diff options
Diffstat (limited to 'sql')
| -rw-r--r-- | sql/examples/ha_archive.cc | 27 | ||||
| -rw-r--r-- | sql/ha_innodb.cc | 18 |
2 files changed, 24 insertions, 21 deletions
diff --git a/sql/examples/ha_archive.cc b/sql/examples/ha_archive.cc index 436c72702a0..5c252569f82 100644 --- a/sql/examples/ha_archive.cc +++ b/sql/examples/ha_archive.cc @@ -43,18 +43,20 @@ handle bulk inserts as well (that is if someone was trying to read at the same time since we would want to flush). - A "meta" file is kept. All this file does is contain information on - the number of rows. + A "meta" file is kept alongside the data file. This file serves two purpose. + The first purpose is to track the number of rows in the table. The second + purpose is to determine if the table was closed properly or not. When the + meta file is first opened it is marked as dirty. It is opened when the table + itself is opened for writing. When the table is closed the new count for rows + is written to the meta file and the file is marked as clean. If the meta file + is opened and it is marked as dirty, it is assumed that a crash occured. At + this point an error occurs and the user is told to rebuild the file. + A rebuild scans the rows and rewrites the meta file. If corruption is found + in the data file then the meta file is not repaired. - No attempts at durability are made. You can corrupt your data. A repair - method was added to repair the meta file that stores row information, - but if your data file gets corrupted I haven't solved that. I could - create a repair that would solve this, but do you want to take a - chance of loosing your data? + At some point a recovery method for such a drastic case needs to be divised. - Locks are row level, and you will get a consistant read. Transactions - will be added later (they are not that hard to add at this - stage). + Locks are row level, and you will get a consistant read. For performance as far as table scans go it is quite fast. I don't have good numbers but locally it has out performed both Innodb and MyISAM. For @@ -89,7 +91,6 @@ compression but may speed up ordered searches). Checkpoint the meta file to allow for faster rebuilds. Dirty open (right now the meta file is repaired if a crash occured). - Transactions. Option to allow for dirty reads, this would lower the sync calls, which would make inserts a lot faster, but would mean highly arbitrary reads. @@ -343,6 +344,7 @@ ARCHIVE_SHARE *ha_archive::get_share(const char *table_name, TABLE *table) opposite. If the meta file will not open we assume it is crashed and leave it up to the user to fix. */ + if (read_meta_file(share->meta_file, &share->rows_recorded)) share->crashed= TRUE; else @@ -393,7 +395,8 @@ int ha_archive::free_share(ARCHIVE_SHARE *share) (void)write_meta_file(share->meta_file, share->rows_recorded, FALSE); if (gzclose(share->archive_write) == Z_ERRNO) rc= 1; - my_close(share->meta_file,MYF(0)); + if (my_close(share->meta_file, MYF(0))) + rc= 1; my_free((gptr) share, MYF(0)); } pthread_mutex_unlock(&archive_mutex); diff --git a/sql/ha_innodb.cc b/sql/ha_innodb.cc index 32b203f7ad6..797f51c0293 100644 --- a/sql/ha_innodb.cc +++ b/sql/ha_innodb.cc @@ -4871,12 +4871,12 @@ ha_innobase::update_table_comment( dict_print_info_on_foreign_keys(FALSE, file, prebuilt->trx, prebuilt->table); flen = ftell(file); - if(length + flen + 3 > 64000) { + if (flen < 0) { + flen = 0; + } else if (length + flen + 3 > 64000) { flen = 64000 - 3 - length; } - ut_ad(flen > 0); - /* allocate buffer for the full string, and read the contents of the temporary file */ @@ -4940,12 +4940,12 @@ ha_innobase::get_foreign_key_create_info(void) prebuilt->trx->op_info = (char*)""; flen = ftell(file); - if(flen > 64000 - 1) { + if (flen < 0) { + flen = 0; + } else if(flen > 64000 - 1) { flen = 64000 - 1; } - ut_ad(flen >= 0); - /* allocate buffer for the string, and read the contents of the temporary file */ @@ -5546,12 +5546,12 @@ innodb_show_status( srv_printf_innodb_monitor(srv_monitor_file); flen = ftell(srv_monitor_file); os_file_set_eof(srv_monitor_file); - if(flen > 64000 - 1) { + if (flen < 0) { + flen = 0; + } else if (flen > 64000 - 1) { flen = 64000 - 1; } - ut_ad(flen > 0); - /* allocate buffer for the string, and read the contents of the temporary file */ |