138 lines
4.8 KiB
Plaintext
138 lines
4.8 KiB
Plaintext
/*****************************************************************************
|
|
|
|
Copyright (c) 2005, 2018, 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 St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
|
|
*****************************************************************************/
|
|
|
|
/** @file page/zipdecompress.ic
|
|
Compressed page interface
|
|
|
|
Created June 2005 by Marko Makela
|
|
*******************************************************/
|
|
|
|
/** NOTE: The functions in this file should only use functions from
|
|
other files in library. The code in this file is used to make a library for
|
|
external tools. */
|
|
|
|
#ifndef zip_decompress_ic
|
|
#define zip_decompress_ic
|
|
|
|
#include "btr0types.h"
|
|
#include "fil0types.h"
|
|
#include "page0types.h"
|
|
|
|
#include "page/page.ic"
|
|
/** Size of an compressed page directory entry */
|
|
#define PAGE_ZIP_DIR_SLOT_SIZE 2
|
|
|
|
/** Gets a pointer to the compressed page trailer (the dense page directory),
|
|
including deleted records (the free list).
|
|
@param[in] page_zip compressed page
|
|
@param[in] n_dense number of entries in the directory
|
|
@return pointer to the dense page directory */
|
|
#define page_zip_dir_start_low(page_zip, n_dense) \
|
|
((page_zip)->data + page_zip_dir_start_offs(page_zip, n_dense))
|
|
/** Gets a pointer to the compressed page trailer (the dense page directory),
|
|
including deleted records (the free list).
|
|
@param[in] page_zip compressed page
|
|
@return pointer to the dense page directory */
|
|
#define page_zip_dir_start(page_zip) \
|
|
page_zip_dir_start_low(page_zip, page_zip_dir_elems(page_zip))
|
|
|
|
/** 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 */
|
|
{
|
|
ulint size;
|
|
|
|
if (!page_zip->ssize) {
|
|
return (0);
|
|
}
|
|
|
|
size = (UNIV_ZIP_SIZE_MIN >> 1) << page_zip->ssize;
|
|
|
|
ut_ad(size >= UNIV_ZIP_SIZE_MIN);
|
|
ut_ad(size <= UNIV_PAGE_SIZE);
|
|
|
|
return (size);
|
|
}
|
|
|
|
#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 */
|
|
{
|
|
ut_ad(page_zip);
|
|
ut_ad(page_zip->data);
|
|
ut_ad(page_zip->ssize <= PAGE_ZIP_SSIZE_MAX);
|
|
ut_ad(page_zip_get_size(page_zip) > PAGE_DATA + PAGE_ZIP_DIR_SLOT_SIZE);
|
|
ut_ad(page_zip->m_start <= page_zip->m_end);
|
|
ut_ad(page_zip->m_end < page_zip_get_size(page_zip));
|
|
ut_ad(page_zip->n_blobs <
|
|
page_zip_get_size(page_zip) / BTR_EXTERN_FIELD_REF_SIZE);
|
|
return (TRUE);
|
|
}
|
|
#endif /* UNIV_DEBUG */
|
|
|
|
/** Gets the number of elements in the dense page directory,
|
|
including deleted records (the free list).
|
|
@return number of elements in the dense page directory */
|
|
UNIV_INLINE
|
|
ulint page_zip_dir_elems(
|
|
const page_zip_des_t *page_zip) /*!< in: compressed page */
|
|
{
|
|
/* Exclude the page infimum and supremum from the record count. */
|
|
return (page_dir_get_n_heap(page_zip->data) - PAGE_HEAP_NO_USER_LOW);
|
|
}
|
|
|
|
/** Gets the size of the compressed page trailer (the dense page directory),
|
|
including deleted records (the free list).
|
|
@return length of dense page directory, in bytes */
|
|
UNIV_INLINE
|
|
ulint page_zip_dir_size(
|
|
const page_zip_des_t *page_zip) /*!< in: compressed page */
|
|
{
|
|
return (PAGE_ZIP_DIR_SLOT_SIZE * page_zip_dir_elems(page_zip));
|
|
}
|
|
|
|
/** Read a given slot in the dense page directory.
|
|
@return record offset on the uncompressed page, possibly ORed with
|
|
PAGE_ZIP_DIR_SLOT_DEL or PAGE_ZIP_DIR_SLOT_OWNED */
|
|
UNIV_INLINE
|
|
ulint page_zip_dir_get(
|
|
const page_zip_des_t *page_zip, /*!< in: compressed page */
|
|
ulint slot) /*!< in: slot
|
|
(0=first user record) */
|
|
{
|
|
ut_ad(page_zip_simple_validate(page_zip));
|
|
ut_ad(slot < page_zip_dir_size(page_zip) / PAGE_ZIP_DIR_SLOT_SIZE);
|
|
return (mach_read_from_2(page_zip->data + page_zip_get_size(page_zip) -
|
|
PAGE_ZIP_DIR_SLOT_SIZE * (slot + 1)));
|
|
}
|
|
#endif
|