/***************************************************************************** Copyright (c) 1995, 2012, Oracle and/or its affiliates. All Rights Reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. 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 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/fsp0fsp.h File space management Created 12/18/1995 Heikki Tuuri *******************************************************/ #ifndef fsp0fsp_h #define fsp0fsp_h #include "univ.i" #include "mtr0mtr.h" #include "fut0lst.h" #include "ut0byte.h" #include "page0types.h" #include "fsp0types.h" /**********************************************************************//** Initializes the file space system. */ UNIV_INTERN void fsp_init(void); /*==========*/ /**********************************************************************//** Gets the current free limit of the system tablespace. The free limit means the place of the first page which has never been put to the free list for allocation. The space above that address is initialized to zero. Sets also the global variable log_fsp_current_free_limit. @return free limit in megabytes */ UNIV_INTERN ulint fsp_header_get_free_limit(void); /*===========================*/ /**********************************************************************//** Gets the size of the system tablespace from the tablespace header. If we do not have an auto-extending data file, this should be equal to the size of the data files. If there is an auto-extending data file, this can be smaller. @return size in pages */ UNIV_INTERN ulint fsp_header_get_tablespace_size(void); /*================================*/ /**********************************************************************//** Reads the file space size stored in the header page. @return tablespace size stored in the space header */ UNIV_INTERN ulint fsp_get_size_low( /*=============*/ page_t* page); /*!< in: header page (page 0 in the tablespace) */ /**********************************************************************//** Reads the space id from the first page of a tablespace. @return space id, ULINT UNDEFINED if error */ UNIV_INTERN ulint fsp_header_get_space_id( /*====================*/ const page_t* page); /*!< in: first page of a tablespace */ /**********************************************************************//** Reads the space flags from the first page of a tablespace. @return flags */ UNIV_INTERN ulint fsp_header_get_flags( /*=================*/ const page_t* page); /*!< in: first page of a tablespace */ /**********************************************************************//** Reads the compressed page size from the first page of a tablespace. @return compressed page size in bytes, or 0 if uncompressed */ UNIV_INTERN ulint fsp_header_get_zip_size( /*====================*/ const page_t* page); /*!< in: first page of a tablespace */ /**********************************************************************//** Writes the space id and compressed page size to a tablespace header. This function is used past the buffer pool when we in fil0fil.c create a new single-table tablespace. */ UNIV_INTERN void fsp_header_init_fields( /*===================*/ page_t* page, /*!< in/out: first page in the space */ ulint space_id, /*!< in: space id */ ulint flags); /*!< in: tablespace flags (FSP_SPACE_FLAGS): 0, or table->flags if newer than COMPACT */ /**********************************************************************//** Initializes the space header of a new created space and creates also the insert buffer tree root if space == 0. */ UNIV_INTERN void fsp_header_init( /*============*/ ulint space, /*!< in: space id */ ulint size, /*!< in: current size in blocks */ mtr_t* mtr); /*!< in: mini-transaction handle */ /**********************************************************************//** Increases the space size field of a space. */ UNIV_INTERN void fsp_header_inc_size( /*================*/ ulint space, /*!< in: space id */ ulint size_inc,/*!< in: size increment in pages */ mtr_t* mtr); /*!< in: mini-transaction handle */ /**********************************************************************//** Creates a new segment. @return the block where the segment header is placed, x-latched, NULL if could not create segment because of lack of space */ UNIV_INTERN buf_block_t* fseg_create( /*========*/ ulint space, /*!< in: space id */ ulint page, /*!< in: page where the segment header is placed: if this is != 0, the page must belong to another segment, if this is 0, a new page will be allocated and it will belong to the created segment */ ulint byte_offset, /*!< in: byte offset of the created segment header on the page */ mtr_t* mtr); /*!< in: mtr */ /**********************************************************************//** Creates a new segment. @return the block where the segment header is placed, x-latched, NULL if could not create segment because of lack of space */ UNIV_INTERN buf_block_t* fseg_create_general( /*================*/ ulint space, /*!< in: space id */ ulint page, /*!< in: page where the segment header is placed: if this is != 0, the page must belong to another segment, if this is 0, a new page will be allocated and it will belong to the created segment */ ulint byte_offset, /*!< in: byte offset of the created segment header on the page */ ibool has_done_reservation, /*!< in: TRUE if the caller has already done the reservation for the pages with fsp_reserve_free_extents (at least 2 extents: one for the inode and the other for the segment) then there is no need to do the check for this individual operation */ mtr_t* mtr); /*!< in: mtr */ /**********************************************************************//** Calculates the number of pages reserved by a segment, and how many pages are currently used. @return number of reserved pages */ UNIV_INTERN ulint fseg_n_reserved_pages( /*==================*/ fseg_header_t* header, /*!< in: segment header */ ulint* used, /*!< out: number of pages used (<= reserved) */ mtr_t* mtr); /*!< in: mtr handle */ /**********************************************************************//** Allocates a single free page from a segment. This function implements the intelligent allocation strategy which tries to minimize file space fragmentation. @param[in/out] seg_header segment header @param[in] hint hint of which page would be desirable @param[in] direction if the new page is needed because of an index page split, and records are inserted there in order, into which direction they go alphabetically: FSP_DOWN, FSP_UP, FSP_NO_DIR @param[in/out] mtr mini-transaction @return X-latched block, or NULL if no page could be allocated */ #define fseg_alloc_free_page(seg_header, hint, direction, mtr) \ fseg_alloc_free_page_general(seg_header, hint, direction, \ FALSE, mtr, mtr) /**********************************************************************//** Allocates a single free page from a segment. This function implements the intelligent allocation strategy which tries to minimize file space fragmentation. @retval NULL if no page could be allocated @retval block, rw_lock_x_lock_count(&block->lock) == 1 if allocation succeeded (init_mtr == mtr, or the page was not previously freed in mtr) @retval block (not allocated or initialized) otherwise */ UNIV_INTERN buf_block_t* fseg_alloc_free_page_general( /*=========================*/ fseg_header_t* seg_header,/*!< in/out: segment header */ ulint hint, /*!< in: hint of which page would be desirable */ byte direction,/*!< in: if the new page is needed because of an index page split, and records are inserted there in order, into which direction they go alphabetically: FSP_DOWN, FSP_UP, FSP_NO_DIR */ ibool has_done_reservation, /*!< in: TRUE if the caller has already done the reservation for the page with fsp_reserve_free_extents, then there is no need to do the check for this individual page */ mtr_t* mtr, /*!< in/out: mini-transaction */ mtr_t* init_mtr)/*!< in/out: mtr or another mini-transaction in which the page should be initialized. If init_mtr!=mtr, but the page is already latched in mtr, do not initialize the page. */ __attribute__((warn_unused_result, nonnull)); /**********************************************************************//** Reserves free pages from a tablespace. All mini-transactions which may use several pages from the tablespace should call this function beforehand and reserve enough free extents so that they certainly will be able to do their operation, like a B-tree page split, fully. Reservations must be released with function fil_space_release_free_extents! The alloc_type below has the following meaning: FSP_NORMAL means an operation which will probably result in more space usage, like an insert in a B-tree; FSP_UNDO means allocation to undo logs: if we are deleting rows, then this allocation will in the long run result in less space usage (after a purge); FSP_CLEANING means allocation done in a physical record delete (like in a purge) or other cleaning operation which will result in less space usage in the long run. We prefer the latter two types of allocation: when space is scarce, FSP_NORMAL allocations will not succeed, but the latter two allocations will succeed, if possible. The purpose is to avoid dead end where the database is full but the user cannot free any space because these freeing operations temporarily reserve some space. Single-table tablespaces whose size is < 32 pages are a special case. In this function we would liberally reserve several 64 page extents for every page split or merge in a B-tree. But we do not want to waste disk space if the table only occupies < 32 pages. That is why we apply different rules in that special case, just ensuring that there are 3 free pages available. @return TRUE if we were able to make the reservation */ UNIV_INTERN ibool fsp_reserve_free_extents( /*=====================*/ ulint* n_reserved,/*!< out: number of extents actually reserved; if we return TRUE and the tablespace size is < 64 pages, then this can be 0, otherwise it is n_ext */ ulint space, /*!< in: space id */ ulint n_ext, /*!< in: number of extents to reserve */ ulint alloc_type,/*!< in: FSP_NORMAL, FSP_UNDO, or FSP_CLEANING */ mtr_t* mtr); /*!< in: mtr */ /**********************************************************************//** This function should be used to get information on how much we still will be able to insert new data to the database without running out the tablespace. Only free extents are taken into account and we also subtract the safety margin required by the above function fsp_reserve_free_extents. @return available space in kB */ UNIV_INTERN ullint fsp_get_available_space_in_free_extents( /*====================================*/ ulint space); /*!< in: space id */ /**********************************************************************//** Frees a single page of a segment. */ UNIV_INTERN void fseg_free_page( /*===========*/ fseg_header_t* seg_header, /*!< in: segment header */ ulint space, /*!< in: space id */ ulint page, /*!< in: page offset */ mtr_t* mtr); /*!< in: mtr handle */ /**********************************************************************//** Frees part of a segment. This function can be used to free a segment by repeatedly calling this function in different mini-transactions. Doing the freeing in a single mini-transaction might result in too big a mini-transaction. @return TRUE if freeing completed */ UNIV_INTERN ibool fseg_free_step( /*===========*/ fseg_header_t* header, /*!< in, own: segment header; NOTE: if the header resides on the first page of the frag list of the segment, this pointer becomes obsolete after the last freeing step */ mtr_t* mtr); /*!< in: mtr */ /**********************************************************************//** Frees part of a segment. Differs from fseg_free_step because this function leaves the header page unfreed. @return TRUE if freeing completed, except the header page */ UNIV_INTERN ibool fseg_free_step_not_header( /*======================*/ fseg_header_t* header, /*!< in: segment header which must reside on the first fragment page of the segment */ mtr_t* mtr); /*!< in: mtr */ /***********************************************************************//** Checks if a page address is an extent descriptor page address. @return TRUE if a descriptor page */ UNIV_INLINE ibool fsp_descr_page( /*===========*/ ulint zip_size,/*!< in: compressed page size in bytes; 0 for uncompressed pages */ ulint page_no);/*!< in: page number */ /***********************************************************//** Parses a redo log record of a file page init. @return end of log record or NULL */ UNIV_INTERN byte* fsp_parse_init_file_page( /*=====================*/ byte* ptr, /*!< in: buffer */ byte* end_ptr, /*!< in: buffer end */ buf_block_t* block); /*!< in: block or NULL */ /*******************************************************************//** Validates the file space system and its segments. @return TRUE if ok */ UNIV_INTERN ibool fsp_validate( /*=========*/ ulint space); /*!< in: space id */ /*******************************************************************//** Prints info of a file space. */ UNIV_INTERN void fsp_print( /*======*/ ulint space); /*!< in: space id */ #ifdef UNIV_DEBUG /*******************************************************************//** Validates a segment. @return TRUE if ok */ UNIV_INTERN ibool fseg_validate( /*==========*/ fseg_header_t* header, /*!< in: segment header */ mtr_t* mtr); /*!< in: mtr */ #endif /* UNIV_DEBUG */ #ifdef UNIV_BTR_PRINT /*******************************************************************//** Writes info of a segment. */ UNIV_INTERN void fseg_print( /*=======*/ fseg_header_t* header, /*!< in: segment header */ mtr_t* mtr); /*!< in: mtr */ #endif /* UNIV_BTR_PRINT */ #ifndef UNIV_NONINL #include "fsp0fsp.ic" #endif #endif