Re: TODO Item - Return compressed length of TOAST datatypes - Mailing list pgsql-patches

Alvaro Herrera wrote:
> On Thu, Jul 07, 2005 at 03:01:46PM +1200, Mark Kirkwood wrote:
>
>>Neil Conway wrote:
>
>
>>>elog(ERROR) is usually used for "can't happen" errors.
>>
>>I have attached a little change to varlena.c that uses it. I left the
>>ereport as it was, but am not fussed about it either way.
>
>
> I am, because it gives useless messages to the translators to work on.
> elog parameters are not marked for translation, ereport are (errmsg and
> friends, really).  So please don't do that.
>

Ok, didn't realize the difference! Revised patch attached that uses elog.

Neil, I will runs some tests to see if there is any performance saving
with the first-call-only business.

Cheers

Mark

Index: src/backend/utils/adt/varlena.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/utils/adt/varlena.c,v
retrieving revision 1.125
diff -c -r1.125 varlena.c
*** src/backend/utils/adt/varlena.c    6 Jul 2005 19:02:52 -0000    1.125
--- src/backend/utils/adt/varlena.c    7 Jul 2005 03:40:44 -0000
***************
*** 28,34 ****
  #include "utils/builtins.h"
  #include "utils/lsyscache.h"
  #include "utils/pg_locale.h"
- #include "utils/syscache.h"


  typedef struct varlena unknown;
--- 28,33 ----
***************
*** 2364,2385 ****
      {
          /* On the first call lookup the datatype of the supplied argument */
          Oid                argtypeid = get_fn_expr_argtype(fcinfo->flinfo, 0);
!         HeapTuple        tp;
!         int                typlen;

!         tp = SearchSysCache(TYPEOID,
!                             ObjectIdGetDatum(argtypeid),
!                             0, 0, 0);
!         if (!HeapTupleIsValid(tp))
          {
              /* Oid not in pg_type, should never happen. */
!             ereport(ERROR,
!                     (errcode(ERRCODE_INTERNAL_ERROR),
!                      errmsg("invalid typid: %u", argtypeid)));
          }
!
!         typlen = ((Form_pg_type)GETSTRUCT(tp))->typlen;
!         ReleaseSysCache(tp);
          fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
                                                        sizeof(int));
          *(int *)fcinfo->flinfo->fn_extra = typlen;
--- 2363,2377 ----
      {
          /* On the first call lookup the datatype of the supplied argument */
          Oid                argtypeid = get_fn_expr_argtype(fcinfo->flinfo, 0);
!         int                typlen    = get_typlen(argtypeid);

!
!         if (typlen == 0)
          {
              /* Oid not in pg_type, should never happen. */
!             elog(ERROR, "cache lookup failed for type %u", argtypeid);
          }
!
          fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
                                                        sizeof(int));
          *(int *)fcinfo->flinfo->fn_extra = typlen;