btr0cur.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

	/* The first parameter means that no lock checking and undo logging
	is made in the insert */

	err = btr_cur_pessimistic_insert(BTR_NO_UNDO_LOG_FLAG
					| BTR_NO_LOCKING_FLAG
					| BTR_KEEP_SYS_FLAG,
					cursor, new_entry, &rec,
					&dummy_big_rec, NULL, mtr);
	ut_a(rec);
	ut_a(err == DB_SUCCESS);
	ut_a(dummy_big_rec == NULL);

	rec_set_field_extern_bits(rec, index, ext_vect, n_ext_vect, mtr);
	offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);

	if (!rec_get_deleted_flag(rec, rec_offs_comp(offsets))) {
		/* The new inserted record owns its possible externally
		stored fields */

		btr_cur_unmark_extern_fields(rec, mtr, offsets);
	}

	lock_rec_restore_from_page_infimum(rec, page);

	/* If necessary, restore also the correct lock state for a new,
	preceding supremum record created in a page split. While the old
	record was nonexistent, the supremum might have inherited its locks
	from a wrong record. */

	if (!was_first) {
		btr_cur_pess_upd_restore_supremum(rec, mtr);
	}

return_after_reservations:
	mem_heap_free(heap);

	if (n_extents > 0) {
		fil_space_release_free_extents(index->space, n_reserved);
	}

	*big_rec = big_rec_vec;

	return(err);
}

/*==================== B-TREE DELETE MARK AND UNMARK ===============*/

/********************************************************************
Writes the redo log record for delete marking or unmarking of an index
record. */
UNIV_INLINE
void
btr_cur_del_mark_set_clust_rec_log(
/*===============================*/
	ulint		flags,	/* in: flags */
	rec_t*		rec,	/* in: record */
	dict_index_t*	index,	/* in: index of the record */
	ibool		val,	/* in: value to set */
	trx_t*		trx,	/* in: deleting transaction */
	dulint		roll_ptr,/* in: roll ptr to the undo log record */
	mtr_t*		mtr)	/* in: mtr */
{
	byte*	log_ptr;
	ut_ad(flags < 256);
	ut_ad(val <= 1);

	ut_ad(!!page_rec_is_comp(rec) == index->table->comp);

	log_ptr = mlog_open_and_write_index(mtr, rec, index,
			page_rec_is_comp(rec)
			? MLOG_COMP_REC_CLUST_DELETE_MARK
			: MLOG_REC_CLUST_DELETE_MARK,
			1 + 1 + DATA_ROLL_PTR_LEN + 14 + 2);

	if (!log_ptr) {
		/* Logging in mtr is switched off during crash recovery */
		return;
	}

	mach_write_to_1(log_ptr, flags);
	log_ptr++;
	mach_write_to_1(log_ptr, val);
	log_ptr++;

	log_ptr = row_upd_write_sys_vals_to_log(index, trx, roll_ptr, log_ptr,
									mtr);
	mach_write_to_2(log_ptr, ut_align_offset(rec, UNIV_PAGE_SIZE));
	log_ptr += 2;

	mlog_close(mtr, log_ptr);
}

/********************************************************************
Parses the redo log record for delete marking or unmarking of a clustered
index record. */

byte*
btr_cur_parse_del_mark_set_clust_rec(
/*=================================*/
				/* out: end of log record or NULL */
	byte*		ptr,	/* in: buffer */
	byte*		end_ptr,/* in: buffer end */
	dict_index_t*	index,	/* in: index corresponding to page */
	page_t*		page)	/* in: page or NULL */
{
	ulint	flags;
	ulint	val;
	ulint	pos;
	dulint	trx_id;
	dulint	roll_ptr;
	ulint	offset;
	rec_t*	rec;

	ut_ad(!page || !!page_is_comp(page) == index->table->comp);

	if (end_ptr < ptr + 2) {

		return(NULL);
	}
	
	flags = mach_read_from_1(ptr);
	ptr++;
	val = mach_read_from_1(ptr);
	ptr++;

	ptr = row_upd_parse_sys_vals(ptr, end_ptr, &pos, &trx_id, &roll_ptr);

	if (ptr == NULL) {

		return(NULL);
	}

	if (end_ptr < ptr + 2) {

		return(NULL);
	}

	offset = mach_read_from_2(ptr);
	ptr += 2;

	ut_a(offset <= UNIV_PAGE_SIZE);

	if (page) {
		rec = page + offset;
	
		if (!(flags & BTR_KEEP_SYS_FLAG)) {
			mem_heap_t*	heap		= NULL;
			ulint		offsets_[REC_OFFS_NORMAL_SIZE];
			*offsets_ = (sizeof offsets_) / sizeof *offsets_;

			row_upd_rec_sys_fields_in_recovery(rec,
					rec_get_offsets(rec, index, offsets_,
					ULINT_UNDEFINED, &heap),
					pos, trx_id, roll_ptr);
			if (UNIV_LIKELY_NULL(heap)) {
				mem_heap_free(heap);
			}
		}

		/* We do not need to reserve btr_search_latch, as the page
		is only being recovered, and there cannot be a hash index to
		it. */

		rec_set_deleted_flag(rec, page_is_comp(page), val);
	}
	
	return(ptr);
}

/***************************************************************
Marks a clustered index record deleted. Writes an undo log record to
undo log on this delete marking. Writes in the trx id field the id
of the deleting transaction, and in the roll ptr field pointer to the
undo log record created. */

ulint
btr_cur_del_mark_set_clust_rec(
/*===========================*/
				/* out: DB_SUCCESS, DB_LOCK_WAIT, or error
				number */
	ulint		flags,	/* in: undo logging and locking flags */
	btr_cur_t*	cursor,	/* in: cursor */
	ibool		val,	/* in: value to set */
	que_thr_t*	thr,	/* in: query thread */
	mtr_t*		mtr)	/* in: mtr */
{
	dict_index_t*	index;
	buf_block_t*	block;
	dulint		roll_ptr;
	ulint		err;
	rec_t*		rec;
	trx_t*		trx;
	mem_heap_t*	heap		= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets		= offsets_;
	*offsets_ = (sizeof offsets_) / sizeof *offsets_;

	rec = btr_cur_get_rec(cursor);
	index = cursor->index;
	ut_ad(!!page_rec_is_comp(rec) == index->table->comp);
	offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap);

#ifdef UNIV_DEBUG
	if (btr_cur_print_record_ops && thr) {
		btr_cur_trx_report(thr_get_trx(thr), index, "del mark ");
		rec_print_new(stderr, rec, offsets);
	}
#endif /* UNIV_DEBUG */

	ut_ad(index->type & DICT_CLUSTERED);
	ut_ad(!rec_get_deleted_flag(rec, rec_offs_comp(offsets)));

	err = lock_clust_rec_modify_check_and_lock(flags,
						rec, index, offsets, thr);

	if (err != DB_SUCCESS) {

		if (UNIV_LIKELY_NULL(heap)) {
			mem_heap_free(heap);
		}
		return(err);
	}

	err = trx_undo_report_row_operation(flags, TRX_UNDO_MODIFY_OP, thr,
						index, NULL, NULL, 0, rec,
						&roll_ptr);
	if (err != DB_SUCCESS) {

		if (UNIV_LIKELY_NULL(heap)) {
			mem_heap_free(heap);
		}
		return(err);
	}

	block = buf_block_align(rec);

	if (block->is_hashed) {
		rw_lock_x_lock(&btr_search_latch);
	}

	rec_set_deleted_flag(rec, rec_offs_comp(offsets), val);

	trx = thr_get_trx(thr);
	
	if (!(flags & BTR_KEEP_SYS_FLAG)) {
		row_upd_rec_sys_fields(rec, index, offsets, trx, roll_ptr);
	}
	
	if (block->is_hashed) {
		rw_lock_x_unlock(&btr_search_latch);
	}

	btr_cur_del_mark_set_clust_rec_log(flags, rec, index, val, trx,
							roll_ptr, mtr);
	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
	return(DB_SUCCESS);
}

/********************************************************************
Writes the redo log record for a delete mark setting of a secondary
index record. */
UNIV_INLINE
void
btr_cur_del_mark_set_sec_rec_log(
/*=============================*/
	rec_t*		rec,	/* in: record */
	ibool		val,	/* in: value to set */
	mtr_t*		mtr)	/* in: mtr */
{
	byte*	log_ptr;
	ut_ad(val <= 1);

	log_ptr = mlog_open(mtr, 11 + 1 + 2);

	if (!log_ptr) {
		/* Logging in mtr is switched off during crash recovery:
		in that case mlog_open returns NULL */
		return;
	}

	log_ptr = mlog_write_initial_log_record_fast(
			rec, MLOG_REC_SEC_DELETE_MARK, log_ptr, mtr);
	mach_write_to_1(log_ptr, val);
	log_ptr++;

	mach_write_to_2(log_ptr, ut_align_offset(rec, UNIV_PAGE_SIZE));
	log_ptr += 2;

	mlog_close(mtr, log_ptr);
}

/********************************************************************
Parses the redo log record for delete marking or unmarking of a secondary
index record. */

byte*
btr_cur_parse_del_mark_set_sec_rec(
/*===============================*/
				/* out: end of log record or NULL */
	byte*		ptr,	/* in: buffer */
	byte*		end_ptr,/* in: buffer end */
	page_t*		page)	/* in: page or NULL */
{
	ulint	val;
	ulint	offset;
	rec_t*	rec;

	if (end_ptr < ptr + 3) {

		return(NULL);
	}
	
	val = mach_read_from_1(ptr);
	ptr++;

	offset = mach_read_from_2(ptr);
	ptr += 2;

	ut_a(offset <= UNIV_PAGE_SIZE);

	if (page) {
		rec = page + offset;
	
		/* We do not need to reserve btr_search_latch, as the page
		is only being recovered, and there cannot be a hash index to
		it. */

		rec_set_deleted_flag(rec, page_is_comp(page), val);
	}
	
	return(ptr);
}
	
/***************************************************************
Sets a secondary index record delete mark to TRUE or FALSE. */

ulint
btr_cur_del_mark_set_sec_rec(
/*=========================*/
				/* out: DB_SUCCESS, DB_LOCK_WAIT, or error
				number */
	ulint		flags,	/* in: locking flag */
	btr_cur_t*	cursor,	/* in: cursor */
	ibool		val,	/* in: value to set */
	que_thr_t*	thr,	/* in: query thread */
	mtr_t*		mtr)	/* in: mtr */
{
	buf_block_t*	block;
	rec_t*		rec;
	ulint		err;

	rec = btr_cur_get_rec(cursor);

#ifdef UNIV_DEBUG
	if (btr_cur_print_record_ops && thr) {
		btr_cur_trx_report(thr_get_trx(thr), cursor->index,
				"del mark ");
		rec_print(stderr, rec, cursor->index);
	}
#endif /* UNIV_DEBUG */

	err = lock_sec_rec_modify_check_and_lock(flags, rec, cursor->index,
									thr);
	if (err != DB_SUCCESS) {

		return(err);
	}

	block = buf_block_align(rec);
	ut_ad(!!page_is_comp(buf_block_get_frame(block))
			== cursor->index->table->comp);
	
	if (block->is_hashed) {
		rw_lock_x_lock(&btr_search_latch);
	}

	rec_set_deleted_flag(rec, page_is_comp(buf_block_get_frame(block)),
									val);

	if (block->is_hashed) {
		rw_lock_x_unlock(&btr_search_latch);
	}

	btr_cur_del_mark_set_sec_rec_log(rec, val, mtr);

	return(DB_SUCCESS);
}

/***************************************************************
Sets a secondary index record delete mark to FALSE. This function is only
used by the insert buffer insert merge mechanism. */

void
btr_cur_del_unmark_for_ibuf(
/*========================*/
	rec_t*		rec,	/* in: record to delete unmark */
	mtr_t*		mtr)	/* in: mtr */
{
	/* We do not need to reserve btr_search_latch, as the page has just
	been read to the buffer pool and there cannot be a hash index to it. */

	rec_set_deleted_flag(rec, page_is_comp(buf_frame_align(rec)), FALSE);

	btr_cur_del_mark_set_sec_rec_log(rec, FALSE, mtr);
}

/*==================== B-TREE RECORD REMOVE =========================*/

/*****************************************************************
Tries to compress a page of the tree on the leaf level. It is assumed
that mtr holds an x-latch on the tree and on the cursor page. To avoid
deadlocks, mtr must also own x-latches to brothers of page, if those
brothers exist. NOTE: it is assumed that the caller has reserved enough
free extents so that the compression will always succeed if done! */

void
btr_cur_compress(
/*=============*/
	btr_cur_t*	cursor,	/* in: cursor on the page to compress;
				cursor does not stay valid */
	mtr_t*		mtr)	/* in: mtr */
{
	ut_ad(mtr_memo_contains(mtr,
				dict_tree_get_lock(btr_cur_get_tree(cursor)),
							MTR_MEMO_X_LOCK));
	ut_ad(mtr_memo_contains(mtr, buf_block_align(
						btr_cur_get_page(cursor)),
				MTR_MEMO_PAGE_X_FIX));
	ut_ad(btr_page_get_level(btr_cur_get_page(cursor), mtr) == 0);

	btr_compress(cursor, mtr);	
}

/*****************************************************************
Tries to compress a page of the tree if it seems useful. It is assumed
that mtr holds an x-latch on the tree and on the cursor page. To avoid
deadlocks, mtr must also own x-latches to brothers of page, if those
brothers exist. NOTE: it is assumed that the caller has reserved enough
free extents so that the compression will always succeed if done! */

ibool
btr_cur_compress_if_useful(
/*=======================*/
				/* out: TRUE if compression occurred */
	btr_cur_t*	cursor,	/* in: cursor on the page to compress;
				cursor does not stay valid if compression
				occurs */
	mtr_t*		mtr)	/* in: mtr */
{
	ut_ad(mtr_memo_contains(mtr,
				dict_tree_get_lock(btr_cur_get_tree(cursor)),
							MTR_MEMO_X_LOCK));
	ut_ad(mtr_memo_contains(mtr, buf_block_align(
						btr_cur_get_page(cursor)),
				MTR_MEMO_PAGE_X_FIX));

	if (btr_cur_compress_recommendation(cursor, mtr)) {

		btr_compress(cursor, mtr);

		return(TRUE);
	}

	return(FALSE);
}

/***********************************************************
Removes the record on which the tree cursor is positioned on a leaf page.
It is assumed that the mtr has an x-latch on the page where the cursor is
positioned, but no latch on the whole tree. */

ibool
btr_cur_optimistic_delete(
/*======================*/
				/* out: TRUE if success, i.e., the page
				did not become too empty */
	btr_cur_t*	cursor,	/* in: cursor on leaf page, on the record to
				delete; cursor stays valid: if deletion
				succeeds, on fun