diff options
Diffstat (limited to 'storage/myisammrg/ha_myisammrg.cc')
| -rw-r--r-- | storage/myisammrg/ha_myisammrg.cc | 668 |
1 files changed, 579 insertions, 89 deletions
diff --git a/storage/myisammrg/ha_myisammrg.cc b/storage/myisammrg/ha_myisammrg.cc index 8a914e8a2de..f91b0dc7a92 100644 --- a/storage/myisammrg/ha_myisammrg.cc +++ b/storage/myisammrg/ha_myisammrg.cc @@ -14,6 +14,82 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +/* + MyISAM MERGE tables + + A MyISAM MERGE table is kind of a union of zero or more MyISAM tables. + + Besides the normal form file (.frm) a MERGE table has a meta file + (.MRG) with a list of tables. These are paths to the MyISAM table + files. The last two components of the path contain the database name + and the table name respectively. + + When a MERGE table is open, there exists an TABLE object for the MERGE + table itself and a TABLE object for each of the MyISAM tables. For + abbreviated writing, I call the MERGE table object "parent" and the + MyISAM table objects "children". + + A MERGE table is almost always opened through open_and_lock_tables() + and hence through open_tables(). When the parent appears in the list + of tables to open, the initial open of the handler does nothing but + read the meta file and collect a list of TABLE_LIST objects for the + children. This list is attached to the parent TABLE object as + TABLE::child_l. The end of the children list is saved in + TABLE::child_last_l. + + Back in open_tables(), add_merge_table_list() is called. It updates + each list member with the lock type and a back pointer to the parent + TABLE_LIST object TABLE_LIST::parent_l. The list is then inserted in + the list of tables to open, right behind the parent. Consequently, + open_tables() opens the children, one after the other. The TABLE + references of the TABLE_LIST objects are implicitly set to the open + tables. The children are opened as independent MyISAM tables, right as + if they are used by the SQL statement. + + TABLE_LIST::parent_l is required to find the parent 1. when the last + child has been opened and children are to be attached, and 2. when an + error happens during child open and the child list must be removed + from the queuery list. In these cases the current child does not have + TABLE::parent set or does not have a TABLE at all respectively. + + When the last child is open, attach_merge_children() is called. It + removes the list of children from the open list. Then the children are + "attached" to the parent. All required references between parent and + children are set up. + + The MERGE storage engine sets up an array with references to the + low-level MyISAM table objects (MI_INFO). It remembers the state of + the table in MYRG_INFO::children_attached. + + Every child TABLE::parent references the parent TABLE object. That way + TABLE objects belonging to a MERGE table can be identified. + TABLE::parent is required because the parent and child TABLE objects + can live longer than the parent TABLE_LIST object. So the path + child->pos_in_table_list->parent_l->table can be broken. + + If necessary, the compatibility of parent and children is checked. + This check is necessary when any of the objects are reopend. This is + detected by comparing the current table def version against the + remembered child def version. On parent open, the list members are + initialized to an "impossible"/"undefined" version value. So the check + is always executed on the first attach. + + The version check is done in myisammrg_attach_children_callback(), + which is called for every child. ha_myisammrg::attach_children() + initializes 'need_compat_check' to FALSE and + myisammrg_attach_children_callback() sets it ot TRUE if a table + def version mismatches the remembered child def version. + + Finally the parent TABLE::children_attached is set. + + --- + + On parent open the storage engine structures are allocated and initialized. + They stay with the open table until its final close. + + +*/ + #ifdef USE_PRAGMA_IMPLEMENTATION #pragma implementation // gcc: Class implementation #endif @@ -22,14 +98,11 @@ #include "mysql_priv.h" #include <mysql/plugin.h> #include <m_ctype.h> +#include "../myisam/ha_myisam.h" #include "ha_myisammrg.h" #include "myrg_def.h" -/***************************************************************************** -** MyISAM MERGE tables -*****************************************************************************/ - static handler *myisammrg_create_handler(handlerton *hton, TABLE_SHARE *table, MEM_ROOT *mem_root) @@ -38,10 +111,23 @@ static handler *myisammrg_create_handler(handlerton *hton, } +/** + @brief Constructor +*/ + ha_myisammrg::ha_myisammrg(handlerton *hton, TABLE_SHARE *table_arg) :handler(hton, table_arg), file(0) {} + +/** + @brief Destructor +*/ + +ha_myisammrg::~ha_myisammrg(void) +{} + + static const char *ha_myisammrg_exts[] = { ".MRG", NullS @@ -89,25 +175,311 @@ const char *ha_myisammrg::index_type(uint key_number) } -int ha_myisammrg::open(const char *name, int mode, uint test_if_locked) +/** + @brief Callback function for open of a MERGE parent table. + + @detail This function adds a TABLE_LIST object for a MERGE child table + to a list of tables of the parent TABLE object. It is called for + each child table. + + The list of child TABLE_LIST objects is kept in the TABLE object of + the parent for the whole life time of the MERGE table. It is + inserted in the statement list behind the MERGE parent TABLE_LIST + object when the MERGE table is opened. It is removed from the + statement list after the last child is opened. + + All memeory used for the child TABLE_LIST objects and the strings + referred by it are taken from the parent TABLE::mem_root. Thus they + are all freed implicitly at the final close of the table. + + TABLE::child_l -> TABLE_LIST::next_global -> TABLE_LIST::next_global + # # ^ # ^ + # # | # | + # # +--------- TABLE_LIST::prev_global + # # | + # |<--- TABLE_LIST::prev_global | + # | + TABLE::child_last_l -----------------------------------------+ + + @param[in] callback_param data pointer as given to myrg_parent_open() + @param[in] filename file name of MyISAM table + without extension. + + @return status + @retval 0 OK + @retval != 0 Error +*/ + +static int myisammrg_parent_open_callback(void *callback_param, + const char *filename) +{ + ha_myisammrg *ha_myrg; + TABLE *parent; + TABLE_LIST *child_l; + const char *db; + const char *table_name; + uint dirlen; + char dir_path[FN_REFLEN]; + DBUG_ENTER("myisammrg_parent_open_callback"); + + /* Extract child table name and database name from filename. */ + dirlen= dirname_length(filename); + if (dirlen >= FN_REFLEN) + { + /* purecov: begin inspected */ + DBUG_PRINT("error", ("name too long: '%.64s'", filename)); + my_errno= ENAMETOOLONG; + DBUG_RETURN(1); + /* purecov: end */ + } + table_name= filename + dirlen; + dirlen--; /* Strip off trailing '/'. */ + memcpy(dir_path, filename, dirlen); + dir_path[dirlen]= '\0'; + db= base_name(dir_path); + dirlen-= db - dir_path; /* This is now the length of 'db'. */ + DBUG_PRINT("myrg", ("open: '%s'.'%s'", db, table_name)); + + ha_myrg= (ha_myisammrg*) callback_param; + parent= ha_myrg->table_ptr(); + + /* Get a TABLE_LIST object. */ + if (!(child_l= (TABLE_LIST*) alloc_root(&parent->mem_root, + sizeof(TABLE_LIST)))) + { + /* purecov: begin inspected */ + DBUG_PRINT("error", ("my_malloc error: %d", my_errno)); + DBUG_RETURN(1); + /* purecov: end */ + } + bzero((char*) child_l, sizeof(TABLE_LIST)); + + /* Set database (schema) name. */ + child_l->db_length= dirlen; + child_l->db= strmake_root(&parent->mem_root, db, dirlen); + /* Set table name. */ + child_l->table_name_length= strlen(table_name); + child_l->table_name= strmake_root(&parent->mem_root, table_name, + child_l->table_name_length); + /* Convert to lowercase if required. */ + if (lower_case_table_names && child_l->table_name_length) + child_l->table_name_length= my_casedn_str(files_charset_info, + child_l->table_name); + /* Set alias. */ + child_l->alias= child_l->table_name; + + /* Initialize table map to 'undefined'. */ + child_l->init_child_def_version(); + + /* Link TABLE_LIST object into the parent list. */ + if (!parent->child_last_l) + { + /* Initialize parent->child_last_l when handling first child. */ + parent->child_last_l= &parent->child_l; + } + *parent->child_last_l= child_l; + child_l->prev_global= parent->child_last_l; + parent->child_last_l= &child_l->next_global; + + DBUG_RETURN(0); +} + + +/** + @brief Callback function for attaching a MERGE child table. + + @detail This function retrieves the MyISAM table handle from the + next child table. It is called for each child table. + + @param[in] callback_param data pointer as given to + myrg_attach_children() + + @return pointer to open MyISAM table structure + @retval !=NULL OK, returning pointer + @retval NULL, my_errno == 0 Ok, no more child tables + @retval NULL, my_errno != 0 error +*/ + +static MI_INFO *myisammrg_attach_children_callback(void *callback_param) +{ + ha_myisammrg *ha_myrg; + TABLE *parent; + TABLE *child; + TABLE_LIST *child_l; + MI_INFO *myisam; + DBUG_ENTER("myisammrg_attach_children_callback"); + + my_errno= 0; + ha_myrg= (ha_myisammrg*) callback_param; + parent= ha_myrg->table_ptr(); + + /* Get child list item. */ + child_l= ha_myrg->next_child_attach; + if (!child_l) + { + DBUG_PRINT("myrg", ("No more children to attach")); + DBUG_RETURN(NULL); + } + child= child_l->table; + DBUG_PRINT("myrg", ("child table: '%s'.'%s' 0x%lx", child->s->db.str, + child->s->table_name.str, (long) child)); + /* + Prepare for next child. Used as child_l in next call to this function. + We cannot rely on a NULL-terminated chain. + */ + if (&child_l->next_global == parent->child_last_l) + { + DBUG_PRINT("myrg", ("attaching last child")); + ha_myrg->next_child_attach= NULL; + } + else + ha_myrg->next_child_attach= child_l->next_global; + + /* Set parent reference. */ + child->parent= parent; + + /* + Do a quick compatibility check. The table def version is set when + the table share is created. The child def version is copied + from the table def version after a sucessful compatibility check. + We need to repeat the compatibility check only if a child is opened + from a different share than last time it was used with this MERGE + table. + */ + DBUG_PRINT("myrg", ("table_def_version last: %lu current: %lu", + (ulong) child_l->get_child_def_version(), + (ulong) child->s->get_table_def_version())); + if (child_l->get_child_def_version() != child->s->get_table_def_version()) + ha_myrg->need_compat_check= TRUE; + + /* + If parent is temporary, children must be temporary too and vice + versa. This check must be done for every child on every open because + the table def version can overlap between temporary and + non-temporary tables. We need to detect the case where a + non-temporary table has been replaced with a temporary table of the + same version. Or vice versa. A very unlikely case, but it could + happen. + */ + if (child->s->tmp_table != parent->s->tmp_table) + { + DBUG_PRINT("error", ("temporary table mismatch parent: %d child: %d", + parent->s->tmp_table, child->s->tmp_table)); + my_errno= HA_ERR_WRONG_MRG_TABLE_DEF; + goto err; + } + + /* Extract the MyISAM table structure pointer from the handler object. */ + if ((child->file->ht->db_type != DB_TYPE_MYISAM) || + !(myisam= ((ha_myisam*) child->file)->file_ptr())) + { + DBUG_PRINT("error", ("no MyISAM handle for child table: '%s'.'%s' 0x%lx", + child->s->db.str, child->s->table_name.str, + (long) child)); + my_errno= HA_ERR_WRONG_MRG_TABLE_DEF; + } + DBUG_PRINT("myrg", ("MyISAM handle: 0x%lx my_errno: %d", + (long) myisam, my_errno)); + + err: + DBUG_RETURN(my_errno ? NULL : myisam); +} + + +/** + @brief Open a MERGE parent table, not its children. + + @detail This function initializes the MERGE storage engine structures + and adds a child list of TABLE_LIST to the parent TABLE. + + @param[in] name MERGE table path name + @param[in] mode read/write mode, unused + @param[in] test_if_locked open flags + + @return status + @retval 0 OK + @retval -1 Error, my_errno gives reason +*/ + +int ha_myisammrg::open(const char *name, int mode __attribute__((unused)), + uint test_if_locked) +{ + DBUG_ENTER("ha_myisammrg::open"); + DBUG_PRINT("myrg", ("name: '%s' table: 0x%lx", name, (long) table)); + DBUG_PRINT("myrg", ("test_if_locked: %u", test_if_locked)); + + /* Save for later use. */ + this->test_if_locked= test_if_locked; + + /* retrieve children table list. */ + my_errno= 0; + if (!(file= myrg_parent_open(name, myisammrg_parent_open_callback, this))) + { + DBUG_PRINT("error", ("my_errno %d", my_errno)); + DBUG_RETURN(my_errno ? my_errno : -1); + } + DBUG_PRINT("myrg", ("MYRG_INFO: 0x%lx", (long) file)); + DBUG_RETURN(0); +} + + +/** + @brief Attach children to a MERGE table. + + @detail Let the storage engine attach its children through a callback + function. Check table definitions for consistency. + + @note Special thd->open_options may be in effect. We can make use of + them in attach. I.e. we use HA_OPEN_FOR_REPAIR to report the names + of mismatching child tables. We cannot transport these options in + ha_myisammrg::test_if_locked because they may change after the + parent is opened. The parent is kept open in the table cache over + multiple statements and can be used by other threads. Open options + can change over time. + + @return status + @retval 0 OK + @retval != 0 Error, my_errno gives reason +*/ + +int ha_myisammrg::attach_children(void) { - MI_KEYDEF *keyinfo; - MI_COLUMNDEF *recinfo; - MYRG_TABLE *u_table; - uint recs; - uint keys= table->s->keys; - int error; - char name_buff[FN_REFLEN]; + MYRG_TABLE *u_table; + MI_COLUMNDEF *recinfo; + MI_KEYDEF *keyinfo; + uint recs; + uint keys= table->s->keys; + int error; + DBUG_ENTER("ha_myisammrg::attach_children"); + DBUG_PRINT("myrg", ("table: '%s'.'%s' 0x%lx", table->s->db.str, + table->s->table_name.str, (long) table)); + DBUG_PRINT("myrg", ("test_if_locked: %u", this->test_if_locked)); + DBUG_ASSERT(!this->file->children_attached); + + /* + Initialize variables that are used, modified, and/or set by + myisammrg_attach_children_callback(). + 'next_child_attach' traverses the chain of TABLE_LIST objects + that has been compiled during myrg_parent_open(). Every call + to myisammrg_attach_children_callback() moves the pointer to + the next object. + 'need_compat_check' is set by myisammrg_attach_children_callback() + if a child fails the table def version check. + 'my_errno' is set by myisammrg_attach_children_callback() in + case of an error. + */ + next_child_attach= table->child_l; + need_compat_check= FALSE; + my_errno= 0; - DBUG_PRINT("info", ("ha_myisammrg::open")); - if (!(file=myrg_open(fn_format(name_buff,name,"","", - MY_UNPACK_FILENAME|MY_APPEND_EXT), - mode, test_if_locked))) + if (myrg_attach_children(this->file, this->test_if_locked | + current_thd->open_options, + myisammrg_attach_children_callback, this)) { - DBUG_PRINT("info", ("ha_myisammrg::open exit %d", my_errno)); - return (my_errno ? my_errno : -1); + DBUG_PRINT("error", ("my_errno %d", my_errno)); + DBUG_RETURN(my_errno ? my_errno : -1); } - DBUG_PRINT("info", ("ha_myisammrg::open myrg_extrafunc...")); + DBUG_PRINT("myrg", ("calling myrg_extrafunc")); myrg_extrafunc(file, query_cache_invalidate_by_MyISAM_filename_ref); if (!(test_if_locked == HA_OPEN_WAIT_IF_LOCKED || test_if_locked == HA_OPEN_ABORT_IF_LOCKED)) @@ -116,69 +488,147 @@ int ha_myisammrg::open(const char *name, int mode, uint test_if_locked) if (!(test_if_locked & HA_OPEN_WAIT_IF_LOCKED)) myrg_extra(file,HA_EXTRA_WAIT_LOCK,0); - if (table->s->reclength != stats.mean_rec_length && stats.mean_rec_length) - { - DBUG_PRINT("error",("reclength: %lu mean_rec_length: %lu", - table->s->reclength, stats.mean_rec_length)); - if (test_if_locked & HA_OPEN_FOR_REPAIR) - myrg_print_wrong_table(file->open_tables->table->filename); - error= HA_ERR_WRONG_MRG_TABLE_DEF; - goto err; - } - if ((error= table2myisam(table, &keyinfo, &recinfo, &recs))) - { - /* purecov: begin inspected */ - DBUG_PRINT("error", ("Failed to convert TABLE object to MyISAM " - "key and column definition")); - goto err; - /* purecov: end */ - } - for (u_table= file->open_tables; u_table < file->end_table; u_table++) + /* + The compatibility check is required only if one or more children do + not match their table def version from the last check. This will + always happen at the first attach because the reference child def + version is initialized to 'undefined' at open. + */ + DBUG_PRINT("myrg", ("need_compat_check: %d", need_compat_check)); + if (need_compat_check) { - if (check_definition(keyinfo, recinfo, keys, recs, - u_table->table->s->keyinfo, u_table->table->s->rec, - u_table->table->s->base.keys, - u_table->table->s->base.fields, false)) + TABLE_LIST *child_l; + + if (table->s->reclength != stats.mean_rec_length && stats.mean_rec_length) { - error= HA_ERR_WRONG_MRG_TABLE_DEF; + DBUG_PRINT("error",("reclength: %lu mean_rec_length: %lu", + table->s->reclength, stats.mean_rec_length)); if (test_if_locked & HA_OPEN_FOR_REPAIR) - myrg_print_wrong_table(u_table->table->filename); - else + myrg_print_wrong_table(file->open_tables->table->filename); + error= HA_ERR_WRONG_MRG_TABLE_DEF; + goto err; + } + /* + Both recinfo and keyinfo are allocated by my_multi_malloc(), thus + only recinfo must be freed. + */ + if ((error= table2myisam(table, &keyinfo, &recinfo, &recs))) + { + /* purecov: begin inspected */ + DBUG_PRINT("error", ("failed to convert TABLE object to MyISAM " + "key and column definition")); + goto err; + /* purecov: end */ + } + for (u_table= file->open_tables; u_table < file->end_table; u_table++) + { + if (check_definition(keyinfo, recinfo, keys, recs, + u_table->table->s->keyinfo, u_table->table->s->rec, + u_table->table->s->base.keys, + u_table->table->s->base.fields, false)) { - my_free((uchar*) recinfo, MYF(0)); - goto err; + DBUG_PRINT("error", ("table definition mismatch: '%s'", + u_table->table->filename)); + error= HA_ERR_WRONG_MRG_TABLE_DEF; + if (!(this->test_if_locked & HA_OPEN_FOR_REPAIR)) + { + my_free((uchar*) recinfo, MYF(0)); + goto err; + } + myrg_print_wrong_table(u_table->table->filename); } } + my_free((uchar*) recinfo, MYF(0)); + if (error == HA_ERR_WRONG_MRG_TABLE_DEF) + goto err; + + /* All checks passed so far. Now update child def version. */ + for (child_l= table->child_l; ; child_l= child_l->next_global) + { + child_l->set_child_def_version( + child_l->table->s->get_table_def_version()); + + if (&child_l->next_global == table->child_last_l) + break; + } } - my_free((uchar*) recinfo, MYF(0)); - if (error == HA_ERR_WRONG_MRG_TABLE_DEF) - goto err; #if !defined(BIG_TABLES) || SIZEOF_OFF_T == 4 /* Merge table has more than 2G rows */ if (table->s->crashed) { + DBUG_PRINT("error", ("MERGE table marked crashed")); error= HA_ERR_WRONG_MRG_TABLE_DEF; goto err; } #endif - return (0); + DBUG_RETURN(0); + err: - myrg_close(file); - file=0; - return (my_errno= error); + myrg_detach_children(file); + DBUG_RETURN(my_errno= error); } + +/** + @brief Detach all children from a MERGE table. + + @note Detach must not touch the children in any way. + They may have been closed at ths point already. + All references to the children should be removed. + + @return status + @retval 0 OK + @retval != 0 Error, my_errno gives reason +*/ + +int ha_myisammrg::detach_children(void) +{ + DBUG_ENTER("ha_myisammrg::detach_children"); + DBUG_ASSERT(this->file && this->file->children_attached); + + if (myrg_detach_children(this->file)) + { + /* purecov: begin inspected */ + DBUG_PRINT("error", ("my_errno %d", my_errno)); + DBUG_RETURN(my_errno ? my_errno : -1); + /* purecov: end */ + } + DBUG_RETURN(0); +} + + +/** + @brief Close a MERGE parent table, not its children. + + @note The children are expected to be closed separately by the caller. + + @return status + @retval 0 OK + @retval != 0 Error, my_errno gives reason +*/ + int ha_myisammrg::close(void) { - return myrg_close(file); + int rc; + DBUG_ENTER("ha_myisammrg::close"); + /* + Children must not be attached here. Unless the MERGE table has no + children. In this case children_attached is always true. + */ + DBUG_ASSERT(!this->file->children_attached || !this->file->tables); + rc= myrg_close(file); + file= 0; + DBUG_RETURN(rc); } int ha_myisammrg::write_row(uchar * buf) { + DBUG_ENTER("ha_myisammrg::write_row"); + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_write_count); if (file->merge_insert_method == MERGE_INSERT_DISABLED || !file->tables) - return (HA_ERR_TABLE_READONLY); + DBUG_RETURN(HA_ERR_TABLE_READONLY); if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT) table->timestamp_field->set_time(); @@ -186,13 +636,14 @@ int ha_myisammrg::write_row(uchar * buf) { int error; if ((error= update_auto_increment())) - return error; + DBUG_RETURN(error); /* purecov: inspected */ } - return myrg_write(file,buf); + DBUG_RETURN(myrg_write(file,buf)); } int ha_myisammrg::update_row(const uchar * old_data, uchar * new_data) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_update_count); if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE) table->timestamp_field->set_time(); @@ -201,6 +652,7 @@ int ha_myisammrg::update_row(const uchar * old_data, uchar * new_data) int ha_myisammrg::delete_row(const uchar * buf) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_delete_count); return myrg_delete(file,buf); } @@ -209,6 +661,7 @@ int ha_myisammrg::index_read_map(uchar * buf, const uchar * key, key_part_map keypart_map, enum ha_rkey_function find_flag) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_read_key_count); int error=myrg_rkey(file,buf,active_index, key, keypart_map, find_flag); table->status=error ? STATUS_NOT_FOUND: 0; @@ -219,6 +672,7 @@ int ha_myisammrg::index_read_idx_map(uchar * buf, uint index, const uchar * key, key_part_map keypart_map, enum ha_rkey_function find_flag) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_read_key_count); int error=myrg_rkey(file,buf,index, key, keypart_map, find_flag); table->status=error ? STATUS_NOT_FOUND: 0; @@ -228,6 +682,7 @@ int ha_myisammrg::index_read_idx_map(uchar * buf, uint index, const uchar * key, int ha_myisammrg::index_read_last_map(uchar *buf, const uchar *key, key_part_map keypart_map) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_read_key_count); int error=myrg_rkey(file,buf,active_index, key, keypart_map, HA_READ_PREFIX_LAST); @@ -237,6 +692,7 @@ int ha_myisammrg::index_read_last_map(uchar *buf, const uchar *key, int ha_myisammrg::index_next(uchar * buf) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_read_next_count); int error=myrg_rnext(file,buf,active_index); table->status=error ? STATUS_NOT_FOUND: 0; @@ -245,6 +701,7 @@ int ha_myisammrg::index_next(uchar * buf) int ha_myisammrg::index_prev(uchar * buf) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_read_prev_count); int error=myrg_rprev(file,buf, active_index); table->status=error ? STATUS_NOT_FOUND: 0; @@ -253,6 +710,7 @@ int ha_myisammrg::index_prev(uchar * buf) int ha_myisammrg::index_first(uchar * buf) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_read_first_count); int error=myrg_rfirst(file, buf, active_index); table->status=error ? STATUS_NOT_FOUND: 0; @@ -261,6 +719,7 @@ int ha_myisammrg::index_first(uchar * buf) int ha_myisammrg::index_last(uchar * buf) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_read_last_count); int error=myrg_rlast(file, buf, active_index); table->status=error ? STATUS_NOT_FOUND: 0; @@ -271,6 +730,7 @@ int ha_myisammrg::index_next_same(uchar * buf, const uchar *key __attribute__((unused)), uint length __attribute__((unused))) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_read_next_count); int error=myrg_rnext_same(file,buf); table->status=error ? STATUS_NOT_FOUND: 0; @@ -280,12 +740,14 @@ int ha_myisammrg::index_next_same(uchar * buf, int ha_myisammrg::rnd_init(bool scan) { + DBUG_ASSERT(this->file->children_attached); return myrg_reset(file); } int ha_myisammrg::rnd_next(uchar *buf) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_read_rnd_next_count); int error=myrg_rrnd(file, buf, HA_OFFSET_ERROR); table->status=error ? STATUS_NOT_FOUND: 0; @@ -295,6 +757,7 @@ int ha_myisammrg::rnd_next(uchar *buf) int ha_myisammrg::rnd_pos(uchar * buf, uchar *pos) { + DBUG_ASSERT(this->file->children_attached); ha_statistic_increment(&SSV::ha_read_rnd_count); int error=myrg_rrnd(file, buf, my_get_ptr(pos,ref_length)); table->status=error ? STATUS_NOT_FOUND: 0; @@ -303,6 +766,7 @@ int ha_myisammrg::rnd_pos(uchar * buf, uchar *pos) void ha_myisammrg::position(const uchar *record) { + DBUG_ASSERT(this->file->children_attached); ulonglong row_position= myrg_position(file); my_store_ptr(ref, ref_length, (my_off_t) row_position); } @@ -311,6 +775,7 @@ void ha_myisammrg::position(const uchar *record) ha_rows ha_myisammrg::records_in_range(uint inx, key_range *min_key, key_range *max_key) { + DBUG_ASSERT(this->file->children_attached); return (ha_rows) myrg_records_in_range(file, (int) inx, min_key, max_key); } @@ -318,6 +783,7 @@ ha_rows ha_myisammrg::records_in_range(uint inx, key_range *min_key, int ha_myisammrg::info(uint flag) { MYMERGE_INFO mrg_info; + DBUG_ASSERT(this->file->children_attached); (void) myrg_status(file,&mrg_info,flag); /* The following fails if one has not compiled MySQL with -DBIG_TABLES @@ -387,6 +853,23 @@ int ha_myisammrg::info(uint flag) int ha_myisammrg::extra(enum ha_extra_function operation) { + if (operation == HA_EXTRA_ATTACH_CHILDREN) + { + int rc= attach_children(); + if (!rc) + (void) extra(HA_EXTRA_NO_READCHECK); // Not needed in SQL + return(rc); + } + else if (operation == HA_EXTRA_DETACH_CHILDREN) + { + /* + Note that detach must not touch the children in any way. + They may have been closed at ths point already. + */ + int rc= detach_children(); + return(rc); + } + /* As this is just a mapping, we don't have to force the underlying tables to be closed */ if (operation == HA_EXTRA_FORCE_REOPEN || @@ -404,6 +887,7 @@ int ha_myisammrg::reset(void) int ha_myisammrg::extra_opt(enum ha_extra_function operation, ulong cache_size) { + DBUG_ASSERT(this->file->children_attached); if ((specialflag & SPECIAL_SAFE_MODE) && operation == HA_EXTRA_WRITE_CACHE) return 0; return myrg_extra(file, operation, (void*) &cache_size); @@ -411,11 +895,13 @@ int ha_myisammrg::extra_opt(enum ha_extra_function operation, ulong cache_size) int ha_myisammrg::external_lock(THD *thd, int lock_type) { + DBUG_ASSERT(this->file->children_attached); return myrg_lock_database(file,lock_type); } uint ha_myisammrg::lock_count(void) const { + DBUG_ASSERT(this->file->children_attached); return file->tables; } @@ -425,6 +911,7 @@ THR_LOCK_DATA **ha_myisammrg::store_lock(THD *thd, enum thr_lock_type lock_type) { MYRG_TABLE *open_table; + DBUG_ASSERT(this->file->children_attached); for (open_table=file->open_tables ; open_table != file->end_table ; @@ -519,47 +1006,50 @@ int ha_myisammrg::create(const char *name, register TABLE *form, uint dirlgt= dirname_length(name); DBUG_ENTER("ha_myisammrg::create"); + /* Allocate a table_names array in thread mem_root. */ if (!(table_names= (const char**) thd->alloc((create_info->merge_list.elements+1) * sizeof(char*)))) DBUG_RETURN(HA_ERR_OUT_OF_MEM); + + /* Create child path names. */ for (pos= table_names; tables; tables= tables->next_local) { const char *table_name; - TABLE *tbl= 0; - if (create_info->options & HA_LEX_CREATE_TMP_TABLE) - tbl= find_temporary_table(thd, tables); - if (!tbl) - { - /* - Construct the path to the MyISAM table. Try to meet two conditions: - 1.) Allow to include MyISAM tables from different databases, and - 2.) allow for moving DATADIR around in the file system. - The first means that we need paths in the .MRG file. The second - means that we should not have absolute paths in the .MRG file. - The best, we can do, is to use 'mysql_data_home', which is '.' - in mysqld and may be an absolute path in an embedded server. - This means that it might not be possible to move the DATADIR of - an embedded server without changing the paths in the .MRG file. - */ - uint length= build_table_filename(buff, sizeof(buff), - tables->db, tables->table_name, "", 0); - /* - If a MyISAM table is in the same directory as the MERGE table, - we use the table name without a path. This means that the - DATADIR can easily be moved even for an embedded server as long - as the MyISAM tables are from the same database as the MERGE table. - */ - if ((dirname_length(buff) == dirlgt) && ! memcmp(buff, name, dirlgt)) - table_name= tables->table_name; - else - if (! (table_name= thd->strmake(buff, length))) - DBUG_RETURN(HA_ERR_OUT_OF_MEM); - } + + /* + Construct the path to the MyISAM table. Try to meet two conditions: + 1.) Allow to include MyISAM tables from different databases, and + 2.) allow for moving DATADIR around in the file system. + The first means that we need paths in the .MRG file. The second + means that we should not have absolute paths in the .MRG file. + The best, we can do, is to use 'mysql_data_home', which is '.' + in mysqld and may be an absolute path in an embedded server. + This means that it might not be possible to move the DATADIR of + an embedded server without changing the paths in the .MRG file. + + Do the same even for temporary tables. MERGE children are now + opened through the table cache. They are opened by db.table_name, + not by their path name. + */ + uint length= build_table_filename(buff, sizeof(buff), + tables->db, tables->table_name, "", 0); + /* + If a MyISAM table is in the same directory as the MERGE table, + we use the table name without a path. This means that the + DATADIR can easily be moved even for an embedded server as long + as the MyISAM tables are from the same database as the MERGE table. + */ + if ((dirname_length(buff) == dirlgt) && ! memcmp(buff, name, dirlgt)) + table_name= tables->table_name; else - table_name= tbl->s->path.str; + if (! (table_name= thd->strmake(buff, length))) + DBUG_RETURN(HA_ERR_OUT_OF_MEM); /* purecov: inspected */ + *pos++= table_name; } *pos=0; + + /* Create a MERGE meta file from the table_names array. */ DBUG_RETURN(myrg_create(fn_format(buff,name,"","", MY_RESOLVE_SYMLINKS| MY_UNPACK_FILENAME|MY_APPEND_EXT), @@ -642,7 +1132,7 @@ static int myisammrg_init(void *p) myisammrg_hton->db_type= DB_TYPE_MRG_MYISAM; myisammrg_hton->create= myisammrg_create_handler; myisammrg_hton->panic= myisammrg_panic; - myisammrg_hton->flags= HTON_CAN_RECREATE|HTON_NO_PARTITION; + myisammrg_hton->flags= HTON_NO_PARTITION; return 0; } |