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

Copyright (c) 2005, 2016, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2012, Facebook Inc.

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.

This program is also distributed with certain software (including
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
separately licensed software that they have included with MySQL.

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 include/page0zip.h
Compressed page interface

Created June 2005 by Marko Makela
*******************************************************/

#ifndef page0zip_h
#define page0zip_h

#ifdef UNIV_MATERIALIZE
# undef UNIV_INLINE
# define UNIV_INLINE
#endif

#ifdef UNIV_INNOCHECKSUM
#include "univ.i"
#include "buf0buf.h"
#include "ut0crc32.h"
#include "buf0checksum.h"
#include "mach0data.h"
#include "zlib.h"
#endif /* UNIV_INNOCHECKSUM */

#ifndef UNIV_INNOCHECKSUM
#include "mtr0types.h"
#include "page0types.h"
#endif /* !UNIV_INNOCHECKSUM */

#include "buf0types.h"

#ifndef UNIV_INNOCHECKSUM
#include "dict0types.h"
#include "srv0srv.h"
#include "trx0types.h"
#include "mem0mem.h"

/* Compression level to be used by zlib. Settable by user. */
extern uint	page_zip_level;

/* Default compression level. */
#define DEFAULT_COMPRESSION_LEVEL	6
/** Start offset of the area that will be compressed */
#define PAGE_ZIP_START			PAGE_NEW_SUPREMUM_END
/** Size of an compressed page directory entry */
#define PAGE_ZIP_DIR_SLOT_SIZE		2
/** Predefine the sum of DIR_SLOT, TRX_ID & ROLL_PTR */
#define PAGE_ZIP_CLUST_LEAF_SLOT_SIZE		\
		(PAGE_ZIP_DIR_SLOT_SIZE		\
		+ DATA_TRX_ID_LEN		\
		+ DATA_ROLL_PTR_LEN)
/** Mask of record offsets */
#define PAGE_ZIP_DIR_SLOT_MASK		0x3fff
/** 'owned' flag */
#define PAGE_ZIP_DIR_SLOT_OWNED		0x4000
/** 'deleted' flag */
#define PAGE_ZIP_DIR_SLOT_DEL		0x8000

/* Whether or not to log compressed page images to avoid possible
compression algorithm changes in zlib. */
extern my_bool	page_zip_log_pages;

/**********************************************************************//**
Determine the size of a compressed page in bytes.
@return size in bytes */
UNIV_INLINE
ulint
page_zip_get_size(
/*==============*/
	const page_zip_des_t*	page_zip)	/*!< in: compressed page */
	MY_ATTRIBUTE((warn_unused_result));
/**********************************************************************//**
Set the size of a compressed page in bytes. */
UNIV_INLINE
void
page_zip_set_size(
/*==============*/
	page_zip_des_t*	page_zip,	/*!< in/out: compressed page */
	ulint		size);		/*!< in: size in bytes */

#ifndef UNIV_HOTBACKUP
/** Determine if a record is so big that it needs to be stored externally.
@param[in]	rec_size	length of the record in bytes
@param[in]	comp		nonzero=compact format
@param[in]	n_fields	number of fields in the record; ignored if
tablespace is not compressed
@param[in]	page_size	page size
@return FALSE if the entire record can be stored locally on the page */
UNIV_INLINE
ibool
page_zip_rec_needs_ext(
	ulint			rec_size,
	ulint			comp,
	ulint			n_fields,
	const page_size_t&	page_size)
	MY_ATTRIBUTE((warn_unused_result));

/**********************************************************************//**
Determine the guaranteed free space on an empty page.
@return minimum payload size on the page */
ulint
page_zip_empty_size(
/*================*/
	ulint	n_fields,	/*!< in: number of columns in the index */
	ulint	zip_size)	/*!< in: compressed page size in bytes */
	MY_ATTRIBUTE((const));

/** Check whether a tuple is too big for compressed table
@param[in]	index	dict index object
@param[in]	entry	entry for the index
@return	true if it's too big, otherwise false */
bool
page_zip_is_too_big(
	const dict_index_t*	index,
	const dtuple_t*		entry);
#endif /* !UNIV_HOTBACKUP */

/**********************************************************************//**
Initialize a compressed page descriptor. */
UNIV_INLINE
void
page_zip_des_init(
/*==============*/
	page_zip_des_t*	page_zip);	/*!< in/out: compressed page
					descriptor */

/**********************************************************************//**
Configure the zlib allocator to use the given memory heap. */
void
page_zip_set_alloc(
/*===============*/
	void*		stream,		/*!< in/out: zlib stream */
	mem_heap_t*	heap);		/*!< in: memory heap to use */

/**********************************************************************//**
Compress a page.
@return TRUE on success, FALSE on failure; page_zip will be left
intact on failure. */
ibool
page_zip_compress(
/*==============*/
	page_zip_des_t*		page_zip,	/*!< in: size; out: data,
						n_blobs, m_start, m_end,
						m_nonempty */
	const page_t*		page,		/*!< in: uncompressed page */
	dict_index_t*		index,		/*!< in: index of the B-tree
						node */
	ulint			level,		/*!< in: commpression level */
	const redo_page_compress_t* page_comp_info,
						/*!< in: used for applying
						TRUNCATE log
						record during recovery */
	mtr_t*			mtr);		/*!< in/out: mini-transaction,
						or NULL */

/**********************************************************************//**
Write the index information for the compressed page.
@return used size of buf */
ulint
page_zip_fields_encode(
/*===================*/
	ulint			n,	/*!< in: number of fields
					to compress */
	const dict_index_t*	index,	/*!< in: index comprising
					at least n fields */
	ulint			trx_id_pos,
					/*!< in: position of the trx_id column
					in the index, or ULINT_UNDEFINED if
					this is a non-leaf page */
	byte*			buf);	/*!< out: buffer of (n + 1) * 2 bytes */

/**********************************************************************//**
Decompress a page.  This function should tolerate errors on the compressed
page.  Instead of letting assertions fail, it will return FALSE if an
inconsistency is detected.
@return TRUE on success, FALSE on failure */
ibool
page_zip_decompress(
/*================*/
	page_zip_des_t*	page_zip,/*!< in: data, ssize;
				out: m_start, m_end, m_nonempty, n_blobs */
	page_t*		page,	/*!< out: uncompressed page, may be trashed */
	ibool		all)	/*!< in: TRUE=decompress the whole page;
				FALSE=verify but do not copy some
				page header fields that should not change
				after page creation */
	MY_ATTRIBUTE((nonnull(1,2)));

#ifdef UNIV_DEBUG
/**********************************************************************//**
Validate a compressed page descriptor.
@return TRUE if ok */
UNIV_INLINE
ibool
page_zip_simple_validate(
/*=====================*/
	const page_zip_des_t*	page_zip);	/*!< in: compressed page
						descriptor */
#endif /* UNIV_DEBUG */

#ifdef UNIV_ZIP_DEBUG
/**********************************************************************//**
Check that the compressed and decompressed pages match.
@return TRUE if valid, FALSE if not */
ibool
page_zip_validate_low(
/*==================*/
	const page_zip_des_t*	page_zip,/*!< in: compressed page */
	const page_t*		page,	/*!< in: uncompressed page */
	const dict_index_t*	index,	/*!< in: index of the page, if known */
	ibool			sloppy)	/*!< in: FALSE=strict,
					TRUE=ignore the MIN_REC_FLAG */
	MY_ATTRIBUTE((nonnull(1,2)));
/**********************************************************************//**
Check that the compressed and decompressed pages match. */
ibool
page_zip_validate(
/*==============*/
	const page_zip_des_t*	page_zip,/*!< in: compressed page */
	const page_t*		page,	/*!< in: uncompressed page */
	const dict_index_t*	index)	/*!< in: index of the page, if known */
	MY_ATTRIBUTE((nonnull(1,2)));
#endif /* UNIV_ZIP_DEBUG */

/**********************************************************************//**
Determine how big record can be inserted without recompressing the page.
@return a positive number indicating the maximum size of a record
whose insertion is guaranteed to succeed, or zero or negative */
UNIV_INLINE
lint
page_zip_max_ins_size(
/*==================*/
	const page_zip_des_t*	page_zip,/*!< in: compressed page */
	ibool			is_clust)/*!< in: TRUE if clustered index */
	MY_ATTRIBUTE((warn_unused_result));

/**********************************************************************//**
Determine if enough space is available in the modification log.
@return TRUE if page_zip_write_rec() will succeed */
UNIV_INLINE
ibool
page_zip_available(
/*===============*/
	const page_zip_des_t*	page_zip,/*!< in: compressed page */
	ibool			is_clust,/*!< in: TRUE if clustered index */
	ulint			length,	/*!< in: combined size of the record */
	ulint			create)	/*!< in: nonzero=add the record to
					the heap */
	MY_ATTRIBUTE((warn_unused_result));

/**********************************************************************//**
Write data to the uncompressed header portion of a page.  The data must
already have been written to the uncompressed page. */
UNIV_INLINE
void
page_zip_write_header(
/*==================*/
	page_zip_des_t*	page_zip,/*!< in/out: compressed page */
	const byte*	str,	/*!< in: address on the uncompressed page */
	ulint		length,	/*!< in: length of the data */
	mtr_t*		mtr)	/*!< in: mini-transaction, or NULL */
	MY_ATTRIBUTE((nonnull(1,2)));

/**********************************************************************//**
Write an entire record on the compressed page.  The data must already
have been written to the uncompressed page. */
void
page_zip_write_rec(
/*===============*/
	page_zip_des_t*	page_zip,/*!< in/out: compressed page */
	const byte*	rec,	/*!< in: record being written */
	dict_index_t*	index,	/*!< in: the index the record belongs to */
	const ulint*	offsets,/*!< in: rec_get_offsets(rec, index) */
	ulint		create)	/*!< in: nonzero=insert, zero=update */
	MY_ATTRIBUTE((nonnull));

/***********************************************************//**
Parses a log record of writing a BLOB pointer of a record.
@return end of log record or NULL */
byte*
page_zip_parse_write_blob_ptr(
/*==========================*/
	byte*		ptr,	/*!< in: redo log buffer */
	byte*		end_ptr,/*!< in: redo log buffer end */
	page_t*		page,	/*!< in/out: uncompressed page */
	page_zip_des_t*	page_zip);/*!< in/out: compressed page */

/**********************************************************************//**
Write a BLOB pointer of a record on the leaf page of a clustered index.
The information must already have been updated on the uncompressed page. */
void
page_zip_write_blob_ptr(
/*====================*/
	page_zip_des_t*	page_zip,/*!< in/out: compressed page */
	const byte*	rec,	/*!< in/out: record whose data is being
				written */
	dict_index_t*	index,	/*!< in: index of the page */
	const ulint*	offsets,/*!< in: rec_get_offsets(rec, index) */
	ulint		n,	/*!< in: column index */
	mtr_t*		mtr);	/*!< in: mini-transaction handle,
				or NULL if no logging is needed */

/***********************************************************//**
Parses a log record of writing the node pointer of a record.
@return end of log record or NULL */
byte*
page_zip_parse_write_node_ptr(
/*==========================*/
	byte*		ptr,	/*!< in: redo log buffer */
	byte*		end_ptr,/*!< in: redo log buffer end */
	page_t*		page,	/*!< in/out: uncompressed page */
	page_zip_des_t*	page_zip);/*!< in/out: compressed page */

/**********************************************************************//**
Write the node pointer of a record on a non-leaf compressed page. */
void
page_zip_write_node_ptr(
/*====================*/
	page_zip_des_t*	page_zip,/*!< in/out: compressed page */
	byte*		rec,	/*!< in/out: record */
	ulint		size,	/*!< in: data size of rec */
	ulint		ptr,	/*!< in: node pointer */
	mtr_t*		mtr);	/*!< in: mini-transaction, or NULL */

/**********************************************************************//**
Write the trx_id and roll_ptr of a record on a B-tree leaf node page. */
void
page_zip_write_trx_id_and_roll_ptr(
/*===============================*/
	page_zip_des_t*	page_zip,/*!< in/out: compressed page */
	byte*		rec,	/*!< in/out: record */
	const ulint*	offsets,/*!< in: rec_get_offsets(rec, index) */
	ulint		trx_id_col,/*!< in: column number of TRX_ID in rec */
	trx_id_t	trx_id,	/*!< in: transaction identifier */
	roll_ptr_t	roll_ptr)/*!< in: roll_ptr */
	MY_ATTRIBUTE((nonnull));

/**********************************************************************//**
Write the "deleted" flag of a record on a compressed page.  The flag must
already have been written on the uncompressed page. */
void
page_zip_rec_set_deleted(
/*=====================*/
	page_zip_des_t*	page_zip,/*!< in/out: compressed page */
	const byte*	rec,	/*!< in: record on the uncompressed page */
	ulint		flag)	/*!< in: the deleted flag (nonzero=TRUE) */
	MY_ATTRIBUTE((nonnull));

/**********************************************************************//**
Write the "owned" flag of a record on a compressed page.  The n_owned field
must already have been written on the uncompressed page. */
void
page_zip_rec_set_owned(
/*===================*/
	page_zip_des_t*	page_zip,/*!< in/out: compressed page */
	const byte*	rec,	/*!< in: record on the uncompressed page */
	ulint		flag)	/*!< in: the owned flag (nonzero=TRUE) */
	MY_ATTRIBUTE((nonnull));

/**********************************************************************//**
Insert a record to the dense page directory. */
void
page_zip_dir_insert(
/*================*/
	page_zip_des_t*	page_zip,/*!< in/out: compressed page */
	const byte*	prev_rec,/*!< in: record after which to insert */
	const byte*	free_rec,/*!< in: record from which rec was
				allocated, or NULL */
	byte*		rec);	/*!< in: record to insert */

/**********************************************************************//**
Shift the dense page directory and the array of BLOB pointers
when a record is deleted. */
void
page_zip_dir_delete(
/*================*/
	page_zip_des_t*		page_zip,	/*!< in/out: compressed page */
	byte*			rec,		/*!< in: deleted record */
	const dict_index_t*	index,		/*!< in: index of rec */
	const ulint*		offsets,	/*!< in: rec_get_offsets(rec) */
	const byte*		free)		/*!< in: previous start of
						the free list */
	MY_ATTRIBUTE((nonnull(1,2,3,4)));

/**********************************************************************//**
Add a slot to the dense page directory. */
void
page_zip_dir_add_slot(
/*==================*/
	page_zip_des_t*	page_zip,	/*!< in/out: compressed page */
	ulint		is_clustered)	/*!< in: nonzero for clustered index,
					zero for others */
	MY_ATTRIBUTE((nonnull));

/***********************************************************//**
Parses a log record of writing to the header of a page.
@return end of log record or NULL */
byte*
page_zip_parse_write_header(
/*========================*/
	byte*		ptr,	/*!< in: redo log buffer */
	byte*		end_ptr,/*!< in: redo log buffer end */
	page_t*		page,	/*!< in/out: uncompressed page */
	page_zip_des_t*	page_zip);/*!< in/out: compressed page */

/**********************************************************************//**
Write data to the uncompressed header portion of a page.  The data must
already have been written to the uncompressed page.
However, the data portion of the uncompressed page may differ from
the compressed page when a record is being inserted in
page_cur_insert_rec_low(). */
UNIV_INLINE
void
page_zip_write_header(
/*==================*/
	page_zip_des_t*	page_zip,/*!< in/out: compressed page */
	const byte*	str,	/*!< in: address on the uncompressed page */
	ulint		length,	/*!< in: length of the data */
	mtr_t*		mtr)	/*!< in: mini-transaction, or NULL */
	MY_ATTRIBUTE((nonnull(1,2)));

/**********************************************************************//**
Reorganize and compress a page.  This is a low-level operation for
compressed pages, to be used when page_zip_compress() fails.
On success, a redo log entry MLOG_ZIP_PAGE_COMPRESS will be written.
The function btr_page_reorganize() should be preferred whenever possible.
IMPORTANT: if page_zip_reorganize() is invoked on a leaf page of a
non-clustered index, the caller must update the insert buffer free
bits in the same mini-transaction in such a way that the modification
will be redo-logged.
@return TRUE on success, FALSE on failure; page_zip will be left
intact on failure, but page will be overwritten. */
ibool
page_zip_reorganize(
/*================*/
	buf_block_t*	block,	/*!< in/out: page with compressed page;
				on the compressed page, in: size;
				out: data, n_blobs,
				m_start, m_end, m_nonempty */
	dict_index_t*	index,	/*!< in: index of the B-tree node */
	mtr_t*		mtr)	/*!< in: mini-transaction */
	MY_ATTRIBUTE((nonnull));
#ifndef UNIV_HOTBACKUP
/**********************************************************************//**
Copy the records of a page byte for byte.  Do not copy the page header
or trailer, except those B-tree header fields that are directly
related to the storage of records.  Also copy PAGE_MAX_TRX_ID.
NOTE: The caller must update the lock table and the adaptive hash index. */
void
page_zip_copy_recs(
/*===============*/
	page_zip_des_t*		page_zip,	/*!< out: copy of src_zip
						(n_blobs, m_start, m_end,
						m_nonempty, data[0..size-1]) */
	page_t*			page,		/*!< out: copy of src */
	const page_zip_des_t*	src_zip,	/*!< in: compressed page */
	const page_t*		src,		/*!< in: page */
	dict_index_t*		index,		/*!< in: index of the B-tree */
	mtr_t*			mtr);		/*!< in: mini-transaction */
#endif /* !UNIV_HOTBACKUP */

/**********************************************************************//**
Parses a log record of compressing an index page.
@return end of log record or NULL */
byte*
page_zip_parse_compress(
/*====================*/
	byte*		ptr,		/*!< in: buffer */
	byte*		end_ptr,	/*!< in: buffer end */
	page_t*		page,		/*!< out: uncompressed page */
	page_zip_des_t*	page_zip);	/*!< out: compressed page */

#endif /* !UNIV_INNOCHECKSUM */

/** Calculate the compressed page checksum.
@param[in]	data			compressed page
@param[in]	size			size of compressed page
@param[in]	algo			algorithm to use
@param[in]	use_legacy_big_endian	only used if algo is
SRV_CHECKSUM_ALGORITHM_CRC32 or SRV_CHECKSUM_ALGORITHM_STRICT_CRC32 - if true
then use big endian byteorder when converting byte strings to integers.
@return page checksum */
uint32_t
page_zip_calc_checksum(
	const void*			data,
	ulint				size,
	srv_checksum_algorithm_t	algo,
	bool				use_legacy_big_endian = false);

/**********************************************************************//**
Verify a compressed page's checksum.
@return TRUE if the stored checksum is valid according to the value of
innodb_checksum_algorithm */
ibool
page_zip_verify_checksum(
/*=====================*/
	const void*	data,	/*!< in: compressed page */
	ulint		size	/*!< in: size of compressed page */
#ifdef UNIV_INNOCHECKSUM
	/* these variables are used only for innochecksum tool. */
	,uintmax_t	page_no,	/*!< in: page number of
					given read_buf */
	bool		strict_check,	/*!< in: true if strict-check
					option is enable */
	bool		is_log_enabled, /*!< in: true if log option is
					enable */
	FILE*		log_file	/*!< in: file pointer to
					log_file */
#endif /* UNIV_INNOCHECKSUM */
);

#ifndef UNIV_INNOCHECKSUM
/**********************************************************************//**
Write a log record of compressing an index page without the data on the page. */
UNIV_INLINE
void
page_zip_compress_write_log_no_data(
/*================================*/
	ulint		level,	/*!< in: compression level */
	const page_t*	page,	/*!< in: page that is compressed */
	dict_index_t*	index,	/*!< in: index */
	mtr_t*		mtr);	/*!< in: mtr */
/**********************************************************************//**
Parses a log record of compressing an index page without the data.
@return end of log record or NULL */
UNIV_INLINE
byte*
page_zip_parse_compress_no_data(
/*============================*/
	byte*		ptr,		/*!< in: buffer */
	byte*		end_ptr,	/*!< in: buffer end */
	page_t*		page,		/*!< in: uncompressed page */
	page_zip_des_t*	page_zip,	/*!< out: compressed page */
	dict_index_t*	index)		/*!< in: index */
	MY_ATTRIBUTE((nonnull(1,2)));

/**********************************************************************//**
Reset the counters used for filling
INFORMATION_SCHEMA.innodb_cmp_per_index. */
UNIV_INLINE
void
page_zip_reset_stat_per_index();
/*===========================*/

#ifdef UNIV_MATERIALIZE
# undef UNIV_INLINE
# define UNIV_INLINE	UNIV_INLINE_ORIGINAL
#endif

#ifndef UNIV_NONINL
# include "page0zip.ic"
#endif
#endif /* !UNIV_INNOCHECKSUM */

#endif /* page0zip_h */
