diff options
Diffstat (limited to 'src/backend/utils/adt/varlena.c')
| -rw-r--r-- | src/backend/utils/adt/varlena.c | 47 |
1 files changed, 46 insertions, 1 deletions
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c index f114f96cf7..0568c2eea7 100644 --- a/src/backend/utils/adt/varlena.c +++ b/src/backend/utils/adt/varlena.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.124 2005/07/04 18:56:44 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.125 2005/07/06 19:02:52 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -28,6 +28,7 @@ #include "utils/builtins.h" #include "utils/lsyscache.h" #include "utils/pg_locale.h" +#include "utils/syscache.h" typedef struct varlena unknown; @@ -2348,3 +2349,47 @@ md5_bytea(PG_FUNCTION_ARGS) result_text = PG_STR_GET_TEXT(hexsum); PG_RETURN_TEXT_P(result_text); } + +/* + * Return the length of a datum, possibly compressed + */ +Datum +pg_column_size(PG_FUNCTION_ARGS) +{ + Datum value = PG_GETARG_DATUM(0); + int result; + + /* fn_extra stores the fixed column length, or -1 for varlena. */ + if (fcinfo->flinfo->fn_extra == NULL) /* first call? */ + { + /* 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; + } + + if (*(int *)fcinfo->flinfo->fn_extra != -1) + PG_RETURN_INT32(*(int *)fcinfo->flinfo->fn_extra); + else + { + result = toast_datum_size(value) - VARHDRSZ; + PG_RETURN_INT32(result); + } +} |