/****************************************************** Transaction undo log (c) 1996 Innobase Oy Created 3/26/1996 Heikki Tuuri *******************************************************/ #include "data0type.h" #include "page0page.h" /*************************************************************************** Builds a roll pointer dulint. */ UNIV_INLINE dulint trx_undo_build_roll_ptr( /*====================*/ /* out: roll pointer */ ibool is_insert, /* in: TRUE if insert undo log */ ulint rseg_id, /* in: rollback segment id */ ulint page_no, /* in: page number */ ulint offset) /* in: offset of the undo entry within page */ { #if DATA_ROLL_PTR_LEN != 7 # error "DATA_ROLL_PTR_LEN != 7" #endif ut_ad(rseg_id < 128); return(ut_dulint_create(is_insert * 128 * 256 * 256 + rseg_id * 256 * 256 + (page_no / 256) / 256, (page_no % (256 * 256)) * 256 * 256 + offset)); } /*************************************************************************** Decodes a roll pointer dulint. */ UNIV_INLINE void trx_undo_decode_roll_ptr( /*=====================*/ dulint roll_ptr, /* in: roll pointer */ ibool* is_insert, /* out: TRUE if insert undo log */ ulint* rseg_id, /* out: rollback segment id */ ulint* page_no, /* out: page number */ ulint* offset) /* out: offset of the undo entry within page */ { ulint low; ulint high; #if DATA_ROLL_PTR_LEN != 7 # error "DATA_ROLL_PTR_LEN != 7" #endif #if TRUE != 1 # error "TRUE != 1" #endif high = ut_dulint_get_high(roll_ptr); low = ut_dulint_get_low(roll_ptr); *offset = low % (256 * 256); *is_insert = high / (256 * 256 * 128); /* TRUE == 1 */ *rseg_id = (high / (256 * 256)) % 128; *page_no = (high % (256 * 256)) * 256 * 256 + (low / 256) / 256; } /*************************************************************************** Returns TRUE if the roll pointer is of the insert type. */ UNIV_INLINE ibool trx_undo_roll_ptr_is_insert( /*========================*/ /* out: TRUE if insert undo log */ dulint roll_ptr) /* in: roll pointer */ { ulint high; #if DATA_ROLL_PTR_LEN != 7 # error "DATA_ROLL_PTR_LEN != 7" #endif #if TRUE != 1 # error "TRUE != 1" #endif high = ut_dulint_get_high(roll_ptr); return(high / (256 * 256 * 128)); } /********************************************************************* Writes a roll ptr to an index page. In case that the size changes in some future version, this function should be used instead of mach_write_... */ UNIV_INLINE void trx_write_roll_ptr( /*===============*/ byte* ptr, /* in: pointer to memory where written */ dulint roll_ptr) /* in: roll ptr */ { #if DATA_ROLL_PTR_LEN != 7 # error "DATA_ROLL_PTR_LEN != 7" #endif mach_write_to_7(ptr, roll_ptr); } /********************************************************************* Reads a roll ptr from an index page. In case that the roll ptr size changes in some future version, this function should be used instead of mach_read_... */ UNIV_INLINE dulint trx_read_roll_ptr( /*==============*/ /* out: roll ptr */ const byte* ptr) /* in: pointer to memory from where to read */ { #if DATA_ROLL_PTR_LEN != 7 # error "DATA_ROLL_PTR_LEN != 7" #endif return(mach_read_from_7(ptr)); } /********************************************************************** Gets an undo log page and x-latches it. */ UNIV_INLINE page_t* trx_undo_page_get( /*==============*/ /* out: pointer to page x-latched */ ulint space, /* in: space where placed */ ulint zip_size, /* in: compressed page size in bytes or 0 for uncompressed pages */ ulint page_no, /* in: page number */ mtr_t* mtr) /* in: mtr */ { buf_block_t* block = buf_page_get(space, zip_size, page_no, RW_X_LATCH, mtr); #ifdef UNIV_SYNC_DEBUG buf_block_dbg_add_level(block, SYNC_TRX_UNDO_PAGE); #endif /* UNIV_SYNC_DEBUG */ return(buf_block_get_frame(block)); } /********************************************************************** Gets an undo log page and s-latches it. */ UNIV_INLINE page_t* trx_undo_page_get_s_latched( /*========================*/ /* out: pointer to page s-latched */ ulint space, /* in: space where placed */ ulint zip_size, /* in: compressed page size in bytes or 0 for uncompressed pages */ ulint page_no, /* in: page number */ mtr_t* mtr) /* in: mtr */ { buf_block_t* block = buf_page_get(space, zip_size, page_no, RW_S_LATCH, mtr); #ifdef UNIV_SYNC_DEBUG buf_block_dbg_add_level(block, SYNC_TRX_UNDO_PAGE); #endif /* UNIV_SYNC_DEBUG */ return(buf_block_get_frame(block)); } /********************************************************************** Returns the start offset of the undo log records of the specified undo log on the page. */ UNIV_INLINE ulint trx_undo_page_get_start( /*====================*/ /* out: start offset */ page_t* undo_page,/* in: undo log page */ ulint page_no,/* in: undo log header page number */ ulint offset) /* in: undo log header offset on page */ { ulint start; if (page_no == page_get_page_no(undo_page)) { start = mach_read_from_2(offset + undo_page + TRX_UNDO_LOG_START); } else { start = TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE; } return(start); } /********************************************************************** Returns the end offset of the undo log records of the specified undo log on the page. */ UNIV_INLINE ulint trx_undo_page_get_end( /*==================*/ /* out: end offset */ page_t* undo_page,/* in: undo log page */ ulint page_no,/* in: undo log header page number */ ulint offset) /* in: undo log header offset on page */ { trx_ulogf_t* log_hdr; ulint end; if (page_no == page_get_page_no(undo_page)) { log_hdr = undo_page + offset; end = mach_read_from_2(log_hdr + TRX_UNDO_NEXT_LOG); if (end == 0) { end = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE); } } else { end = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE); } return(end); } /********************************************************************** Returns the previous undo record on the page in the specified log, or NULL if none exists. */ UNIV_INLINE trx_undo_rec_t* trx_undo_page_get_prev_rec( /*=======================*/ /* out: pointer to record, NULL if none */ trx_undo_rec_t* rec, /* in: undo log record */ ulint page_no,/* in: undo log header page number */ ulint offset) /* in: undo log header offset on page */ { page_t* undo_page; ulint start; undo_page = (page_t*) ut_align_down(rec, UNIV_PAGE_SIZE); start = trx_undo_page_get_start(undo_page, page_no, offset); if (start + undo_page == rec) { return(NULL); } return(undo_page + mach_read_from_2(rec - 2)); } /********************************************************************** Returns the next undo log record on the page in the specified log, or NULL if none exists. */ UNIV_INLINE trx_undo_rec_t* trx_undo_page_get_next_rec( /*=======================*/ /* out: pointer to record, NULL if none */ trx_undo_rec_t* rec, /* in: undo log record */ ulint page_no,/* in: undo log header page number */ ulint offset) /* in: undo log header offset on page */ { page_t* undo_page; ulint end; ulint next; undo_page = (page_t*) ut_align_down(rec, UNIV_PAGE_SIZE); end = trx_undo_page_get_end(undo_page, page_no, offset); next = mach_read_from_2(rec); if (next == end) { return(NULL); } return(undo_page + next); } /********************************************************************** Returns the last undo record on the page in the specified undo log, or NULL if none exists. */ UNIV_INLINE trx_undo_rec_t* trx_undo_page_get_last_rec( /*=======================*/ /* out: pointer to record, NULL if none */ page_t* undo_page,/* in: undo log page */ ulint page_no,/* in: undo log header page number */ ulint offset) /* in: undo log header offset on page */ { ulint start; ulint end; start = trx_undo_page_get_start(undo_page, page_no, offset); end = trx_undo_page_get_end(undo_page, page_no, offset); if (start == end) { return(NULL); } return(undo_page + mach_read_from_2(undo_page + end - 2)); } /********************************************************************** Returns the first undo record on the page in the specified undo log, or NULL if none exists. */ UNIV_INLINE trx_undo_rec_t* trx_undo_page_get_first_rec( /*========================*/ /* out: pointer to record, NULL if none */ page_t* undo_page,/* in: undo log page */ ulint page_no,/* in: undo log header page number */ ulint offset) /* in: undo log header offset on page */ { ulint start; ulint end; start = trx_undo_page_get_start(undo_page, page_no, offset); end = trx_undo_page_get_end(undo_page, page_no, offset); if (start == end) { return(NULL); } return(undo_page + start); }