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Diffstat (limited to 'storage/myisammrg/ha_myisammrg.cc')
| -rw-r--r-- | storage/myisammrg/ha_myisammrg.cc | 1785 |
1 files changed, 1785 insertions, 0 deletions
diff --git a/storage/myisammrg/ha_myisammrg.cc b/storage/myisammrg/ha_myisammrg.cc new file mode 100644 index 00000000..d37636ab --- /dev/null +++ b/storage/myisammrg/ha_myisammrg.cc @@ -0,0 +1,1785 @@ +/* Copyright (c) 2000, 2011, Oracle and/or its affiliates + Copyright (c) 2009, 2016, MariaDB + + 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 02110-1335 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 handler object as + ha_myisammrg::children_l. The end of the children list is saved in + ha_myisammrg::children_last_l. + + Back in open_tables(), handler::extra(HA_EXTRA_ADD_CHILDREN_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 by open_table(). The children are opened as + independent MyISAM tables, right as if they are used by the SQL + statement. + + When all tables from the statement query list are open, + handler::extra(HA_EXTRA_ATTACH_CHILDREN) is called. It "attaches" the + children 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. + + 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. + + The children chain remains in the statement query list until the table + is closed or the children are detached. This is done so that the + children are locked by lock_tables(). + + At statement end the children are detached. At the next statement + begin the open-add-attach sequence repeats. There is no exception for + LOCK TABLES. The fresh establishment of the parent-child relationship + before every statement catches numerous cases of ALTER/FLUSH/DROP/etc + of parent or children during LOCK TABLES. + + --- + + 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 + +#define MYSQL_SERVER 1 +#include <my_global.h> +#include "sql_priv.h" +#include "unireg.h" +#include "sql_cache.h" // query_cache_* +#include "sql_show.h" // append_identifier +#include "sql_table.h" // build_table_filename +#include <m_ctype.h> +#include "../myisam/ha_myisam.h" +#include "ha_myisammrg.h" +#include "myrg_def.h" +#include "thr_malloc.h" // init_sql_alloc +#include "sql_class.h" // THD +#include "debug_sync.h" + +static handler *myisammrg_create_handler(handlerton *hton, + TABLE_SHARE *table, + MEM_ROOT *mem_root) +{ + return new (mem_root) ha_myisammrg(hton, table); +} + + +/** + @brief Constructor +*/ + +ha_myisammrg::ha_myisammrg(handlerton *hton, TABLE_SHARE *table_arg) + :handler(hton, table_arg), file(0), is_cloned(0) +{ + init_sql_alloc(rg_key_memory_children, &children_mem_root, + FN_REFLEN, 0, MYF(0)); +} + + +/** + @brief Destructor +*/ + +ha_myisammrg::~ha_myisammrg(void) +{ + free_root(&children_mem_root, MYF(0)); +} + + +static const char *ha_myisammrg_exts[] = { + MYRG_NAME_EXT, + NullS +}; +extern int table2myisam(TABLE *table_arg, MI_KEYDEF **keydef_out, + MI_COLUMNDEF **recinfo_out, uint *records_out); +extern int check_definition(MI_KEYDEF *t1_keyinfo, + MI_COLUMNDEF *t1_recinfo, + uint t1_keys, uint t1_recs, + MI_KEYDEF *t2_keyinfo, + MI_COLUMNDEF *t2_recinfo, + uint t2_keys, uint t2_recs, bool strict, + TABLE *table_arg); +static void split_file_name(const char *file_name, + LEX_STRING *db, LEX_STRING *name); + + +extern "C" void myrg_print_wrong_table(const char *table_name) +{ + LEX_STRING db= {NULL, 0}, name; + char buf[FN_REFLEN]; + split_file_name(table_name, &db, &name); + memcpy(buf, db.str, db.length); + buf[db.length]= '.'; + memcpy(buf + db.length + 1, name.str, name.length); + buf[db.length + name.length + 1]= 0; + /* + Push an error to be reported as part of CHECK/REPAIR result-set. + Note that calling my_error() from handler is a hack which is kept + here to avoid refactoring. Normally engines should report errors + through return value which will be interpreted by caller using + handler::print_error() call. + */ + my_error(ER_ADMIN_WRONG_MRG_TABLE, MYF(0), buf); +} + + +const char *ha_myisammrg::index_type(uint key_number) +{ + return ((table->key_info[key_number].flags & HA_FULLTEXT) ? + "FULLTEXT" : + (table->key_info[key_number].flags & HA_SPATIAL) ? + "SPATIAL" : + (table->key_info[key_number].algorithm == HA_KEY_ALG_RTREE) ? + "RTREE" : + "BTREE"); +} + + +/** + Callback function for open of a MERGE parent table. + + @param[in] callback_param data pointer as given to myrg_parent_open() + this is used to pass the handler handle + @param[in] filename file name of MyISAM table + without extension. + + @return status + @retval 0 OK + @retval != 0 Error + + @detail + + This function adds a TABLE_LIST object for a MERGE child table to a + list of tables in the parent handler object. It is called for each + child table. + + The list of child TABLE_LIST objects is kept in the handler object + of the parent for the whole life time of the MERGE table. It is + inserted in the statement query list behind the MERGE parent + TABLE_LIST object when the MERGE table is opened. It is removed from + the statement query list at end of statement or at children detach. + + All memory used for the child TABLE_LIST objects and the strings + referred by it are taken from the parent + ha_myisammrg::children_mem_root. Thus they are all freed implicitly at + the final close of the table. + + children_l -> TABLE_LIST::next_global -> TABLE_LIST::next_global + # # ^ # ^ + # # | # | + # # +--------- TABLE_LIST::prev_global + # # | + # |<--- TABLE_LIST::prev_global | + # | + children_last_l -----------------------------------------+ +*/ + +CPP_UNNAMED_NS_START + +extern "C" int myisammrg_parent_open_callback(void *callback_param, + const char *filename) +{ + ha_myisammrg *ha_myrg= (ha_myisammrg*) callback_param; + TABLE *parent= ha_myrg->table_ptr(); + Mrg_child_def *mrg_child_def; + char *db; + char *table_name; + size_t dirlen; + size_t db_length; + size_t table_name_length; + char dir_path[FN_REFLEN]; + char name_buf[NAME_LEN]; + DBUG_ENTER("myisammrg_parent_open_callback"); + + /* + Depending on MySQL version, filename may be encoded by table name to + file name encoding or not. Always encoded if parent table is created + by 5.1.46+. Encoded if parent is created by 5.1.6+ and child table is + in different database. + */ + if (!has_path(filename)) + { + /* Child is in the same database as parent. */ + db_length= parent->s->db.length; + db= strmake_root(&ha_myrg->children_mem_root, parent->s->db.str, db_length); + /* Child table name is encoded in parent dot-MRG starting with 5.1.46. */ + if (parent->s->mysql_version >= 50146) + { + table_name_length= filename_to_tablename(filename, name_buf, + sizeof(name_buf)); + table_name= strmake_root(&ha_myrg->children_mem_root, name_buf, + table_name_length); + } + else + { + table_name_length= strlen(filename); + table_name= strmake_root(&ha_myrg->children_mem_root, filename, + table_name_length); + } + } + else + { + DBUG_ASSERT(strlen(filename) < sizeof(dir_path)); + fn_format(dir_path, filename, "", "", 0); + /* Extract child table name and database name from filename. */ + dirlen= dirname_length(dir_path); + /* Child db/table name is encoded in parent dot-MRG starting with 5.1.6. */ + if (parent->s->mysql_version >= 50106) + { + table_name_length= filename_to_tablename(dir_path + dirlen, name_buf, + sizeof(name_buf)); + table_name= strmake_root(&ha_myrg->children_mem_root, name_buf, + table_name_length); + dir_path[dirlen - 1]= 0; + dirlen= dirname_length(dir_path); + db_length= filename_to_tablename(dir_path + dirlen, name_buf, sizeof(name_buf)); + db= strmake_root(&ha_myrg->children_mem_root, name_buf, db_length); + } + else + { + table_name_length= strlen(dir_path + dirlen); + table_name= strmake_root(&ha_myrg->children_mem_root, dir_path + dirlen, + table_name_length); + dir_path[dirlen - 1]= 0; + dirlen= dirname_length(dir_path); + db_length= strlen(dir_path + dirlen); + db= strmake_root(&ha_myrg->children_mem_root, dir_path + dirlen, + db_length); + } + } + + if (! db || ! table_name) + DBUG_RETURN(1); + + DBUG_PRINT("myrg", ("open: '%.*s'.'%.*s'", (int) db_length, db, + (int) table_name_length, table_name)); + + /* Convert to lowercase if required. */ + if (lower_case_table_names && table_name_length) + { + /* purecov: begin tested */ + table_name_length= my_casedn_str(files_charset_info, table_name); + /* purecov: end */ + } + + mrg_child_def= new (&ha_myrg->children_mem_root) + Mrg_child_def(db, db_length, table_name, table_name_length); + + if (! mrg_child_def || + ha_myrg->child_def_list.push_back(mrg_child_def, + &ha_myrg->children_mem_root)) + { + DBUG_RETURN(1); + } + DBUG_RETURN(0); +} + +CPP_UNNAMED_NS_END + + +/* + Set external_ref for the child MyISAM tables. They need this to be set in + order to check for killed status. +*/ +static void myrg_set_external_ref(MYRG_INFO *m_info, void *ext_ref_arg) +{ + int i; + for (i= 0; i < (int)m_info->tables; i++) + { + m_info->open_tables[i].table->external_ref= ext_ref_arg; + } +} + +/** + Open a MERGE parent table, but not its children. + + @param[in] name MERGE table path name + @param[in] mode read/write mode, unused + @param[in] test_if_locked_arg open flags + + @return status + @retval 0 OK + @retval -1 Error, my_errno gives reason + + @detail + This function initializes the MERGE storage engine structures + and adds a child list of TABLE_LIST to the parent handler. +*/ + +int ha_myisammrg::open(const char *name, int mode __attribute__((unused)), + uint test_if_locked_arg) +{ + DBUG_ENTER("ha_myisammrg::open"); + DBUG_PRINT("myrg", ("name: '%s' table: %p", name, table)); + DBUG_PRINT("myrg", ("test_if_locked_arg: %u", test_if_locked_arg)); + + /* Must not be used when table is open. */ + DBUG_ASSERT(!this->file); + + /* Save for later use. */ + test_if_locked= test_if_locked_arg; + + /* In case this handler was open and closed before, free old data. */ + free_root(&this->children_mem_root, MYF(MY_MARK_BLOCKS_FREE)); + + /* + Initialize variables that are used, modified, and/or set by + myisammrg_parent_open_callback(). + 'children_l' is the head of the children chain. + 'children_last_l' points to the end of the children chain. + 'my_errno' is set by myisammrg_parent_open_callback() in + case of an error. + */ + children_l= NULL; + children_last_l= NULL; + child_def_list.empty(); + my_errno= 0; + + /* retrieve children table list. */ + if (is_cloned) + { + /* + Open and attaches the MyISAM tables,that are under the MERGE table + parent, on the MyISAM storage engine interface directly within the + MERGE engine. The new MyISAM table instances, as well as the MERGE + clone itself, are not visible in the table cache. This is not a + problem because all locking is handled by the original MERGE table + from which this is cloned of. + */ + if (!(file= myrg_open(name, table->db_stat, HA_OPEN_IGNORE_IF_LOCKED))) + { + DBUG_PRINT("error", ("my_errno %d", my_errno)); + DBUG_RETURN(my_errno ? my_errno : -1); + } + + file->children_attached= TRUE; + myrg_set_external_ref(file, (void*)table); + + info(HA_STATUS_NO_LOCK | HA_STATUS_VARIABLE | HA_STATUS_CONST); + } + else if (!(file= myrg_parent_open(name, myisammrg_parent_open_callback, this))) + { + /* purecov: begin inspected */ + DBUG_PRINT("error", ("my_errno %d", my_errno)); + DBUG_RETURN(my_errno ? my_errno : -1); + /* purecov: end */ + } + DBUG_PRINT("myrg", ("MYRG_INFO: %p child tables: %u", + file, file->tables)); + DBUG_RETURN(0); +} + + +/** + Add list of MERGE children to a TABLE_LIST chain. + + @return status + @retval 0 OK + @retval != 0 Error + + @detail + When a MERGE parent table has just been opened, insert the + TABLE_LIST chain from the MERGE handler into the table list used for + opening tables for this statement. This lets the children be opened + too. +*/ + +int ha_myisammrg::add_children_list(void) +{ + TABLE_LIST *parent_l= this->table->pos_in_table_list; + THD *thd= table->in_use; + List_iterator_fast<Mrg_child_def> it(child_def_list); + Mrg_child_def *mrg_child_def; + DBUG_ENTER("ha_myisammrg::add_children_list"); + DBUG_PRINT("myrg", ("table: '%s'.'%s' %p", this->table->s->db.str, + this->table->s->table_name.str, this->table)); + + /* Must call this with open table. */ + DBUG_ASSERT(this->file); + + /* Ignore this for empty MERGE tables (UNION=()). */ + if (!this->file->tables) + { + DBUG_PRINT("myrg", ("empty merge table union")); + goto end; + } + + /* Must not call this with attached children. */ + DBUG_ASSERT(!this->file->children_attached); + + /* Must not call this with children list in place. */ + DBUG_ASSERT(this->children_l == NULL); + + /* + Prevent inclusion of another MERGE table, which could make infinite + recursion. + */ + if (parent_l->parent_l) + { + my_error(ER_ADMIN_WRONG_MRG_TABLE, MYF(0), parent_l->alias.str); + DBUG_RETURN(1); + } + + while ((mrg_child_def= it++)) + { + TABLE_LIST *child_l; + LEX_CSTRING db; + LEX_CSTRING table_name; + + child_l= (TABLE_LIST*) thd->alloc(sizeof(TABLE_LIST)); + db.str= (char*) thd->memdup(mrg_child_def->db.str, mrg_child_def->db.length+1); + db.length= mrg_child_def->db.length; + table_name.str= (char*) thd->memdup(mrg_child_def->name.str, + mrg_child_def->name.length+1); + table_name.length= mrg_child_def->name.length; + + if (child_l == NULL || db.str == NULL || table_name.str == NULL) + DBUG_RETURN(1); + + child_l->init_one_table(&db, &table_name, 0, parent_l->lock_type); + /* Set parent reference. Used to detect MERGE in children list. */ + child_l->parent_l= parent_l; + /* Copy select_lex. Used in unique_table() at least. */ + child_l->select_lex= parent_l->select_lex; + /* Set the expected table version, to not cause spurious re-prepare. */ + child_l->set_table_ref_id(mrg_child_def->get_child_table_ref_type(), + mrg_child_def->get_child_def_version()); + /* + Copy parent's prelocking attribute to allow opening of child + temporary residing in the prelocking list. + */ + child_l->prelocking_placeholder= parent_l->prelocking_placeholder; + /* + For statements which acquire a SNW metadata lock on a parent table and + then later try to upgrade it to an X lock (e.g. ALTER TABLE), SNW + locks should be also taken on the children tables. + + Otherwise we end up in a situation where the thread trying to upgrade SNW + to X lock on the parent also holds a SR metadata lock and a read + thr_lock.c lock on the child. As a result, another thread might be + blocked on the thr_lock.c lock for the child after successfully acquiring + a SR or SW metadata lock on it. If at the same time this second thread + has a shared metadata lock on the parent table or there is some other + thread which has a shared metadata lock on the parent and is waiting for + this second thread, we get a deadlock. This deadlock cannot be properly + detected by the MDL subsystem as part of the waiting happens within + thr_lock.c. By taking SNW locks on the child tables we ensure that any + thread which waits for a thread doing SNW -> X upgrade, does this within + the MDL subsystem and thus potential deadlocks are exposed to the deadlock + detector. + + We don't do the same thing for SNRW locks as this would allow + DDL on implicitly locked underlying tables of a MERGE table. + */ + if (! thd->locked_tables_mode && + parent_l->mdl_request.type == MDL_SHARED_UPGRADABLE) + child_l->mdl_request.set_type(MDL_SHARED_NO_WRITE); + /* Link TABLE_LIST object into the children list. */ + if (this->children_last_l) + child_l->prev_global= this->children_last_l; + else + { + /* Initialize children_last_l when handling first child. */ + this->children_last_l= &this->children_l; + } + *this->children_last_l= child_l; + this->children_last_l= &child_l->next_global; + } + + /* Insert children into the table list. */ + if (parent_l->next_global) + parent_l->next_global->prev_global= this->children_last_l; + *this->children_last_l= parent_l->next_global; + parent_l->next_global= this->children_l; + this->children_l->prev_global= &parent_l->next_global; + /* + We have to update LEX::query_tables_last if children are added to + the tail of the table list in order to be able correctly add more + elements to it (e.g. as part of prelocking process). + */ + if (thd->lex->query_tables_last == &parent_l->next_global) + thd->lex->query_tables_last= this->children_last_l; + /* + The branch below works only when re-executing a prepared + statement or a stored routine statement: + We've just modified query_tables_last. Keep it in sync with + query_tables_last_own, if it was set by the prelocking code. + This ensures that the check that prohibits double updates (*) + can correctly identify what tables belong to the main statement. + (*) A double update is, e.g. when a user issues UPDATE t1 and + t1 has an AFTER UPDATE trigger that also modifies t1. + */ + if (thd->lex->query_tables_own_last == &parent_l->next_global) + thd->lex->query_tables_own_last= this->children_last_l; + +end: + DBUG_RETURN(0); +} + + +/** + A context of myrg_attach_children() callback. +*/ + +class Mrg_attach_children_callback_param +{ +public: + /** + 'need_compat_check' is set by myisammrg_attach_children_callback() + if a child fails the table def version check. + */ + bool need_compat_check; + /** TABLE_LIST identifying this merge parent. */ + TABLE_LIST *parent_l; + /** Iterator position, the current child to attach. */ + TABLE_LIST *next_child_attach; + List_iterator_fast<Mrg_child_def> def_it; + Mrg_child_def *mrg_child_def; +public: + Mrg_attach_children_callback_param(TABLE_LIST *parent_l_arg, + TABLE_LIST *first_child, + List<Mrg_child_def> &child_def_list) + :need_compat_check(FALSE), + parent_l(parent_l_arg), + next_child_attach(first_child), + def_it(child_def_list), + mrg_child_def(def_it++) + {} + void next() + { + next_child_attach= next_child_attach->next_global; + if (next_child_attach && next_child_attach->parent_l != parent_l) + next_child_attach= NULL; + if (mrg_child_def) + mrg_child_def= def_it++; + } +}; + + +/** + Callback function for attaching a MERGE child table. + + @param[in] callback_param data pointer as given to myrg_attach_children() + this is used to pass the handler handle + + @return pointer to open MyISAM table structure + @retval !=NULL OK, returning pointer + @retval NULL, Error. + + @detail + This function retrieves the MyISAM table handle from the + next child table. It is called for each child table. +*/ + +CPP_UNNAMED_NS_START + +extern "C" MI_INFO *myisammrg_attach_children_callback(void *callback_param) +{ + Mrg_attach_children_callback_param *param= + (Mrg_attach_children_callback_param*) callback_param; + TABLE *parent= param->parent_l->table; + TABLE *child; + TABLE_LIST *child_l= param->next_child_attach; + Mrg_child_def *mrg_child_def= param->mrg_child_def; + MI_INFO *myisam= NULL; + DBUG_ENTER("myisammrg_attach_children_callback"); + + /* + Number of children in the list and MYRG_INFO::tables_count, + which is used by caller of this function, should always match. + */ + DBUG_ASSERT(child_l); + + child= child_l->table; + /* Prepare for next child. */ + param->next(); + + /* + When MERGE table is opened for CHECK or REPAIR TABLE statements, + failure to open any of underlying tables is ignored until this moment + (this is needed to provide complete list of the problematic underlying + tables in CHECK/REPAIR TABLE output). + Here we detect such a situation and report an appropriate error. + */ + if (! child) + { + DBUG_PRINT("error", ("failed to open underlying table '%s'.'%s'", + child_l->db.str, child_l->table_name.str)); + /* + This should only happen inside of CHECK/REPAIR TABLE or + for the tables added by the pre-locking code. + */ + DBUG_ASSERT(current_thd->open_options & HA_OPEN_FOR_REPAIR || + child_l->prelocking_placeholder); + goto end; + } + + /* + 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 successful 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) mrg_child_def->get_child_def_version(), + (ulong) child->s->get_table_def_version())); + if (mrg_child_def->get_child_def_version() != child->s->get_table_def_version()) + param->need_compat_check= TRUE; + + /* + If child is temporary, parent must be temporary as well. Other + parent/child combinations are allowed. 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. (Note that the condition was different from + 5.1.23/6.0.4(Bug#19627) to 5.5.6 (Bug#36171): child->s->tmp_table != + parent->s->tmp_table. Tables were required to have the same status.) + */ + 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)); + goto end; + } + + /* 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' %p", + child->s->db.str, child->s->table_name.str, + child)); + } + + DBUG_PRINT("myrg", ("MyISAM handle: %p", myisam)); + + end: + + if (!myisam && + (current_thd->open_options & HA_OPEN_FOR_REPAIR)) + { + char buf[2*NAME_LEN + 1 + 1]; + strxnmov(buf, sizeof(buf) - 1, child_l->db.str, ".", + child_l->table_name.str, NULL); + /* + Push an error to be reported as part of CHECK/REPAIR result-set. + Note that calling my_error() from handler is a hack which is kept + here to avoid refactoring. Normally engines should report errors + through return value which will be interpreted by caller using + handler::print_error() call. + */ + my_error(ER_ADMIN_WRONG_MRG_TABLE, MYF(0), buf); + } + + DBUG_RETURN(myisam); +} + +CPP_UNNAMED_NS_END + +/** + Returns a cloned instance of the current handler. + + @return A cloned handler instance. + */ +handler *ha_myisammrg::clone(const char *name, MEM_ROOT *mem_root) +{ + MYRG_TABLE *u_table,*newu_table; + ha_myisammrg *new_handler= + (ha_myisammrg*) get_new_handler(table->s, mem_root, table->s->db_type()); + if (!new_handler) + return NULL; + + /* Inform ha_myisammrg::open() that it is a cloned handler */ + new_handler->is_cloned= TRUE; + /* + Allocate handler->ref here because otherwise ha_open will allocate it + on this->table->mem_root and we will not be able to reclaim that memory + when the clone handler object is destroyed. + */ + if (!(new_handler->ref= (uchar*) alloc_root(mem_root, ALIGN_SIZE(ref_length)*2))) + { + delete new_handler; + return NULL; + } + + if (new_handler->ha_open(table, name, table->db_stat, + HA_OPEN_IGNORE_IF_LOCKED)) + { + delete new_handler; + return NULL; + } + + /* + Iterate through the original child tables and + copy the state into the cloned child tables. + We need to do this because all the child tables + can be involved in delete. + */ + newu_table= new_handler->file->open_tables; + for (u_table= file->open_tables; u_table < file->end_table; u_table++) + { + newu_table->table->state= u_table->table->state; + newu_table++; + } + + return new_handler; + } + + +/** + Attach children to a MERGE table. + + @return status + @retval 0 OK + @retval != 0 Error, my_errno gives reason + + @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. +*/ + +int ha_myisammrg::attach_children(void) +{ + MYRG_TABLE *u_table; + MI_COLUMNDEF *recinfo; + MI_KEYDEF *keyinfo; + uint recs; + uint keys= table->s->keys; + TABLE_LIST *parent_l= table->pos_in_table_list; + int error; + Mrg_attach_children_callback_param param(parent_l, this->children_l, child_def_list); + DBUG_ENTER("ha_myisammrg::attach_children"); + DBUG_PRINT("myrg", ("table: '%s'.'%s' %p", table->s->db.str, + table->s->table_name.str, table)); + DBUG_PRINT("myrg", ("test_if_locked: %u", this->test_if_locked)); + + /* Must call this with open table. */ + DBUG_ASSERT(this->file); + + /* + A MERGE table with no children (empty union) is always seen as + attached internally. + */ + if (!this->file->tables) + { + DBUG_PRINT("myrg", ("empty merge table union")); + goto end; + } + DBUG_PRINT("myrg", ("child tables: %u", this->file->tables)); + + /* Must not call this with attached children. */ + DBUG_ASSERT(!this->file->children_attached); + + DEBUG_SYNC(current_thd, "before_myisammrg_attach"); + /* Must call this with children list in place. */ + DBUG_ASSERT(this->table->pos_in_table_list->next_global == this->children_l); + + if (myrg_attach_children(this->file, this->test_if_locked | + current_thd->open_options, + myisammrg_attach_children_callback, ¶m, + (my_bool *) ¶m.need_compat_check)) + { + error= my_errno; + goto err; + } + 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)) + myrg_extra(file,HA_EXTRA_NO_WAIT_LOCK,0); + info(HA_STATUS_NO_LOCK | HA_STATUS_VARIABLE | HA_STATUS_CONST); + if (!(test_if_locked & HA_OPEN_WAIT_IF_LOCKED)) + myrg_extra(file,HA_EXTRA_WAIT_LOCK,0); + + /* + 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", param.need_compat_check)); + if (param.need_compat_check) + { + TABLE_LIST *child_l; + + 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) + { + /* purecov: begin inspected */ + myrg_print_wrong_table(file->open_tables->table->filename); + /* purecov: end */ + } + 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, NULL)) + { + 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(recinfo); + goto err; + } + /* purecov: begin inspected */ + myrg_print_wrong_table(u_table->table->filename); + /* purecov: end */ + } + } + my_free(recinfo); + if (error == HA_ERR_WRONG_MRG_TABLE_DEF) + goto err; /* purecov: inspected */ + + List_iterator_fast<Mrg_child_def> def_it(child_def_list); + DBUG_ASSERT(this->children_l); + for (child_l= this->children_l; ; child_l= child_l->next_global) + { + Mrg_child_def *mrg_child_def= def_it++; + mrg_child_def->set_child_def_version( + child_l->table->s->get_table_ref_type(), + child_l->table->s->get_table_def_version()); + + if (&child_l->next_global == this->children_last_l) + break; + } + } +#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 + + end: + DBUG_RETURN(0); + +err: + DBUG_PRINT("error", ("attaching MERGE children failed: %d", error)); + print_error(error, MYF(0)); + detach_children(); + DBUG_RETURN(my_errno= error); +} + + +/** + Detach all children from a MERGE table and from the query list of tables. + + @return status + @retval 0 OK + @retval != 0 Error, my_errno gives reason + + @note + Detach must not touch the child TABLE objects in any way. + They may have been closed at ths point already. + All references to the children should be removed. +*/ + +int ha_myisammrg::detach_children(void) +{ + TABLE_LIST *child_l; + DBUG_ENTER("ha_myisammrg::detach_children"); + + /* Must call this with open table. */ + DBUG_ASSERT(this->file); + + /* A MERGE table with no children (empty union) cannot be detached. */ + if (!this->file->tables) + { + DBUG_PRINT("myrg", ("empty merge table union")); + goto end; + } + + if (this->children_l) + { + THD *thd= table->in_use; + + /* Clear TABLE references. */ + for (child_l= this->children_l; ; child_l= child_l->next_global) + { + /* + Do not DBUG_ASSERT(child_l->table); open_tables might be + incomplete. + + Clear the table reference. + */ + child_l->table= NULL; + /* Similarly, clear the ticket reference. */ + child_l->mdl_request.ticket= NULL; + + /* Break when this was the last child. */ + if (&child_l->next_global == this->children_last_l) + break; + } + /* + Remove children from the table list. This won't fail if called + twice. The list is terminated after removal. + + If the parent is LEX::query_tables_own_last and pre-locked tables + follow (tables used by stored functions or triggers), the children + are inserted behind the parent and before the pre-locked tables. But + we do not adjust LEX::query_tables_own_last. The pre-locked tables + could have chopped off the list by clearing + *LEX::query_tables_own_last. This did also chop off the children. If + we would copy the reference from *this->children_last_l in this + case, we would put the chopped off pre-locked tables back to the + list. So we refrain from copying it back, if the destination has + been set to NULL meanwhile. + */ + if (this->children_l->prev_global && *this->children_l->prev_global) + *this->children_l->prev_global= *this->children_last_l; + if (*this->children_last_l) + (*this->children_last_l)->prev_global= this->children_l->prev_global; + + /* + If table elements being removed are at the end of table list we + need to adjust LEX::query_tables_last member to point to the + new last element of the list. + */ + if (thd->lex->query_tables_last == this->children_last_l) + thd->lex->query_tables_last= this->children_l->prev_global; + + /* + If the statement requires prelocking, and prelocked + tables were added right after merge children, modify the + last own table pointer to point at prev_global of the merge + parent. + */ + if (thd->lex->query_tables_own_last == this->children_last_l) + thd->lex->query_tables_own_last= this->children_l->prev_global; + + /* Terminate child list. So it cannot be tried to remove again. */ + *this->children_last_l= NULL; + this->children_l->prev_global= NULL; + + /* Forget about the children, we don't own their memory. */ + this->children_l= NULL; + this->children_last_l= NULL; + } + + if (!this->file->children_attached) + { + DBUG_PRINT("myrg", ("merge children are already detached")); + goto end; + } + + if (myrg_detach_children(this->file)) + { + /* purecov: begin inspected */ + print_error(my_errno, MYF(0)); + DBUG_RETURN(my_errno ? my_errno : -1); + /* purecov: end */ + } + + end: + DBUG_RETURN(0); +} + + +/** + Close a MERGE parent table, but not its children. + + @return status + @retval 0 OK + @retval != 0 Error, my_errno gives reason + + @note + The children are expected to be closed separately by the caller. +*/ + +int ha_myisammrg::close(void) +{ + int rc; + DBUG_ENTER("ha_myisammrg::close"); + /* + There are cases where children are not explicitly detached before + close. detach_children() protects itself against double detach. + */ + if (!is_cloned) + detach_children(); + + rc= myrg_close(file); + file= 0; + DBUG_RETURN(rc); +} + +int ha_myisammrg::write_row(const uchar * buf) +{ + DBUG_ENTER("ha_myisammrg::write_row"); + DBUG_ASSERT(this->file->children_attached); + + if (file->merge_insert_method == MERGE_INSERT_DISABLED || !file->tables) + DBUG_RETURN(HA_ERR_TABLE_READONLY); + + if (table->next_number_field && buf == table->record[0]) + { + int error; + if ((error= update_auto_increment())) + DBUG_RETURN(error); /* purecov: inspected */ + } + DBUG_RETURN(myrg_write(file,buf)); +} + +int ha_myisammrg::update_row(const uchar * old_data, const uchar * new_data) +{ + DBUG_ASSERT(this->file->children_attached); + return myrg_update(file,old_data,new_data); +} + +int ha_myisammrg::delete_row(const uchar * buf) +{ + DBUG_ASSERT(this->file->children_attached); + return myrg_delete(file,buf); +} + +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); + int error=myrg_rkey(file,buf,active_index, key, keypart_map, find_flag); + return error; +} + +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); + int error=myrg_rkey(file,buf,index, key, keypart_map, find_flag); + return error; +} + +int ha_myisammrg::index_read_last_map(uchar *buf, const uchar *key, + key_part_map keypart_map) +{ + DBUG_ASSERT(this->file->children_attached); + int error=myrg_rkey(file,buf,active_index, key, keypart_map, + HA_READ_PREFIX_LAST); + return error; +} + +int ha_myisammrg::index_next(uchar * buf) +{ + DBUG_ASSERT(this->file->children_attached); + int error=myrg_rnext(file,buf,active_index); + return error; +} + +int ha_myisammrg::index_prev(uchar * buf) +{ + DBUG_ASSERT(this->file->children_attached); + int error=myrg_rprev(file,buf, active_index); + return error; +} + +int ha_myisammrg::index_first(uchar * buf) +{ + DBUG_ASSERT(this->file->children_attached); + int error=myrg_rfirst(file, buf, active_index); + return error; +} + +int ha_myisammrg::index_last(uchar * buf) +{ + DBUG_ASSERT(this->file->children_attached); + int error=myrg_rlast(file, buf, active_index); + return error; +} + +int ha_myisammrg::index_next_same(uchar * buf, + const uchar *key __attribute__((unused)), + uint length __attribute__((unused))) +{ + int error; + DBUG_ASSERT(this->file->children_attached); + do + { + error= myrg_rnext_same(file,buf); + } while (error == HA_ERR_RECORD_DELETED); + return error; +} + + +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); + int error=myrg_rrnd(file, buf, HA_OFFSET_ERROR); + return error; +} + + +int ha_myisammrg::rnd_pos(uchar * buf, uchar *pos) +{ + DBUG_ASSERT(this->file->children_attached); + int error=myrg_rrnd(file, buf, my_get_ptr(pos,ref_length)); + return error; +} + +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); +} + + +ha_rows ha_myisammrg::records_in_range(uint inx, + const key_range *min_key, + const key_range *max_key, + page_range *pages) +{ + DBUG_ASSERT(this->file->children_attached); + return (ha_rows) myrg_records_in_range(file, (int) inx, min_key, max_key, + pages); +} + + +int ha_myisammrg::delete_all_rows() +{ + int err= 0; + MYRG_TABLE *table; + DBUG_ENTER("ha_myisammrg::delete_all_rows"); + + for (table= file->open_tables; table != file->end_table; table++) + { + if ((err= mi_delete_all_rows(table->table))) + break; + } + + DBUG_RETURN(err); +} + + +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 + and one has more than 2^32 rows in the merge tables. + */ + stats.records = (ha_rows) mrg_info.records; + stats.deleted = (ha_rows) mrg_info.deleted; +#if !defined(BIG_TABLES) || SIZEOF_OFF_T == 4 + if ((mrg_info.records >= (ulonglong) 1 << 32) || + (mrg_info.deleted >= (ulonglong) 1 << 32)) + table->s->crashed= 1; +#endif + stats.data_file_length= mrg_info.data_file_length; + if (mrg_info.errkey >= (int) table_share->keys) + { + /* + If value of errkey is higher than the number of keys + on the table set errkey to MAX_KEY. This will be + treated as unknown key case and error message generator + won't try to locate key causing segmentation fault. + */ + mrg_info.errkey= MAX_KEY; + } + table->s->keys_in_use.set_prefix(table->s->keys); + stats.mean_rec_length= mrg_info.reclength; + + /* + The handler::block_size is used all over the code in index scan cost + calculations. It is used to get number of disk seeks required to + retrieve a number of index tuples. + If the merge table has N underlying tables, then (assuming underlying + tables have equal size, the only "simple" approach we can use) + retrieving X index records from a merge table will require N times more + disk seeks compared to doing the same on a MyISAM table with equal + number of records. + In the edge case (file_tables > myisam_block_size) we'll get + block_size==0, and index calculation code will act as if we need one + disk seek to retrieve one index tuple. + + TODO: In 5.2 index scan cost calculation will be factored out into a + virtual function in class handler and we'll be able to remove this hack. + */ + stats.block_size= 0; + if (file->tables) + stats.block_size= myisam_block_size / file->tables; + + stats.update_time= 0; +#if SIZEOF_OFF_T > 4 + ref_length=6; // Should be big enough +#else + ref_length=4; // Can't be > than my_off_t +#endif + if (flag & HA_STATUS_CONST) + { + if (table->s->key_parts && mrg_info.rec_per_key) + { +#ifdef HAVE_valgrind + /* + valgrind may be unhappy about it, because optimizer may access values + between file->keys and table->key_parts, that will be uninitialized. + It's safe though, because even if opimizer will decide to use a key + with such a number, it'll be an error later anyway. + */ + bzero((char*) table->key_info[0].rec_per_key, + sizeof(table->key_info[0].rec_per_key[0]) * table->s->key_parts); +#endif + memcpy((char*) table->key_info[0].rec_per_key, + (char*) mrg_info.rec_per_key, + sizeof(table->key_info[0].rec_per_key[0]) * + MY_MIN(file->keys, table->s->key_parts)); + } + } + if (flag & HA_STATUS_ERRKEY) + { + errkey= mrg_info.errkey; + my_store_ptr(dup_ref, ref_length, mrg_info.dupp_key_pos); + } + return 0; +} + + +int ha_myisammrg::extra(enum ha_extra_function operation) +{ + if (operation == HA_EXTRA_ADD_CHILDREN_LIST) + { + int rc= add_children_list(); + return(rc); + } + else 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_IS_ATTACHED_CHILDREN) + { + /* For the upper layer pretend empty MERGE union is never attached. */ + return(file && file->tables && file->children_attached); + } + 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 || + operation == HA_EXTRA_PREPARE_FOR_DROP || + operation == HA_EXTRA_PREPARE_FOR_RENAME) + return 0; + if (operation == HA_EXTRA_MMAP && !opt_myisam_use_mmap) + return 0; + return myrg_extra(file,operation,0); +} + +int ha_myisammrg::reset(void) +{ + /* This is normally called with detached children. */ + return myrg_reset(file); +} + +/* To be used with WRITE_CACHE, EXTRA_CACHE and BULK_INSERT_BEGIN */ + +int ha_myisammrg::extra_opt(enum ha_extra_function operation, ulong cache_size) +{ + DBUG_ASSERT(this->file->children_attached); + return myrg_extra(file, operation, (void*) &cache_size); +} + +int ha_myisammrg::external_lock(THD *thd, int lock_type) +{ + /* + This can be called with no children attached. E.g. FLUSH TABLES + unlocks and re-locks tables under LOCK TABLES, but it does not open + them first. So they are detached all the time. But locking of the + children should work anyway because thd->open_tables is not changed + during FLUSH TABLES. + + If this handler instance has been cloned, we still must call + myrg_lock_database(). + */ + if (is_cloned) + return myrg_lock_database(file, lock_type); + return 0; +} + +uint ha_myisammrg::lock_count(void) const +{ + return 0; +} + + +THR_LOCK_DATA **ha_myisammrg::store_lock(THD *thd, + THR_LOCK_DATA **to, + enum thr_lock_type lock_type) +{ + MYRG_TABLE *open_table; + + /* + This method can be called while another thread is attaching the + children. If the processor reorders instructions or write to memory, + 'children_attached' could be set before 'open_tables' has all the + pointers to the children. Use of a mutex here and in + myrg_attach_children() forces consistent data. + */ + mysql_mutex_lock(&this->file->mutex); + + /* + When MERGE table is open, but not yet attached, other threads + could flush it, which means calling mysql_lock_abort_for_thread() + on this threads TABLE. 'children_attached' is FALSE in this + situation. Since the table is not locked, return no lock data. + */ + if (!this->file->children_attached) + goto end; /* purecov: tested */ + + for (open_table=file->open_tables ; + open_table != file->end_table ; + open_table++) + open_table->table->lock.priority|= THR_LOCK_MERGE_PRIV; + + end: + mysql_mutex_unlock(&this->file->mutex); + return to; +} + + +/* Find out database name and table name from a filename */ + +static void split_file_name(const char *file_name, + LEX_STRING *db, LEX_STRING *name) +{ + size_t dir_length, prefix_length; + char buff[FN_REFLEN]; + + db->length= 0; + strmake_buf(buff, file_name); + dir_length= dirname_length(buff); + if (dir_length > 1) + { + /* Get database */ + buff[dir_length-1]= 0; // Remove end '/' + prefix_length= dirname_length(buff); + db->str= (char*) file_name+ prefix_length; + db->length= dir_length - prefix_length -1; + } + name->str= (char*) file_name+ dir_length; + name->length= (uint) (fn_ext(name->str) - name->str); +} + + +void ha_myisammrg::update_create_info(HA_CREATE_INFO *create_info) +{ + DBUG_ENTER("ha_myisammrg::update_create_info"); + + if (!(create_info->used_fields & HA_CREATE_USED_UNION)) + { + TABLE_LIST *child_table, *end= NULL; + THD *thd=ha_thd(); + + if (children_l != NULL) + { + for (child_table= children_l;; child_table= child_table->next_global) + { + TABLE_LIST *ptr; + + if (!(ptr= (TABLE_LIST *) thd->calloc(sizeof(TABLE_LIST)))) + DBUG_VOID_RETURN; + + if (!(ptr->table_name.str= thd->strmake(child_table->table_name.str, + child_table->table_name.length))) + DBUG_VOID_RETURN; + ptr->table_name.length= child_table->table_name.length; + if (child_table->db.str && !(ptr->db.str= thd->strmake(child_table->db.str, + child_table->db.length))) + DBUG_VOID_RETURN; + ptr->db.length= child_table->db.length; + + if (create_info->merge_list) + end->next_local= ptr; + else + create_info->merge_list= ptr; + end= ptr; + + if (&child_table->next_global == children_last_l) + break; + } + } + } + if (!(create_info->used_fields & HA_CREATE_USED_INSERT_METHOD)) + { + create_info->merge_insert_method = file->merge_insert_method; + } + DBUG_VOID_RETURN; +} + + +int ha_myisammrg::create_mrg(const char *name, HA_CREATE_INFO *create_info) +{ + char buff[FN_REFLEN]; + const char **table_names, **pos; + TABLE_LIST *tables= create_info->merge_list; + THD *thd= ha_thd(); + size_t dirlgt= dirname_length(name); + uint ntables= 0; + DBUG_ENTER("ha_myisammrg::create_mrg"); + + for (tables= create_info->merge_list; tables; tables= tables->next_local) + ntables++; + + /* Allocate a table_names array in thread mem_root. */ + if (!(pos= table_names= (const char**) thd->alloc((ntables + 1) * sizeof(char*)))) + DBUG_RETURN(HA_ERR_OUT_OF_MEM); /* purecov: inspected */ + + /* Create child path names. */ + for (tables= create_info->merge_list; tables; tables= tables->next_local) + { + const char *table_name= buff; + + /* + 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. + */ + size_t length= build_table_filename(buff, sizeof(buff), + tables->db.str, tables->table_name.str, "", 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+= dirlgt; + length-= dirlgt; + } + if (!(table_name= thd->strmake(table_name, 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. */ + int res= myrg_create(name, table_names, create_info->merge_insert_method, 0); + DBUG_RETURN(res); +} + + +int ha_myisammrg::create(const char *name, TABLE *form, + HA_CREATE_INFO *create_info) +{ + char buff[FN_REFLEN]; + DBUG_ENTER("ha_myisammrg::create"); + fn_format(buff, name, "", MYRG_NAME_EXT, MY_UNPACK_FILENAME | MY_APPEND_EXT); + int res= create_mrg(buff, create_info); + DBUG_RETURN(res); +} + + +void ha_myisammrg::append_create_info(String *packet) +{ + const char *current_db; + size_t db_length; + THD *thd= current_thd; + TABLE_LIST *open_table, *first; + + if (file->merge_insert_method != MERGE_INSERT_DISABLED) + { + const char *type; + packet->append(STRING_WITH_LEN(" INSERT_METHOD=")); + type= get_type(&merge_insert_method,file->merge_insert_method-1); + packet->append(type, strlen(type)); + } + /* + There is no sence adding UNION clause in case there is no underlying + tables specified. + */ + if (file->open_tables == file->end_table) + return; + packet->append(STRING_WITH_LEN(" UNION=(")); + + current_db= table->s->db.str; + db_length= table->s->db.length; + + for (first= open_table= children_l;; + open_table= open_table->next_global) + { + LEX_CSTRING db= open_table->db; + + if (open_table != first) + packet->append(','); + /* Report database for mapped table if it isn't in current database */ + if (db.length && + (db_length != db.length || + strncmp(current_db, db.str, db.length))) + { + append_identifier(thd, packet, db.str, db.length); + packet->append('.'); + } + append_identifier(thd, packet, &open_table->table_name); + if (&open_table->next_global == children_last_l) + break; + } + packet->append(')'); +} + + +enum_alter_inplace_result +ha_myisammrg::check_if_supported_inplace_alter(TABLE *altered_table, + Alter_inplace_info *ha_alter_info) +{ + /* + We always support inplace ALTER in the new API, because old + HA_NO_COPY_ON_ALTER table_flags() hack prevents non-inplace ALTER anyway. + */ + return HA_ALTER_INPLACE_EXCLUSIVE_LOCK; +} + + +bool ha_myisammrg::inplace_alter_table(TABLE *altered_table, + Alter_inplace_info *ha_alter_info) +{ + char tmp_path[FN_REFLEN]; + const char *name= table->s->normalized_path.str; + DBUG_ENTER("ha_myisammrg::inplace_alter_table"); + fn_format(tmp_path, name, "", MYRG_NAME_TMPEXT, MY_UNPACK_FILENAME | MY_APPEND_EXT); + int res= create_mrg(tmp_path, ha_alter_info->create_info); + if (res) + mysql_file_delete(rg_key_file_MRG, tmp_path, MYF(0)); + else + { + char path[FN_REFLEN]; + fn_format(path, name, "", MYRG_NAME_EXT, MY_UNPACK_FILENAME | MY_APPEND_EXT); + if (mysql_file_rename(rg_key_file_MRG, tmp_path, path, MYF(0))) + { + res= my_errno; + mysql_file_delete(rg_key_file_MRG, tmp_path, MYF(0)); + } + } + DBUG_RETURN(res); +} + +int ha_myisammrg::check(THD* thd, HA_CHECK_OPT* check_opt) +{ + return this->file->children_attached ? HA_ADMIN_OK : HA_ADMIN_CORRUPT; +} + + +ha_rows ha_myisammrg::records() +{ + return myrg_records(file); +} + +uint ha_myisammrg::count_query_cache_dependant_tables(uint8 *tables_type) +{ + MYRG_INFO *file = myrg_info(); + /* + Here should be following statement + (*tables_type)|= HA_CACHE_TBL_NONTRANSACT; + but it has no effect because HA_CACHE_TBL_NONTRANSACT is 0 + */ + return (uint)(file->end_table - file->open_tables); +} + + +my_bool ha_myisammrg::register_query_cache_dependant_tables(THD *thd + __attribute__((unused)), + Query_cache *cache, + Query_cache_block_table **block_table, + uint *n) +{ + MYRG_INFO *file =myrg_info(); + DBUG_ENTER("ha_myisammrg::register_query_cache_dependant_tables"); + + for (MYRG_TABLE *table =file->open_tables; + table != file->end_table ; + table++) + { + char key[MAX_DBKEY_LENGTH]; + uint32 db_length; + uint key_length= cache->filename_2_table_key(key, table->table->filename, + &db_length); + (++(*block_table))->n= ++(*n); + /* + There are not callback function for for MyISAM, and engine data + */ + if (!cache->insert_table(thd, key_length, key, (*block_table), + db_length, 0, + table_cache_type(), + 0, 0, TRUE)) + DBUG_RETURN(TRUE); + } + DBUG_RETURN(FALSE); +} + + +void ha_myisammrg::set_lock_type(enum thr_lock_type lock) +{ + handler::set_lock_type(lock); + if (children_l != NULL) + { + for (TABLE_LIST *child_table= children_l;; + child_table= child_table->next_global) + { + child_table->lock_type= + child_table->table->reginfo.lock_type= lock; + + if (&child_table->next_global == children_last_l) + break; + } + } +} + +extern int myrg_panic(enum ha_panic_function flag); +int myisammrg_panic(handlerton *hton, ha_panic_function flag) +{ + return myrg_panic(flag); +} + +static int myisammrg_init(void *p) +{ + handlerton *myisammrg_hton; + + myisammrg_hton= (handlerton *)p; + +#ifdef HAVE_PSI_INTERFACE + init_myisammrg_psi_keys(); +#endif + + myisammrg_hton->db_type= DB_TYPE_MRG_MYISAM; + myisammrg_hton->create= myisammrg_create_handler; + myisammrg_hton->panic= myisammrg_panic; + myisammrg_hton->flags= HTON_NO_PARTITION; + myisammrg_hton->tablefile_extensions= ha_myisammrg_exts; + + return 0; +} + +struct st_mysql_storage_engine myisammrg_storage_engine= +{ MYSQL_HANDLERTON_INTERFACE_VERSION }; + +maria_declare_plugin(myisammrg) +{ + MYSQL_STORAGE_ENGINE_PLUGIN, + &myisammrg_storage_engine, + "MRG_MyISAM", + "MySQL AB", + "Collection of identical MyISAM tables", + PLUGIN_LICENSE_GPL, + myisammrg_init, /* Plugin Init */ + NULL, /* Plugin Deinit */ + 0x0100, /* 1.0 */ + NULL, /* status variables */ + NULL, /* system variables */ + "1.0", /* string version */ + MariaDB_PLUGIN_MATURITY_STABLE /* maturity */ +} +maria_declare_plugin_end; |