예제 #1
0
파일: heaptuple.c 프로젝트: johto/postgres
/*
 * heap_fill_tuple
 *		Load data portion of a tuple from values/isnull arrays
 *
 * We also fill the null bitmap (if any) and set the infomask bits
 * that reflect the tuple's data contents.
 *
 * NOTE: it is now REQUIRED that the caller have pre-zeroed the data area.
 */
void
heap_fill_tuple(TupleDesc tupleDesc,
				Datum *values, bool *isnull,
				char *data, Size data_size,
				uint16 *infomask, bits8 *bit)
{
	bits8	   *bitP;
	int			bitmask;
	int			i;
	int			numberOfAttributes = tupleDesc->natts;
	Form_pg_attribute *att = tupleDesc->attrs;

#ifdef USE_ASSERT_CHECKING
	char	   *start = data;
#endif

	if (bit != NULL)
	{
		bitP = &bit[-1];
		bitmask = HIGHBIT;
	}
	else
	{
		/* just to keep compiler quiet */
		bitP = NULL;
		bitmask = 0;
	}

	*infomask &= ~(HEAP_HASNULL | HEAP_HASVARWIDTH | HEAP_HASEXTERNAL);

	for (i = 0; i < numberOfAttributes; i++)
	{
		Size		data_length;

		if (bit != NULL)
		{
			if (bitmask != HIGHBIT)
				bitmask <<= 1;
			else
			{
				bitP += 1;
				*bitP = 0x0;
				bitmask = 1;
			}

			if (isnull[i])
			{
				*infomask |= HEAP_HASNULL;
				continue;
			}

			*bitP |= bitmask;
		}

		/*
		 * XXX we use the att_align macros on the pointer value itself, not on
		 * an offset.  This is a bit of a hack.
		 */

		if (att[i]->attbyval)
		{
			/* pass-by-value */
			data = (char *) att_align_nominal(data, att[i]->attalign);
			store_att_byval(data, values[i], att[i]->attlen);
			data_length = att[i]->attlen;
		}
		else if (att[i]->attlen == -1)
		{
			/* varlena */
			Pointer		val = DatumGetPointer(values[i]);

			*infomask |= HEAP_HASVARWIDTH;
			if (VARATT_IS_EXTERNAL(val))
			{
				if (VARATT_IS_EXTERNAL_EXPANDED(val))
				{
					/*
					 * we want to flatten the expanded value so that the
					 * constructed tuple doesn't depend on it
					 */
					ExpandedObjectHeader *eoh = DatumGetEOHP(values[i]);

					data = (char *) att_align_nominal(data,
													  att[i]->attalign);
					data_length = EOH_get_flat_size(eoh);
					EOH_flatten_into(eoh, data, data_length);
				}
				else
				{
					*infomask |= HEAP_HASEXTERNAL;
					/* no alignment, since it's short by definition */
					data_length = VARSIZE_EXTERNAL(val);
					memcpy(data, val, data_length);
				}
			}
			else if (VARATT_IS_SHORT(val))
			{
				/* no alignment for short varlenas */
				data_length = VARSIZE_SHORT(val);
				memcpy(data, val, data_length);
			}
			else if (VARLENA_ATT_IS_PACKABLE(att[i]) &&
					 VARATT_CAN_MAKE_SHORT(val))
			{
				/* convert to short varlena -- no alignment */
				data_length = VARATT_CONVERTED_SHORT_SIZE(val);
				SET_VARSIZE_SHORT(data, data_length);
				memcpy(data + 1, VARDATA(val), data_length - 1);
			}
			else
			{
				/* full 4-byte header varlena */
				data = (char *) att_align_nominal(data,
												  att[i]->attalign);
				data_length = VARSIZE(val);
				memcpy(data, val, data_length);
			}
		}
		else if (att[i]->attlen == -2)
		{
			/* cstring ... never needs alignment */
			*infomask |= HEAP_HASVARWIDTH;
			Assert(att[i]->attalign == 'c');
			data_length = strlen(DatumGetCString(values[i])) + 1;
			memcpy(data, DatumGetPointer(values[i]), data_length);
		}
		else
		{
			/* fixed-length pass-by-reference */
			data = (char *) att_align_nominal(data, att[i]->attalign);
			Assert(att[i]->attlen > 0);
			data_length = att[i]->attlen;
			memcpy(data, DatumGetPointer(values[i]), data_length);
		}

		data += data_length;
	}

	Assert((data - start) == data_size);
}
예제 #2
0
파일: heaptuple.c 프로젝트: BenjaminYu/gpdb
/*
 * heap_fill_tuple
 *		Load data portion of a tuple from values/isnull arrays
 *
 * We also fill the null bitmap (if any) and set the infomask bits
 * that reflect the tuple's data contents.
 *
 * NOTE: it is now REQUIRED that the caller have pre-zeroed the data area.
 *
 *
 * @param isnull will only be used if <code>bit</code> is non-NULL
 * @param bit should be non-NULL (refer to td->t_bits) if isnull is set and contains non-null values
 */
Size
heap_fill_tuple(TupleDesc tupleDesc,
				Datum *values, bool *isnull,
				char *data, uint16 *infomask, bits8 *bit)
{
	char	   *start = data;
	bits8	   *bitP;
	int			bitmask;
	int			i;
	int			numberOfAttributes = tupleDesc->natts;
	Form_pg_attribute *att = tupleDesc->attrs;

	if (bit != NULL)
	{
		bitP = &bit[-1];
		bitmask = HIGHBIT;
	}
	else
	{
		/* just to keep compiler quiet */
		bitP = NULL;
		bitmask = 0;
	}

	*infomask &= ~(HEAP_HASNULL | HEAP_HASVARWIDTH | HEAP_HASEXTENDED);

	for (i = 0; i < numberOfAttributes; i++)
	{
		Size		data_length;

		if (bit != NULL)
		{
			if (bitmask != HIGHBIT)
				bitmask <<= 1;
			else
			{
				bitP += 1;
				*bitP = 0x0;
				bitmask = 1;
			}

			if (isnull[i])
			{
				*infomask |= HEAP_HASNULL;
				continue;
			}

			*bitP |= bitmask;
		}

		/*
		 * XXX we use the att_align macros on the pointer value itself, not on
		 * an offset.  This is a bit of a hack.
		 */

		if (att[i]->attbyval)
		{
			/* pass-by-value */
			data = (char *) att_align_zero(data, att[i]->attalign);
			store_att_byval(data, values[i], att[i]->attlen);
			data_length = att[i]->attlen;
		}
		else if (att[i]->attlen == -1)
		{
			/* varlena */
			*infomask |= HEAP_HASVARWIDTH;
			if (VARATT_IS_COMPRESSED_D(values[i]))
				*infomask |= HEAP_HASCOMPRESSED;
			if (VARATT_IS_EXTERNAL_D(values[i])) 
			{
				*infomask |= HEAP_HASEXTERNAL;
				data = (char *) att_align_zero(data, att[i]->attalign);
				data_length = VARSIZE_EXTERNAL(DatumGetPointer(values[i]));
				memcpy(data, DatumGetPointer(values[i]), data_length);
			}
			else if (VARATT_IS_SHORT_D(values[i])) 
			{
				/* no alignment for short varlenas */
				data_length = VARSIZE_SHORT(DatumGetPointer(values[i]));
				memcpy(data, DatumGetPointer(values[i]), data_length);
			}
			else if (VARATT_COULD_SHORT_D(values[i]) &&
					 att[i]->atttypid != INT2VECTOROID &&
					 att[i]->atttypid != OIDVECTOROID &&
					 att[i]->atttypid < FirstNormalObjectId)
			{
				/* convert to short varlena -- no alignment */
				data_length = VARSIZE_D(values[i]) - VARHDRSZ + VARHDRSZ_SHORT;
				*data = VARSIZE_TO_SHORT_D(values[i]);
				memcpy(data+1,
					   VARDATA_D(values[i]),
					   data_length-1);
			}
			else
			{
				/* must store full 4-byte header varlena */
				data = (char *) att_align_zero(data, att[i]->attalign);
				data_length = VARSIZE(DatumGetPointer(values[i]));
				memcpy(data, DatumGetPointer(values[i]), data_length);
			}
		}
		else if (att[i]->attlen == -2)
		{
			/* cstring */
			data = (char *) att_align_zero(data, att[i]->attalign);
			*infomask |= HEAP_HASVARWIDTH;
			data_length = strlen(DatumGetCString(values[i])) + 1;
			memcpy(data, DatumGetPointer(values[i]), data_length);
		}
		else
		{
			/* fixed-length pass-by-reference */
			data = (char *) att_align_zero(data, att[i]->attalign);
			Assert(att[i]->attlen > 0);
			data_length = att[i]->attlen;
			memcpy(data, DatumGetPointer(values[i]), data_length);
		}

		data += data_length;
	}
	return data - start;
}