Move generic slot support functions from heaptuple.c into execTuples.c.

heaptuple.c was never a particular good fit for slot_getattr(),
slot_getsomeattrs() and slot_getmissingattrs(), but in upcoming
changes slots will be made more abstract (allowing slots that contain
different types of tuples), making it clearly the wrong place.

Note that slot_deform_tuple() remains in it's current place, as it
clearly deals with a HeapTuple.  getmissingattrs() also remains, but
it's less clear that that's correct - but execTuples.c wouldn't be the
right place.

Author: Ashutosh Bapat.
Discussion: https://postgr.es/m/20180220224318.gw4oe5jadhpmcdnm@alap3.anarazel.de
This commit is contained in:
Andres Freund 2018-10-14 15:18:16 -07:00
parent e73ca79fc7
commit 9d906f1119
4 changed files with 201 additions and 189 deletions

View File

@ -80,7 +80,7 @@
/*
* Return the missing value of an attribute, or NULL if there isn't one.
*/
static Datum
Datum
getmissingattr(TupleDesc tupleDesc,
int attnum, bool *isnull)
{
@ -111,43 +111,6 @@ getmissingattr(TupleDesc tupleDesc,
return PointerGetDatum(NULL);
}
/*
* Fill in missing values for a TupleTableSlot.
*
* This is only exposed because it's needed for JIT compiled tuple
* deforming. That exception aside, there should be no callers outside of this
* file.
*/
void
slot_getmissingattrs(TupleTableSlot *slot, int startAttNum, int lastAttNum)
{
AttrMissing *attrmiss = NULL;
int missattnum;
if (slot->tts_tupleDescriptor->constr)
attrmiss = slot->tts_tupleDescriptor->constr->missing;
if (!attrmiss)
{
/* no missing values array at all, so just fill everything in as NULL */
memset(slot->tts_values + startAttNum, 0,
(lastAttNum - startAttNum) * sizeof(Datum));
memset(slot->tts_isnull + startAttNum, 1,
(lastAttNum - startAttNum) * sizeof(bool));
}
else
{
/* if there is a missing values array we must process them one by one */
for (missattnum = startAttNum;
missattnum < lastAttNum;
missattnum++)
{
slot->tts_values[missattnum] = attrmiss[missattnum].am_value;
slot->tts_isnull[missattnum] = !attrmiss[missattnum].am_present;
}
}
}
/*
* heap_compute_data_size
* Determine size of the data area of a tuple to be constructed
@ -1398,7 +1361,7 @@ heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
* re-computing information about previously extracted attributes.
* slot->tts_nvalid is the number of attributes already extracted.
*/
static void
void
slot_deform_tuple(TupleTableSlot *slot, int natts)
{
HeapTuple tuple = slot->tts_tuple;
@ -1492,153 +1455,6 @@ slot_deform_tuple(TupleTableSlot *slot, int natts)
slot->tts_slow = slow;
}
/*
* slot_getattr
* This function fetches an attribute of the slot's current tuple.
* It is functionally equivalent to heap_getattr, but fetches of
* multiple attributes of the same tuple will be optimized better,
* because we avoid O(N^2) behavior from multiple calls of
* nocachegetattr(), even when attcacheoff isn't usable.
*
* A difference from raw heap_getattr is that attnums beyond the
* slot's tupdesc's last attribute will be considered NULL even
* when the physical tuple is longer than the tupdesc.
*/
Datum
slot_getattr(TupleTableSlot *slot, int attnum, bool *isnull)
{
HeapTuple tuple = slot->tts_tuple;
TupleDesc tupleDesc = slot->tts_tupleDescriptor;
HeapTupleHeader tup;
/*
* system attributes are handled by heap_getsysattr
*/
if (attnum <= 0)
{
if (tuple == NULL) /* internal error */
elog(ERROR, "cannot extract system attribute from virtual tuple");
if (tuple == &(slot->tts_minhdr)) /* internal error */
elog(ERROR, "cannot extract system attribute from minimal tuple");
return heap_getsysattr(tuple, attnum, tupleDesc, isnull);
}
/*
* fast path if desired attribute already cached
*/
if (attnum <= slot->tts_nvalid)
{
*isnull = slot->tts_isnull[attnum - 1];
return slot->tts_values[attnum - 1];
}
/*
* return NULL if attnum is out of range according to the tupdesc
*/
if (attnum > tupleDesc->natts)
{
*isnull = true;
return (Datum) 0;
}
/*
* otherwise we had better have a physical tuple (tts_nvalid should equal
* natts in all virtual-tuple cases)
*/
if (tuple == NULL) /* internal error */
elog(ERROR, "cannot extract attribute from empty tuple slot");
/*
* return NULL or missing value if attnum is out of range according to the
* tuple
*
* (We have to check this separately because of various inheritance and
* table-alteration scenarios: the tuple could be either longer or shorter
* than the tupdesc.)
*/
tup = tuple->t_data;
if (attnum > HeapTupleHeaderGetNatts(tup))
return getmissingattr(slot->tts_tupleDescriptor, attnum, isnull);
/*
* check if target attribute is null: no point in groveling through tuple
*/
if (HeapTupleHasNulls(tuple) && att_isnull(attnum - 1, tup->t_bits))
{
*isnull = true;
return (Datum) 0;
}
/*
* If the attribute's column has been dropped, we force a NULL result.
* This case should not happen in normal use, but it could happen if we
* are executing a plan cached before the column was dropped.
*/
if (TupleDescAttr(tupleDesc, attnum - 1)->attisdropped)
{
*isnull = true;
return (Datum) 0;
}
/*
* Extract the attribute, along with any preceding attributes.
*/
slot_deform_tuple(slot, attnum);
/*
* The result is acquired from tts_values array.
*/
*isnull = slot->tts_isnull[attnum - 1];
return slot->tts_values[attnum - 1];
}
/*
* slot_getsomeattrs
* This function forces the entries of the slot's Datum/isnull
* arrays to be valid at least up through the attnum'th entry.
*/
void
slot_getsomeattrs(TupleTableSlot *slot, int attnum)
{
HeapTuple tuple;
int attno;
/* Quick out if we have 'em all already */
if (slot->tts_nvalid >= attnum)
return;
/* Check for caller error */
if (attnum <= 0 || attnum > slot->tts_tupleDescriptor->natts)
elog(ERROR, "invalid attribute number %d", attnum);
/*
* otherwise we had better have a physical tuple (tts_nvalid should equal
* natts in all virtual-tuple cases)
*/
tuple = slot->tts_tuple;
if (tuple == NULL) /* internal error */
elog(ERROR, "cannot extract attribute from empty tuple slot");
/*
* load up any slots available from physical tuple
*/
attno = HeapTupleHeaderGetNatts(tuple->t_data);
attno = Min(attno, attnum);
slot_deform_tuple(slot, attno);
attno = slot->tts_nvalid;
/*
* If tuple doesn't have all the atts indicated by attnum, read the rest
* as NULLs or missing values
*/
if (attno < attnum)
slot_getmissingattrs(slot, attno, attnum);
slot->tts_nvalid = attnum;
}
/*
* slot_attisnull
* Detect whether an attribute of the slot is null, without

View File

@ -54,6 +54,7 @@
#include "postgres.h"
#include "access/htup_details.h"
#include "access/tupdesc_details.h"
#include "access/tuptoaster.h"
#include "funcapi.h"
#include "catalog/pg_type.h"
@ -959,6 +960,195 @@ ExecInitNullTupleSlot(EState *estate, TupleDesc tupType)
return ExecStoreAllNullTuple(slot);
}
/* ---------------------------------------------------------------
* Routines for setting/accessing attributes in a slot.
* ---------------------------------------------------------------
*/
/*
* Fill in missing values for a TupleTableSlot.
*
* This is only exposed because it's needed for JIT compiled tuple
* deforming. That exception aside, there should be no callers outside of this
* file.
*/
void
slot_getmissingattrs(TupleTableSlot *slot, int startAttNum, int lastAttNum)
{
AttrMissing *attrmiss = NULL;
int missattnum;
if (slot->tts_tupleDescriptor->constr)
attrmiss = slot->tts_tupleDescriptor->constr->missing;
if (!attrmiss)
{
/* no missing values array at all, so just fill everything in as NULL */
memset(slot->tts_values + startAttNum, 0,
(lastAttNum - startAttNum) * sizeof(Datum));
memset(slot->tts_isnull + startAttNum, 1,
(lastAttNum - startAttNum) * sizeof(bool));
}
else
{
/* if there is a missing values array we must process them one by one */
for (missattnum = startAttNum;
missattnum < lastAttNum;
missattnum++)
{
slot->tts_values[missattnum] = attrmiss[missattnum].am_value;
slot->tts_isnull[missattnum] = !attrmiss[missattnum].am_present;
}
}
}
/*
* slot_getattr
* This function fetches an attribute of the slot's current tuple.
* It is functionally equivalent to heap_getattr, but fetches of
* multiple attributes of the same tuple will be optimized better,
* because we avoid O(N^2) behavior from multiple calls of
* nocachegetattr(), even when attcacheoff isn't usable.
*
* A difference from raw heap_getattr is that attnums beyond the
* slot's tupdesc's last attribute will be considered NULL even
* when the physical tuple is longer than the tupdesc.
*/
Datum
slot_getattr(TupleTableSlot *slot, int attnum, bool *isnull)
{
HeapTuple tuple = slot->tts_tuple;
TupleDesc tupleDesc = slot->tts_tupleDescriptor;
HeapTupleHeader tup;
/*
* system attributes are handled by heap_getsysattr
*/
if (attnum <= 0)
{
if (tuple == NULL) /* internal error */
elog(ERROR, "cannot extract system attribute from virtual tuple");
if (tuple == &(slot->tts_minhdr)) /* internal error */
elog(ERROR, "cannot extract system attribute from minimal tuple");
return heap_getsysattr(tuple, attnum, tupleDesc, isnull);
}
/*
* fast path if desired attribute already cached
*/
if (attnum <= slot->tts_nvalid)
{
*isnull = slot->tts_isnull[attnum - 1];
return slot->tts_values[attnum - 1];
}
/*
* return NULL if attnum is out of range according to the tupdesc
*/
if (attnum > tupleDesc->natts)
{
*isnull = true;
return (Datum) 0;
}
/*
* otherwise we had better have a physical tuple (tts_nvalid should equal
* natts in all virtual-tuple cases)
*/
if (tuple == NULL) /* internal error */
elog(ERROR, "cannot extract attribute from empty tuple slot");
/*
* return NULL or missing value if attnum is out of range according to the
* tuple
*
* (We have to check this separately because of various inheritance and
* table-alteration scenarios: the tuple could be either longer or shorter
* than the tupdesc.)
*/
tup = tuple->t_data;
if (attnum > HeapTupleHeaderGetNatts(tup))
return getmissingattr(slot->tts_tupleDescriptor, attnum, isnull);
/*
* check if target attribute is null: no point in groveling through tuple
*/
if (HeapTupleHasNulls(tuple) && att_isnull(attnum - 1, tup->t_bits))
{
*isnull = true;
return (Datum) 0;
}
/*
* If the attribute's column has been dropped, we force a NULL result.
* This case should not happen in normal use, but it could happen if we
* are executing a plan cached before the column was dropped.
*/
if (TupleDescAttr(tupleDesc, attnum - 1)->attisdropped)
{
*isnull = true;
return (Datum) 0;
}
/*
* Extract the attribute, along with any preceding attributes.
*/
slot_deform_tuple(slot, attnum);
/*
* The result is acquired from tts_values array.
*/
*isnull = slot->tts_isnull[attnum - 1];
return slot->tts_values[attnum - 1];
}
/*
* slot_getsomeattrs
* This function forces the entries of the slot's Datum/isnull
* arrays to be valid at least up through the attnum'th entry.
*/
void
slot_getsomeattrs(TupleTableSlot *slot, int attnum)
{
HeapTuple tuple;
int attno;
/* Quick out if we have 'em all already */
if (slot->tts_nvalid >= attnum)
return;
/* Check for caller error */
if (attnum <= 0 || attnum > slot->tts_tupleDescriptor->natts)
elog(ERROR, "invalid attribute number %d", attnum);
/*
* otherwise we had better have a physical tuple (tts_nvalid should equal
* natts in all virtual-tuple cases)
*/
tuple = slot->tts_tuple;
if (tuple == NULL) /* internal error */
elog(ERROR, "cannot extract attribute from empty tuple slot");
/*
* load up any slots available from physical tuple
*/
attno = HeapTupleHeaderGetNatts(tuple->t_data);
attno = Min(attno, attnum);
slot_deform_tuple(slot, attno);
attno = slot->tts_nvalid;
/*
* If tuple doesn't have all the atts indicated by attnum, read the rest
* as NULLs or missing values
*/
if (attno < attnum)
slot_getmissingattrs(slot, attno, attnum);
slot->tts_nvalid = attnum;
}
/* ----------------------------------------------------------------
* ExecTypeFromTL
*

View File

@ -835,5 +835,7 @@ extern MinimalTuple minimal_tuple_from_heap_tuple(HeapTuple htup);
extern size_t varsize_any(void *p);
extern HeapTuple heap_expand_tuple(HeapTuple sourceTuple, TupleDesc tupleDesc);
extern MinimalTuple minimal_expand_tuple(HeapTuple sourceTuple, TupleDesc tupleDesc);
struct TupleTableSlot;
extern void slot_deform_tuple(struct TupleTableSlot *slot, int natts);
#endif /* HTUP_DETAILS_H */

View File

@ -173,14 +173,18 @@ extern Datum ExecFetchSlotTupleDatum(TupleTableSlot *slot);
extern HeapTuple ExecMaterializeSlot(TupleTableSlot *slot);
extern TupleTableSlot *ExecCopySlot(TupleTableSlot *dstslot,
TupleTableSlot *srcslot);
extern void slot_getmissingattrs(TupleTableSlot *slot, int startAttNum,
int lastAttNum);
extern Datum slot_getattr(TupleTableSlot *slot, int attnum,
bool *isnull);
extern void slot_getsomeattrs(TupleTableSlot *slot, int attnum);
/* in access/common/heaptuple.c */
extern Datum slot_getattr(TupleTableSlot *slot, int attnum, bool *isnull);
extern void slot_getsomeattrs(TupleTableSlot *slot, int attnum);
extern bool slot_attisnull(TupleTableSlot *slot, int attnum);
extern bool slot_getsysattr(TupleTableSlot *slot, int attnum,
Datum *value, bool *isnull);
extern void slot_getmissingattrs(TupleTableSlot *slot, int startAttNum, int lastAttNum);
extern Datum getmissingattr(TupleDesc tupleDesc,
int attnum, bool *isnull);
#ifndef FRONTEND