postgresql/src/backend/utils/adt/format_type.c

318 lines
7.0 KiB
C

/*-------------------------------------------------------------------------
*
* format_type.c
* Display type names "nicely".
*
*
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/format_type.c,v 1.5 2000/08/26 21:53:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <ctype.h>
#include "fmgr.h"
#include "catalog/pg_type.h"
#include "utils/builtins.h"
#include "utils/numeric.h"
#include "utils/syscache.h"
#define MAX_INT32_LEN 11
#define _textin(str) DirectFunctionCall1(textin, CStringGetDatum(str))
static char *format_type_internal(Oid type_oid, int32 typemod);
static char *
psnprintf(size_t len, const char * fmt, ...)
{
va_list ap;
char * buf;
buf = palloc(len);
va_start(ap, fmt);
vsnprintf(buf, len, fmt, ap);
va_end(ap);
return buf;
}
/*
* SQL function: format_type(type_oid, typemod)
*
* `type_oid' is from pg_type.oid, `typemod' is from
* pg_attribute.atttypmod. This function will get the type name and
* format it and the modifier to canonical SQL format, if the type is
* a standard type. Otherwise you just get pg_type.typname back,
* double quoted if it contains funny characters.
*
* If typemod is null (in the SQL sense) then you won't get any
* "..(x)" type qualifiers. The result is not technically correct,
* because the various types interpret missing type modifiers
* differently, but it can be used as a convenient way to format
* system catalogs, e.g., pg_aggregate, in psql.
*/
Datum
format_type(PG_FUNCTION_ARGS)
{
Oid type_oid;
int32 typemod;
char *result;
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
type_oid = PG_GETARG_OID(0);
if (!PG_ARGISNULL(1))
typemod = PG_GETARG_INT32(1);
else
typemod = -1; /* default typmod */
result = format_type_internal(type_oid, typemod);
PG_RETURN_DATUM(_textin(result));
}
static char *
format_type_internal(Oid type_oid, int32 typemod)
{
bool with_typemod = (typemod >= 0);
HeapTuple tuple;
Oid array_base_type;
int16 typlen;
bool is_array;
char *name;
char *buf;
if (type_oid == InvalidOid)
return pstrdup("-");
tuple = SearchSysCacheTuple(TYPEOID, ObjectIdGetDatum(type_oid),
0, 0, 0);
if (!HeapTupleIsValid(tuple))
return pstrdup("???");
array_base_type = ((Form_pg_type) GETSTRUCT(tuple))->typelem;
typlen = ((Form_pg_type) GETSTRUCT(tuple))->typlen;
if (array_base_type != 0 && typlen < 0)
{
tuple = SearchSysCacheTuple(TYPEOID,
ObjectIdGetDatum(array_base_type),
0, 0, 0);
if (!HeapTupleIsValid(tuple))
return pstrdup("???[]");
is_array = true;
type_oid = array_base_type;
}
else
is_array = false;
switch (type_oid)
{
case BOOLOID:
buf = pstrdup("boolean");
break;
case BPCHAROID:
if (with_typemod)
buf = psnprintf(11 + MAX_INT32_LEN + 1, "character(%d)",
(int) (typemod - VARHDRSZ));
else
buf = pstrdup("character");
break;
case CHAROID:
/* This char type is the single-byte version. You have to
* double-quote it to get at it in the parser.
*/
buf = pstrdup("\"char\"");
break;
case FLOAT4OID:
buf = pstrdup("real");
break;
case FLOAT8OID:
buf = pstrdup("double precision");
break;
case INT2OID:
buf = pstrdup("smallint");
break;
case INT4OID:
buf = pstrdup("integer");
break;
case INT8OID:
buf = pstrdup("bigint");
break;
case NUMERICOID:
if (with_typemod)
buf = psnprintf(10 + 2 * MAX_INT32_LEN + 1, "numeric(%d,%d)",
((typemod - VARHDRSZ) >> 16) & 0xffff,
(typemod - VARHDRSZ) & 0xffff);
else
buf = pstrdup("numeric");
break;
case TIMETZOID:
buf = pstrdup("time with time zone");
break;
case VARBITOID:
if (with_typemod)
buf = psnprintf(13 + MAX_INT32_LEN + 1, "bit varying(%d)",
(int) typemod);
else
buf = pstrdup("bit varying");
break;
case VARCHAROID:
if (with_typemod)
buf = psnprintf(19 + MAX_INT32_LEN + 1,
"character varying(%d)",
(int) (typemod - VARHDRSZ));
else
buf = pstrdup("character varying");
break;
case ZPBITOID:
if (with_typemod)
buf = psnprintf(5 + MAX_INT32_LEN + 1, "bit(%d)",
(int) typemod);
else
buf = pstrdup("bit");
break;
default:
name = NameStr(((Form_pg_type) GETSTRUCT(tuple))->typname);
if (strspn(name, "abcdefghijklmnopqrstuvwxyz0123456789_") != strlen(name)
|| isdigit((int) name[0]))
buf = psnprintf(strlen(name) + 3, "\"%s\"", name);
else
buf = pstrdup(name);
break;
}
if (is_array)
buf = psnprintf(strlen(buf) + 3, "%s[]", buf);
return buf;
}
/*
* type_maximum_size --- determine maximum length of a varlena column
*
* If the max length is indeterminate, return -1. In particular, we return
* -1 for any type not known to this routine. We assume the caller has
* already determined that the type is a varlena type, so it's not
* necessary to look up the type's pg_type tuple here.
*
* This may appear unrelated to format_type(), but in fact the two routines
* share knowledge of the encoding of typmod for different types, so it's
* convenient to keep them together.
*/
int32
type_maximum_size(Oid type_oid, int32 typemod)
{
if (typemod <= 0)
return -1;
switch (type_oid)
{
case BPCHAROID:
case VARCHAROID:
/* typemod includes varlena header */
return typemod;
case NUMERICOID:
/* precision (ie, max # of digits) is in upper bits of typmod */
if (typemod > VARHDRSZ)
{
int precision = ((typemod - VARHDRSZ) >> 16) & 0xffff;
/* Numeric stores 2 decimal digits/byte, plus header */
return (precision + 1) / 2 + NUMERIC_HDRSZ;
}
break;
case VARBITOID:
case ZPBITOID:
/* typemod is the (max) number of bits */
return (typemod + (BITS_PER_BYTE-1)) / BITS_PER_BYTE
+ 2 * sizeof(int32);
}
/* Unknown type, or unlimited-length type such as 'text' */
return -1;
}
/*
* oidvectortypes - converts a vector of type OIDs to "typname" list
*
* The interface for this function is wrong: it should be told how many
* OIDs are significant in the input vector, so that trailing InvalidOid
* argument types can be recognized.
*/
Datum
oidvectortypes(PG_FUNCTION_ARGS)
{
Oid *oidArray = (Oid *) PG_GETARG_POINTER(0);
char *result;
int numargs;
int num;
size_t total;
size_t left;
/* Try to guess how many args there are :-( */
numargs = 0;
for (num = 0; num < FUNC_MAX_ARGS; num++)
{
if (oidArray[num] != InvalidOid)
numargs = num + 1;
}
total = 20 * numargs + 1;
result = palloc(total);
result[0] = '\0';
left = total - 1;
for (num = 0; num < numargs; num++)
{
char * typename = format_type_internal(oidArray[num], -1);
if (left < strlen(typename) + 2)
{
total += strlen(typename) + 2;
result = repalloc(result, total);
left += strlen(typename) + 2;
}
if (num > 0)
{
strcat(result, ", ");
left -= 2;
}
strcat(result, typename);
left -= strlen(typename);
}
PG_RETURN_DATUM(_textin(result));
}