Commit 85036af7 authored by unknown's avatar unknown
Browse files

InnoDB: Fix a bug in BLOB handling; optimize null flag handling. 


innobase/rem/rem0rec.c:
  rec_set_nth_field_extern_bit_new(): Fix a bug
  (read the "extern" flag from the correct position).
  
  rec_set_nth_field_extern_bit_new(),
  rec_convert_dtuple_to_rec_new(),
  rec_copy_prefix_to_buf(): Eliminate variables, reduce branching,
  optimize the handling of the null flags.
parent 384a0c0a

innobase/rem/rem0rec.c

+67 −38
Original line number Diff line number Diff line
@@ -601,30 +601,38 @@ rec_set_nth_field_extern_bit_new( 


	/* read the lengths of fields 0..n */

	for (i = 0; i < n_fields; i++) {

		ibool	is_null;

		ulint	len;

		field = dict_index_get_nth_field(index, i);

		type = dict_col_get_type(dict_field_get_col(field));

		is_null = !(dtype_get_prtype(type) & DATA_NOT_NULL);

		if (is_null) {

			/* nullable field => read the null flag */

			is_null = !!(*nulls & null_mask);

		if (!(dtype_get_prtype(type) & DATA_NOT_NULL)) {

			if (UNIV_UNLIKELY(!(byte) null_mask)) {

				nulls--;

				null_mask = 1;

			}



			if (*nulls & null_mask) {

				null_mask <<= 1;

			if (null_mask == 0x100)

				nulls--, null_mask = 1;

				/* NULL fields cannot be external. */

				ut_ad(i != ith);

				continue;

			}

		if (is_null || field->fixed_len) {

			/* No length (or extern bit) is stored for

			fields that are NULL or fixed-length. */



			null_mask <<= 1;

		}

		if (field->fixed_len) {

			/* fixed-length fields cannot be external

			(Fixed-length fields longer than

			DICT_MAX_COL_PREFIX_LEN will be treated as

			variable-length ones in dict_index_add_col().) */

			ut_ad(i != ith);

			continue;

		}

		len = *lens--;

		lens--;

		if (dtype_get_len(type) > 255

				|| dtype_get_mtype(type) == DATA_BLOB) {

			ulint	len = lens[1];

			if (len & 0x80) { /* 1exxxxxx: 2-byte length */

				if (i == ith) {

					if (!val == !(len & 0x20)) {

					if (!val == !(len & 0x40)) {

						return; /* no change */

					}

					/* toggle the extern bit */
@@ -823,6 +831,7 @@ rec_convert_dtuple_to_rec_new( 
	byte*		lens;

	ulint		len;

	ulint		i;

	ulint		n_node_ptr_field;

	ulint		fixed_len;

	ulint		null_mask	= 1;

	const ulint	n_fields	= dtuple_get_n_fields(dtuple);
@@ -831,16 +840,26 @@ rec_convert_dtuple_to_rec_new( 
	ut_ad(index->table->comp);



	ut_ad(n_fields > 0);

	switch (status) {



	/* Try to ensure that the memset() between the for() loops

	completes fast.  The address is not exact, but UNIV_PREFETCH

	should never generate a memory fault. */

	UNIV_PREFETCH_RW(rec - REC_N_NEW_EXTRA_BYTES - n_fields);

	UNIV_PREFETCH_RW(rec);



	switch (UNIV_EXPECT(status, REC_STATUS_ORDINARY)) {

	case REC_STATUS_ORDINARY:

		ut_ad(n_fields <= dict_index_get_n_fields(index));

		n_node_ptr_field = ULINT_UNDEFINED;

		break;

	case REC_STATUS_NODE_PTR:

		ut_ad(n_fields == dict_index_get_n_unique_in_tree(index) + 1);

		n_node_ptr_field = n_fields - 1;

		break;

	case REC_STATUS_INFIMUM:

	case REC_STATUS_SUPREMUM:

		ut_ad(n_fields == 1);

		n_node_ptr_field = ULINT_UNDEFINED;

		goto init;

	default:

		ut_a(0);
@@ -852,15 +871,18 @@ rec_convert_dtuple_to_rec_new( 
	rec += (index->n_nullable + 7) / 8;



	for (i = 0; i < n_fields; i++) {

		if (UNIV_UNLIKELY(i == n_node_ptr_field)) {

#ifdef UNIV_DEBUG

			field = dtuple_get_nth_field(dtuple, i);

			type = dfield_get_type(field);

		len = dfield_get_len(field);

		if (status == REC_STATUS_NODE_PTR && i == n_fields - 1) {

			fixed_len = 4;

			ut_ad(dtype_get_prtype(type) & DATA_NOT_NULL);

			ut_ad(len == 4);

			continue;

			ut_ad(dfield_get_len(field) == 4);

#endif /* UNIV_DEBUG */

			goto init;

		}

		field = dtuple_get_nth_field(dtuple, i);

		type = dfield_get_type(field);

		len = dfield_get_len(field);

		fixed_len = dict_index_get_nth_field(index, i)->fixed_len;



		if (!(dtype_get_prtype(type) & DATA_NOT_NULL)) {
@@ -902,28 +924,34 @@ rec_convert_dtuple_to_rec_new( 
		type = dfield_get_type(field);

		len = dfield_get_len(field);



		if (status == REC_STATUS_NODE_PTR && i == n_fields - 1) {

			fixed_len = 4;

		if (UNIV_UNLIKELY(i == n_node_ptr_field)) {

			ut_ad(dtype_get_prtype(type) & DATA_NOT_NULL);

			ut_ad(len == 4);

			goto copy;

			memcpy(end, dfield_get_data(field), len);

			break;

		}

		fixed_len = dict_index_get_nth_field(index, i)->fixed_len;



		if (!(dtype_get_prtype(type) & DATA_NOT_NULL)) {

			/* nullable field */

			ut_ad(index->n_nullable > 0);



			if (UNIV_UNLIKELY(!(byte) null_mask)) {

				nulls--;

				null_mask = 1;

			}



			ut_ad(*nulls < null_mask);



			/* set the null flag if necessary */

			if (len == UNIV_SQL_NULL) {

				*nulls |= null_mask;

			}

				null_mask <<= 1;

			if (null_mask == 0x100)

				nulls--, null_mask = 1;

			if (len == UNIV_SQL_NULL)

				continue;

			}



			null_mask <<= 1;

		}

		/* only nullable fields can be null */

		ut_ad(len != UNIV_SQL_NULL);

		if (fixed_len) {
@@ -942,7 +970,7 @@ rec_convert_dtuple_to_rec_new( 
				*lens-- = (byte) len;

			}

		}

	copy:



		memcpy(end, dfield_get_data(field), len);

		end += len;

	}
@@ -1105,7 +1133,6 @@ rec_copy_prefix_to_buf( 
	dtype_t*	type;

	ulint		i;

	ulint		prefix_len;

	ibool		is_null;

	ulint		null_mask;

	ulint		status;
@@ -1146,20 +1173,22 @@ rec_copy_prefix_to_buf( 
	for (i = 0; i < n_fields; i++) {

		field = dict_index_get_nth_field(index, i);

		type = dict_col_get_type(dict_field_get_col(field));

		is_null = !(dtype_get_prtype(type) & DATA_NOT_NULL);

		if (is_null) {

		if (!(dtype_get_prtype(type) & DATA_NOT_NULL)) {

			/* nullable field => read the null flag */

			is_null = !!(*nulls & null_mask);

			null_mask <<= 1;

			if (null_mask == 0x100) {

				--nulls;

				UNIV_PREFETCH_R(nulls);

			if (UNIV_UNLIKELY(!(byte) null_mask)) {

				nulls--;

				null_mask = 1;

			}



			if (*nulls & null_mask) {

				null_mask <<= 1;

				continue;

			}



			null_mask <<= 1;

		}



		if (is_null) {

		} else if (field->fixed_len) {

		if (field->fixed_len) {

			prefix_len += field->fixed_len;

		} else {

			ulint	len = *lens--;