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Adjust creation/destruction of TupleDesc data structure to reduce the

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number of palloc calls.  This has a salutory impact on plpgsql operations
with record variables (which create and destroy tupdescs constantly)
and probably helps a bit in some other cases too.
This commit is contained in:
Tom Lane
2005-03-07 04:42:17 +00:00
parent e3d7de6b99
commit a52b4fb131
4 changed files with 82 additions and 104 deletions
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137
src/backend/access/common/tupdesc.c
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@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/common/tupdesc.c,v 1.108 2004/12/31 21:59:07 pgsql Exp $
* $PostgreSQL: pgsql/src/backend/access/common/tupdesc.c,v 1.109 2005/03/07 04:42:16 tgl Exp $
*
* NOTES
* some of the executor utility code such as "ExecTypeFromTL" should be
@@ -31,19 +31,19 @@
#include "utils/typcache.h"
/* ----------------------------------------------------------------
* CreateTemplateTupleDesc
*
* This function allocates and zeros a tuple descriptor structure.
/*
* CreateTemplateTupleDesc
* This function allocates an empty tuple descriptor structure.
*
* Tuple type ID information is initially set for an anonymous record type;
* caller can overwrite this if needed.
* ----------------------------------------------------------------
*/
TupleDesc
CreateTemplateTupleDesc(int natts, bool hasoid)
{
TupleDesc desc;
char *stg;
int attroffset;
/*
* sanity checks
@@ -51,15 +51,33 @@ CreateTemplateTupleDesc(int natts, bool hasoid)
AssertArg(natts >= 0);
/*
* Allocate enough memory for the tuple descriptor, and zero the
* attrs[] array since TupleDescInitEntry assumes that the array is
* filled with NULL pointers.
* Allocate enough memory for the tuple descriptor, including the
* attribute rows, and set up the attribute row pointers.
*
* Note: we assume that sizeof(struct tupleDesc) is a multiple of
* the struct pointer alignment requirement, and hence we don't need
* to insert alignment padding between the struct and the array of
* attribute row pointers.
*/
desc = (TupleDesc) palloc(sizeof(struct tupleDesc));
attroffset = sizeof(struct tupleDesc) + natts * sizeof(Form_pg_attribute);
attroffset = MAXALIGN(attroffset);
stg = palloc(attroffset + natts * MAXALIGN(ATTRIBUTE_TUPLE_SIZE));
desc = (TupleDesc) stg;
if (natts > 0)
desc->attrs = (Form_pg_attribute *)
palloc0(natts * sizeof(Form_pg_attribute));
{
Form_pg_attribute *attrs;
int i;
attrs = (Form_pg_attribute *) (stg + sizeof(struct tupleDesc));
desc->attrs = attrs;
stg += attroffset;
for (i = 0; i < natts; i++)
{
attrs[i] = (Form_pg_attribute) stg;
stg += MAXALIGN(ATTRIBUTE_TUPLE_SIZE);
}
}
else
desc->attrs = NULL;
@@ -75,15 +93,16 @@ CreateTemplateTupleDesc(int natts, bool hasoid)
return desc;
}
/* ----------------------------------------------------------------
* CreateTupleDesc
*
/*
* CreateTupleDesc
* This function allocates a new TupleDesc pointing to a given
* Form_pg_attribute array
* Form_pg_attribute array.
*
* Note: if the TupleDesc is ever freed, the Form_pg_attribute array
* will not be freed thereby.
*
* Tuple type ID information is initially set for an anonymous record type;
* caller can overwrite this if needed.
* ----------------------------------------------------------------
*/
TupleDesc
CreateTupleDesc(int natts, bool hasoid, Form_pg_attribute *attrs)
@@ -106,14 +125,12 @@ CreateTupleDesc(int natts, bool hasoid, Form_pg_attribute *attrs)
return desc;
}
/* ----------------------------------------------------------------
* CreateTupleDescCopy
*
/*
* CreateTupleDescCopy
* This function creates a new TupleDesc by copying from an existing
* TupleDesc
* TupleDesc.
*
* !!! Constraints and defaults are not copied !!!
* ----------------------------------------------------------------
* !!! Constraints and defaults are not copied !!!
*/
TupleDesc
CreateTupleDescCopy(TupleDesc tupdesc)
@@ -121,38 +138,25 @@ CreateTupleDescCopy(TupleDesc tupdesc)
TupleDesc desc;
int i;
desc = (TupleDesc) palloc(sizeof(struct tupleDesc));
desc->natts = tupdesc->natts;
if (desc->natts > 0)
{
desc->attrs = (Form_pg_attribute *)
palloc(desc->natts * sizeof(Form_pg_attribute));
for (i = 0; i < desc->natts; i++)
{
desc->attrs[i] = (Form_pg_attribute) palloc(ATTRIBUTE_TUPLE_SIZE);
memcpy(desc->attrs[i], tupdesc->attrs[i], ATTRIBUTE_TUPLE_SIZE);
desc->attrs[i]->attnotnull = false;
desc->attrs[i]->atthasdef = false;
}
}
else
desc->attrs = NULL;
desc = CreateTemplateTupleDesc(tupdesc->natts, tupdesc->tdhasoid);
desc->constr = NULL;
for (i = 0; i < desc->natts; i++)
{
memcpy(desc->attrs[i], tupdesc->attrs[i], ATTRIBUTE_TUPLE_SIZE);
desc->attrs[i]->attnotnull = false;
desc->attrs[i]->atthasdef = false;
}
desc->tdtypeid = tupdesc->tdtypeid;
desc->tdtypmod = tupdesc->tdtypmod;
desc->tdhasoid = tupdesc->tdhasoid;
return desc;
}
/* ----------------------------------------------------------------
* CreateTupleDescCopyConstr
*
/*
* CreateTupleDescCopyConstr
* This function creates a new TupleDesc by copying from an existing
* TupleDesc (including its constraints and defaults)
* ----------------------------------------------------------------
* TupleDesc (including its constraints and defaults).
*/
TupleDesc
CreateTupleDescCopyConstr(TupleDesc tupdesc)
@@ -161,20 +165,12 @@ CreateTupleDescCopyConstr(TupleDesc tupdesc)
TupleConstr *constr = tupdesc->constr;
int i;
desc = (TupleDesc) palloc(sizeof(struct tupleDesc));
desc->natts = tupdesc->natts;
if (desc->natts > 0)
desc = CreateTemplateTupleDesc(tupdesc->natts, tupdesc->tdhasoid);
for (i = 0; i < desc->natts; i++)
{
desc->attrs = (Form_pg_attribute *)
palloc(desc->natts * sizeof(Form_pg_attribute));
for (i = 0; i < desc->natts; i++)
{
desc->attrs[i] = (Form_pg_attribute) palloc(ATTRIBUTE_TUPLE_SIZE);
memcpy(desc->attrs[i], tupdesc->attrs[i], ATTRIBUTE_TUPLE_SIZE);
}
memcpy(desc->attrs[i], tupdesc->attrs[i], ATTRIBUTE_TUPLE_SIZE);
}
else
desc->attrs = NULL;
if (constr)
{
@@ -208,12 +204,9 @@ CreateTupleDescCopyConstr(TupleDesc tupdesc)
desc->constr = cpy;
}
else
desc->constr = NULL;
desc->tdtypeid = tupdesc->tdtypeid;
desc->tdtypmod = tupdesc->tdtypmod;
desc->tdhasoid = tupdesc->tdhasoid;
return desc;
}
@@ -226,10 +219,6 @@ FreeTupleDesc(TupleDesc tupdesc)
{
int i;
for (i = 0; i < tupdesc->natts; i++)
pfree(tupdesc->attrs[i]);
if (tupdesc->attrs)
pfree(tupdesc->attrs);
if (tupdesc->constr)
{
if (tupdesc->constr->num_defval > 0)
@@ -379,12 +368,10 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
return true;
}
/* ----------------------------------------------------------------
* TupleDescInitEntry
*
/*
* TupleDescInitEntry
* This function initializes a single attribute structure in
* a preallocated tuple descriptor.
* ----------------------------------------------------------------
* a previously allocated tuple descriptor.
*/
void
TupleDescInitEntry(TupleDesc desc,
@@ -404,18 +391,12 @@ TupleDescInitEntry(TupleDesc desc,
AssertArg(PointerIsValid(desc));
AssertArg(attributeNumber >= 1);
AssertArg(attributeNumber <= desc->natts);
AssertArg(!PointerIsValid(desc->attrs[attributeNumber - 1]));
/*
* allocate storage for this attribute
*/
att = (Form_pg_attribute) palloc(ATTRIBUTE_TUPLE_SIZE);
desc->attrs[attributeNumber - 1] = att;
/*
* initialize the attribute fields
*/
att = desc->attrs[attributeNumber - 1];
att->attrelid = 0; /* dummy value */
/*