/* Copyright (c) 2004, 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 St, Fifth Floor, Boston, MA 02110-1301 USA */ #ifdef USE_PRAGMA_IMPLEMENTATION #pragma implementation // gcc: Class implementation #endif #include "sql_priv.h" #include "probes_mysql.h" #include "sql_class.h" // SSV #include "sql_table.h" #include #include "ha_archive.h" #include #include /* First, if you want to understand storage engines you should look at ha_example.cc and ha_example.h. This example was written as a test case for a customer who needed a storage engine without indexes that could compress data very well. So, welcome to a completely compressed storage engine. This storage engine only does inserts. No replace, deletes, or updates. All reads are complete table scans. Compression is done through a combination of packing and making use of the zlib library We keep a file pointer open for each instance of ha_archive for each read but for writes we keep one open file handle just for that. We flush it only if we have a read occur. azip handles compressing lots of records at once much better then doing lots of little records between writes. It is possible to not lock on writes but this would then mean we couldn't 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 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. 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. 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 Innodb the question will be if the table can be fit into the buffer pool. For MyISAM its a question of how much the file system caches the MyISAM file. With enough free memory MyISAM is faster. Its only when the OS doesn't have enough memory to cache entire table that archive turns out to be any faster. Examples between MyISAM (packed) and Archive. Table with 76695844 identical rows: 29680807 a_archive.ARZ 920350317 a.MYD Table with 8991478 rows (all of Slashdot's comments): 1922964506 comment_archive.ARZ 2944970297 comment_text.MYD TODO: Allow users to set compression level. Allow adjustable block size. Implement versioning, should be easy. Allow for errors, find a way to mark bad rows. Add optional feature so that rows can be flushed at interval (which will cause less compression but may speed up ordered searches). Checkpoint the meta file to allow for faster rebuilds. 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. -Brian */ /* Variables for archive share methods */ mysql_mutex_t archive_mutex; static HASH archive_open_tables; /* The file extension */ #define ARZ ".ARZ" // The data file #define ARN ".ARN" // Files used during an optimize call #define ARM ".ARM" // Meta file (deprecated) /* uchar + uchar */ #define DATA_BUFFER_SIZE 2 // Size of the data used in the data file #define ARCHIVE_CHECK_HEADER 254 // The number we use to determine corruption #ifdef HAVE_PSI_INTERFACE extern "C" PSI_file_key arch_key_file_data; #endif /* Static declarations for handerton */ static handler *archive_create_handler(handlerton *hton, TABLE_SHARE *table, MEM_ROOT *mem_root); int archive_discover(handlerton *hton, THD* thd, const char *db, const char *name, uchar **frmblob, size_t *frmlen); /* Number of rows that will force a bulk insert. */ #define ARCHIVE_MIN_ROWS_TO_USE_BULK_INSERT 2 /* Size of header used for row */ #define ARCHIVE_ROW_HEADER_SIZE 4 static handler *archive_create_handler(handlerton *hton, TABLE_SHARE *table, MEM_ROOT *mem_root) { return new (mem_root) ha_archive(hton, table); } /* Used for hash table that tracks open tables. */ static uchar* archive_get_key(ARCHIVE_SHARE *share, size_t *length, my_bool not_used __attribute__((unused))) { *length=share->table_name_length; return (uchar*) share->table_name; } #ifdef HAVE_PSI_INTERFACE PSI_mutex_key az_key_mutex_archive_mutex, az_key_mutex_ARCHIVE_SHARE_mutex; static PSI_mutex_info all_archive_mutexes[]= { { &az_key_mutex_archive_mutex, "archive_mutex", PSI_FLAG_GLOBAL}, { &az_key_mutex_ARCHIVE_SHARE_mutex, "ARCHIVE_SHARE::mutex", 0} }; PSI_file_key arch_key_file_metadata, arch_key_file_data, arch_key_file_frm; static PSI_file_info all_archive_files[]= { { &arch_key_file_metadata, "metadata", 0}, { &arch_key_file_data, "data", 0}, { &arch_key_file_frm, "FRM", 0} }; static void init_archive_psi_keys(void) { const char* category= "archive"; int count; if (PSI_server == NULL) return; count= array_elements(all_archive_mutexes); PSI_server->register_mutex(category, all_archive_mutexes, count); count= array_elements(all_archive_files); PSI_server->register_file(category, all_archive_files, count); } #endif /* HAVE_PSI_INTERFACE */ /* Initialize the archive handler. SYNOPSIS archive_db_init() void * RETURN FALSE OK TRUE Error */ int archive_db_init(void *p) { DBUG_ENTER("archive_db_init"); handlerton *archive_hton; #ifdef HAVE_PSI_INTERFACE init_archive_psi_keys(); #endif archive_hton= (handlerton *)p; archive_hton->state= SHOW_OPTION_YES; archive_hton->db_type= DB_TYPE_ARCHIVE_DB; archive_hton->create= archive_create_handler; archive_hton->flags= HTON_NO_FLAGS; archive_hton->discover= archive_discover; if (mysql_mutex_init(az_key_mutex_archive_mutex, &archive_mutex, MY_MUTEX_INIT_FAST)) goto error; if (my_hash_init(&archive_open_tables, table_alias_charset, 32, 0, 0, (my_hash_get_key) archive_get_key, 0, 0)) { mysql_mutex_destroy(&archive_mutex); } else { DBUG_RETURN(FALSE); } error: DBUG_RETURN(TRUE); } /* Release the archive handler. SYNOPSIS archive_db_done() void RETURN FALSE OK */ int archive_db_done(void *p) { my_hash_free(&archive_open_tables); mysql_mutex_destroy(&archive_mutex); return 0; } ha_archive::ha_archive(handlerton *hton, TABLE_SHARE *table_arg) :handler(hton, table_arg), delayed_insert(0), bulk_insert(0) { /* Set our original buffer from pre-allocated memory */ buffer.set((char *)byte_buffer, IO_SIZE, system_charset_info); /* The size of the offset value we will use for position() */ ref_length= sizeof(my_off_t); archive_reader_open= FALSE; } int archive_discover(handlerton *hton, THD* thd, const char *db, const char *name, uchar **frmblob, size_t *frmlen) { DBUG_ENTER("archive_discover"); DBUG_PRINT("archive_discover", ("db: %s, name: %s", db, name)); azio_stream frm_stream; char az_file[FN_REFLEN]; char *frm_ptr; MY_STAT file_stat; build_table_filename(az_file, sizeof(az_file) - 1, db, name, ARZ, 0); if (!(mysql_file_stat(/* arch_key_file_data */ 0, az_file, &file_stat, MYF(0)))) goto err; if (!(azopen(&frm_stream, az_file, O_RDONLY|O_BINARY))) { if (errno == EROFS || errno == EACCES) DBUG_RETURN(my_errno= errno); DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); } if (frm_stream.frm_length == 0) goto err; frm_ptr= (char *)my_malloc(sizeof(char) * frm_stream.frm_length, MYF(0)); azread_frm(&frm_stream, frm_ptr); azclose(&frm_stream); *frmlen= frm_stream.frm_length; *frmblob= (uchar*) frm_ptr; DBUG_RETURN(0); err: my_errno= 0; DBUG_RETURN(1); } /* This method reads the header of a datafile and returns whether or not it was successful. */ int ha_archive::read_data_header(azio_stream *file_to_read) { int error; unsigned long ret; uchar data_buffer[DATA_BUFFER_SIZE]; DBUG_ENTER("ha_archive::read_data_header"); if (azrewind(file_to_read) == -1) DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); if (file_to_read->version >= 3) DBUG_RETURN(0); /* Everything below this is just legacy to version 2< */ DBUG_PRINT("ha_archive", ("Reading legacy data header")); ret= azread(file_to_read, data_buffer, DATA_BUFFER_SIZE, &error); if (ret != DATA_BUFFER_SIZE) { DBUG_PRINT("ha_archive", ("Reading, expected %d got %lu", DATA_BUFFER_SIZE, ret)); DBUG_RETURN(1); } if (error) { DBUG_PRINT("ha_archive", ("Compression error (%d)", error)); DBUG_RETURN(1); } DBUG_PRINT("ha_archive", ("Check %u", data_buffer[0])); DBUG_PRINT("ha_archive", ("Version %u", data_buffer[1])); if ((data_buffer[0] != (uchar)ARCHIVE_CHECK_HEADER) && (data_buffer[1] != (uchar)ARCHIVE_VERSION)) DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); DBUG_RETURN(0); } /* We create the shared memory space that we will use for the open table. No matter what we try to get or create a share. This is so that a repair table operation can occur. See ha_example.cc for a longer description. */ ARCHIVE_SHARE *ha_archive::get_share(const char *table_name, int *rc) { uint length; DBUG_ENTER("ha_archive::get_share"); mysql_mutex_lock(&archive_mutex); length=(uint) strlen(table_name); if (!(share=(ARCHIVE_SHARE*) my_hash_search(&archive_open_tables, (uchar*) table_name, length))) { char *tmp_name; azio_stream archive_tmp; if (!my_multi_malloc(MYF(MY_WME | MY_ZEROFILL), &share, sizeof(*share), &tmp_name, length+1, NullS)) { mysql_mutex_unlock(&archive_mutex); *rc= HA_ERR_OUT_OF_MEM; DBUG_RETURN(NULL); } share->use_count= 0; share->table_name_length= length; share->table_name= tmp_name; share->crashed= FALSE; share->archive_write_open= FALSE; fn_format(share->data_file_name, table_name, "", ARZ, MY_REPLACE_EXT | MY_UNPACK_FILENAME); strmov(share->table_name, table_name); DBUG_PRINT("ha_archive", ("Data File %s", share->data_file_name)); /* We will use this lock for rows. */ mysql_mutex_init(az_key_mutex_ARCHIVE_SHARE_mutex, &share->mutex, MY_MUTEX_INIT_FAST); /* We read the meta file, but do not mark it dirty. Since we are not doing a write we won't mark it dirty (and we won't open it for anything but reading... open it for write and we will generate null compression writes). */ if (!(azopen(&archive_tmp, share->data_file_name, O_RDONLY|O_BINARY))) { *rc= my_errno ? my_errno : -1; mysql_mutex_unlock(&archive_mutex); my_free(share); DBUG_RETURN(NULL); } stats.auto_increment_value= archive_tmp.auto_increment + 1; share->rows_recorded= (ha_rows)archive_tmp.rows; share->crashed= archive_tmp.dirty; /* If archive version is less than 3, It should be upgraded before use. */ if (archive_tmp.version < ARCHIVE_VERSION) *rc= HA_ERR_TABLE_NEEDS_UPGRADE; azclose(&archive_tmp); (void) my_hash_insert(&archive_open_tables, (uchar*) share); thr_lock_init(&share->lock); } share->use_count++; DBUG_PRINT("ha_archive", ("archive table %.*s has %d open handles now", share->table_name_length, share->table_name, share->use_count)); if (share->crashed) *rc= HA_ERR_CRASHED_ON_USAGE; mysql_mutex_unlock(&archive_mutex); DBUG_RETURN(share); } /* Free the share. See ha_example.cc for a description. */ int ha_archive::free_share() { int rc= 0; DBUG_ENTER("ha_archive::free_share"); DBUG_PRINT("ha_archive", ("archive table %.*s has %d open handles on entrance", share->table_name_length, share->table_name, share->use_count)); mysql_mutex_lock(&archive_mutex); if (!--share->use_count) { my_hash_delete(&archive_open_tables, (uchar*) share); thr_lock_delete(&share->lock); mysql_mutex_destroy(&share->mutex); /* We need to make sure we don't reset the crashed state. If we open a crashed file, wee need to close it as crashed unless it has been repaired. Since we will close the data down after this, we go on and count the flush on close; */ if (share->archive_write_open) { if (azclose(&(share->archive_write))) rc= 1; } my_free(share); } mysql_mutex_unlock(&archive_mutex); DBUG_RETURN(rc); } int ha_archive::init_archive_writer() { DBUG_ENTER("ha_archive::init_archive_writer"); /* It is expensive to open and close the data files and since you can't have a gzip file that can be both read and written we keep a writer open that is shared amoung all open tables. */ if (!(azopen(&(share->archive_write), share->data_file_name, O_RDWR|O_BINARY))) { DBUG_PRINT("ha_archive", ("Could not open archive write file")); share->crashed= TRUE; DBUG_RETURN(1); } share->archive_write_open= TRUE; DBUG_RETURN(0); } /* No locks are required because it is associated with just one handler instance */ int ha_archive::init_archive_reader() { DBUG_ENTER("ha_archive::init_archive_reader"); /* It is expensive to open and close the data files and since you can't have a gzip file that can be both read and written we keep a writer open that is shared amoung all open tables. */ if (!archive_reader_open) { if (!(azopen(&archive, share->data_file_name, O_RDONLY|O_BINARY))) { DBUG_PRINT("ha_archive", ("Could not open archive read file")); share->crashed= TRUE; DBUG_RETURN(1); } archive_reader_open= TRUE; } DBUG_RETURN(0); } /* We just implement one additional file extension. */ static const char *ha_archive_exts[] = { ARZ, NullS }; const char **ha_archive::bas_ext() const { return ha_archive_exts; } /* When opening a file we: Create/get our shared structure. Init out lock. We open the file we will read from. */ int ha_archive::open(const char *name, int mode, uint open_options) { int rc= 0; DBUG_ENTER("ha_archive::open"); DBUG_PRINT("ha_archive", ("archive table was opened for crash: %s", (open_options & HA_OPEN_FOR_REPAIR) ? "yes" : "no")); share= get_share(name, &rc); /* Allow open on crashed table in repair mode only. Block open on 5.0 ARCHIVE table. Though we have almost all routines to access these tables, they were not well tested. For now we have to refuse to open such table to avoid potential data loss. */ switch (rc) { case 0: break; case HA_ERR_CRASHED_ON_USAGE: if (open_options & HA_OPEN_FOR_REPAIR) break; /* fall through */ case HA_ERR_TABLE_NEEDS_UPGRADE: free_share(); /* fall through */ default: DBUG_RETURN(rc); } DBUG_ASSERT(share); record_buffer= create_record_buffer(table->s->reclength + ARCHIVE_ROW_HEADER_SIZE); if (!record_buffer) { free_share(); DBUG_RETURN(HA_ERR_OUT_OF_MEM); } thr_lock_data_init(&share->lock, &lock, NULL); DBUG_PRINT("ha_archive", ("archive table was crashed %s", rc == HA_ERR_CRASHED_ON_USAGE ? "yes" : "no")); if (rc == HA_ERR_CRASHED_ON_USAGE && open_options & HA_OPEN_FOR_REPAIR) { DBUG_RETURN(0); } DBUG_RETURN(rc); } /* Closes the file. SYNOPSIS close(); IMPLEMENTATION: We first close this storage engines file handle to the archive and then remove our reference count to the table (and possibly free it as well). RETURN 0 ok 1 Error */ int ha_archive::close(void) { int rc= 0; DBUG_ENTER("ha_archive::close"); destroy_record_buffer(record_buffer); /* First close stream */ if (archive_reader_open) { if (azclose(&archive)) rc= 1; } /* then also close share */ rc|= free_share(); DBUG_RETURN(rc); } /** Copy a frm blob between streams. @param src The source stream. @param dst The destination stream. @return Zero on success, non-zero otherwise. */ int ha_archive::frm_copy(azio_stream *src, azio_stream *dst) { int rc= 0; char *frm_ptr; if (!(frm_ptr= (char *) my_malloc(src->frm_length, MYF(0)))) return HA_ERR_OUT_OF_MEM; /* Write file offset is set to the end of the file. */ if (azread_frm(src, frm_ptr) || azwrite_frm(dst, frm_ptr, src->frm_length)) rc= my_errno ? my_errno : HA_ERR_INTERNAL_ERROR; my_free(frm_ptr); return rc; } /* We create our data file here. The format is pretty simple. You can read about the format of the data file above. Unlike other storage engines we do not "pack" our data. Since we are about to do a general compression, packing would just be a waste of CPU time. If the table has blobs they are written after the row in the order of creation. */ int ha_archive::create(const char *name, TABLE *table_arg, HA_CREATE_INFO *create_info) { char name_buff[FN_REFLEN]; char linkname[FN_REFLEN]; int error; azio_stream create_stream; /* Archive file we are working with */ File frm_file; /* File handler for readers */ MY_STAT file_stat; // Stat information for the data file uchar *frm_ptr; DBUG_ENTER("ha_archive::create"); stats.auto_increment_value= create_info->auto_increment_value; for (uint key= 0; key < table_arg->s->keys; key++) { KEY *pos= table_arg->key_info+key; KEY_PART_INFO *key_part= pos->key_part; KEY_PART_INFO *key_part_end= key_part + pos->key_parts; for (; key_part != key_part_end; key_part++) { Field *field= key_part->field; if (!(field->flags & AUTO_INCREMENT_FLAG)) { error= -1; DBUG_PRINT("ha_archive", ("Index error in creating archive table")); goto error; } } } /* We reuse name_buff since it is available. */ if (create_info->data_file_name && create_info->data_file_name[0] != '#') { DBUG_PRINT("ha_archive", ("archive will create stream file %s", create_info->data_file_name)); fn_format(name_buff, create_info->data_file_name, "", ARZ, MY_REPLACE_EXT | MY_UNPACK_FILENAME); fn_format(linkname, name, "", ARZ, MY_REPLACE_EXT | MY_UNPACK_FILENAME); } else { fn_format(name_buff, name, "", ARZ, MY_REPLACE_EXT | MY_UNPACK_FILENAME); linkname[0]= 0; } /* There is a chance that the file was "discovered". In this case just use whatever file is there. */ if (!(mysql_file_stat(/* arch_key_file_data */ 0, name_buff, &file_stat, MYF(0)))) { my_errno= 0; if (!(azopen(&create_stream, name_buff, O_CREAT|O_RDWR|O_BINARY))) { error= errno; goto error2; } if (linkname[0]) my_symlink(name_buff, linkname, MYF(0)); fn_format(name_buff, name, "", ".frm", MY_REPLACE_EXT | MY_UNPACK_FILENAME); /* Here is where we open up the frm and pass it to archive to store */ if ((frm_file= mysql_file_open(arch_key_file_frm, name_buff, O_RDONLY, MYF(0))) >= 0) { if (!mysql_file_fstat(frm_file, &file_stat, MYF(MY_WME))) { frm_ptr= (uchar *)my_malloc(sizeof(uchar) * file_stat.st_size, MYF(0)); if (frm_ptr) { mysql_file_read(frm_file, frm_ptr, file_stat.st_size, MYF(0)); azwrite_frm(&create_stream, (char *)frm_ptr, file_stat.st_size); my_free(frm_ptr); } } mysql_file_close(frm_file, MYF(0)); } if (create_info->comment.str) azwrite_comment(&create_stream, create_info->comment.str, create_info->comment.length); /* Yes you need to do this, because the starting value for the autoincrement may not be zero. */ create_stream.auto_increment= stats.auto_increment_value ? stats.auto_increment_value - 1 : 0; if (azclose(&create_stream)) { error= errno; goto error2; } } else my_errno= 0; DBUG_PRINT("ha_archive", ("Creating File %s", name_buff)); DBUG_PRINT("ha_archive", ("Creating Link %s", linkname)); DBUG_RETURN(0); error2: delete_table(name); error: /* Return error number, if we got one */ DBUG_RETURN(error ? error : -1); } /* This is where the actual row is written out. */ int ha_archive::real_write_row(uchar *buf, azio_stream *writer) { my_off_t written; unsigned int r_pack_length; DBUG_ENTER("ha_archive::real_write_row"); /* We pack the row for writing */ r_pack_length= pack_row(buf); written= azwrite(writer, record_buffer->buffer, r_pack_length); if (written != r_pack_length) { DBUG_PRINT("ha_archive", ("Wrote %d bytes expected %d", (uint32) written, (uint32)r_pack_length)); DBUG_RETURN(-1); } if (!delayed_insert || !bulk_insert) share->dirty= TRUE; DBUG_RETURN(0); } /* Calculate max length needed for row. This includes the bytes required for the length in the header. */ uint32 ha_archive::max_row_length(const uchar *buf) { uint32 length= (uint32)(table->s->reclength + table->s->fields*2); length+= ARCHIVE_ROW_HEADER_SIZE; uint *ptr, *end; for (ptr= table->s->blob_field, end=ptr + table->s->blob_fields ; ptr != end ; ptr++) { if (!table->field[*ptr]->is_null()) length += 2 + ((Field_blob*)table->field[*ptr])->get_length(); } return length; } unsigned int ha_archive::pack_row(uchar *record) { uchar *ptr; DBUG_ENTER("ha_archive::pack_row"); if (fix_rec_buff(max_row_length(record))) DBUG_RETURN(HA_ERR_OUT_OF_MEM); /* purecov: inspected */ /* Copy null bits */ memcpy(record_buffer->buffer+ARCHIVE_ROW_HEADER_SIZE, record, table->s->null_bytes); ptr= record_buffer->buffer + table->s->null_bytes + ARCHIVE_ROW_HEADER_SIZE; for (Field **field=table->field ; *field ; field++) { if (!((*field)->is_null())) ptr= (*field)->pack(ptr, record + (*field)->offset(record)); } int4store(record_buffer->buffer, (int)(ptr - record_buffer->buffer - ARCHIVE_ROW_HEADER_SIZE)); DBUG_PRINT("ha_archive",("Pack row length %u", (unsigned int) (ptr - record_buffer->buffer - ARCHIVE_ROW_HEADER_SIZE))); DBUG_RETURN((unsigned int) (ptr - record_buffer->buffer)); } /* Look at ha_archive::open() for an explanation of the row format. Here we just write out the row. Wondering about start_bulk_insert()? We don't implement it for archive since it optimizes for lots of writes. The only save for implementing start_bulk_insert() is that we could skip setting dirty to true each time. */ int ha_archive::write_row(uchar *buf) { int rc; uchar *read_buf= NULL; ulonglong temp_auto; uchar *record= table->record[0]; DBUG_ENTER("ha_archive::write_row"); if (share->crashed) DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); ha_statistic_increment(&SSV::ha_write_count); if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT) table->timestamp_field->set_time(); mysql_mutex_lock(&share->mutex); if (!share->archive_write_open && init_archive_writer()) { rc= HA_ERR_CRASHED_ON_USAGE; goto error; } if (table->next_number_field && record == table->record[0]) { KEY *mkey= &table->s->key_info[0]; // We only support one key right now update_auto_increment(); temp_auto= table->next_number_field->val_int(); /* We don't support decremening auto_increment. They make the performance just cry. */ if (temp_auto <= share->archive_write.auto_increment && mkey->flags & HA_NOSAME) { rc= HA_ERR_FOUND_DUPP_KEY; goto error; } #ifdef DEAD_CODE /* Bad news, this will cause a search for the unique value which is very expensive since we will have to do a table scan which will lock up all other writers during this period. This could perhaps be optimized in the future. */ { /* First we create a buffer that we can use for reading rows, and can pass to get_row(). */ if (!(read_buf= (uchar*) my_malloc(table->s->reclength, MYF(MY_WME)))) { rc= HA_ERR_OUT_OF_MEM; goto error; } /* All of the buffer must be written out or we won't see all of the data */ azflush(&(share->archive_write), Z_SYNC_FLUSH); /* Set the position of the local read thread to the beginning position. */ if (read_data_header(&archive)) { rc= HA_ERR_CRASHED_ON_USAGE; goto error; } Field *mfield= table->next_number_field; while (!(get_row(&archive, read_buf))) { if (!memcmp(read_buf + mfield->offset(record), table->next_number_field->ptr, mfield->max_display_length())) { rc= HA_ERR_FOUND_DUPP_KEY; goto error; } } } #endif else { if (temp_auto > share->archive_write.auto_increment) stats.auto_increment_value= (share->archive_write.auto_increment= temp_auto) + 1; } } /* Notice that the global auto_increment has been increased. In case of a failed row write, we will never try to reuse the value. */ share->rows_recorded++; rc= real_write_row(buf, &(share->archive_write)); error: mysql_mutex_unlock(&share->mutex); if (read_buf) my_free(read_buf); DBUG_RETURN(rc); } void ha_archive::get_auto_increment(ulonglong offset, ulonglong increment, ulonglong nb_desired_values, ulonglong *first_value, ulonglong *nb_reserved_values) { *nb_reserved_values= ULONGLONG_MAX; *first_value= share->archive_write.auto_increment + 1; } /* Initialized at each key walk (called multiple times unlike rnd_init()) */ int ha_archive::index_init(uint keynr, bool sorted) { DBUG_ENTER("ha_archive::index_init"); active_index= keynr; DBUG_RETURN(0); } /* No indexes, so if we get a request for an index search since we tell the optimizer that we have unique indexes, we scan */ int ha_archive::index_read(uchar *buf, const uchar *key, uint key_len, enum ha_rkey_function find_flag) { int rc; DBUG_ENTER("ha_archive::index_read"); MYSQL_INDEX_READ_ROW_START(table_share->db.str, table_share->table_name.str); rc= index_read_idx(buf, active_index, key, key_len, find_flag); MYSQL_INDEX_READ_ROW_DONE(rc); DBUG_RETURN(rc); } int ha_archive::index_read_idx(uchar *buf, uint index, const uchar *key, uint key_len, enum ha_rkey_function find_flag) { int rc; bool found= 0; KEY *mkey= &table->s->key_info[index]; current_k_offset= mkey->key_part->offset; current_key= key; current_key_len= key_len; DBUG_ENTER("ha_archive::index_read_idx"); rc= rnd_init(TRUE); if (rc) goto error; while (!(get_row(&archive, buf))) { if (!memcmp(current_key, buf + current_k_offset, current_key_len)) { found= 1; break; } } if (found) { /* notify handler that a record has been found */ table->status= 0; DBUG_RETURN(0); } error: DBUG_RETURN(rc ? rc : HA_ERR_END_OF_FILE); } int ha_archive::index_next(uchar * buf) { bool found= 0; int rc; DBUG_ENTER("ha_archive::index_next"); MYSQL_INDEX_READ_ROW_START(table_share->db.str, table_share->table_name.str); while (!(get_row(&archive, buf))) { if (!memcmp(current_key, buf+current_k_offset, current_key_len)) { found= 1; break; } } rc= found ? 0 : HA_ERR_END_OF_FILE; MYSQL_INDEX_READ_ROW_DONE(rc); DBUG_RETURN(rc); } /* All calls that need to scan the table start with this method. If we are told that it is a table scan we rewind the file to the beginning, otherwise we assume the position will be set. */ int ha_archive::rnd_init(bool scan) { DBUG_ENTER("ha_archive::rnd_init"); if (share->crashed) DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); init_archive_reader(); /* We rewind the file so that we can read from the beginning if scan */ if (scan) { scan_rows= stats.records; DBUG_PRINT("info", ("archive will retrieve %llu rows", (unsigned long long) scan_rows)); if (read_data_header(&archive)) DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); } DBUG_RETURN(0); } /* This is the method that is used to read a row. It assumes that the row is positioned where you want it. */ int ha_archive::get_row(azio_stream *file_to_read, uchar *buf) { int rc; DBUG_ENTER("ha_archive::get_row"); DBUG_PRINT("ha_archive", ("Picking version for get_row() %d -> %d", (uchar)file_to_read->version, ARCHIVE_VERSION)); if (file_to_read->version == ARCHIVE_VERSION) rc= get_row_version3(file_to_read, buf); else rc= get_row_version2(file_to_read, buf); DBUG_PRINT("ha_archive", ("Return %d\n", rc)); DBUG_RETURN(rc); } /* Reallocate buffer if needed */ bool ha_archive::fix_rec_buff(unsigned int length) { DBUG_ENTER("ha_archive::fix_rec_buff"); DBUG_PRINT("ha_archive", ("Fixing %u for %u", length, record_buffer->length)); DBUG_ASSERT(record_buffer->buffer); if (length > record_buffer->length) { uchar *newptr; if (!(newptr=(uchar*) my_realloc((uchar*) record_buffer->buffer, length, MYF(MY_ALLOW_ZERO_PTR)))) DBUG_RETURN(1); record_buffer->buffer= newptr; record_buffer->length= length; } DBUG_ASSERT(length <= record_buffer->length); DBUG_RETURN(0); } int ha_archive::unpack_row(azio_stream *file_to_read, uchar *record) { DBUG_ENTER("ha_archive::unpack_row"); unsigned int read; int error; uchar size_buffer[ARCHIVE_ROW_HEADER_SIZE]; unsigned int row_len; /* First we grab the length stored */ read= azread(file_to_read, size_buffer, ARCHIVE_ROW_HEADER_SIZE, &error); if (error == Z_STREAM_ERROR || (read && read < ARCHIVE_ROW_HEADER_SIZE)) DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); /* If we read nothing we are at the end of the file */ if (read == 0 || read != ARCHIVE_ROW_HEADER_SIZE) DBUG_RETURN(HA_ERR_END_OF_FILE); row_len= uint4korr(size_buffer); DBUG_PRINT("ha_archive",("Unpack row length %u -> %u", row_len, (unsigned int)table->s->reclength)); if (fix_rec_buff(row_len)) { DBUG_RETURN(HA_ERR_OUT_OF_MEM); } DBUG_ASSERT(row_len <= record_buffer->length); read= azread(file_to_read, record_buffer->buffer, row_len, &error); if (read != row_len || error) { DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); } /* Copy null bits */ const uchar *ptr= record_buffer->buffer; /* Field::unpack() is not called when field is NULL. For VARCHAR Field::unpack() only unpacks as much bytes as occupied by field value. In these cases respective memory area on record buffer is not initialized. These uninitialized areas may be accessed by CHECKSUM TABLE or by optimizer using temporary table (BUG#12997905). We may remove this memset() when they're fixed. */ memset(record, 0, table->s->reclength); memcpy(record, ptr, table->s->null_bytes); ptr+= table->s->null_bytes; for (Field **field=table->field ; *field ; field++) { if (!((*field)->is_null_in_record(record))) { ptr= (*field)->unpack(record + (*field)->offset(table->record[0]), ptr); } } DBUG_RETURN(0); } int ha_archive::get_row_version3(azio_stream *file_to_read, uchar *buf) { DBUG_ENTER("ha_archive::get_row_version3"); int returnable= unpack_row(file_to_read, buf); DBUG_RETURN(returnable); } int ha_archive::get_row_version2(azio_stream *file_to_read, uchar *buf) { unsigned int read; int error; uint *ptr, *end; char *last; size_t total_blob_length= 0; MY_BITMAP *read_set= table->read_set; DBUG_ENTER("ha_archive::get_row_version2"); read= azread(file_to_read, (voidp)buf, table->s->reclength, &error); /* If we read nothing we are at the end of the file */ if (read == 0) DBUG_RETURN(HA_ERR_END_OF_FILE); if (read != table->s->reclength) { DBUG_PRINT("ha_archive::get_row_version2", ("Read %u bytes expected %u", read, (unsigned int)table->s->reclength)); DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); } if (error == Z_STREAM_ERROR || error == Z_DATA_ERROR ) DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); /* If the record is the wrong size, the file is probably damaged, unless we are dealing with a delayed insert or a bulk insert. */ if ((ulong) read != table->s->reclength) DBUG_RETURN(HA_ERR_END_OF_FILE); /* Calculate blob length, we use this for our buffer */ for (ptr= table->s->blob_field, end=ptr + table->s->blob_fields ; ptr != end ; ptr++) { if (bitmap_is_set(read_set, (((Field_blob*) table->field[*ptr])->field_index))) total_blob_length += ((Field_blob*) table->field[*ptr])->get_length(); } /* Adjust our row buffer if we need be */ buffer.alloc(total_blob_length); last= (char *)buffer.ptr(); /* Loop through our blobs and read them */ for (ptr= table->s->blob_field, end=ptr + table->s->blob_fields ; ptr != end ; ptr++) { size_t size= ((Field_blob*) table->field[*ptr])->get_length(); if (size) { if (bitmap_is_set(read_set, ((Field_blob*) table->field[*ptr])->field_index)) { read= azread(file_to_read, last, size, &error); if (error) DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); if ((size_t) read != size) DBUG_RETURN(HA_ERR_END_OF_FILE); ((Field_blob*) table->field[*ptr])->set_ptr(size, (uchar*) last); last += size; } else { (void)azseek(file_to_read, size, SEEK_CUR); } } } DBUG_RETURN(0); } /* Called during ORDER BY. Its position is either from being called sequentially or by having had ha_archive::rnd_pos() called before it is called. */ int ha_archive::rnd_next(uchar *buf) { int rc; DBUG_ENTER("ha_archive::rnd_next"); MYSQL_READ_ROW_START(table_share->db.str, table_share->table_name.str, TRUE); if (share->crashed) DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); if (!scan_rows) { rc= HA_ERR_END_OF_FILE; goto end; } scan_rows--; ha_statistic_increment(&SSV::ha_read_rnd_next_count); current_position= aztell(&archive); rc= get_row(&archive, buf); table->status=rc ? STATUS_NOT_FOUND: 0; end: MYSQL_READ_ROW_DONE(rc); DBUG_RETURN(rc); } /* Thanks to the table flag HA_REC_NOT_IN_SEQ this will be called after each call to ha_archive::rnd_next() if an ordering of the rows is needed. */ void ha_archive::position(const uchar *record) { DBUG_ENTER("ha_archive::position"); my_store_ptr(ref, ref_length, current_position); DBUG_VOID_RETURN; } /* This is called after a table scan for each row if the results of the scan need to be ordered. It will take *pos and use it to move the cursor in the file so that the next row that is called is the correctly ordered row. */ int ha_archive::rnd_pos(uchar * buf, uchar *pos) { int rc; DBUG_ENTER("ha_archive::rnd_pos"); MYSQL_READ_ROW_START(table_share->db.str, table_share->table_name.str, FALSE); ha_statistic_increment(&SSV::ha_read_rnd_next_count); current_position= (my_off_t)my_get_ptr(pos, ref_length); if (azseek(&archive, current_position, SEEK_SET) == (my_off_t)(-1L)) { rc= HA_ERR_CRASHED_ON_USAGE; goto end; } rc= get_row(&archive, buf); end: MYSQL_READ_ROW_DONE(rc); DBUG_RETURN(rc); } /* This method repairs the meta file. It does this by walking the datafile and rewriting the meta file. If EXTENDED repair is requested, we attempt to recover as much data as possible. */ int ha_archive::repair(THD* thd, HA_CHECK_OPT* check_opt) { DBUG_ENTER("ha_archive::repair"); int rc= optimize(thd, check_opt); if (rc) DBUG_RETURN(HA_ADMIN_CORRUPT); share->crashed= FALSE; DBUG_RETURN(0); } /* The table can become fragmented if data was inserted, read, and then inserted again. What we do is open up the file and recompress it completely. */ int ha_archive::optimize(THD* thd, HA_CHECK_OPT* check_opt) { int rc= 0; azio_stream writer; char writer_filename[FN_REFLEN]; DBUG_ENTER("ha_archive::optimize"); mysql_mutex_lock(&share->mutex); init_archive_reader(); // now we close both our writer and our reader for the rename if (share->archive_write_open) { azclose(&(share->archive_write)); share->archive_write_open= FALSE; } /* Lets create a file to contain the new data */ fn_format(writer_filename, share->table_name, "", ARN, MY_REPLACE_EXT | MY_UNPACK_FILENAME); if (!(azopen(&writer, writer_filename, O_CREAT|O_RDWR|O_BINARY))) { mysql_mutex_unlock(&share->mutex); DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); } /* Transfer the embedded FRM so that the file can be discoverable. Write file offset is set to the end of the file. */ if ((rc= frm_copy(&archive, &writer))) goto error; /* An extended rebuild is a lot more effort. We open up each row and re-record it. Any dead rows are removed (aka rows that may have been partially recorded). As of Archive format 3, this is the only type that is performed, before this version it was just done on T_EXTEND */ if (1) { DBUG_PRINT("ha_archive", ("archive extended rebuild")); /* Now we will rewind the archive file so that we are positioned at the start of the file. */ rc= read_data_header(&archive); /* On success of writing out the new header, we now fetch each row and insert it into the new archive file. */ if (!rc) { share->rows_recorded= 0; stats.auto_increment_value= 1; share->archive_write.auto_increment= 0; my_bitmap_map *org_bitmap= dbug_tmp_use_all_columns(table, table->read_set); while (!(rc= get_row(&archive, table->record[0]))) { real_write_row(table->record[0], &writer); /* Long term it should be possible to optimize this so that it is not called on each row. */ if (table->found_next_number_field) { Field *field= table->found_next_number_field; ulonglong auto_value= (ulonglong) field->val_int(table->record[0] + field->offset(table->record[0])); if (share->archive_write.auto_increment < auto_value) stats.auto_increment_value= (share->archive_write.auto_increment= auto_value) + 1; } } dbug_tmp_restore_column_map(table->read_set, org_bitmap); share->rows_recorded= (ha_rows)writer.rows; } DBUG_PRINT("info", ("recovered %llu archive rows", (unsigned long long)share->rows_recorded)); DBUG_PRINT("ha_archive", ("recovered %llu archive rows", (unsigned long long)share->rows_recorded)); /* If REPAIR ... EXTENDED is requested, try to recover as much data from data file as possible. In this case if we failed to read a record, we assume EOF. This allows massive data loss, but we can hardly do more with broken zlib stream. And this is the only way to restore at least what is still recoverable. */ if (rc && rc != HA_ERR_END_OF_FILE && !(check_opt->flags & T_EXTEND)) goto error; } azclose(&writer); share->dirty= FALSE; azclose(&archive); // make the file we just wrote be our data file rc= my_rename(writer_filename, share->data_file_name, MYF(0)); mysql_mutex_unlock(&share->mutex); DBUG_RETURN(rc); error: DBUG_PRINT("ha_archive", ("Failed to recover, error was %d", rc)); azclose(&writer); mysql_mutex_unlock(&share->mutex); DBUG_RETURN(rc); } /* Below is an example of how to setup row level locking. */ THR_LOCK_DATA **ha_archive::store_lock(THD *thd, THR_LOCK_DATA **to, enum thr_lock_type lock_type) { if (lock_type == TL_WRITE_DELAYED) delayed_insert= TRUE; else delayed_insert= FALSE; if (lock_type != TL_IGNORE && lock.type == TL_UNLOCK) { /* Here is where we get into the guts of a row level lock. If TL_UNLOCK is set If we are not doing a LOCK TABLE or DISCARD/IMPORT TABLESPACE, then allow multiple writers */ if ((lock_type >= TL_WRITE_CONCURRENT_INSERT && lock_type <= TL_WRITE) && !thd_in_lock_tables(thd) && !thd_tablespace_op(thd)) lock_type = TL_WRITE_ALLOW_WRITE; /* In queries of type INSERT INTO t1 SELECT ... FROM t2 ... MySQL would use the lock TL_READ_NO_INSERT on t2, and that would conflict with TL_WRITE_ALLOW_WRITE, blocking all inserts to t2. Convert the lock to a normal read lock to allow concurrent inserts to t2. */ if (lock_type == TL_READ_NO_INSERT && !thd_in_lock_tables(thd)) lock_type = TL_READ; lock.type=lock_type; } *to++= &lock; return to; } void ha_archive::update_create_info(HA_CREATE_INFO *create_info) { DBUG_ENTER("ha_archive::update_create_info"); ha_archive::info(HA_STATUS_AUTO); if (!(create_info->used_fields & HA_CREATE_USED_AUTO)) { create_info->auto_increment_value= stats.auto_increment_value; } if (!(my_readlink(share->real_path, share->data_file_name, MYF(0)))) create_info->data_file_name= share->real_path; DBUG_VOID_RETURN; } /* Hints for optimizer, see ha_tina for more information */ int ha_archive::info(uint flag) { DBUG_ENTER("ha_archive::info"); /* If dirty, we lock, and then reset/flush the data. I found that just calling azflush() doesn't always work. */ mysql_mutex_lock(&share->mutex); if (share->dirty == TRUE) { if (share->dirty == TRUE) { DBUG_PRINT("ha_archive", ("archive flushing out rows for scan")); azflush(&(share->archive_write), Z_SYNC_FLUSH); share->dirty= FALSE; } } /* This should be an accurate number now, though bulk and delayed inserts can cause the number to be inaccurate. */ stats.records= share->rows_recorded; mysql_mutex_unlock(&share->mutex); stats.deleted= 0; DBUG_PRINT("ha_archive", ("Stats rows is %d\n", (int)stats.records)); /* Costs quite a bit more to get all information */ if (flag & (HA_STATUS_TIME | HA_STATUS_CONST | HA_STATUS_VARIABLE)) { MY_STAT file_stat; // Stat information for the data file (void) mysql_file_stat(/* arch_key_file_data */ 0, share->data_file_name, &file_stat, MYF(MY_WME)); if (flag & HA_STATUS_TIME) stats.update_time= (ulong) file_stat.st_mtime; if (flag & HA_STATUS_CONST) { stats.max_data_file_length= share->rows_recorded * stats.mean_rec_length; stats.max_data_file_length= MAX_FILE_SIZE; stats.create_time= (ulong) file_stat.st_ctime; } if (flag & HA_STATUS_VARIABLE) { stats.delete_length= 0; stats.data_file_length= file_stat.st_size; stats.index_file_length=0; stats.mean_rec_length= stats.records ? ulong(stats.data_file_length / stats.records) : table->s->reclength; } } if (flag & HA_STATUS_AUTO) { init_archive_reader(); mysql_mutex_lock(&share->mutex); azflush(&archive, Z_SYNC_FLUSH); mysql_mutex_unlock(&share->mutex); stats.auto_increment_value= archive.auto_increment + 1; } DBUG_RETURN(0); } /* This method tells us that a bulk insert operation is about to occur. We set a flag which will keep write_row from saying that its data is dirty. This in turn will keep selects from causing a sync to occur. Basically, yet another optimizations to keep compression working well. */ void ha_archive::start_bulk_insert(ha_rows rows) { DBUG_ENTER("ha_archive::start_bulk_insert"); if (!rows || rows >= ARCHIVE_MIN_ROWS_TO_USE_BULK_INSERT) bulk_insert= TRUE; DBUG_VOID_RETURN; } /* Other side of start_bulk_insert, is end_bulk_insert. Here we turn off the bulk insert flag, and set the share dirty so that the next select will call sync for us. */ int ha_archive::end_bulk_insert() { DBUG_ENTER("ha_archive::end_bulk_insert"); bulk_insert= FALSE; share->dirty= TRUE; DBUG_RETURN(0); } /* We cancel a truncate command. The only way to delete an archive table is to drop it. This is done for security reasons. In a later version we will enable this by allowing the user to select a different row format. */ int ha_archive::truncate() { DBUG_ENTER("ha_archive::truncate"); DBUG_RETURN(HA_ERR_WRONG_COMMAND); } /* We just return state if asked. */ bool ha_archive::is_crashed() const { DBUG_ENTER("ha_archive::is_crashed"); DBUG_RETURN(share->crashed); } /* Simple scan of the tables to make sure everything is ok. */ int ha_archive::check(THD* thd, HA_CHECK_OPT* check_opt) { int rc= 0; const char *old_proc_info; ha_rows count; DBUG_ENTER("ha_archive::check"); old_proc_info= thd_proc_info(thd, "Checking table"); mysql_mutex_lock(&share->mutex); count= share->rows_recorded; /* Flush any waiting data */ if (share->archive_write_open) azflush(&(share->archive_write), Z_SYNC_FLUSH); mysql_mutex_unlock(&share->mutex); if (init_archive_reader()) DBUG_RETURN(HA_ADMIN_CORRUPT); /* Now we will rewind the archive file so that we are positioned at the start of the file. */ read_data_header(&archive); for (ha_rows cur_count= count; cur_count; cur_count--) { if ((rc= get_row(&archive, table->record[0]))) goto error; } /* Now read records that may have been inserted concurrently. Acquire share->mutex so tail of the table is not modified by concurrent writers. */ mysql_mutex_lock(&share->mutex); count= share->rows_recorded - count; if (share->archive_write_open) azflush(&(share->archive_write), Z_SYNC_FLUSH); while (!(rc= get_row(&archive, table->record[0]))) count--; mysql_mutex_unlock(&share->mutex); if ((rc && rc != HA_ERR_END_OF_FILE) || count) goto error; thd_proc_info(thd, old_proc_info); DBUG_RETURN(HA_ADMIN_OK); error: thd_proc_info(thd, old_proc_info); share->crashed= FALSE; DBUG_RETURN(HA_ADMIN_CORRUPT); } /* Check and repair the table if needed. */ bool ha_archive::check_and_repair(THD *thd) { HA_CHECK_OPT check_opt; DBUG_ENTER("ha_archive::check_and_repair"); check_opt.init(); DBUG_RETURN(repair(thd, &check_opt)); } archive_record_buffer *ha_archive::create_record_buffer(unsigned int length) { DBUG_ENTER("ha_archive::create_record_buffer"); archive_record_buffer *r; if (!(r= (archive_record_buffer*) my_malloc(sizeof(archive_record_buffer), MYF(MY_WME)))) { DBUG_RETURN(NULL); /* purecov: inspected */ } r->length= (int)length; if (!(r->buffer= (uchar*) my_malloc(r->length, MYF(MY_WME)))) { my_free(r); DBUG_RETURN(NULL); /* purecov: inspected */ } DBUG_RETURN(r); } void ha_archive::destroy_record_buffer(archive_record_buffer *r) { DBUG_ENTER("ha_archive::destroy_record_buffer"); my_free(r->buffer); my_free(r); DBUG_VOID_RETURN; } struct st_mysql_storage_engine archive_storage_engine= { MYSQL_HANDLERTON_INTERFACE_VERSION }; mysql_declare_plugin(archive) { MYSQL_STORAGE_ENGINE_PLUGIN, &archive_storage_engine, "ARCHIVE", "Brian Aker, MySQL AB", "Archive storage engine", PLUGIN_LICENSE_GPL, archive_db_init, /* Plugin Init */ archive_db_done, /* Plugin Deinit */ 0x0300 /* 3.0 */, NULL, /* status variables */ NULL, /* system variables */ NULL, /* config options */ 0, /* flags */ } mysql_declare_plugin_end;