ibuf0ibuf.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

			     / IBUF_MERGE_THRESHOLD)) {

			        space_ids[*n_stored] = prev_space_id;
				space_versions[*n_stored]
						= fil_space_get_version(
							prev_space_id);
				page_nos[*n_stored] = prev_page_no;

				(*n_stored)++;

				sum_volumes += volume_for_page;
			}

			if (rec_space_id != first_space_id
			    || rec_page_no / IBUF_MERGE_AREA
			       != first_page_no / IBUF_MERGE_AREA) {

		    		break;
			}

			volume_for_page = 0;
		}

		if (rec_page_no == 1 && rec_space_id == 0) {
			/* Supremum record */

			break;
		}

		rec_volume = ibuf_rec_get_volume(rec);

		volume_for_page += rec_volume;
		
		prev_page_no = rec_page_no;
		prev_space_id = rec_space_id;

		rec = page_rec_get_next(rec);
	}

#ifdef UNIV_IBUF_DEBUG
	ut_a(*n_stored <= IBUF_MAX_N_PAGES_MERGED);
#endif
/*	fprintf(stderr, "Ibuf merge batch %lu pages %lu volume\n", *n_stored,
							sum_volumes); */
	return(sum_volumes);
}

/*************************************************************************
Contracts insert buffer trees by reading pages to the buffer pool. */
static
ulint
ibuf_contract_ext(
/*==============*/
			/* out: a lower limit for the combined size in bytes
			of entries which will be merged from ibuf trees to the
			pages read, 0 if ibuf is empty */
	ulint*	n_pages,/* out: number of pages to which merged */
	ibool	sync)	/* in: TRUE if the caller wants to wait for the
			issued read with the highest tablespace address
			to complete */
{
	ulint		rnd_pos;
	ibuf_data_t*	data;
	btr_pcur_t	pcur;
	ulint		space;
	ibool		all_trees_empty;
	ulint		page_nos[IBUF_MAX_N_PAGES_MERGED];
	ulint		space_ids[IBUF_MAX_N_PAGES_MERGED];
	ib_longlong	space_versions[IBUF_MAX_N_PAGES_MERGED];
	ulint		n_stored;
	ulint		sum_sizes;
	mtr_t		mtr;

	*n_pages = 0;
loop:
	ut_ad(!ibuf_inside());

	mutex_enter(&ibuf_mutex);

	ut_ad(ibuf_validate_low());	

	/* Choose an ibuf tree at random (though there really is only one tree
	in the current implementation) */
	ibuf_rnd += 865558671;

	rnd_pos = ibuf_rnd % ibuf->size;

	all_trees_empty = TRUE;

	data = UT_LIST_GET_FIRST(ibuf->data_list);

	for (;;) {
		if (!data->empty) {
			all_trees_empty = FALSE;
		
			if (rnd_pos < data->size) {

				break;
			}
		
			rnd_pos -= data->size;
		}
			
		data = UT_LIST_GET_NEXT(data_list, data);

		if (data == NULL) {
			if (all_trees_empty) {
				mutex_exit(&ibuf_mutex);

				return(0);
			}
			
			data = UT_LIST_GET_FIRST(ibuf->data_list);
		}
	}

	ut_ad(data);

	space = data->index->space;

	ut_a(space == 0);	/* We currently only have an ibuf tree in
				space 0 */
	mtr_start(&mtr);

	ibuf_enter();
	
	/* Open a cursor to a randomly chosen leaf of the tree, at a random
	position within the leaf */

	btr_pcur_open_at_rnd_pos(data->index, BTR_SEARCH_LEAF, &pcur, &mtr);

	if (0 == page_get_n_recs(btr_pcur_get_page(&pcur))) {

		/* This tree is empty */
	    
	    	data->empty = TRUE;

	    	ibuf_exit();

	    	mtr_commit(&mtr);
	    	btr_pcur_close(&pcur);

	    	mutex_exit(&ibuf_mutex);

	    	goto loop;
	}
	
	mutex_exit(&ibuf_mutex);

	sum_sizes = ibuf_get_merge_page_nos(TRUE, btr_pcur_get_rec(&pcur),
			space_ids, space_versions, page_nos, &n_stored);
#ifdef UNIV_IBUF_DEBUG
	/* fprintf(stderr, "Ibuf contract sync %lu pages %lu volume %lu\n",
		sync, n_stored, sum_sizes); */
#endif
	ibuf_exit();

	mtr_commit(&mtr);
	btr_pcur_close(&pcur);

	buf_read_ibuf_merge_pages(sync, space_ids, space_versions, page_nos,
								   n_stored);
	*n_pages = n_stored;
	
	return(sum_sizes + 1);
}

/*************************************************************************
Contracts insert buffer trees by reading pages to the buffer pool. */

ulint
ibuf_contract(
/*==========*/
			/* out: a lower limit for the combined size in bytes
			of entries which will be merged from ibuf trees to the
			pages read, 0 if ibuf is empty */
	ibool	sync)	/* in: TRUE if the caller wants to wait for the
			issued read with the highest tablespace address
			to complete */
{
	ulint	n_pages;

	return(ibuf_contract_ext(&n_pages, sync));
}

/*************************************************************************
Contracts insert buffer trees by reading pages to the buffer pool. */

ulint
ibuf_contract_for_n_pages(
/*======================*/
			/* out: a lower limit for the combined size in bytes
			of entries which will be merged from ibuf trees to the
			pages read, 0 if ibuf is empty */
	ibool	sync,	/* in: TRUE if the caller wants to wait for the
			issued read with the highest tablespace address
			to complete */
	ulint	n_pages)/* in: try to read at least this many pages to
			the buffer pool and merge the ibuf contents to
			them */
{
	ulint	sum_bytes	= 0;
	ulint	sum_pages 	= 0;
	ulint	n_bytes;
	ulint	n_pag2;
	
	while (sum_pages < n_pages) {
		n_bytes = ibuf_contract_ext(&n_pag2, sync);
		
		if (n_bytes == 0) {
			return(sum_bytes);
		}

		sum_bytes += n_bytes;
		sum_pages += n_pag2;
	}

	return(sum_bytes);
}

/*************************************************************************
Contract insert buffer trees after insert if they are too big. */
UNIV_INLINE
void
ibuf_contract_after_insert(
/*=======================*/
	ulint	entry_size)	/* in: size of a record which was inserted
				into an ibuf tree */
{
	ibool	sync;
	ulint	sum_sizes;
	ulint	size;

	mutex_enter(&ibuf_mutex);

	if (ibuf->size < ibuf->max_size + IBUF_CONTRACT_ON_INSERT_NON_SYNC) {
		mutex_exit(&ibuf_mutex);

		return;
	}

	sync = FALSE;
	
	if (ibuf->size >= ibuf->max_size + IBUF_CONTRACT_ON_INSERT_SYNC) {

		sync = TRUE;
	}

	mutex_exit(&ibuf_mutex);

	/* Contract at least entry_size many bytes */
	sum_sizes = 0;
	size = 1;

	while ((size > 0) && (sum_sizes < entry_size)) {

		size = ibuf_contract(sync);
		sum_sizes += size;
	}
}

/*************************************************************************
Gets an upper limit for the combined size of entries buffered in the insert
buffer for a given page. */

ulint
ibuf_get_volume_buffered(
/*=====================*/
				/* out: upper limit for the volume of
				buffered inserts for the index page, in bytes;
				we may also return UNIV_PAGE_SIZE, if the
				entries for the index page span on several
				pages in the insert buffer */
	btr_pcur_t*	pcur,	/* in: pcur positioned at a place in an
				insert buffer tree where we would insert an
				entry for the index page whose number is
				page_no, latch mode has to be BTR_MODIFY_PREV
				or BTR_MODIFY_TREE */
	ulint		space,	/* in: space id */
	ulint		page_no,/* in: page number of an index page */
	mtr_t*		mtr)	/* in: mtr */
{
	ulint	volume;
	rec_t*	rec;
	page_t*	page;
	ulint	prev_page_no;
	page_t*	prev_page;
	ulint	next_page_no;
	page_t*	next_page;
	
	ut_a(trx_sys_multiple_tablespace_format);

	ut_ad((pcur->latch_mode == BTR_MODIFY_PREV)
				|| (pcur->latch_mode == BTR_MODIFY_TREE));

	/* Count the volume of records earlier in the alphabetical order than
	pcur */

	volume = 0;
	
	rec = btr_pcur_get_rec(pcur);

	page = buf_frame_align(rec);

	if (page_rec_is_supremum(rec)) {
		rec = page_rec_get_prev(rec);
	}

	for (;;) {
		if (page_rec_is_infimum(rec)) {

			break;
		}
		
		if (page_no != ibuf_rec_get_page_no(rec)
		    || space != ibuf_rec_get_space(rec)) {

			goto count_later;
		}

		volume += ibuf_rec_get_volume(rec);

		rec = page_rec_get_prev(rec);
	}

	/* Look at the previous page */
	
	prev_page_no = btr_page_get_prev(page, mtr);

	if (prev_page_no == FIL_NULL) {

		goto count_later;
	}

	prev_page = buf_page_get(0, prev_page_no, RW_X_LATCH, mtr);

#ifdef UNIV_SYNC_DEBUG
	buf_page_dbg_add_level(prev_page, SYNC_TREE_NODE);
#endif /* UNIV_SYNC_DEBUG */

	rec = page_get_supremum_rec(prev_page);
	rec = page_rec_get_prev(rec);
	
	for (;;) {
		if (page_rec_is_infimum(rec)) {

			/* We cannot go to yet a previous page, because we
			do not have the x-latch on it, and cannot acquire one
			because of the latching order: we have to give up */
		
			return(UNIV_PAGE_SIZE);
		}
		
		if (page_no != ibuf_rec_get_page_no(rec)
		    || space != ibuf_rec_get_space(rec)) {

			goto count_later;
		}

		volume += ibuf_rec_get_volume(rec);

		rec = page_rec_get_prev(rec);
	}
		
count_later:
	rec = btr_pcur_get_rec(pcur);

	if (!page_rec_is_supremum(rec)) {
		rec = page_rec_get_next(rec);
	}

	for (;;) {
		if (page_rec_is_supremum(rec)) {

			break;
		}
		
		if (page_no != ibuf_rec_get_page_no(rec)
		    || space != ibuf_rec_get_space(rec)) {

			return(volume);
		}

		volume += ibuf_rec_get_volume(rec);

		rec = page_rec_get_next(rec);
	}

	/* Look at the next page */
	
	next_page_no = btr_page_get_next(page, mtr);

	if (next_page_no == FIL_NULL) {

		return(volume);
	}

	next_page = buf_page_get(0, next_page_no, RW_X_LATCH, mtr);

#ifdef UNIV_SYNC_DEBUG
	buf_page_dbg_add_level(next_page, SYNC_TREE_NODE);
#endif /* UNIV_SYNC_DEBUG */

	rec = page_get_infimum_rec(next_page);
	rec = page_rec_get_next(rec);

	for (;;) {
		if (page_rec_is_supremum(rec)) {

			/* We give up */
		
			return(UNIV_PAGE_SIZE);
		}
		
		if (page_no != ibuf_rec_get_page_no(rec)
		    || space != ibuf_rec_get_space(rec)) {

			return(volume);
		}

		volume += ibuf_rec_get_volume(rec);

		rec = page_rec_get_next(rec);
	}
}

/*************************************************************************
Reads the biggest tablespace id from the high end of the insert buffer
tree and updates the counter in fil_system. */

void
ibuf_update_max_tablespace_id(void)
/*===============================*/
{
	ulint		max_space_id;
	rec_t*		rec;
	byte*		field;
	ulint		len;
	ibuf_data_t*	ibuf_data;
	dict_index_t*	ibuf_index;
	btr_pcur_t	pcur;
	mtr_t		mtr;

	ibuf_data = fil_space_get_ibuf_data(0);

	ibuf_index = ibuf_data->index;
	ut_a(!ibuf_index->table->comp);

	ibuf_enter();

	mtr_start(&mtr);

	btr_pcur_open_at_index_side(FALSE, ibuf_index, BTR_SEARCH_LEAF,
							&pcur, TRUE, &mtr);
	btr_pcur_move_to_prev(&pcur, &mtr);

	if (btr_pcur_is_before_first_on_page(&pcur, &mtr)) {
		/* The tree is empty */

		max_space_id = 0;
	} else {
		rec = btr_pcur_get_rec(&pcur);

		field = rec_get_nth_field_old(rec, 0, &len);

		ut_a(len == 4);
		
		max_space_id = mach_read_from_4(field);
	}

	mtr_commit(&mtr);
	ibuf_exit();

	/* printf("Maximum space id in insert buffer %lu\n", max_space_id); */

	fil_set_max_space_id_if_bigger(max_space_id);
}

/*************************************************************************
Makes an index insert to the insert buffer, instead of directly to the disk
page, if this is possible. */
static
ulint
ibuf_insert_low(
/*============*/
				/* out: DB_SUCCESS, DB_FAIL, DB_STRONG_FAIL */
	ulint		mode,	/* in: BTR_MODIFY_PREV or BTR_MODIFY_TREE */
	dtuple_t*	entry,	/* in: index entry to insert */
	dict_index_t*	index,	/* in: index where to insert; must not be
				unique or clustered */
	ulint		space,	/* in: space id where to insert */
	ulint		page_no,/* in: page number where to insert */
	que_thr_t*	thr)	/* in: query thread */
{
	big_rec_t*	dummy_big_rec;
	ulint		entry_size;