/******************************************************
Compressed page interface

(c) 2005 Innobase Oy

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

#ifndef page0zip_h
#define page0zip_h

#ifdef UNIV_MATERIALIZE
# undef UNIV_INLINE
# define UNIV_INLINE
#endif

#include "mtr0types.h"
#include "page0types.h"
#include "dict0types.h"
#include "ut0byte.h"

/**************************************************************************
Determine if a record is so big that it needs to be stored externally. */
UNIV_INLINE
ibool
page_zip_rec_needs_ext(
/*===================*/
				/* out: FALSE if the entire record
				can be stored locally on the page */
	ulint	rec_size,	/* in: length of the record in bytes */
	ulint	comp,		/* in: nonzero=compact format */
	ulint	zip_size)	/* in: compressed page size in bytes, or 0 */
	__attribute__((const));

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

/**************************************************************************
Compress a page. */

ibool
page_zip_compress(
/*==============*/
				/* out: TRUE on success, FALSE on failure;
				page_zip will be left intact on failure. */
	page_zip_des_t*	page_zip,/* in: size; out: data, n_blobs,
				m_start, m_end */
	const page_t*	page,	/* in: uncompressed page */
	dict_index_t*	index,	/* in: index of the B-tree node */
	mtr_t*		mtr)	/* in: mini-transaction, or NULL */
	__attribute__((warn_unused_result, nonnull(1,2,3)));

/**************************************************************************
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. */

ibool
page_zip_decompress(
/*================*/
				/* out: TRUE on success, FALSE on failure */
	page_zip_des_t*	page_zip,/* in: data, size;
				out: m_start, m_end, n_blobs */
	page_t*		page)	/* out: uncompressed page, may be trashed */
	__attribute__((warn_unused_result, nonnull));

#ifdef UNIV_DEBUG
/**************************************************************************
Validate a compressed page descriptor. */
UNIV_INLINE
ibool
page_zip_simple_validate(
/*=====================*/
						/* out: TRUE if ok */
	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. */

ibool
page_zip_validate(
/*==============*/
	const page_zip_des_t*	page_zip,/* in: compressed page */
	const page_t*		page)	/* in: uncompressed page */
	__attribute__((nonnull));
#endif /* UNIV_ZIP_DEBUG */

/**************************************************************************
Determine if enough space is available for a page_zip_write_rec() call
in the modification log. */
UNIV_INLINE
ibool
page_zip_available(
/*===============*/
					/* out: TRUE if page_zip_write_rec()
					will succeed */
	const page_zip_des_t*	page_zip,/* in: compressed page */
	dict_index_t*		index,	/* in: index of the B-tree node */
	ulint			length,	/* in: combined size of the record */
	ulint			create)	/* in: nonzero=add the record to
					the heap */
	__attribute__((warn_unused_result, nonnull, pure));

/**************************************************************************
Ensure that enough space is available in the modification log.
If not, try to compress the page. */
UNIV_INLINE
ibool
page_zip_alloc(
/*===========*/
				/* out: TRUE if enough space is available */
	page_zip_des_t*	page_zip,/* in/out: compressed page;
				will only be modified if compression is needed
				and successful */
	const page_t*	page,	/* in: uncompressed page */
	dict_index_t*	index,	/* in: index of the B-tree node */
	ulint		length,	/* in: combined size of the record */
	ulint		create,	/* in: nonzero=add the record to the heap */
	mtr_t*		mtr)	/* in: mini-transaction, or NULL */
	__attribute__((warn_unused_result, nonnull(1,2,3)));

/**************************************************************************
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 */
	__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 */
	__attribute__((nonnull));

/***************************************************************
Parses a log record of writing a BLOB pointer of a record. */

byte*
page_zip_parse_write_blob_ptr(
/*==========================*/
				/* out: end of log record or NULL */
	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 */
	__attribute__((nonnull(1,2,3,4)));

/***************************************************************
Parses a log record of writing the node pointer of a record. */

byte*
page_zip_parse_write_node_ptr(
/*==========================*/
				/* out: end of log record or NULL */
	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 */
	__attribute__((nonnull(1,2)));

/**************************************************************************
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 */
	dulint		trx_id,	/* in: transaction identifier */
	dulint		roll_ptr)/* in: roll_ptr */
	__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) */
	__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) */
	__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 */
	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 */
	__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 */
	__attribute__((nonnull));

/***************************************************************
Parses a log record of writing to the header of a page. */

byte*
page_zip_parse_write_header(
/*========================*/
				/* out: end of log record or NULL */
	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 */
	__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. */

ibool
page_zip_reorganize(
/*================*/
				/* out: TRUE on success, FALSE on failure;
				page and page_zip will be left intact
				on failure. */
	page_zip_des_t*	page_zip,/* in: size; out: data, n_blobs,
				m_start, m_end */
	page_t*		page,	/* in/out: uncompressed page */
	dict_index_t*	index,	/* in: index of the B-tree node */
	mtr_t*		mtr)	/* in: mini-transaction */
	__attribute__((warn_unused_result, nonnull));
/**************************************************************************
Copy a page byte for byte, except for the file page header and trailer. */

void
page_zip_copy(
/*==========*/
	page_zip_des_t*		page_zip,	/* out: copy of src_zip */
	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 */
	__attribute__((nonnull(1,2,3,4)));

/**************************************************************************
Parses a log record of compressing an index page. */

byte*
page_zip_parse_compress(
/*====================*/
				/* out: end of log record or NULL */
	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 */
	__attribute__((nonnull(1,2)));

/**************************************************************************
Calculate the compressed page checksum. */

ulint
page_zip_calc_checksum(
/*===================*/
                                /* out: page checksum */
        const void*     data,   /* in: compressed page */
        ulint           size)   /* in: size of compressed page */
	__attribute__((nonnull));

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

#ifndef UNIV_NONINL
# include "page0zip.ic"
#endif

#endif /* page0zip_h */