Tom Lane 234a02b2a8 Replace direct assignments to VARATT_SIZEP(x) with SET_VARSIZE(x, len).
Get rid of VARATT_SIZE and VARATT_DATA, which were simply redundant with
VARSIZE and VARDATA, and as a consequence almost no code was using the
longer names.  Rename the length fields of struct varlena and various
derived structures to catch anyplace that was accessing them directly;
and clean up various places so caught.  In itself this patch doesn't
change any behavior at all, but it is necessary infrastructure if we hope
to play any games with the representation of varlena headers.
Greg Stark and Tom Lane
2007-02-27 23:48:10 +00:00

113 lines
2.7 KiB
C

/* $PostgreSQL: pgsql/src/tutorial/funcs.c,v 1.17 2007/02/27 23:48:10 tgl Exp $ */
/******************************************************************************
These are user-defined functions that can be bound to a Postgres backend
and called by Postgres to execute SQL functions of the same name.
The calling format for these functions is defined by the CREATE FUNCTION
SQL statement that binds them to the backend.
NOTE: this file shows examples of "old style" function call conventions.
See funcs_new.c for examples of "new style".
*****************************************************************************/
#include "postgres.h" /* general Postgres declarations */
#include "executor/executor.h" /* for GetAttributeByName() */
#include "utils/geo_decls.h" /* for point type */
PG_MODULE_MAGIC;
/* These prototypes just prevent possible warnings from gcc. */
int add_one(int arg);
float8 *add_one_float8(float8 *arg);
Point *makepoint(Point *pointx, Point *pointy);
text *copytext(text *t);
text *concat_text(text *arg1, text *arg2);
bool c_overpaid(HeapTupleHeader t, /* the current instance of EMP */
int32 limit);
/* By Value */
int
add_one(int arg)
{
return arg + 1;
}
/* By Reference, Fixed Length */
float8 *
add_one_float8(float8 *arg)
{
float8 *result = (float8 *) palloc(sizeof(float8));
*result = *arg + 1.0;
return result;
}
Point *
makepoint(Point *pointx, Point *pointy)
{
Point *new_point = (Point *) palloc(sizeof(Point));
new_point->x = pointx->x;
new_point->y = pointy->y;
return new_point;
}
/* By Reference, Variable Length */
text *
copytext(text *t)
{
/*
* VARSIZE is the total size of the struct in bytes.
*/
text *new_t = (text *) palloc(VARSIZE(t));
SET_VARSIZE(new_t, VARSIZE(t));
/*
* VARDATA is a pointer to the data region of the struct.
*/
memcpy((void *) VARDATA(new_t), /* destination */
(void *) VARDATA(t), /* source */
VARSIZE(t) - VARHDRSZ); /* how many bytes */
return new_t;
}
text *
concat_text(text *arg1, text *arg2)
{
int32 arg1_size = VARSIZE(arg1) - VARHDRSZ;
int32 arg2_size = VARSIZE(arg2) - VARHDRSZ;
int32 new_text_size = arg1_size + arg2_size + VARHDRSZ;
text *new_text = (text *) palloc(new_text_size);
SET_VARSIZE(new_text, new_text_size);
memcpy(VARDATA(new_text), VARDATA(arg1), arg1_size);
memcpy(VARDATA(new_text) + arg1_size, VARDATA(arg2), arg2_size);
return new_text;
}
/* Composite types */
bool
c_overpaid(HeapTupleHeader t, /* the current instance of EMP */
int32 limit)
{
bool isnull;
int32 salary;
salary = DatumGetInt32(GetAttributeByName(t, "salary", &isnull));
if (isnull)
return false;
return salary > limit;
}