trx0rec.c
上传用户:tsgydb
上传日期:2007-04-14
资源大小:10674k
文件大小:31k
- /******************************************************
- Transaction undo log record
- (c) 1996 Innobase Oy
- Created 3/26/1996 Heikki Tuuri
- *******************************************************/
- #include "trx0rec.h"
- #ifdef UNIV_NONINL
- #include "trx0rec.ic"
- #endif
- #include "fsp0fsp.h"
- #include "mach0data.h"
- #include "trx0rseg.h"
- #include "trx0trx.h"
- #include "trx0undo.h"
- #include "dict0dict.h"
- #include "ut0mem.h"
- #include "row0upd.h"
- #include "que0que.h"
- #include "trx0purge.h"
- #include "row0row.h"
- /*=========== UNDO LOG RECORD CREATION AND DECODING ====================*/
- /**************************************************************************
- Writes the mtr log entry of the inserted undo log record on the undo log
- page. */
- UNIV_INLINE
- void
- trx_undof_page_add_undo_rec_log(
- /*============================*/
- page_t* undo_page, /* in: undo log page */
- ulint old_free, /* in: start offset of the inserted entry */
- ulint new_free, /* in: end offset of the entry */
- mtr_t* mtr) /* in: mtr */
- {
- byte* log_ptr;
- ulint len;
- #ifdef notdefined
- ulint i;
- byte* prev_rec_ptr;
- byte* ptr;
- ulint min_len;
- ut_ad(new_free >= old_free + 4);
- i = 0;
- ptr = undo_page + old_free + 2;
-
- if (old_free > mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
- + TRX_UNDO_PAGE_START)) {
- prev_rec_ptr = undo_page + mach_read_from_2(ptr - 4) + 2;
- min_len = ut_min(new_free - old_free - 4,
- (undo_page + old_free - 2) - prev_rec_ptr);
- for (;;) {
- if (i >= min_len) {
- break;
- } else if ((*ptr == *prev_rec_ptr)
- || ((*ptr == *prev_rec_ptr + 1)
- && (ptr + 1 == suffix))) {
- i++;
- ptr++;
- prev_rec_ptr++;
- } else {
- break;
- }
- }
- }
-
- mlog_write_initial_log_record(undo_page, MLOG_UNDO_INSERT, mtr);
- mlog_catenate_ulint(mtr, old_free, MLOG_2BYTES);
- mlog_catenate_ulint_compressed(mtr, i);
- mlog_catenate_string(mtr, ptr, new_free - old_free - 2 - i);
- #endif
- log_ptr = mlog_open(mtr, 30 + MLOG_BUF_MARGIN);
- if (log_ptr == NULL) {
- return;
- }
- log_ptr = mlog_write_initial_log_record_fast(undo_page,
- MLOG_UNDO_INSERT, log_ptr, mtr);
- len = new_free - old_free - 4;
- mach_write_to_2(log_ptr, len);
- log_ptr += 2;
- if (len < 256) {
- ut_memcpy(log_ptr, undo_page + old_free + 2, len);
- log_ptr += len;
- }
- mlog_close(mtr, log_ptr);
- if (len >= MLOG_BUF_MARGIN) {
- mlog_catenate_string(mtr, undo_page + old_free + 2, len);
- }
- }
- /***************************************************************
- Parses a redo log record of adding an undo log record. */
- byte*
- trx_undo_parse_add_undo_rec(
- /*========================*/
- /* out: end of log record or NULL */
- byte* ptr, /* in: buffer */
- byte* end_ptr,/* in: buffer end */
- page_t* page) /* in: page or NULL */
- {
- ulint len;
- byte* rec;
- ulint first_free;
- if (end_ptr < ptr + 2) {
- return(NULL);
- }
- len = mach_read_from_2(ptr);
- ptr += 2;
- if (end_ptr < ptr + len) {
- return(NULL);
- }
-
- if (page == NULL) {
- return(ptr + len);
- }
-
- first_free = mach_read_from_2(page + TRX_UNDO_PAGE_HDR
- + TRX_UNDO_PAGE_FREE);
- rec = page + first_free;
-
- mach_write_to_2(rec, first_free + 4 + len);
- mach_write_to_2(rec + 2 + len, first_free);
- mach_write_to_2(page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE,
- first_free + 4 + len);
- ut_memcpy(rec + 2, ptr, len);
- return(ptr + len);
- }
-
- /**************************************************************************
- Calculates the free space left for extending an undo log record. */
- UNIV_INLINE
- ulint
- trx_undo_left(
- /*==========*/
- /* out: bytes left */
- page_t* page, /* in: undo log page */
- byte* ptr) /* in: pointer to page */
- {
- /* The '- 10' is a safety margin, in case we have some small
- calculation error below */
- return(UNIV_PAGE_SIZE - (ptr - page) - 10 - FIL_PAGE_DATA_END);
- }
- /**************************************************************************
- Reports in the undo log of an insert of a clustered index record. */
- static
- ulint
- trx_undo_page_report_insert(
- /*========================*/
- /* out: offset of the inserted entry
- on the page if succeed, 0 if fail */
- page_t* undo_page, /* in: undo log page */
- trx_t* trx, /* in: transaction */
- dict_index_t* index, /* in: clustered index */
- dtuple_t* clust_entry, /* in: index entry which will be
- inserted to the clustered index */
- mtr_t* mtr) /* in: mtr */
- {
- ulint first_free;
- byte* ptr;
- ulint len;
- dfield_t* field;
- ulint flen;
- ulint i;
-
- ut_ad(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
- + TRX_UNDO_PAGE_TYPE) == TRX_UNDO_INSERT);
- first_free = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
- + TRX_UNDO_PAGE_FREE);
- ptr = undo_page + first_free;
-
- ut_ad(first_free <= UNIV_PAGE_SIZE);
- if (trx_undo_left(undo_page, ptr) < 30) {
- /* NOTE: the value 30 must be big enough such that the general
- fields written below fit on the undo log page */
- return(0);
- }
- /* Reserve 2 bytes for the pointer to the next undo log record */
- ptr += 2;
-
- /* Store first some general parameters to the undo log */
- mach_write_to_1(ptr, TRX_UNDO_INSERT_REC);
- ptr++;
- len = mach_dulint_write_much_compressed(ptr, trx->undo_no);
- ptr += len;
- len = mach_dulint_write_much_compressed(ptr, (index->table)->id);
- ptr += len;
- /*----------------------------------------*/
- /* Store then the fields required to uniquely determine the record
- to be inserted in the clustered index */
- for (i = 0; i < dict_index_get_n_unique(index); i++) {
- field = dtuple_get_nth_field(clust_entry, i);
- flen = dfield_get_len(field);
- if (trx_undo_left(undo_page, ptr) < 5) {
- return(0);
- }
- len = mach_write_compressed(ptr, flen);
- ptr += len;
- if (flen != UNIV_SQL_NULL) {
- if (trx_undo_left(undo_page, ptr) < flen) {
- return(0);
- }
- ut_memcpy(ptr, dfield_get_data(field), flen);
- ptr += flen;
- }
- }
- if (trx_undo_left(undo_page, ptr) < 2) {
- return(0);
- }
- /*----------------------------------------*/
- /* Write pointers to the previous and the next undo log records */
- if (trx_undo_left(undo_page, ptr) < 2) {
- return(0);
- }
- mach_write_to_2(ptr, first_free);
- ptr += 2;
- mach_write_to_2(undo_page + first_free, ptr - undo_page);
- mach_write_to_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE,
- ptr - undo_page);
- /* Write the log entry to the REDO log of this change in the UNDO log */
- trx_undof_page_add_undo_rec_log(undo_page, first_free,
- ptr - undo_page, mtr);
- return(first_free);
- }
- /**************************************************************************
- Reads from an undo log record the general parameters. */
- byte*
- trx_undo_rec_get_pars(
- /*==================*/
- /* out: remaining part of undo log
- record after reading these values */
- trx_undo_rec_t* undo_rec, /* in: undo log record */
- ulint* type, /* out: undo record type:
- TRX_UNDO_INSERT_REC, ... */
- ulint* cmpl_info, /* out: compiler info, relevant only
- for update type records */
- dulint* undo_no, /* out: undo log record number */
- dulint* table_id) /* out: table id */
- {
- byte* ptr;
- ulint len;
- ulint type_cmpl;
- ptr = undo_rec + 2;
- type_cmpl = mach_read_from_1(ptr);
- ptr++;
-
- *type = type_cmpl & (TRX_UNDO_CMPL_INFO_MULT - 1);
- *cmpl_info = type_cmpl / TRX_UNDO_CMPL_INFO_MULT;
- *undo_no = mach_dulint_read_much_compressed(ptr);
- len = mach_dulint_get_much_compressed_size(*undo_no);
- ptr += len;
- *table_id = mach_dulint_read_much_compressed(ptr);
- len = mach_dulint_get_much_compressed_size(*table_id);
- ptr += len;
- return(ptr);
- }
- /**************************************************************************
- Reads from an undo log record a stored column value. */
- UNIV_INLINE
- byte*
- trx_undo_rec_get_col_val(
- /*=====================*/
- /* out: remaining part of undo log record after
- reading these values */
- byte* ptr, /* in: pointer to remaining part of undo log record */
- byte** field, /* out: pointer to stored field */
- ulint* len) /* out: length of the field, or UNIV_SQL_NULL */
- {
- *len = mach_read_compressed(ptr);
- ptr += mach_get_compressed_size(*len);
- *field = ptr;
-
- if (*len != UNIV_SQL_NULL) {
- ptr += *len;
- }
- return(ptr);
- }
- /***********************************************************************
- Builds a row reference from an undo log record. */
- byte*
- trx_undo_rec_get_row_ref(
- /*=====================*/
- /* out: pointer to remaining part of undo
- record */
- byte* ptr, /* in: remaining part of a copy of an undo log
- record, at the start of the row reference;
- NOTE that this copy of the undo log record must
- be preserved as long as the row reference is
- used, as we do NOT copy the data in the
- record! */
- dict_index_t* index, /* in: clustered index */
- dtuple_t** ref, /* out, own: row reference */
- mem_heap_t* heap) /* in: memory heap from which the memory
- needed is allocated */
- {
- ulint i;
- dfield_t* dfield;
- byte* field;
- ulint len;
- ulint ref_len;
-
- ut_ad(index && ptr && ref && heap);
-
- ref_len = dict_index_get_n_unique(index);
- *ref = dtuple_create(heap, ref_len);
- dict_index_copy_types(*ref, index, ref_len);
- for (i = 0; i < ref_len; i++) {
- dfield = dtuple_get_nth_field(*ref, i);
- ptr = trx_undo_rec_get_col_val(ptr, &field, &len);
- dfield_set_data(dfield, field, len);
- }
- return(ptr);
- }
- /***********************************************************************
- Skips a row reference from an undo log record. */
- byte*
- trx_undo_rec_skip_row_ref(
- /*======================*/
- /* out: pointer to remaining part of undo
- record */
- byte* ptr, /* in: remaining part in update undo log
- record, at the start of the row reference */
- dict_index_t* index) /* in: clustered index */
- {
- ulint i;
- byte* field;
- ulint len;
- ulint ref_len;
-
- ut_ad(index && ptr);
-
- ref_len = dict_index_get_n_unique(index);
- for (i = 0; i < ref_len; i++) {
- ptr = trx_undo_rec_get_col_val(ptr, &field, &len);
- }
- return(ptr);
- }
- /**************************************************************************
- Reports in the undo log of an update or delete marking of a clustered index
- record. */
- static
- ulint
- trx_undo_page_report_modify(
- /*========================*/
- /* out: byte offset of the inserted
- undo log entry on the page if succeed,
- 0 if fail */
- page_t* undo_page, /* in: undo log page */
- trx_t* trx, /* in: transaction */
- dict_index_t* index, /* in: clustered index where update or
- delete marking is done */
- rec_t* rec, /* in: clustered index record which
- has NOT yet been modified */
- upd_t* update, /* in: update vector which tells the
- columns to be updated; in the case of
- a delete, this should be set to NULL */
- ulint cmpl_info, /* in: compiler info on secondary
- index updates */
- mtr_t* mtr) /* in: mtr */
- {
- dict_table_t* table;
- upd_field_t* upd_field;
- dict_col_t* col;
- ulint first_free;
- byte* ptr;
- ulint len;
- byte* field;
- ulint flen;
- ulint pos;
- dulint roll_ptr;
- dulint trx_id;
- ulint bits;
- ulint col_no;
- byte* old_ptr;
- ulint type_cmpl;
- ulint i;
-
- ut_ad(index->type & DICT_CLUSTERED);
- ut_ad(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
- + TRX_UNDO_PAGE_TYPE) == TRX_UNDO_UPDATE);
- table = index->table;
-
- first_free = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
- + TRX_UNDO_PAGE_FREE);
- ptr = undo_page + first_free;
-
- ut_ad(first_free <= UNIV_PAGE_SIZE);
- if (trx_undo_left(undo_page, ptr) < 50) {
- /* NOTE: the value 50 must be big enough so that the general
- fields written below fit on the undo log page */
- return(0);
- }
- /* Reserve 2 bytes for the pointer to the next undo log record */
- ptr += 2;
- /* Store first some general parameters to the undo log */
- if (update) {
- if (rec_get_deleted_flag(rec)) {
- type_cmpl = TRX_UNDO_UPD_DEL_REC;
- } else {
- type_cmpl = TRX_UNDO_UPD_EXIST_REC;
- }
- } else {
- type_cmpl = TRX_UNDO_DEL_MARK_REC;
- }
- type_cmpl = type_cmpl | (cmpl_info * TRX_UNDO_CMPL_INFO_MULT);
- mach_write_to_1(ptr, type_cmpl);
-
- ptr++;
- len = mach_dulint_write_much_compressed(ptr, trx->undo_no);
- ptr += len;
- len = mach_dulint_write_much_compressed(ptr, table->id);
- ptr += len;
- /*----------------------------------------*/
- /* Store the state of the info bits */
- bits = rec_get_info_bits(rec);
- mach_write_to_1(ptr, bits);
- ptr += 1;
- /* Store the values of the system columns */
- trx_id = dict_index_rec_get_sys_col(index, DATA_TRX_ID, rec);
- roll_ptr = dict_index_rec_get_sys_col(index, DATA_ROLL_PTR, rec);
- len = mach_dulint_write_compressed(ptr, trx_id);
- ptr += len;
- len = mach_dulint_write_compressed(ptr, roll_ptr);
- ptr += len;
- /*----------------------------------------*/
- /* Store then the fields required to uniquely determine the
- record which will be modified in the clustered index */
- for (i = 0; i < dict_index_get_n_unique(index); i++) {
- field = rec_get_nth_field(rec, i, &flen);
- if (trx_undo_left(undo_page, ptr) < 4) {
- return(0);
- }
- len = mach_write_compressed(ptr, flen);
- ptr += len;
- if (flen != UNIV_SQL_NULL) {
- if (trx_undo_left(undo_page, ptr) < flen) {
- return(0);
- }
- ut_memcpy(ptr, field, flen);
- ptr += flen;
- }
- }
- /*----------------------------------------*/
- /* Save to the undo log the old values of the columns to be updated. */
- if (update) {
- if (trx_undo_left(undo_page, ptr) < 5) {
- return(0);
- }
- len = mach_write_compressed(ptr, upd_get_n_fields(update));
- ptr += len;
- for (i = 0; i < upd_get_n_fields(update); i++) {
- upd_field = upd_get_nth_field(update, i);
- pos = upd_field->field_no;
- /* Write field number to undo log */
- if (trx_undo_left(undo_page, ptr) < 5) {
- return(0);
- }
- len = mach_write_compressed(ptr, pos);
- ptr += len;
- /* Save the old value of field */
- field = rec_get_nth_field(rec, pos, &flen);
- if (trx_undo_left(undo_page, ptr) < 5) {
- return(0);
- }
- len = mach_write_compressed(ptr, flen);
- ptr += len;
- if (flen != UNIV_SQL_NULL) {
- if (trx_undo_left(undo_page, ptr) < flen) {
- return(0);
- }
- ut_memcpy(ptr, field, flen);
- ptr += flen;
- }
- }
- }
- /*----------------------------------------*/
- /* In the case of a delete marking, and also in the case of an update
- where any ordering field of any index changes, store the values of all
- columns which occur as ordering fields in any index. This info is used
- in the purge of old versions where we use it to build and search the
- delete marked index records, to look if we can remove them from the
- index tree. */
- if (!update || !(cmpl_info & UPD_NODE_NO_ORD_CHANGE)) {
- (trx->update_undo)->del_marks = TRUE;
- if (trx_undo_left(undo_page, ptr) < 5) {
- return(0);
- }
-
- old_ptr = ptr;
- /* Reserve 2 bytes to write the number of bytes the stored fields
- take in this undo record */
- ptr += 2;
- for (col_no = 0; col_no < dict_table_get_n_cols(table); col_no++) {
- col = dict_table_get_nth_col(table, col_no);
- if (col->ord_part > 0) {
-
- pos = dict_index_get_nth_col_pos(index, col_no);
- /* Write field number to undo log */
- if (trx_undo_left(undo_page, ptr) < 5) {
-
- return(0);
- }
- len = mach_write_compressed(ptr, pos);
- ptr += len;
-
- /* Save the old value of field */
- field = rec_get_nth_field(rec, pos, &flen);
-
- if (trx_undo_left(undo_page, ptr) < 5) {
-
- return(0);
- }
- len = mach_write_compressed(ptr, flen);
- ptr += len;
- if (flen != UNIV_SQL_NULL) {
- if (trx_undo_left(undo_page, ptr) < flen) {
-
- return(0);
- }
- ut_memcpy(ptr, field, flen);
- ptr += flen;
- }
- }
- }
- mach_write_to_2(old_ptr, ptr - old_ptr);
- }
- /*----------------------------------------*/
- /* Write pointers to the previous and the next undo log records */
- if (trx_undo_left(undo_page, ptr) < 2) {
- return(0);
- }
-
- mach_write_to_2(ptr, first_free);
- ptr += 2;
- mach_write_to_2(undo_page + first_free, ptr - undo_page);
- mach_write_to_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE,
- ptr - undo_page);
- /* Write to the REDO log about this change in the UNDO log */
- trx_undof_page_add_undo_rec_log(undo_page, first_free,
- ptr - undo_page, mtr);
- return(first_free);
- }
- /**************************************************************************
- Reads from an undo log update record the system field values of the old
- version. */
- byte*
- trx_undo_update_rec_get_sys_cols(
- /*=============================*/
- /* out: remaining part of undo log
- record after reading these values */
- byte* ptr, /* in: remaining part of undo log
- record after reading general
- parameters */
- dulint* trx_id, /* out: trx id */
- dulint* roll_ptr, /* out: roll ptr */
- ulint* info_bits) /* out: info bits state */
- {
- ulint len;
- /* Read the state of the info bits */
- *info_bits = mach_read_from_1(ptr);
- ptr += 1;
- /* Read the values of the system columns */
- *trx_id = mach_dulint_read_compressed(ptr);
- len = mach_dulint_get_compressed_size(*trx_id);
- ptr += len;
- *roll_ptr = mach_dulint_read_compressed(ptr);
- len = mach_dulint_get_compressed_size(*roll_ptr);
- ptr += len;
- return(ptr);
- }
- /**************************************************************************
- Reads from an update undo log record the number of updated fields. */
- UNIV_INLINE
- byte*
- trx_undo_update_rec_get_n_upd_fields(
- /*=================================*/
- /* out: remaining part of undo log record after
- reading this value */
- byte* ptr, /* in: pointer to remaining part of undo log record */
- ulint* n) /* out: number of fields */
- {
- *n = mach_read_compressed(ptr);
- ptr += mach_get_compressed_size(*n);
- return(ptr);
- }
- /**************************************************************************
- Reads from an update undo log record a stored field number. */
- UNIV_INLINE
- byte*
- trx_undo_update_rec_get_field_no(
- /*=============================*/
- /* out: remaining part of undo log record after
- reading this value */
- byte* ptr, /* in: pointer to remaining part of undo log record */
- ulint* field_no)/* out: field number */
- {
- *field_no = mach_read_compressed(ptr);
- ptr += mach_get_compressed_size(*field_no);
- return(ptr);
- }
- /***********************************************************************
- Builds an update vector based on a remaining part of an undo log record. */
- byte*
- trx_undo_update_rec_get_update(
- /*===========================*/
- /* out: remaining part of the record */
- byte* ptr, /* in: remaining part in update undo log
- record, after reading the row reference
- NOTE that this copy of the undo log record must
- be preserved as long as the update vector is
- used, as we do NOT copy the data in the
- record! */
- dict_index_t* index, /* in: clustered index */
- ulint type, /* in: TRX_UNDO_UPD_EXIST_REC,
- TRX_UNDO_UPD_DEL_REC, or
- TRX_UNDO_DEL_MARK_REC; in the last case,
- only trx id and roll ptr fields are added to
- the update vector */
- dulint trx_id, /* in: transaction id from this undorecord */
- dulint roll_ptr,/* in: roll pointer from this undo record */
- ulint info_bits,/* in: info bits from this undo record */
- mem_heap_t* heap, /* in: memory heap from which the memory
- needed is allocated */
- upd_t** upd) /* out, own: update vector */
- {
- upd_field_t* upd_field;
- upd_t* update;
- ulint n_fields;
- byte* buf;
- byte* field;
- ulint len;
- ulint field_no;
- ulint i;
-
- if (type != TRX_UNDO_DEL_MARK_REC) {
- ptr = trx_undo_update_rec_get_n_upd_fields(ptr, &n_fields);
- } else {
- n_fields = 0;
- }
- update = upd_create(n_fields + 2, heap);
- update->info_bits = info_bits;
- /* Store first trx id and roll ptr to update vector */
- upd_field = upd_get_nth_field(update, n_fields);
- buf = mem_heap_alloc(heap, DATA_TRX_ID_LEN);
- trx_write_trx_id(buf, trx_id);
- upd_field_set_field_no(upd_field,
- dict_index_get_sys_col_pos(index, DATA_TRX_ID),
- index);
- dfield_set_data(&(upd_field->new_val), buf, DATA_TRX_ID_LEN);
- upd_field = upd_get_nth_field(update, n_fields + 1);
- buf = mem_heap_alloc(heap, DATA_ROLL_PTR_LEN);
- trx_write_roll_ptr(buf, roll_ptr);
- upd_field_set_field_no(upd_field,
- dict_index_get_sys_col_pos(index, DATA_ROLL_PTR),
- index);
- dfield_set_data(&(upd_field->new_val), buf, DATA_ROLL_PTR_LEN);
-
- /* Store then the updated ordinary columns to update vector */
- for (i = 0; i < n_fields; i++) {
- ptr = trx_undo_update_rec_get_field_no(ptr, &field_no);
- ptr = trx_undo_rec_get_col_val(ptr, &field, &len);
- upd_field = upd_get_nth_field(update, i);
- upd_field_set_field_no(upd_field, field_no, index);
- dfield_set_data(&(upd_field->new_val), field, len);
- }
- *upd = update;
- return(ptr);
- }
-
- /***********************************************************************
- Builds a partial row from an update undo log record. It contains the
- columns which occur as ordering in any index of the table. */
- byte*
- trx_undo_rec_get_partial_row(
- /*=========================*/
- /* out: pointer to remaining part of undo
- record */
- byte* ptr, /* in: remaining part in update undo log
- record of a suitable type, at the start of
- the stored index columns;
- NOTE that this copy of the undo log record must
- be preserved as long as the partial row is
- used, as we do NOT copy the data in the
- record! */
- dict_index_t* index, /* in: clustered index */
- dtuple_t** row, /* out, own: partial row */
- mem_heap_t* heap) /* in: memory heap from which the memory
- needed is allocated */
- {
- dfield_t* dfield;
- byte* field;
- ulint len;
- ulint field_no;
- ulint col_no;
- ulint row_len;
- ulint total_len;
- byte* start_ptr;
- ulint i;
-
- ut_ad(index && ptr && row && heap);
-
- row_len = dict_table_get_n_cols(index->table);
- *row = dtuple_create(heap, row_len);
- dict_table_copy_types(*row, index->table);
- start_ptr = ptr;
- total_len = mach_read_from_2(ptr);
- ptr += 2;
-
- for (i = 0;; i++) {
- if (ptr == start_ptr + total_len) {
- break;
- }
-
- ptr = trx_undo_update_rec_get_field_no(ptr, &field_no);
- col_no = dict_index_get_nth_col_no(index, field_no);
-
- ptr = trx_undo_rec_get_col_val(ptr, &field, &len);
- dfield = dtuple_get_nth_field(*row, col_no);
- dfield_set_data(dfield, field, len);
- }
- return(ptr);
- }
- /***************************************************************************
- Erases the unused undo log page end. */
- static
- void
- trx_undo_erase_page_end(
- /*====================*/
- page_t* undo_page, /* in: undo page whose end to erase */
- mtr_t* mtr) /* in: mtr */
- {
- ulint first_free;
- ulint i;
-
- first_free = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
- + TRX_UNDO_PAGE_FREE);
- for (i = first_free; i < UNIV_PAGE_SIZE - FIL_PAGE_DATA_END; i++) {
- undo_page[i] = 0xFF;
- }
- mlog_write_initial_log_record(undo_page, MLOG_UNDO_ERASE_END, mtr);
- }
-
- /***************************************************************
- Parses a redo log record of erasing of an undo page end. */
- byte*
- trx_undo_parse_erase_page_end(
- /*==========================*/
- /* out: end of log record or NULL */
- byte* ptr, /* in: buffer */
- byte* end_ptr,/* in: buffer end */
- page_t* page, /* in: page or NULL */
- mtr_t* mtr) /* in: mtr or NULL */
- {
- ut_ad(ptr && end_ptr);
- if (page == NULL) {
- return(ptr);
- }
- trx_undo_erase_page_end(page, mtr);
- return(ptr);
- }
- /***************************************************************************
- Writes information to an undo log about an insert, update, or a delete marking
- of a clustered index record. This information is used in a rollback of the
- transaction and in consistent reads that must look to the history of this
- transaction. */
- ulint
- trx_undo_report_row_operation(
- /*==========================*/
- /* out: DB_SUCCESS or error code */
- ulint flags, /* in: if BTR_NO_UNDO_LOG_FLAG bit is
- set, does nothing */
- ulint op_type, /* in: TRX_UNDO_INSERT_OP or
- TRX_UNDO_MODIFY_OP */
- que_thr_t* thr, /* in: query thread */
- dict_index_t* index, /* in: clustered index */
- dtuple_t* clust_entry, /* in: in the case of an insert,
- index entry to insert into the
- clustered index, otherwise NULL */
- upd_t* update, /* in: in the case of an update,
- the update vector, otherwise NULL */
- ulint cmpl_info, /* in: compiler info on secondary
- index updates */
- rec_t* rec, /* in: case of an update or delete
- marking, the record in the clustered
- index, otherwise NULL */
- dulint* roll_ptr) /* out: rollback pointer to the
- inserted undo log record,
- ut_dulint_zero if BTR_NO_UNDO_LOG
- flag was specified */
- {
- trx_t* trx;
- trx_undo_t* undo;
- page_t* undo_page;
- ulint offset;
- mtr_t mtr;
- ulint page_no;
- ibool is_insert;
- trx_rseg_t* rseg;
-
- if (flags & BTR_NO_UNDO_LOG_FLAG) {
- *roll_ptr = ut_dulint_zero;
- return(DB_SUCCESS);
- }
-
- ut_ad(thr);
- ut_ad(index->type & DICT_CLUSTERED);
- ut_ad((op_type != TRX_UNDO_INSERT_OP)
- || (clust_entry && !update && !rec));
-
- trx = thr_get_trx(thr);
- rseg = trx->rseg;
-
- mutex_enter(&(trx->undo_mutex));
- /* If the undo log is not assigned yet, assign one */
- if (op_type == TRX_UNDO_INSERT_OP) {
- if (trx->insert_undo == NULL) {
- trx_undo_assign_undo(trx, TRX_UNDO_INSERT);
- }
- undo = trx->insert_undo;
- is_insert = TRUE;
- } else {
- ut_ad(op_type == TRX_UNDO_MODIFY_OP);
- if (trx->update_undo == NULL) {
- trx_undo_assign_undo(trx, TRX_UNDO_UPDATE);
- }
- undo = trx->update_undo;
- is_insert = FALSE;
- }
- if (undo == NULL) {
- /* Did not succeed: out of space */
- mutex_exit(&(trx->undo_mutex));
- return(DB_OUT_OF_FILE_SPACE);
- }
- page_no = undo->last_page_no;
-
- mtr_start(&mtr);
- for (;;) {
- undo_page = buf_page_get_gen(undo->space, page_no,
- RW_X_LATCH, undo->guess_page,
- BUF_GET,
- #ifdef UNIV_SYNC_DEBUG
- IB__FILE__, __LINE__,
- #endif
- &mtr);
- buf_page_dbg_add_level(undo_page, SYNC_TRX_UNDO_PAGE);
- if (op_type == TRX_UNDO_INSERT_OP) {
- offset = trx_undo_page_report_insert(undo_page, trx,
- index, clust_entry,
- &mtr);
- } else {
- offset = trx_undo_page_report_modify(undo_page, trx,
- index, rec, update,
- cmpl_info, &mtr);
- }
- if (offset == 0) {
- /* The record did not fit on the page. We erase the
- end segment of the undo log page and write a log
- record of it: this is to ensure that in the debug
- version the replicate page constructed using the log
- records stays identical to the original page */
- trx_undo_erase_page_end(undo_page, &mtr);
- }
-
- mtr_commit(&mtr);
- if (offset != 0) {
- /* Success */
- break;
- }
- ut_ad(page_no == undo->last_page_no);
-
- /* We have to extend the undo log by one page */
- mtr_start(&mtr);
- /* When we add a page to an undo log, this is analogous to
- a pessimistic insert in a B-tree, and we must reserve the
- counterpart of the tree latch, which is the rseg mutex. */
- mutex_enter(&(rseg->mutex));
-
- page_no = trx_undo_add_page(trx, undo, &mtr);
- mutex_exit(&(rseg->mutex));
-
- if (page_no == FIL_NULL) {
- /* Did not succeed: out of space */
- mutex_exit(&(trx->undo_mutex));
- mtr_commit(&mtr);
- return(DB_OUT_OF_FILE_SPACE);
- }
- }
- undo->empty = FALSE;
- undo->top_page_no = page_no;
- undo->top_offset = offset;
- undo->top_undo_no = trx->undo_no;
- undo->guess_page = undo_page;
- UT_DULINT_INC(trx->undo_no);
-
- mutex_exit(&(trx->undo_mutex));
- *roll_ptr = trx_undo_build_roll_ptr(is_insert, rseg->id, page_no,
- offset);
- return(DB_SUCCESS);
- }
- /*============== BUILDING PREVIOUS VERSION OF A RECORD ===============*/
- /**********************************************************************
- Copies an undo record to heap. This function can be called if we know that
- the undo log record exists. */
- trx_undo_rec_t*
- trx_undo_get_undo_rec_low(
- /*======================*/
- /* out, own: copy of the record */
- dulint roll_ptr, /* in: roll pointer to record */
- mem_heap_t* heap) /* in: memory heap where copied */
- {
- ulint rseg_id;
- ulint page_no;
- ulint offset;
- page_t* undo_page;
- trx_rseg_t* rseg;
- ibool is_insert;
- mtr_t mtr;
- trx_undo_rec_t* undo_rec;
-
- trx_undo_decode_roll_ptr(roll_ptr, &is_insert, &rseg_id, &page_no,
- &offset);
- rseg = trx_rseg_get_on_id(rseg_id);
- mtr_start(&mtr);
-
- undo_page = trx_undo_page_get_s_latched(rseg->space, page_no, &mtr);
-
- undo_rec = trx_undo_rec_copy(undo_page + offset, heap);
- mtr_commit(&mtr);
- return(undo_rec);
- }
- /**********************************************************************
- Copies an undo record to heap. */
- ulint
- trx_undo_get_undo_rec(
- /*==================*/
- /* out: DB_SUCCESS, or
- DB_MISSING_HISTORY if the undo log
- has been truncated and we cannot
- fetch the old version; NOTE: the
- caller must have latches on the
- clustered index page and purge_view */
- dulint roll_ptr, /* in: roll pointer to record */
- dulint trx_id, /* in: id of the trx that generated
- the roll pointer: it points to an
- undo log of this transaction */
- trx_undo_rec_t** undo_rec, /* out, own: copy of the record */
- mem_heap_t* heap) /* in: memory heap where copied */
- {
- ut_ad(rw_lock_own(&(purge_sys->latch), RW_LOCK_SHARED));
- if (!trx_purge_update_undo_must_exist(trx_id)) {
- /* It may be that the necessary undo log has already been
- deleted */
- return(DB_MISSING_HISTORY);
- }
- *undo_rec = trx_undo_get_undo_rec_low(roll_ptr, heap);
-
- return(DB_SUCCESS);
- }
- /***********************************************************************
- Build a previous version of a clustered index record. This function checks
- that the caller has a latch on the index page of the clustered index record
- and an s-latch on the purge_view. This guarantees that the stack of versions
- is locked. */
- ulint
- trx_undo_prev_version_build(
- /*========================*/
- /* out: DB_SUCCESS, or DB_MISSING_HISTORY if
- the previous version is not >= purge_view,
- which means that it may have been removed */
- rec_t* index_rec,/* in: clustered index record in the
- index tree */
- mtr_t* index_mtr,/* in: mtr which contains the latch to
- index_rec page and purge_view */
- rec_t* rec, /* in: version of a clustered index record */
- dict_index_t* index, /* in: clustered index */
- mem_heap_t* heap, /* in: memory heap from which the memory
- needed is allocated */
- rec_t** old_vers)/* out, own: previous version, or NULL if
- rec is the first inserted version, or if
- history data has been deleted */
- {
- trx_undo_rec_t* undo_rec;
- dtuple_t* entry;
- dulint rec_trx_id;
- ulint type;
- dulint undo_no;
- dulint table_id;
- dulint trx_id;
- dulint roll_ptr;
- upd_t* update;
- byte* ptr;
- ulint info_bits;
- ulint cmpl_info;
- byte* buf;
- ulint err;
- ut_ad(rw_lock_own(&(purge_sys->latch), RW_LOCK_SHARED));
- ut_ad(mtr_memo_contains(index_mtr, buf_block_align(index_rec),
- MTR_MEMO_PAGE_S_FIX) ||
- mtr_memo_contains(index_mtr, buf_block_align(index_rec),
- MTR_MEMO_PAGE_X_FIX));
- roll_ptr = row_get_rec_roll_ptr(rec, index);
- if (trx_undo_roll_ptr_is_insert(roll_ptr)) {
- /* The record rec is the first inserted version */
- *old_vers = NULL;
- return(DB_SUCCESS);
- }
- rec_trx_id = row_get_rec_trx_id(rec, index);
-
- err = trx_undo_get_undo_rec(roll_ptr, rec_trx_id, &undo_rec, heap);
- if (err != DB_SUCCESS) {
- *old_vers = NULL;
- return(err);
- }
- ptr = trx_undo_rec_get_pars(undo_rec, &type, &cmpl_info, &undo_no,
- &table_id);
- ptr = trx_undo_update_rec_get_sys_cols(ptr, &trx_id, &roll_ptr,
- &info_bits);
- ptr = trx_undo_rec_skip_row_ref(ptr, index);
- trx_undo_update_rec_get_update(ptr, index, type, trx_id, roll_ptr,
- info_bits, heap, &update);
- if (row_upd_changes_field_size(rec, index, update)) {
- entry = row_rec_to_index_entry(ROW_COPY_DATA, index, rec, heap);
- row_upd_clust_index_replace_new_col_vals(entry, update);
- buf = mem_heap_alloc(heap, rec_get_converted_size(entry));
- *old_vers = rec_convert_dtuple_to_rec(buf, entry);
- } else {
- buf = mem_heap_alloc(heap, rec_get_size(rec));
- *old_vers = rec_copy(buf, rec);
- row_upd_rec_in_place(*old_vers, update);
- }
- return(DB_SUCCESS);
- }