/****************************************************** 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; const byte* log_end; ulint len; log_ptr = mlog_open(mtr, 11 + 13 + MLOG_BUF_MARGIN); if (log_ptr == NULL) { return; } log_end = &log_ptr[11 + 13 + MLOG_BUF_MARGIN]; 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 (log_ptr + len <= log_end) { memcpy(log_ptr, undo_page + old_free + 2, len); mlog_close(mtr, log_ptr + len); } else { mlog_close(mtr, log_ptr); 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 */ ibool* updated_extern, /* out: TRUE if we updated an externally stored fild */ 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++; if (type_cmpl & TRX_UNDO_UPD_EXTERN) { *updated_extern = TRUE; type_cmpl -= TRX_UNDO_UPD_EXTERN; } else { *updated_extern = FALSE; } *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. */ static 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) { if (*len >= UNIV_EXTERN_STORAGE_FIELD) { ptr += (*len - UNIV_EXTERN_STORAGE_FIELD); } else { 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 */ { dfield_t* dfield; byte* field; ulint len; ulint ref_len; ulint i; ut_ad(index && ptr && ref && heap); ut_a(index->type & DICT_CLUSTERED); 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 */ { byte* field; ulint len; ulint ref_len; ulint i; ut_ad(index && ptr); ut_a(index->type & DICT_CLUSTERED); 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 */ const ulint* offsets, /* in: rec_get_offsets(rec, index) */ 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; 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; byte* type_cmpl_ptr; ulint i; ut_a(index->type & DICT_CLUSTERED); ut_ad(rec_offs_validate(rec, index, offsets)); 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, dict_table_is_comp(table))) { 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); type_cmpl_ptr = ptr; 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, dict_table_is_comp(table)); mach_write_to_1(ptr, bits); ptr += 1; /* Store the values of the system columns */ field = rec_get_nth_field(rec, offsets, dict_index_get_sys_col_pos( index, DATA_TRX_ID), &len); ut_ad(len == DATA_TRX_ID_LEN); trx_id = trx_read_trx_id(field); field = rec_get_nth_field(rec, offsets, dict_index_get_sys_col_pos( index, DATA_ROLL_PTR), &len); ut_ad(len == DATA_ROLL_PTR_LEN); roll_ptr = trx_read_roll_ptr(field); 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, offsets, 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, offsets, pos, &flen); if (trx_undo_left(undo_page, ptr) < 5) { return(0); } if (rec_offs_nth_extern(offsets, pos)) { /* If a field has external storage, we add to flen the flag */ len = mach_write_compressed( ptr, UNIV_EXTERN_STORAGE_FIELD + flen); /* Notify purge that it eventually has to free the old externally stored field */ trx->update_undo->del_marks = TRUE; *type_cmpl_ptr = *type_cmpl_ptr | TRX_UNDO_UPD_EXTERN; } else { 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. Note that starting from 4.0.14 also externally stored fields can be ordering in some index. But we always store at least 384 first bytes locally to the clustered index record, which means we can construct the column prefix fields in the index from the stored data. */ 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++) { const dict_col_t* 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, offsets, 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, NULL if an error detected, which means that the record is corrupted */ 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 undo record */ dulint roll_ptr,/* in: roll pointer from this undo record */ ulint info_bits,/* in: info bits from this undo record */ trx_t* trx, /* in: transaction */ 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; ut_a(index->type & DICT_CLUSTERED); 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, trx); 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, trx); dfield_set_data(&(upd_field->new_val), buf, DATA_ROLL_PTR_LEN); /* Store then the updated ordinary columns to the update vector */ for (i = 0; i < n_fields; i++) { ptr = trx_undo_update_rec_get_field_no(ptr, &field_no); if (field_no >= dict_index_get_n_fields(index)) { fprintf(stderr, "InnoDB: Error: trying to access" " update undo rec field %lu in ", (ulong) field_no); dict_index_name_print(stderr, trx, index); fprintf(stderr, "\n" "InnoDB: but index has only %lu fields\n" "InnoDB: Submit a detailed bug report" " to http://bugs.mysql.com\n" "InnoDB: Run also CHECK TABLE ", (ulong) dict_index_get_n_fields(index)); ut_print_name(stderr, trx, TRUE, index->table_name); fprintf(stderr, "\n" "InnoDB: n_fields = %lu, i = %lu, ptr %p\n", (ulong) n_fields, (ulong) i, ptr); return(NULL); } 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, trx); if (len != UNIV_SQL_NULL && len >= UNIV_EXTERN_STORAGE_FIELD) { upd_field->extern_storage = TRUE; len -= UNIV_EXTERN_STORAGE_FIELD; } 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; first_free = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE); memset(undo_page + first_free, 0xff, (UNIV_PAGE_SIZE - FIL_PAGE_DATA_END) - first_free); 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 __attribute__((unused)), /* 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: 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; ulint page_no; ibool is_insert; trx_rseg_t* rseg; mtr_t mtr; ulint err = DB_SUCCESS; mem_heap_t* heap = NULL; ulint offsets_[REC_OFFS_NORMAL_SIZE]; ulint* offsets = offsets_; *offsets_ = (sizeof offsets_) / sizeof *offsets_; ut_a(index->type & DICT_CLUSTERED); if (flags & BTR_NO_UNDO_LOG_FLAG) { *roll_ptr = ut_dulint_zero; return(err); } ut_ad(thr); 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) { err = 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) { err = trx_undo_assign_undo(trx, TRX_UNDO_UPDATE); } undo = trx->update_undo; is_insert = FALSE; } if (err != DB_SUCCESS) { /* Did not succeed: return the error encountered */ mutex_exit(&(trx->undo_mutex)); return(err); } 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, __FILE__, __LINE__, &mtr); #ifdef UNIV_SYNC_DEBUG buf_page_dbg_add_level(undo_page, SYNC_TRX_UNDO_PAGE); #endif /* UNIV_SYNC_DEBUG */ if (op_type == TRX_UNDO_INSERT_OP) { offset = trx_undo_page_report_insert( undo_page, trx, index, clust_entry, &mtr); } else { offsets = rec_get_offsets(rec, index, offsets, ULINT_UNDEFINED, &heap); offset = trx_undo_page_report_modify( undo_page, trx, index, rec, offsets, 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); if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } 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); if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } return(err); } /*============== 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 */ { trx_undo_rec_t* undo_rec; ulint rseg_id; ulint page_no; ulint offset; page_t* undo_page; trx_rseg_t* rseg; ibool is_insert; mtr_t mtr; 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 */ { #ifdef UNIV_SYNC_DEBUG ut_ad(rw_lock_own(&(purge_sys->latch), RW_LOCK_SHARED)); #endif /* UNIV_SYNC_DEBUG */ 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, DB_ERROR if corrupted record */ rec_t* index_rec,/* in: clustered index record in the index tree */ mtr_t* index_mtr __attribute__((unused)), /* 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 */ ulint* offsets,/* in: rec_get_offsets(rec, 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; dulint old_roll_ptr; upd_t* update; byte* ptr; ulint info_bits; ulint cmpl_info; ibool dummy_extern; byte* buf; ulint err; #ifdef UNIV_SYNC_DEBUG ut_ad(rw_lock_own(&(purge_sys->latch), RW_LOCK_SHARED)); #endif /* UNIV_SYNC_DEBUG */ 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)); ut_ad(rec_offs_validate(rec, index, offsets)); if (!(index->type & DICT_CLUSTERED)) { fprintf(stderr, "InnoDB: Error: trying to access" " update undo rec for non-clustered index %s\n" "InnoDB: Submit a detailed bug report to" " http://bugs.mysql.com\n" "InnoDB: index record ", index->name); rec_print(stderr, index_rec, index); fputs("\n" "InnoDB: record version ", stderr); rec_print_new(stderr, rec, offsets); putc('\n', stderr); return(DB_ERROR); } roll_ptr = row_get_rec_roll_ptr(rec, index, offsets); old_roll_ptr = roll_ptr; *old_vers = NULL; if (trx_undo_roll_ptr_is_insert(roll_ptr)) { /* The record rec is the first inserted version */ return(DB_SUCCESS); } rec_trx_id = row_get_rec_trx_id(rec, index, offsets); err = trx_undo_get_undo_rec(roll_ptr, rec_trx_id, &undo_rec, heap); if (err != DB_SUCCESS) { return(err); } ptr = trx_undo_rec_get_pars(undo_rec, &type, &cmpl_info, &dummy_extern, &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); ptr = trx_undo_update_rec_get_update(ptr, index, type, trx_id, roll_ptr, info_bits, NULL, heap, &update); if (ut_dulint_cmp(table_id, index->table->id) != 0) { ptr = NULL; fprintf(stderr, "InnoDB: Error: trying to access update undo rec" " for table %s\n" "InnoDB: but the table id in the" " undo record is wrong\n" "InnoDB: Submit a detailed bug report" " to http://bugs.mysql.com\n" "InnoDB: Run also CHECK TABLE %s\n", index->table_name, index->table_name); } if (ptr == NULL) { /* The record was corrupted, return an error; these printfs should catch an elusive bug in row_vers_old_has_index_entry */ fprintf(stderr, "InnoDB: table %s, index %s, n_uniq %lu\n" "InnoDB: undo rec address %p, type %lu cmpl_info %lu\n" "InnoDB: undo rec table id %lu %lu," " index table id %lu %lu\n" "InnoDB: dump of 150 bytes in undo rec: ", index->table_name, index->name, (ulong) dict_index_get_n_unique(index), undo_rec, (ulong) type, (ulong) cmpl_info, (ulong) ut_dulint_get_high(table_id), (ulong) ut_dulint_get_low(table_id), (ulong) ut_dulint_get_high(index->table->id), (ulong) ut_dulint_get_low(index->table->id)); ut_print_buf(stderr, undo_rec, 150); fputs("\n" "InnoDB: index record ", stderr); rec_print(stderr, index_rec, index); fputs("\n" "InnoDB: record version ", stderr); rec_print_new(stderr, rec, offsets); fprintf(stderr, "\n" "InnoDB: Record trx id %lu %lu, update rec" " trx id %lu %lu\n" "InnoDB: Roll ptr in rec %lu %lu, in update rec" " %lu %lu\n", (ulong) ut_dulint_get_high(rec_trx_id), (ulong) ut_dulint_get_low(rec_trx_id), (ulong) ut_dulint_get_high(trx_id), (ulong) ut_dulint_get_low(trx_id), (ulong) ut_dulint_get_high(old_roll_ptr), (ulong) ut_dulint_get_low(old_roll_ptr), (ulong) ut_dulint_get_high(roll_ptr), (ulong) ut_dulint_get_low(roll_ptr)); trx_purge_sys_print(); return(DB_ERROR); } if (row_upd_changes_field_size_or_external(index, offsets, update)) { ulint* ext_vect; ulint n_ext_vect; /* We have to set the appropriate extern storage bits in the old version of the record: the extern bits in rec for those fields that update does NOT update, as well as the the bits for those fields that update updates to become externally stored fields. Store the info to ext_vect: */ ext_vect = mem_alloc(sizeof(ulint) * rec_offs_n_fields(offsets)); n_ext_vect = btr_push_update_extern_fields(ext_vect, offsets, update); entry = row_rec_to_index_entry(ROW_COPY_DATA, index, rec, heap); row_upd_index_replace_new_col_vals(entry, index, update, heap); buf = mem_heap_alloc(heap, rec_get_converted_size(index, entry)); *old_vers = rec_convert_dtuple_to_rec(buf, index, entry); /* Now set the extern bits in the old version of the record */ rec_set_field_extern_bits(*old_vers, index, ext_vect, n_ext_vect, NULL); mem_free(ext_vect); } else { buf = mem_heap_alloc(heap, rec_offs_size(offsets)); *old_vers = rec_copy(buf, rec, offsets); rec_offs_make_valid(*old_vers, index, offsets); row_upd_rec_in_place(*old_vers, offsets, update); } return(DB_SUCCESS); }