diff options
Diffstat (limited to 'src/include/access/tupmacs.h')
| -rw-r--r-- | src/include/access/tupmacs.h | 149 |
1 files changed, 119 insertions, 30 deletions
diff --git a/src/include/access/tupmacs.h b/src/include/access/tupmacs.h index ab856087a70..eb977189e14 100644 --- a/src/include/access/tupmacs.h +++ b/src/include/access/tupmacs.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2000, PostgreSQL, Inc * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: tupmacs.h,v 1.14 2000/03/17 02:36:37 tgl Exp $ + * $Id: tupmacs.h,v 1.15 2000/12/27 23:59:13 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -22,50 +22,79 @@ #define att_isnull(ATT, BITS) (!((BITS)[(ATT) >> 3] & (1 << ((ATT) & 0x07)))) /* - * given a Form_pg_attribute and a pointer into a tuple's data - * area, return the correct value or pointer. + * Given a Form_pg_attribute and a pointer into a tuple's data area, + * return the correct value or pointer. * - * We return a 4 byte (char *) value in all cases. If the attribute has - * "byval" false or has variable length, we return the same pointer - * into the tuple data area that we're passed. Otherwise, we return - * the 1, 2, or 4 bytes pointed to by it, properly extended to 4 - * bytes, depending on the length of the attribute. + * We return a Datum value in all cases. If the attribute has "byval" false, + * we return the same pointer into the tuple data area that we're passed. + * Otherwise, we return the correct number of bytes fetched from the data + * area and extended to Datum form. * - * note that T must already be properly LONGALIGN/SHORTALIGN'd for - * this to work correctly. + * On machines where Datum is 8 bytes, we support fetching 8-byte byval + * attributes; otherwise, only 1, 2, and 4-byte values are supported. * - * the double-cast is to stop gcc from (correctly) complaining about - * casting integer types with size < sizeof(char *) to (char *). - * sign-extension may get weird if you use an integer type that - * isn't the same size as (char *) for the first cast. (on the other - * hand, it's safe to use another type for the (foo *)(T).) - * - * attbyval seems to be fairly redundant. We have to return a pointer if - * the value is longer than 4 bytes or has variable length; returning the - * value would be useless. In fact, for at least the variable length case, - * the caller assumes we return a pointer regardless of attbyval. - * I would eliminate attbyval altogether, but I don't know how. -BRYANH. + * Note that T must already be properly aligned for this to work correctly. + */ +#define fetchatt(A,T) fetch_att(T, (A)->attbyval, (A)->attlen) + +/* + * Same, but work from byval/len parameters rather than Form_pg_attribute. */ -#define fetchatt(A, T) \ +#if SIZEOF_DATUM == 8 + +#define fetch_att(T,attbyval,attlen) \ ( \ - (*(A))->attbyval && (*(A))->attlen != -1 ? \ + (attbyval) ? \ ( \ - (*(A))->attlen > (int) sizeof(int16) ? \ + (attlen) == (int) sizeof(Datum) ? \ + *((Datum *)(T)) \ + : \ + ( \ + (attlen) == (int) sizeof(int32) ? \ + Int32GetDatum(*((int32 *)(T))) \ + : \ ( \ - (char *) (long) *((int32 *)(T)) \ + (attlen) == (int) sizeof(int16) ? \ + Int16GetDatum(*((int16 *)(T))) \ + : \ + ( \ + AssertMacro((attlen) == 1), \ + CharGetDatum(*((char *)(T))) \ + ) \ ) \ + ) \ + ) \ + : \ + PointerGetDatum((char *) (T)) \ +) + +#else /* SIZEOF_DATUM != 8 */ + +#define fetch_att(T,attbyval,attlen) \ +( \ + (attbyval) ? \ + ( \ + (attlen) == (int) sizeof(int32) ? \ + Int32GetDatum(*((int32 *)(T))) \ : \ ( \ - (*(A))->attlen < (int) sizeof(int16) ? \ - (char *) (long) *((char *)(T)) \ + (attlen) == (int) sizeof(int16) ? \ + Int16GetDatum(*((int16 *)(T))) \ : \ - (char *) (long) *((int16 *)(T))) \ + ( \ + AssertMacro((attlen) == 1), \ + CharGetDatum(*((char *)(T))) \ + ) \ ) \ + ) \ : \ - (char *) (T) \ + PointerGetDatum((char *) (T)) \ ) -/* att_align aligns the given offset as needed for a datum of length attlen +#endif /* SIZEOF_DATUM == 8 */ + +/* + * att_align aligns the given offset as needed for a datum of length attlen * and alignment requirement attalign. In practice we don't need the length. * The attalign cases are tested in what is hopefully something like their * frequency of occurrence. @@ -81,6 +110,10 @@ ))) \ ) +/* + * att_addlength increments the given offset by the length of the attribute. + * attval is only accessed if we are dealing with a varlena attribute. + */ #define att_addlength(cur_offset, attlen, attval) \ ( \ ((attlen) != -1) ? \ @@ -93,4 +126,60 @@ ) \ ) +/* + * store_att_byval is a partial inverse of fetch_att: store a given Datum + * value into a tuple data area at the specified address. However, it only + * handles the byval case, because in typical usage the caller needs to + * distinguish by-val and by-ref cases anyway, and so a do-it-all macro + * wouldn't be convenient. + */ +#if SIZEOF_DATUM == 8 + +#define store_att_byval(T,newdatum,attlen) \ + do { \ + switch (attlen) \ + { \ + case sizeof(char): \ + *(char *) (T) = DatumGetChar(newdatum); \ + break; \ + case sizeof(int16): \ + *(int16 *) (T) = DatumGetInt16(newdatum); \ + break; \ + case sizeof(int32): \ + *(int32 *) (T) = DatumGetInt32(newdatum); \ + break; \ + case sizeof(Datum): \ + *(Datum *) (T) = (newdatum); \ + break; \ + default: \ + elog(ERROR, "store_att_byval: unsupported byval length %d", \ + (int) (attlen)); \ + break; \ + } \ + } while (0) + +#else /* SIZEOF_DATUM != 8 */ + +#define store_att_byval(T,newdatum,attlen) \ + do { \ + switch (attlen) \ + { \ + case sizeof(char): \ + *(char *) (T) = DatumGetChar(newdatum); \ + break; \ + case sizeof(int16): \ + *(int16 *) (T) = DatumGetInt16(newdatum); \ + break; \ + case sizeof(int32): \ + *(int32 *) (T) = DatumGetInt32(newdatum); \ + break; \ + default: \ + elog(ERROR, "store_att_byval: unsupported byval length %d", \ + (int) (attlen)); \ + break; \ + } \ + } while (0) + +#endif /* SIZEOF_DATUM == 8 */ + #endif |