/
columninfo.c
169 lines (138 loc) · 3.67 KB
/
columninfo.c
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/*-------
* Module: columninfo.c
*
* Description: This module contains routines related to
* reading and storing the field information from a query.
*
* Classes: ColumnInfoClass (Functions prefix: "CI_")
*
* API functions: none
*
* Comments: See "readme.txt" for copyright and license information.
*-------
*/
#include "pgtypes.h"
#include "columninfo.h"
#include "connection.h"
#include <stdlib.h>
#include <string.h>
#include "pgapifunc.h"
#include <libpq-fe.h>
ColumnInfoClass *
CI_Constructor(void)
{
ColumnInfoClass *rv;
rv = (ColumnInfoClass *) malloc(sizeof(ColumnInfoClass));
if (rv)
{
rv->refcount = 0;
rv->num_fields = 0;
rv->coli_array = NULL;
}
return rv;
}
void
CI_Destructor(ColumnInfoClass *self)
{
CI_free_memory(self);
free(self);
}
/*
* Read in field descriptions from a libpq result set.
* If self is not null, then also store the information.
* If self is null, then just read, don't store.
*/
BOOL
CI_read_fields_from_pgres(ColumnInfoClass *self, PGresult *pgres)
{
CSTR func = "CI_read_fields";
Int2 lf;
int new_num_fields;
OID new_adtid, new_relid = 0, new_attid = 0;
Int2 new_adtsize;
Int4 new_atttypmod = -1;
char *new_field_name;
/* at first read in the number of fields that are in the query */
new_num_fields = PQnfields(pgres);
mylog("num_fields = %d\n", new_num_fields);
if (self)
{
/* according to that allocate memory */
CI_set_num_fields(self, new_num_fields);
if (NULL == self->coli_array)
return FALSE;
}
/* now read in the descriptions */
for (lf = 0; lf < new_num_fields; lf++)
{
new_field_name = PQfname(pgres, lf);
new_relid = PQftable(pgres, lf);
new_attid = PQftablecol(pgres, lf);
new_adtid = PQftype(pgres, lf);
new_adtsize = PQfsize(pgres, lf);
mylog("READING ATTTYPMOD\n");
new_atttypmod = PQfmod(pgres, lf);
/* Subtract the header length */
switch (new_adtid)
{
case PG_TYPE_DATETIME:
case PG_TYPE_TIMESTAMP_NO_TMZONE:
case PG_TYPE_TIME:
case PG_TYPE_TIME_WITH_TMZONE:
break;
default:
new_atttypmod -= 4;
}
if (new_atttypmod < 0)
new_atttypmod = -1;
mylog("%s: fieldname='%s', adtid=%d, adtsize=%d, atttypmod=%d (rel,att)=(%d,%d)\n", func, new_field_name, new_adtid, new_adtsize, new_atttypmod, new_relid, new_attid);
if (self)
CI_set_field_info(self, lf, new_field_name, new_adtid, new_adtsize, new_atttypmod, new_relid, new_attid);
}
return TRUE;
}
void
CI_free_memory(ColumnInfoClass *self)
{
register Int2 lf;
int num_fields = self->num_fields;
/* Safe to call even if null */
self->num_fields = 0;
if (self->coli_array)
{
for (lf = 0; lf < num_fields; lf++)
{
if (self->coli_array[lf].name)
{
free(self->coli_array[lf].name);
self->coli_array[lf].name = NULL;
}
}
free(self->coli_array);
self->coli_array = NULL;
}
}
void
CI_set_num_fields(ColumnInfoClass *self, int new_num_fields)
{
CI_free_memory(self); /* always safe to call */
self->num_fields = new_num_fields;
self->coli_array = (struct srvr_info *) calloc(sizeof(struct srvr_info), self->num_fields);
}
void
CI_set_field_info(ColumnInfoClass *self, int field_num, char *new_name,
OID new_adtid, Int2 new_adtsize, Int4 new_atttypmod,
OID new_relid, OID new_attid)
{
/* check bounds */
if ((field_num < 0) || (field_num >= self->num_fields))
return;
/* store the info */
self->coli_array[field_num].name = strdup(new_name);
self->coli_array[field_num].adtid= new_adtid;
self->coli_array[field_num].adtsize = new_adtsize;
self->coli_array[field_num].atttypmod = new_atttypmod;
self->coli_array[field_num].display_size = PG_ADT_UNSET;
self->coli_array[field_num].relid = new_relid;
self->coli_array[field_num].attid = new_attid;
}