mariadb/include/page0zip.h
marko d1f9c8ecea branches/zip: Minor fixes to get a page with one record compress/decompress.
A page with multiple records or deleted records still does not compress
or decompress properly.

buf_flush_init_for_writing(): Initialize block->page_zip properly so that all
assertions in page0zip can be enabled.

page_zip_decompress(): Note that corrupt data should not lead to assertions.

page_zip_dir_set(): Correct the interface.  Fix off-by-one error.
page_zip_dir_get(): Fix off-by-one error.

page0zip.c: Replace n_heap with n_dense and add comments about
the infimum and supremum records whenever we subtract 2 from heap_no.
Fix some programming errors.
2005-11-25 12:34:38 +00:00

208 lines
6.4 KiB
C

/******************************************************
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"
/**************************************************************************
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: compressed page */
const page_t* page); /* in: uncompressed page */
/**************************************************************************
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 */
page_t* page, /* out: uncompressed page, may be trashed */
mtr_t* mtr) /* in: mini-transaction handle,
or NULL if no logging is needed */
__attribute__((warn_unused_result, nonnull(1, 2)));
#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 */
/**************************************************************************
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 */
#endif /* UNIV_DEBUG */
/*****************************************************************
Gets the size of the compressed page trailer (the dense page directory). */
UNIV_INLINE
ulint
page_zip_dir_size(
/*==============*/
/* out: length of dense page
directory, in bytes */
const page_zip_des_t* page_zip) /* in: compressed page */
__attribute__((pure));
/*****************************************************************
Read a given slot in the dense page directory. */
UNIV_INLINE
ulint
page_zip_dir_get(
/*==============*/
/* out: record offset
on the uncompressed page,
possibly ORed with
PAGE_ZIP_DIR_SLOT_DEL or
PAGE_ZIP_DIR_SLOT_OWNED */
const page_zip_des_t* page_zip, /* in: compressed page */
ulint slot) /* in: slot
(0=first user record) */
__attribute__((pure));
/*****************************************************************
Write a given slot in the dense page directory. */
UNIV_INLINE
void
page_zip_dir_set(
/*==============*/
page_zip_des_t* page_zip, /* in: compressed page */
ulint slot, /* in: slot (0=first user record) */
ulint offs); /* in: offset, possibly ORed with
PAGE_ZIP_DIR_SLOT_DEL or
PAGE_ZIP_DIR_SLOT_OWNED */
/**************************************************************************
Determine the encoded length of an integer in the modification log. */
UNIV_INLINE
ulint
page_zip_ulint_size(
/*================*/
/* out: length of the integer, in bytes */
ulint num) /* in: the integer */
__attribute__((const));
/**************************************************************************
Determine the size of a modification log entry. */
UNIV_INLINE
ulint
page_zip_entry_size(
/*================*/
/* out: length of the log entry, in bytes */
ulint pos, /* in: offset of the uncompressed page */
ulint length) /* in: length of the data */
__attribute__((const));
/**************************************************************************
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 */
ulint size) /* in: size of modification log entries */
__attribute__((nonnull));
/**************************************************************************
Determine if enough space is available in the modification log. */
UNIV_INLINE
ibool
page_zip_available(
/*===============*/
/* out: TRUE if enough space
is available */
const page_zip_des_t* page_zip,/* in: compressed page */
ulint size) /* in: requested size of
modification log entries */
__attribute__((warn_unused_result, nonnull, pure));
#ifdef UNIV_DEBUG
/**************************************************************************
Determine if enough space is available in the modification log. */
ibool
page_zip_available_noninline(
/*=========================*/
/* out: TRUE if enough space
is available */
const page_zip_des_t* page_zip,/* in: compressed page */
ulint size)
__attribute__((warn_unused_result, nonnull, pure));
#endif /* UNIV_DEBUG */
/**************************************************************************
Write data to the compressed portion of a page. The data must already
have been written to the uncompressed page. */
void
page_zip_write(
/*===========*/
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 */
__attribute__((nonnull, deprecated));
/**************************************************************************
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 */
__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 */