfoFindDataOffset(tup->t_info) +
147 attr->attcacheoff);
148 }
149 else
150 return nocache_index_getattr(tup, attnum, tupleDesc);
151 }
152 else
153 {
154 if (att_isnull(attnum - 1, (bits8 *) tup + sizeof(IndexTupleData)))
155 {
156 *isnull = true;
157 return (Datum) 0;
158 }
159 else
160 return nocache_index_getattr(tup, attnum, tupleDesc);
161 }
Datum nocache_index_getattr(IndexTuple tup, int attnum, TupleDesc tupleDesc)
Definition: indextuple.c:241

References Assert(), att_isnull(), CompactAttribute::attcacheoff, attnum, fetchatt, IndexInfoFindDataOffset(), IndexTupleHasNulls(), nocache_index_getattr(), IndexTupleData::t_info, and TupleDescCompactAttr().

Referenced by _bt_advance_array_keys(), _bt_check_compare(), _bt_check_rowcompare(), _bt_compare(), _bt_keep_natts(), _bt_keep_natts_fast(), _bt_load(), _bt_mkscankey(), _bt_set_startikey(), _bt_tuple_before_array_skeys(), _hash_checkqual(), bt_normalize_tuple(), comparetup_index_btree_tiebreak(), gintuple_get_attrnum(), gintuple_get_key(), gistchoose(), gistDeCompressAtt(), gistFetchTuple(), gistindex_keytest(), gistMakeUnionItVec(), gistSplitByKey(), readtup_index(), removeabbrev_index(), and tuplesort_putindextuplevalues().

◆ index_truncate_tuple()

IndexTuple index_truncate_tuple ( TupleDesc  sourceDescriptor,
IndexTuple  source,
int  leavenatts 
)

Definition at line 576 of file indextuple.c.

578{
579 TupleDesc truncdesc;
581 bool isnull[INDEX_MAX_KEYS];
582 IndexTuple truncated;
583
584 Assert(leavenatts <= sourceDescriptor->natts);
585
586 /* Easy case: no truncation actually required */
587 if (leavenatts == sourceDescriptor->natts)
588 return CopyIndexTuple(source);
589
590 /* Create temporary truncated tuple descriptor */
591 truncdesc = CreateTupleDescTruncatedCopy(sourceDescriptor, leavenatts);
592
593 /* Deform, form copy of tuple with fewer attributes */
594 index_deform_tuple(source, truncdesc, values, isnull);
595 truncated = index_form_tuple(truncdesc, values, isnull);
596 truncated->t_tid = source->t_tid;
598
599 /*
600 * Cannot leak memory here, TupleDescCopy() doesn't allocate any inner
601 * structure, so, plain pfree() should clean all allocated memory
602 */
603 pfree(truncdesc);
604
605 return truncated;
606}
void index_deform_tuple(IndexTuple tup, TupleDesc tupleDescriptor, Datum *values, bool *isnull)
Definition: indextuple.c:456
IndexTuple CopyIndexTuple(IndexTuple source)
Definition: indextuple.c:547
IndexTuple index_form_tuple(TupleDesc tupleDescriptor, const Datum *values, const bool *isnull)
Definition: indextuple.c:44
ItemPointerData t_tid
Definition: itup.h:37
TupleDesc CreateTupleDescTruncatedCopy(TupleDesc tupdesc, int natts)
Definition: tupdesc.c:296

References Assert(), CopyIndexTuple(), CreateTupleDescTruncatedCopy(), index_deform_tuple(), index_form_tuple(), INDEX_MAX_KEYS, IndexTupleSize(), TupleDescData::natts, pfree(), source, IndexTupleData::t_tid, and values.

Referenced by _bt_truncate().

◆ IndexInfoFindDataOffset()

static Size IndexInfoFindDataOffset ( unsigned short  t_info )
inlinestatic

Definition at line 112 of file itup.h.

114{
115 if (!(t_info & INDEX_NULL_MASK))
116 return MAXALIGN(sizeof(IndexTupleData));
117 else
118 return MAXALIGN(sizeof(IndexTupleData) + sizeof(IndexAttributeBitMapData));

References INDEX_NULL_MASK, and MAXALIGN.

Referenced by _hash_get_indextuple_hashkey(), bt_page_print_tuples(), index_deform_tuple(), index_form_tuple_context(), index_getattr(), and nocache_index_getattr().

◆ IndexTupleHasNulls()

static bool IndexTupleHasNulls ( const IndexTupleData *  itup )
inlinestatic

Definition at line 77 of file itup.h.

79{
80 return itup->t_info & INDEX_NULL_MASK;

References INDEX_NULL_MASK, and IndexTupleData::t_info.

Referenced by bt_page_print_tuples(), GinFormTuple(), index_deform_tuple(), index_getattr(), nocache_index_getattr(), and spgExtractNodeLabels().

◆ IndexTupleHasVarwidths()

static bool IndexTupleHasVarwidths ( const IndexTupleData *  itup )
inlinestatic

Definition at line 83 of file itup.h.

85{
86 return itup->t_info & INDEX_VAR_MASK;

References INDEX_VAR_MASK, and IndexTupleData::t_info.

Referenced by bt_normalize_tuple(), bt_page_print_tuples(), and nocache_index_getattr().

◆ IndexTupleSize()

static Size IndexTupleSize ( const IndexTupleData *  itup )
inlinestatic

Definition at line 71 of file itup.h.

73{
74 return (itup->t_info & INDEX_SIZE_MASK);

References INDEX_SIZE_MASK, and IndexTupleData::t_info.

Referenced by _bt_buildadd(), _bt_check_third_page(), _bt_dedup_finish_pending(), _bt_dedup_save_htid(), _bt_dedup_start_pending(), _bt_delitems_delete(), _bt_delitems_vacuum(), _bt_doinsert(), _bt_form_posting(), _bt_insert_parent(), _bt_insertonpg(), _bt_mark_page_halfdead(), _bt_recsplitloc(), _bt_restore_page(), _bt_saveitem(), _bt_sort_dedup_finish_pending(), _bt_split(), _bt_truncate(), _hash_doinsert(), _hash_pgaddmultitup(), _hash_splitbucket(), _hash_squeezebucket(), bt_check_level_from_leftmost(), bt_page_print_tuples(), bt_pivot_tuple_identical(), bt_rootdescend(), bt_target_page_check(), bt_tuple_present_callback(), btree_xlog_insert(), btree_xlog_split(), btree_xlog_updates(), BTreeTupleGetHeapTID(), CopyIndexTuple(), decodePageSplitRecord(), entryExecPlaceToPage(), entryIsEnoughSpace(), entrySplitPage(), GetBTPageStatistics(), gin_check_parent_keys_consistency(), ginEntryFillRoot(), GinFormInteriorTuple(), GinFormTuple(), ginHeapTupleFastCollect(), ginHeapTupleFastInsert(), ginRedoInsertEntry(), ginRedoInsertListPage(), ginRedoUpdateMetapage(), ginVacuumEntryPage(), gist_indexsortbuild_levelstate_add(), gist_indexsortbuild_levelstate_flush(), gist_page_items(), gist_page_items_bytea(), gistBuildCallback(), gistfillbuffer(), gistfillitupvec(), gistfitpage(), gistGetItupFromPage(), gistnospace(), gistPlaceItupToPage(), gistplacetopage(), gistRedoPageUpdateRecord(), gistSplit(), gistXLogUpdate(), hash_xlog_move_page_contents(), hash_xlog_squeeze_page(), index_truncate_tuple(), makeSublist(), spgFormInnerTuple(), writeListPage(), and writetup_index().

◆ nocache_index_getattr()

Datum nocache_index_getattr ( IndexTuple  tup,
int  attnum,
TupleDesc  tupleDesc 
)

Definition at line 241 of file indextuple.c.

244{
245 char *tp; /* ptr to data part of tuple */
246 bits8 *bp = NULL; /* ptr to null bitmap in tuple */
247 bool slow = false; /* do we have to walk attrs? */
248 int data_off; /* tuple data offset */
249 int off; /* current offset within data */
250
251 /* ----------------
252 * Three cases:
253 *
254 * 1: No nulls and no variable-width attributes.
255 * 2: Has a null or a var-width AFTER att.
256 * 3: Has nulls or var-widths BEFORE att.
257 * ----------------
258 */
259
260 data_off = IndexInfoFindDataOffset(tup->t_info);
261
262 attnum--;
263
264 if (IndexTupleHasNulls(tup))
265 {
266 /*
267 * there's a null somewhere in the tuple
268 *
269 * check to see if desired att is null
270 */
271
272 /* XXX "knows" t_bits are just after fixed tuple header! */
273 bp = (bits8 *) ((char *) tup + sizeof(IndexTupleData));
274
275 /*
276 * Now check to see if any preceding bits are null...
277 */
278 {
279 int byte = attnum >> 3;
280 int finalbit = attnum & 0x07;
281
282 /* check for nulls "before" final bit of last byte */
283 if ((~bp[byte]) & ((1 << finalbit) - 1))
284 slow = true;
285 else
286 {
287 /* check for nulls in any "earlier" bytes */
288 int i;
289
290 for (i = 0; i < byte; i++)
291 {
292 if (bp[i] != 0xFF)
293 {
294 slow = true;
295 break;
296 }
297 }
298 }
299 }
300 }
301
302 tp = (char *) tup + data_off;
303
304 if (!slow)
305 {
306 CompactAttribute *att;
307
308 /*
309 * If we get here, there are no nulls up to and including the target
310 * attribute. If we have a cached offset, we can use it.
311 */
312 att = TupleDescCompactAttr(tupleDesc, attnum);
313 if (att->attcacheoff >= 0)
314 return fetchatt(att, tp + att->attcacheoff);
315
316 /*
317 * Otherwise, check for non-fixed-length attrs up to and including
318 * target. If there aren't any, it's safe to cheaply initialize the
319 * cached offsets for these attrs.
320 */
321 if (IndexTupleHasVarwidths(tup))
322 {
323 int j;
324
325 for (j = 0; j <= attnum; j++)
326 {
327 if (TupleDescCompactAttr(tupleDesc, j)->attlen <= 0)
328 {
329 slow = true;
330 break;
331 }
332 }
333 }
334 }
335
336 if (!slow)
337 {
338 int natts = tupleDesc->natts;
339 int j = 1;
340
341 /*
342 * If we get here, we have a tuple with no nulls or var-widths up to
343 * and including the target attribute, so we can use the cached offset
344 * ... only we don't have it yet, or we'd not have got here. Since
345 * it's cheap to compute offsets for fixed-width columns, we take the
346 * opportunity to initialize the cached offsets for *all* the leading
347 * fixed-width columns, in hope of avoiding future visits to this
348 * routine.
349 */
350 TupleDescCompactAttr(tupleDesc, 0)->attcacheoff = 0;
351
352 /* we might have set some offsets in the slow path previously */
353 while (j < natts && TupleDescCompactAttr(tupleDesc, j)->attcacheoff > 0)
354 j++;
355
356 off = TupleDescCompactAttr(tupleDesc, j - 1)->attcacheoff +
357 TupleDescCompactAttr(tupleDesc, j - 1)->attlen;
358
359 for (; j < natts; j++)
360 {
361 CompactAttribute *att = TupleDescCompactAttr(tupleDesc, j);
362
363 if (att->attlen <= 0)
364 break;
365
366 off = att_nominal_alignby(off, att->attalignby);
367
368 att->attcacheoff = off;
369
370 off += att->attlen;
371 }
372
373 Assert(j > attnum);
374
375 off = TupleDescCompactAttr(tupleDesc, attnum)->attcacheoff;
376 }
377 else
378 {
379 bool usecache = true;
380 int i;
381
382 /*
383 * Now we know that we have to walk the tuple CAREFULLY. But we still
384 * might be able to cache some offsets for next time.
385 *
386 * Note - This loop is a little tricky. For each non-null attribute,
387 * we have to first account for alignment padding before the attr,
388 * then advance over the attr based on its length. Nulls have no
389 * storage and no alignment padding either. We can use/set
390 * attcacheoff until we reach either a null or a var-width attribute.
391 */
392 off = 0;
393 for (i = 0;; i++) /* loop exit is at "break" */
394 {
395 CompactAttribute *att = TupleDescCompactAttr(tupleDesc, i);
396
397 if (IndexTupleHasNulls(tup) && att_isnull(i, bp))
398 {
399 usecache = false;
400 continue; /* this cannot be the target att */
401 }
402
403 /* If we know the next offset, we can skip the rest */
404 if (usecache && att->attcacheoff >= 0)
405 off = att->attcacheoff;
406 else if (att->attlen == -1)
407 {
408 /*
409 * We can only cache the offset for a varlena attribute if the
410 * offset is already suitably aligned, so that there would be
411 * no pad bytes in any case: then the offset will be valid for
412 * either an aligned or unaligned value.
413 */
414 if (usecache &&
415 off == att_nominal_alignby(off, att->attalignby))
416 att->attcacheoff = off;
417 else
418 {
419 off = att_pointer_alignby(off, att->attalignby, -1,
420 tp + off);
421 usecache = false;
422 }
423 }
424 else
425 {
426 /* not varlena, so safe to use att_nominal_alignby */
427 off = att_nominal_alignby(off, att->attalignby);
428
429 if (usecache)
430 att->attcacheoff = off;
431 }
432
433 if (i == attnum)
434 break;
435
436 off = att_addlength_pointer(off, att->attlen, tp + off);
437
438 if (usecache && att->attlen <= 0)
439 usecache = false;
440 }
441 }
442
443 return fetchatt(TupleDescCompactAttr(tupleDesc, attnum), tp + off);
444}
j
int j
Definition: isn.c:78
static bool IndexTupleHasVarwidths(const IndexTupleData *itup)
Definition: itup.h:83
int16 attlen
Definition: pg_attribute.h:59

References Assert(), att_addlength_pointer, att_isnull(), att_nominal_alignby, att_pointer_alignby, CompactAttribute::attalignby, CompactAttribute::attcacheoff, CompactAttribute::attlen, attlen, attnum, fetchatt, i, IndexInfoFindDataOffset(), IndexTupleHasNulls(), IndexTupleHasVarwidths(), j, TupleDescData::natts, IndexTupleData::t_info, and TupleDescCompactAttr().

Referenced by index_getattr().

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