/*****************************************************************************

Copyright (c) 1995, 2021, Oracle and/or its affiliates.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License, version 2.0,
as published by the Free Software Foundation.

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but not limited to OpenSSL) that is licensed under separate terms,
as designated in a particular file or component or in included license
documentation.  The authors of MySQL hereby grant you an additional
permission to link the program and your derivative works with the
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This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License, version 2.0, for more details.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA

*****************************************************************************/

/******************************************************************//**
@file fut/fut0lst.cc
File-based list utilities

Created 11/28/1995 Heikki Tuuri
***********************************************************************/

#include "univ.i"
#include "fut0lst.h"

#ifdef UNIV_NONINL
#include "fut0lst.ic"
#endif

#include "buf0buf.h"
#include "page0page.h"

/********************************************************************//**
Adds a node to an empty list. */
static
void
flst_add_to_empty(
/*==============*/
	flst_base_node_t*	base,	/*!< in: pointer to base node of
					empty list */
	flst_node_t*		node,	/*!< in: node to add */
	mtr_t*			mtr)	/*!< in: mini-transaction handle */
{
	ulint		space;
	fil_addr_t	node_addr;
	ulint		len;

	ut_ad(mtr && base && node);
	ut_ad(base != node);
	ut_ad(mtr_memo_contains_page_flagged(mtr, base,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	ut_ad(mtr_memo_contains_page_flagged(mtr, node,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	len = flst_get_len(base);
	ut_a(len == 0);

	buf_ptr_get_fsp_addr(node, &space, &node_addr);

	/* Update first and last fields of base node */
	flst_write_addr(base + FLST_FIRST, node_addr, mtr);
	flst_write_addr(base + FLST_LAST, node_addr, mtr);

	/* Set prev and next fields of node to add */
	flst_write_addr(node + FLST_PREV, fil_addr_null, mtr);
	flst_write_addr(node + FLST_NEXT, fil_addr_null, mtr);

	/* Update len of base node */
	mlog_write_ulint(base + FLST_LEN, len + 1, MLOG_4BYTES, mtr);
}

/********************************************************************//**
Adds a node as the last node in a list. */
void
flst_add_last(
/*==========*/
	flst_base_node_t*	base,	/*!< in: pointer to base node of list */
	flst_node_t*		node,	/*!< in: node to add */
	mtr_t*			mtr)	/*!< in: mini-transaction handle */
{
	ulint		space;
	fil_addr_t	node_addr;
	ulint		len;
	fil_addr_t	last_addr;

	ut_ad(mtr && base && node);
	ut_ad(base != node);
	ut_ad(mtr_memo_contains_page_flagged(mtr, base,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	ut_ad(mtr_memo_contains_page_flagged(mtr, node,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	len = flst_get_len(base);
	last_addr = flst_get_last(base, mtr);

	buf_ptr_get_fsp_addr(node, &space, &node_addr);

	/* If the list is not empty, call flst_insert_after */
	if (len != 0) {
		flst_node_t*	last_node;

		if (last_addr.page == node_addr.page) {
			last_node = page_align(node) + last_addr.boffset;
		} else {
			bool			found;
			const page_size_t&	page_size
				= fil_space_get_page_size(space, &found);

			ut_ad(found);

			last_node = fut_get_ptr(space, page_size, last_addr,
						RW_SX_LATCH, mtr);
		}

		flst_insert_after(base, last_node, node, mtr);
	} else {
		/* else call flst_add_to_empty */
		flst_add_to_empty(base, node, mtr);
	}
}

/********************************************************************//**
Adds a node as the first node in a list. */
void
flst_add_first(
/*===========*/
	flst_base_node_t*	base,	/*!< in: pointer to base node of list */
	flst_node_t*		node,	/*!< in: node to add */
	mtr_t*			mtr)	/*!< in: mini-transaction handle */
{
	ulint		space;
	fil_addr_t	node_addr;
	ulint		len;
	fil_addr_t	first_addr;
	flst_node_t*	first_node;

	ut_ad(mtr && base && node);
	ut_ad(base != node);
	ut_ad(mtr_memo_contains_page_flagged(mtr, base,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	ut_ad(mtr_memo_contains_page_flagged(mtr, node,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	len = flst_get_len(base);
	first_addr = flst_get_first(base, mtr);

	buf_ptr_get_fsp_addr(node, &space, &node_addr);

	/* If the list is not empty, call flst_insert_before */
	if (len != 0) {
		if (first_addr.page == node_addr.page) {
			first_node = page_align(node) + first_addr.boffset;
		} else {
			bool			found;
			const page_size_t&	page_size
				= fil_space_get_page_size(space, &found);

			ut_ad(found);

			first_node = fut_get_ptr(space, page_size, first_addr,
						 RW_SX_LATCH, mtr);
		}

		flst_insert_before(base, node, first_node, mtr);
	} else {
		/* else call flst_add_to_empty */
		flst_add_to_empty(base, node, mtr);
	}
}

/********************************************************************//**
Inserts a node after another in a list. */
void
flst_insert_after(
/*==============*/
	flst_base_node_t*	base,	/*!< in: pointer to base node of list */
	flst_node_t*		node1,	/*!< in: node to insert after */
	flst_node_t*		node2,	/*!< in: node to add */
	mtr_t*			mtr)	/*!< in: mini-transaction handle */
{
	ulint		space;
	fil_addr_t	node1_addr;
	fil_addr_t	node2_addr;
	flst_node_t*	node3;
	fil_addr_t	node3_addr;
	ulint		len;

	ut_ad(mtr && node1 && node2 && base);
	ut_ad(base != node1);
	ut_ad(base != node2);
	ut_ad(node2 != node1);
	ut_ad(mtr_memo_contains_page_flagged(mtr, base,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	ut_ad(mtr_memo_contains_page_flagged(mtr, node1,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	ut_ad(mtr_memo_contains_page_flagged(mtr, node2,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));

	buf_ptr_get_fsp_addr(node1, &space, &node1_addr);
	buf_ptr_get_fsp_addr(node2, &space, &node2_addr);

	node3_addr = flst_get_next_addr(node1, mtr);

	/* Set prev and next fields of node2 */
	flst_write_addr(node2 + FLST_PREV, node1_addr, mtr);
	flst_write_addr(node2 + FLST_NEXT, node3_addr, mtr);

	if (!fil_addr_is_null(node3_addr)) {
		/* Update prev field of node3 */
		bool			found;
		const page_size_t&	page_size
			= fil_space_get_page_size(space, &found);

		ut_ad(found);

		node3 = fut_get_ptr(space, page_size,
				    node3_addr, RW_SX_LATCH, mtr);
		flst_write_addr(node3 + FLST_PREV, node2_addr, mtr);
	} else {
		/* node1 was last in list: update last field in base */
		flst_write_addr(base + FLST_LAST, node2_addr, mtr);
	}

	/* Set next field of node1 */
	flst_write_addr(node1 + FLST_NEXT, node2_addr, mtr);

	/* Update len of base node */
	len = flst_get_len(base);
	mlog_write_ulint(base + FLST_LEN, len + 1, MLOG_4BYTES, mtr);
}

/********************************************************************//**
Inserts a node before another in a list. */
void
flst_insert_before(
/*===============*/
	flst_base_node_t*	base,	/*!< in: pointer to base node of list */
	flst_node_t*		node2,	/*!< in: node to insert */
	flst_node_t*		node3,	/*!< in: node to insert before */
	mtr_t*			mtr)	/*!< in: mini-transaction handle */
{
	ulint		space;
	flst_node_t*	node1;
	fil_addr_t	node1_addr;
	fil_addr_t	node2_addr;
	fil_addr_t	node3_addr;
	ulint		len;

	ut_ad(mtr && node2 && node3 && base);
	ut_ad(base != node2);
	ut_ad(base != node3);
	ut_ad(node2 != node3);
	ut_ad(mtr_memo_contains_page_flagged(mtr, base,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	ut_ad(mtr_memo_contains_page_flagged(mtr, node2,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	ut_ad(mtr_memo_contains_page_flagged(mtr, node3,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));

	buf_ptr_get_fsp_addr(node2, &space, &node2_addr);
	buf_ptr_get_fsp_addr(node3, &space, &node3_addr);

	node1_addr = flst_get_prev_addr(node3, mtr);

	/* Set prev and next fields of node2 */
	flst_write_addr(node2 + FLST_PREV, node1_addr, mtr);
	flst_write_addr(node2 + FLST_NEXT, node3_addr, mtr);

	if (!fil_addr_is_null(node1_addr)) {
		bool			found;
		const page_size_t&	page_size
			= fil_space_get_page_size(space, &found);

		ut_ad(found);

		/* Update next field of node1 */
		node1 = fut_get_ptr(space, page_size, node1_addr,
				    RW_SX_LATCH, mtr);
		flst_write_addr(node1 + FLST_NEXT, node2_addr, mtr);
	} else {
		/* node3 was first in list: update first field in base */
		flst_write_addr(base + FLST_FIRST, node2_addr, mtr);
	}

	/* Set prev field of node3 */
	flst_write_addr(node3 + FLST_PREV, node2_addr, mtr);

	/* Update len of base node */
	len = flst_get_len(base);
	mlog_write_ulint(base + FLST_LEN, len + 1, MLOG_4BYTES, mtr);
}

/********************************************************************//**
Removes a node. */
void
flst_remove(
/*========*/
	flst_base_node_t*	base,	/*!< in: pointer to base node of list */
	flst_node_t*		node2,	/*!< in: node to remove */
	mtr_t*			mtr)	/*!< in: mini-transaction handle */
{
	ulint		space;
	flst_node_t*	node1;
	fil_addr_t	node1_addr;
	fil_addr_t	node2_addr;
	flst_node_t*	node3;
	fil_addr_t	node3_addr;
	ulint		len;

	ut_ad(mtr && node2 && base);
	ut_ad(mtr_memo_contains_page_flagged(mtr, base,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	ut_ad(mtr_memo_contains_page_flagged(mtr, node2,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));

	buf_ptr_get_fsp_addr(node2, &space, &node2_addr);

	bool			found;
	const page_size_t&	page_size = fil_space_get_page_size(space,
								    &found);

	ut_ad(found);

	node1_addr = flst_get_prev_addr(node2, mtr);
	node3_addr = flst_get_next_addr(node2, mtr);

	if (!fil_addr_is_null(node1_addr)) {

		/* Update next field of node1 */

		if (node1_addr.page == node2_addr.page) {

			node1 = page_align(node2) + node1_addr.boffset;
		} else {
			node1 = fut_get_ptr(space, page_size,
					    node1_addr, RW_SX_LATCH, mtr);
		}

		ut_ad(node1 != node2);

		flst_write_addr(node1 + FLST_NEXT, node3_addr, mtr);
	} else {
		/* node2 was first in list: update first field in base */
		flst_write_addr(base + FLST_FIRST, node3_addr, mtr);
	}

	if (!fil_addr_is_null(node3_addr)) {
		/* Update prev field of node3 */

		if (node3_addr.page == node2_addr.page) {

			node3 = page_align(node2) + node3_addr.boffset;
		} else {
			node3 = fut_get_ptr(space, page_size,
					    node3_addr, RW_SX_LATCH, mtr);
		}

		ut_ad(node2 != node3);

		flst_write_addr(node3 + FLST_PREV, node1_addr, mtr);
	} else {
		/* node2 was last in list: update last field in base */
		flst_write_addr(base + FLST_LAST, node1_addr, mtr);
	}

	/* Update len of base node */
	len = flst_get_len(base);
	ut_ad(len > 0);

	mlog_write_ulint(base + FLST_LEN, len - 1, MLOG_4BYTES, mtr);
}

/********************************************************************//**
Validates a file-based list.
@return TRUE if ok */
ibool
flst_validate(
/*==========*/
	const flst_base_node_t*	base,	/*!< in: pointer to base node of list */
	mtr_t*			mtr1)	/*!< in: mtr */
{
	ulint			space;
	const flst_node_t*	node;
	fil_addr_t		node_addr;
	fil_addr_t		base_addr;
	ulint			len;
	ulint			i;
	mtr_t			mtr2;

	ut_ad(base);
	ut_ad(mtr_memo_contains_page_flagged(mtr1, base,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));

	/* We use two mini-transaction handles: the first is used to
	lock the base node, and prevent other threads from modifying the
	list. The second is used to traverse the list. We cannot run the
	second mtr without committing it at times, because if the list
	is long, then the x-locked pages could fill the buffer resulting
	in a deadlock. */

	/* Find out the space id */
	buf_ptr_get_fsp_addr(base, &space, &base_addr);

	bool			found;
	const page_size_t&	page_size = fil_space_get_page_size(space,
								    &found);

	ut_ad(found);

	len = flst_get_len(base);
	node_addr = flst_get_first(base, mtr1);

	for (i = 0; i < len; i++) {
		mtr_start(&mtr2);

		node = fut_get_ptr(space, page_size,
				   node_addr, RW_SX_LATCH, &mtr2);
		node_addr = flst_get_next_addr(node, &mtr2);

		mtr_commit(&mtr2); /* Commit mtr2 each round to prevent buffer
				   becoming full */
	}

	ut_a(fil_addr_is_null(node_addr));

	node_addr = flst_get_last(base, mtr1);

	for (i = 0; i < len; i++) {
		mtr_start(&mtr2);

		node = fut_get_ptr(space, page_size,
				   node_addr, RW_SX_LATCH, &mtr2);
		node_addr = flst_get_prev_addr(node, &mtr2);

		mtr_commit(&mtr2); /* Commit mtr2 each round to prevent buffer
				   becoming full */
	}

	ut_a(fil_addr_is_null(node_addr));

	return(TRUE);
}

/********************************************************************//**
Prints info of a file-based list. */
void
flst_print(
/*=======*/
	const flst_base_node_t*	base,	/*!< in: pointer to base node of list */
	mtr_t*			mtr)	/*!< in: mtr */
{
	const buf_frame_t*	frame;
	ulint			len;

	ut_ad(base && mtr);
	ut_ad(mtr_memo_contains_page_flagged(mtr, base,
					     MTR_MEMO_PAGE_X_FIX
					     | MTR_MEMO_PAGE_SX_FIX));
	frame = page_align((byte*) base);

	len = flst_get_len(base);

	ib::info() << "FILE-BASED LIST: Base node in space "
		<< page_get_space_id(frame)
		<< "; page " << page_get_page_no(frame)
		<< "; byte offset " << page_offset(base)
		<< "; len " << len;
}
