diff options
Diffstat (limited to 'sql/ha_partition.cc')
| -rw-r--r-- | sql/ha_partition.cc | 6059 |
1 files changed, 6059 insertions, 0 deletions
diff --git a/sql/ha_partition.cc b/sql/ha_partition.cc new file mode 100644 index 00000000000..d2497081893 --- /dev/null +++ b/sql/ha_partition.cc @@ -0,0 +1,6059 @@ +/* Copyright (C) 2005 MySQL AB + + 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ + +/* + This handler was developed by Mikael Ronstrom for version 5.1 of MySQL. + It is an abstraction layer on top of other handlers such as MyISAM, + InnoDB, Federated, Berkeley DB and so forth. Partitioned tables can also + be handled by a storage engine. The current example of this is NDB + Cluster that has internally handled partitioning. This have benefits in + that many loops needed in the partition handler can be avoided. + + Partitioning has an inherent feature which in some cases is positive and + in some cases is negative. It splits the data into chunks. This makes + the data more manageable, queries can easily be parallelised towards the + parts and indexes are split such that there are less levels in the + index trees. The inherent disadvantage is that to use a split index + one has to scan all index parts which is ok for large queries but for + small queries it can be a disadvantage. + + Partitioning lays the foundation for more manageable databases that are + extremely large. It does also lay the foundation for more parallelism + in the execution of queries. This functionality will grow with later + versions of MySQL. + + You can enable it in your buld by doing the following during your build + process: + ./configure --with-partition + + The partition is setup to use table locks. It implements an partition "SHARE" + that is inserted into a hash by table name. You can use this to store + information of state that any partition handler object will be able to see + if it is using the same table. + + Please read the object definition in ha_partition.h before reading the rest + if this file. +*/ + +#ifdef __GNUC__ +#pragma implementation // gcc: Class implementation +#endif + +#include "mysql_priv.h" + +#ifdef WITH_PARTITION_STORAGE_ENGINE +#include "ha_partition.h" + +#include <mysql/plugin.h> + +static const char *ha_par_ext= ".par"; +#ifdef NOT_USED +static int free_share(PARTITION_SHARE * share); +static PARTITION_SHARE *get_share(const char *table_name, TABLE * table); +#endif + +/**************************************************************************** + MODULE create/delete handler object +****************************************************************************/ + +static handler *partition_create_handler(handlerton *hton, + TABLE_SHARE *share, + MEM_ROOT *mem_root); +static uint partition_flags(); +static uint alter_table_flags(uint flags); + + +static int partition_initialize(void *p) +{ + + handlerton *partition_hton; + partition_hton= (handlerton *)p; + + partition_hton->state= SHOW_OPTION_YES; + partition_hton->db_type= DB_TYPE_PARTITION_DB; + partition_hton->create= partition_create_handler; + partition_hton->partition_flags= partition_flags; + partition_hton->alter_table_flags= alter_table_flags; + partition_hton->flags= HTON_NOT_USER_SELECTABLE | HTON_HIDDEN; + + return 0; +} + +/* + Create new partition handler + + SYNOPSIS + partition_create_handler() + table Table object + + RETURN VALUE + New partition object +*/ + +static handler *partition_create_handler(handlerton *hton, + TABLE_SHARE *share, + MEM_ROOT *mem_root) +{ + ha_partition *file= new (mem_root) ha_partition(hton, share); + if (file && file->initialise_partition(mem_root)) + { + delete file; + file= 0; + } + return file; +} + +/* + HA_CAN_PARTITION: + Used by storage engines that can handle partitioning without this + partition handler + (Partition, NDB) + + HA_CAN_UPDATE_PARTITION_KEY: + Set if the handler can update fields that are part of the partition + function. + + HA_CAN_PARTITION_UNIQUE: + Set if the handler can handle unique indexes where the fields of the + unique key are not part of the fields of the partition function. Thus + a unique key can be set on all fields. + + HA_USE_AUTO_PARTITION + Set if the handler sets all tables to be partitioned by default. +*/ + +static uint partition_flags() +{ + return HA_CAN_PARTITION; +} + +static uint alter_table_flags(uint flags __attribute__((unused))) +{ + return (HA_PARTITION_FUNCTION_SUPPORTED | + HA_FAST_CHANGE_PARTITION); +} + +const uint ha_partition::NO_CURRENT_PART_ID= 0xFFFFFFFF; + +/* + Constructor method + + SYNOPSIS + ha_partition() + table Table object + + RETURN VALUE + NONE +*/ + +ha_partition::ha_partition(handlerton *hton, TABLE_SHARE *share) + :handler(hton, share), m_part_info(NULL), m_create_handler(FALSE), + m_is_sub_partitioned(0), is_clone(FALSE) +{ + DBUG_ENTER("ha_partition::ha_partition(table)"); + init_handler_variables(); + DBUG_VOID_RETURN; +} + + +/* + Constructor method + + SYNOPSIS + ha_partition() + part_info Partition info + + RETURN VALUE + NONE +*/ + +ha_partition::ha_partition(handlerton *hton, partition_info *part_info) + :handler(hton, NULL), m_part_info(part_info), + m_create_handler(TRUE), + m_is_sub_partitioned(m_part_info->is_sub_partitioned()), is_clone(FALSE) +{ + DBUG_ENTER("ha_partition::ha_partition(part_info)"); + init_handler_variables(); + DBUG_ASSERT(m_part_info); + DBUG_VOID_RETURN; +} + + +/* + Initialise handler object + + SYNOPSIS + init_handler_variables() + + RETURN VALUE + NONE +*/ + +void ha_partition::init_handler_variables() +{ + active_index= MAX_KEY; + m_mode= 0; + m_open_test_lock= 0; + m_file_buffer= NULL; + m_name_buffer_ptr= NULL; + m_engine_array= NULL; + m_file= NULL; + m_file_tot_parts= 0; + m_reorged_file= NULL; + m_new_file= NULL; + m_reorged_parts= 0; + m_added_file= NULL; + m_tot_parts= 0; + m_pkey_is_clustered= 0; + m_lock_type= F_UNLCK; + m_part_spec.start_part= NO_CURRENT_PART_ID; + m_scan_value= 2; + m_ref_length= 0; + m_part_spec.end_part= NO_CURRENT_PART_ID; + m_index_scan_type= partition_no_index_scan; + m_start_key.key= NULL; + m_start_key.length= 0; + m_myisam= FALSE; + m_innodb= FALSE; + m_extra_cache= FALSE; + m_extra_cache_size= 0; + m_table_flags= HA_FILE_BASED | HA_REC_NOT_IN_SEQ; + m_low_byte_first= 1; + m_part_field_array= NULL; + m_ordered_rec_buffer= NULL; + m_top_entry= NO_CURRENT_PART_ID; + m_rec_length= 0; + m_last_part= 0; + m_rec0= 0; + m_curr_key_info= 0; + /* + this allows blackhole to work properly + */ + m_no_locks= 0; + +#ifdef DONT_HAVE_TO_BE_INITALIZED + m_start_key.flag= 0; + m_ordered= TRUE; +#endif +} + + +const char *ha_partition::table_type() const +{ + // we can do this since we only support a single engine type + return m_file[0]->table_type(); +} + + +/* + Destructor method + + SYNOPSIS + ~ha_partition() + + RETURN VALUE + NONE +*/ + +ha_partition::~ha_partition() +{ + DBUG_ENTER("ha_partition::~ha_partition()"); + if (m_file != NULL) + { + uint i; + for (i= 0; i < m_tot_parts; i++) + delete m_file[i]; + } + my_free((char*) m_ordered_rec_buffer, MYF(MY_ALLOW_ZERO_PTR)); + + clear_handler_file(); + DBUG_VOID_RETURN; +} + + +/* + Initialise partition handler object + + SYNOPSIS + initialise_partition() + mem_root Allocate memory through this + + RETURN VALUE + 1 Error + 0 Success + + DESCRIPTION + + The partition handler is only a layer on top of other engines. Thus it + can't really perform anything without the underlying handlers. Thus we + add this method as part of the allocation of a handler object. + + 1) Allocation of underlying handlers + If we have access to the partition info we will allocate one handler + instance for each partition. + 2) Allocation without partition info + The cases where we don't have access to this information is when called + in preparation for delete_table and rename_table and in that case we + only need to set HA_FILE_BASED. In that case we will use the .par file + that contains information about the partitions and their engines and + the names of each partition. + 3) Table flags initialisation + We need also to set table flags for the partition handler. This is not + static since it depends on what storage engines are used as underlying + handlers. + The table flags is set in this routine to simulate the behaviour of a + normal storage engine + The flag HA_FILE_BASED will be set independent of the underlying handlers + 4) Index flags initialisation + When knowledge exists on the indexes it is also possible to initialise the + index flags. Again the index flags must be initialised by using the under- + lying handlers since this is storage engine dependent. + The flag HA_READ_ORDER will be reset for the time being to indicate no + ordered output is available from partition handler indexes. Later a merge + sort will be performed using the underlying handlers. + 5) primary_key_is_clustered, has_transactions and low_byte_first is + calculated here. + +*/ + +bool ha_partition::initialise_partition(MEM_ROOT *mem_root) +{ + handler **file_array, *file; + DBUG_ENTER("ha_partition::initialise_partition"); + + if (m_create_handler) + { + m_tot_parts= m_part_info->get_tot_partitions(); + DBUG_ASSERT(m_tot_parts > 0); + if (new_handlers_from_part_info(mem_root)) + DBUG_RETURN(1); + } + else if (!table_share || !table_share->normalized_path.str) + { + /* + Called with dummy table share (delete, rename and alter table) + Don't need to set-up table flags other than + HA_FILE_BASED here + */ + m_table_flags|= HA_FILE_BASED | HA_REC_NOT_IN_SEQ; + DBUG_RETURN(0); + } + else if (get_from_handler_file(table_share->normalized_path.str, mem_root)) + { + mem_alloc_error(2); + DBUG_RETURN(1); + } + /* + We create all underlying table handlers here. We do it in this special + method to be able to report allocation errors. + + Set up table_flags, low_byte_first, primary_key_is_clustered and + has_transactions since they are called often in all kinds of places, + other parameters are calculated on demand. + HA_FILE_BASED is always set for partition handler since we use a + special file for handling names of partitions, engine types. + HA_CAN_GEOMETRY, HA_CAN_FULLTEXT, HA_CAN_SQL_HANDLER, HA_DUPLICATE_POS, + HA_CAN_INSERT_DELAYED is disabled until further investigated. + */ + m_table_flags= (ulong)m_file[0]->ha_table_flags(); + m_low_byte_first= m_file[0]->low_byte_first(); + m_pkey_is_clustered= TRUE; + file_array= m_file; + do + { + file= *file_array; + if (m_low_byte_first != file->low_byte_first()) + { + // Cannot have handlers with different endian + my_error(ER_MIX_HANDLER_ERROR, MYF(0)); + DBUG_RETURN(1); + } + if (!file->primary_key_is_clustered()) + m_pkey_is_clustered= FALSE; + m_table_flags&= file->ha_table_flags(); + } while (*(++file_array)); + m_table_flags&= ~(HA_CAN_GEOMETRY | HA_CAN_FULLTEXT | HA_DUPLICATE_POS | + HA_CAN_SQL_HANDLER | HA_CAN_INSERT_DELAYED | + HA_PRIMARY_KEY_REQUIRED_FOR_POSITION); + m_table_flags|= HA_FILE_BASED | HA_REC_NOT_IN_SEQ; + DBUG_RETURN(0); +} + +/**************************************************************************** + MODULE meta data changes +****************************************************************************/ +/* + Delete a table + + SYNOPSIS + delete_table() + name Full path of table name + + RETURN VALUE + >0 Error + 0 Success + + DESCRIPTION + Used to delete a table. By the time delete_table() has been called all + opened references to this table will have been closed (and your globally + shared references released. The variable name will just be the name of + the table. You will need to remove any files you have created at this + point. + + If you do not implement this, the default delete_table() is called from + handler.cc and it will delete all files with the file extentions returned + by bas_ext(). + + Called from handler.cc by delete_table and ha_create_table(). Only used + during create if the table_flag HA_DROP_BEFORE_CREATE was specified for + the storage engine. +*/ + +int ha_partition::delete_table(const char *name) +{ + int error; + DBUG_ENTER("ha_partition::delete_table"); + + if ((error= del_ren_cre_table(name, NULL, NULL, NULL))) + DBUG_RETURN(error); + DBUG_RETURN(handler::delete_table(name)); +} + + +/* + Rename a table + + SYNOPSIS + rename_table() + from Full path of old table name + to Full path of new table name + + RETURN VALUE + >0 Error + 0 Success + + DESCRIPTION + Renames a table from one name to another from alter table call. + + If you do not implement this, the default rename_table() is called from + handler.cc and it will rename all files with the file extentions returned + by bas_ext(). + + Called from sql_table.cc by mysql_rename_table(). +*/ + +int ha_partition::rename_table(const char *from, const char *to) +{ + int error; + DBUG_ENTER("ha_partition::rename_table"); + + if ((error= del_ren_cre_table(from, to, NULL, NULL))) + DBUG_RETURN(error); + DBUG_RETURN(handler::rename_table(from, to)); +} + + +/* + Create the handler file (.par-file) + + SYNOPSIS + create_handler_files() + name Full path of table name + create_info Create info generated for CREATE TABLE + + RETURN VALUE + >0 Error + 0 Success + + DESCRIPTION + create_handler_files is called to create any handler specific files + before opening the file with openfrm to later call ::create on the + file object. + In the partition handler this is used to store the names of partitions + and types of engines in the partitions. +*/ + +int ha_partition::create_handler_files(const char *path, + const char *old_path, + int action_flag, + HA_CREATE_INFO *create_info) +{ + DBUG_ENTER("ha_partition::create_handler_files()"); + + /* + We need to update total number of parts since we might write the handler + file as part of a partition management command + */ + if (action_flag == CHF_DELETE_FLAG || + action_flag == CHF_RENAME_FLAG) + { + char name[FN_REFLEN]; + char old_name[FN_REFLEN]; + + strxmov(name, path, ha_par_ext, NullS); + strxmov(old_name, old_path, ha_par_ext, NullS); + if ((action_flag == CHF_DELETE_FLAG && + my_delete(name, MYF(MY_WME))) || + (action_flag == CHF_RENAME_FLAG && + my_rename(old_name, name, MYF(MY_WME)))) + { + DBUG_RETURN(TRUE); + } + } + else if (action_flag == CHF_CREATE_FLAG) + { + if (create_handler_file(path)) + { + my_error(ER_CANT_CREATE_HANDLER_FILE, MYF(0)); + DBUG_RETURN(1); + } + } + DBUG_RETURN(0); +} + + +/* + Create a partitioned table + + SYNOPSIS + create() + name Full path of table name + table_arg Table object + create_info Create info generated for CREATE TABLE + + RETURN VALUE + >0 Error + 0 Success + + DESCRIPTION + create() is called to create a table. The variable name will have the name + of the table. When create() is called you do not need to worry about + opening the table. Also, the FRM file will have already been created so + adjusting create_info will not do you any good. You can overwrite the frm + file at this point if you wish to change the table definition, but there + are no methods currently provided for doing that. + + Called from handler.cc by ha_create_table(). +*/ + +int ha_partition::create(const char *name, TABLE *table_arg, + HA_CREATE_INFO *create_info) +{ + char t_name[FN_REFLEN]; + DBUG_ENTER("ha_partition::create"); + + strmov(t_name, name); + DBUG_ASSERT(*fn_rext((char*)name) == '\0'); + if (del_ren_cre_table(t_name, NULL, table_arg, create_info)) + { + handler::delete_table(t_name); + DBUG_RETURN(1); + } + DBUG_RETURN(0); +} + + +/* + Drop partitions as part of ALTER TABLE of partitions + + SYNOPSIS + drop_partitions() + path Complete path of db and table name + + RETURN VALUE + >0 Failure + 0 Success + + DESCRIPTION + Use part_info object on handler object to deduce which partitions to + drop (each partition has a state attached to it) +*/ + +int ha_partition::drop_partitions(const char *path) +{ + List_iterator<partition_element> part_it(m_part_info->partitions); + char part_name_buff[FN_REFLEN]; + uint no_parts= m_part_info->partitions.elements; + uint no_subparts= m_part_info->no_subparts; + uint i= 0; + uint name_variant; + int ret_error; + int error= 0; + DBUG_ENTER("ha_partition::drop_partitions"); + + /* + Assert that it works without HA_FILE_BASED and lower_case_table_name = 2. + We use m_file[0] as long as all partitions have the same storage engine. + */ + DBUG_ASSERT(!strcmp(path, get_canonical_filename(m_file[0], path, + part_name_buff))); + do + { + partition_element *part_elem= part_it++; + if (part_elem->part_state == PART_TO_BE_DROPPED) + { + handler *file; + /* + This part is to be dropped, meaning the part or all its subparts. + */ + name_variant= NORMAL_PART_NAME; + if (m_is_sub_partitioned) + { + List_iterator<partition_element> sub_it(part_elem->subpartitions); + uint j= 0, part; + do + { + partition_element *sub_elem= sub_it++; + part= i * no_subparts + j; + create_subpartition_name(part_name_buff, path, + part_elem->partition_name, + sub_elem->partition_name, name_variant); + file= m_file[part]; + DBUG_PRINT("info", ("Drop subpartition %s", part_name_buff)); + if ((ret_error= file->ha_delete_table(part_name_buff))) + error= ret_error; + if (deactivate_ddl_log_entry(sub_elem->log_entry->entry_pos)) + error= 1; + } while (++j < no_subparts); + } + else + { + create_partition_name(part_name_buff, path, + part_elem->partition_name, name_variant, + TRUE); + file= m_file[i]; + DBUG_PRINT("info", ("Drop partition %s", part_name_buff)); + if ((ret_error= file->ha_delete_table(part_name_buff))) + error= ret_error; + if (deactivate_ddl_log_entry(part_elem->log_entry->entry_pos)) + error= 1; + } + if (part_elem->part_state == PART_IS_CHANGED) + part_elem->part_state= PART_NORMAL; + else + part_elem->part_state= PART_IS_DROPPED; + } + } while (++i < no_parts); + VOID(sync_ddl_log()); + DBUG_RETURN(error); +} + + +/* + Rename partitions as part of ALTER TABLE of partitions + + SYNOPSIS + rename_partitions() + path Complete path of db and table name + + RETURN VALUE + TRUE Failure + FALSE Success + + DESCRIPTION + When reorganising partitions, adding hash partitions and coalescing + partitions it can be necessary to rename partitions while holding + an exclusive lock on the table. + Which partitions to rename is given by state of partitions found by the + partition info struct referenced from the handler object +*/ + +int ha_partition::rename_partitions(const char *path) +{ + List_iterator<partition_element> part_it(m_part_info->partitions); + List_iterator<partition_element> temp_it(m_part_info->temp_partitions); + char part_name_buff[FN_REFLEN]; + char norm_name_buff[FN_REFLEN]; + uint no_parts= m_part_info->partitions.elements; + uint part_count= 0; + uint no_subparts= m_part_info->no_subparts; + uint i= 0; + uint j= 0; + int error= 0; + int ret_error; + uint temp_partitions= m_part_info->temp_partitions.elements; + handler *file; + partition_element *part_elem, *sub_elem; + DBUG_ENTER("ha_partition::rename_partitions"); + + /* + Assert that it works without HA_FILE_BASED and lower_case_table_name = 2. + We use m_file[0] as long as all partitions have the same storage engine. + */ + DBUG_ASSERT(!strcmp(path, get_canonical_filename(m_file[0], path, + norm_name_buff))); + + if (temp_partitions) + { + /* + These are the reorganised partitions that have already been copied. + We delete the partitions and log the delete by inactivating the + delete log entry in the table log. We only need to synchronise + these writes before moving to the next loop since there is no + interaction among reorganised partitions, they cannot have the + same name. + */ + do + { + part_elem= temp_it++; + if (m_is_sub_partitioned) + { + List_iterator<partition_element> sub_it(part_elem->subpartitions); + do + { + sub_elem= sub_it++; + file= m_reorged_file[part_count++]; + create_subpartition_name(norm_name_buff, path, + part_elem->partition_name, + sub_elem->partition_name, + NORMAL_PART_NAME); + DBUG_PRINT("info", ("Delete subpartition %s", norm_name_buff)); + if ((ret_error= file->ha_delete_table(norm_name_buff))) + error= ret_error; + else if (deactivate_ddl_log_entry(sub_elem->log_entry->entry_pos)) + error= 1; + else + sub_elem->log_entry= NULL; /* Indicate success */ + } while (++j < no_subparts); + } + else + { + file= m_reorged_file[part_count++]; + create_partition_name(norm_name_buff, path, + part_elem->partition_name, NORMAL_PART_NAME, + TRUE); + DBUG_PRINT("info", ("Delete partition %s", norm_name_buff)); + if ((ret_error= file->ha_delete_table(norm_name_buff))) + error= ret_error; + else if (deactivate_ddl_log_entry(part_elem->log_entry->entry_pos)) + error= 1; + else + part_elem->log_entry= NULL; /* Indicate success */ + } + } while (++i < temp_partitions); + VOID(sync_ddl_log()); + } + i= 0; + do + { + /* + When state is PART_IS_CHANGED it means that we have created a new + TEMP partition that is to be renamed to normal partition name and + we are to delete the old partition with currently the normal name. + + We perform this operation by + 1) Delete old partition with normal partition name + 2) Signal this in table log entry + 3) Synch table log to ensure we have consistency in crashes + 4) Rename temporary partition name to normal partition name + 5) Signal this to table log entry + It is not necessary to synch the last state since a new rename + should not corrupt things if there was no temporary partition. + + The only other parts we need to cater for are new parts that + replace reorganised parts. The reorganised parts were deleted + by the code above that goes through the temp_partitions list. + Thus the synch above makes it safe to simply perform step 4 and 5 + for those entries. + */ + part_elem= part_it++; + if (part_elem->part_state == PART_IS_CHANGED || + part_elem->part_state == PART_TO_BE_DROPPED || + (part_elem->part_state == PART_IS_ADDED && temp_partitions)) + { + if (m_is_sub_partitioned) + { + List_iterator<partition_element> sub_it(part_elem->subpartitions); + uint part; + + j= 0; + do + { + sub_elem= sub_it++; + part= i * no_subparts + j; + create_subpartition_name(norm_name_buff, path, + part_elem->partition_name, + sub_elem->partition_name, + NORMAL_PART_NAME); + if (part_elem->part_state == PART_IS_CHANGED) + { + file= m_reorged_file[part_count++]; + DBUG_PRINT("info", ("Delete subpartition %s", norm_name_buff)); + if ((ret_error= file->ha_delete_table(norm_name_buff))) + error= ret_error; + else if (deactivate_ddl_log_entry(sub_elem->log_entry->entry_pos)) + error= 1; + VOID(sync_ddl_log()); + } + file= m_new_file[part]; + create_subpartition_name(part_name_buff, path, + part_elem->partition_name, + sub_elem->partition_name, + TEMP_PART_NAME); + DBUG_PRINT("info", ("Rename subpartition from %s to %s", + part_name_buff, norm_name_buff)); + if ((ret_error= file->ha_rename_table(part_name_buff, + norm_name_buff))) + error= ret_error; + else if (deactivate_ddl_log_entry(sub_elem->log_entry->entry_pos)) + error= 1; + else + sub_elem->log_entry= NULL; + } while (++j < no_subparts); + } + else + { + create_partition_name(norm_name_buff, path, + part_elem->partition_name, NORMAL_PART_NAME, + TRUE); + if (part_elem->part_state == PART_IS_CHANGED) + { + file= m_reorged_file[part_count++]; + DBUG_PRINT("info", ("Delete partition %s", norm_name_buff)); + if ((ret_error= file->ha_delete_table(norm_name_buff))) + error= ret_error; + else if (deactivate_ddl_log_entry(part_elem->log_entry->entry_pos)) + error= 1; + VOID(sync_ddl_log()); + } + file= m_new_file[i]; + create_partition_name(part_name_buff, path, + part_elem->partition_name, TEMP_PART_NAME, + TRUE); + DBUG_PRINT("info", ("Rename partition from %s to %s", + part_name_buff, norm_name_buff)); + if ((ret_error= file->ha_rename_table(part_name_buff, + norm_name_buff))) + error= ret_error; + else if (deactivate_ddl_log_entry(part_elem->log_entry->entry_pos)) + error= 1; + else + part_elem->log_entry= NULL; + } + } + } while (++i < no_parts); + VOID(sync_ddl_log()); + DBUG_RETURN(error); +} + + +#define OPTIMIZE_PARTS 1 +#define ANALYZE_PARTS 2 +#define CHECK_PARTS 3 +#define REPAIR_PARTS 4 + +static const char *opt_op_name[]= {NULL, + "optimize", "analyze", "check", "repair" }; + +/* + Optimize table + + SYNOPSIS + optimize() + thd Thread object + check_opt Check/analyze/repair/optimize options + + RETURN VALUES + >0 Error + 0 Success +*/ + +int ha_partition::optimize(THD *thd, HA_CHECK_OPT *check_opt) +{ + DBUG_ENTER("ha_partition::optimize"); + + DBUG_RETURN(handle_opt_partitions(thd, check_opt, + OPTIMIZE_PARTS, + thd->lex->alter_info.flags & + ALTER_OPTIMIZE_PARTITION ? FALSE : TRUE)); +} + + +/* + Analyze table + + SYNOPSIS + analyze() + thd Thread object + check_opt Check/analyze/repair/optimize options + + RETURN VALUES + >0 Error + 0 Success +*/ + +int ha_partition::analyze(THD *thd, HA_CHECK_OPT *check_opt) +{ + DBUG_ENTER("ha_partition::analyze"); + + DBUG_RETURN(handle_opt_partitions(thd, check_opt, + ANALYZE_PARTS, + thd->lex->alter_info.flags & + ALTER_ANALYZE_PARTITION ? FALSE : TRUE)); +} + + +/* + Check table + + SYNOPSIS + check() + thd Thread object + check_opt Check/analyze/repair/optimize options + + RETURN VALUES + >0 Error + 0 Success +*/ + +int ha_partition::check(THD *thd, HA_CHECK_OPT *check_opt) +{ + DBUG_ENTER("ha_partition::check"); + + DBUG_RETURN(handle_opt_partitions(thd, check_opt, + CHECK_PARTS, + thd->lex->alter_info.flags & + ALTER_CHECK_PARTITION ? FALSE : TRUE)); +} + + +/* + Repair table + + SYNOPSIS + repair() + thd Thread object + check_opt Check/analyze/repair/optimize options + + RETURN VALUES + >0 Error + 0 Success +*/ + +int ha_partition::repair(THD *thd, HA_CHECK_OPT *check_opt) +{ + DBUG_ENTER("ha_partition::repair"); + + DBUG_RETURN(handle_opt_partitions(thd, check_opt, + REPAIR_PARTS, + thd->lex->alter_info.flags & + ALTER_REPAIR_PARTITION ? FALSE : TRUE)); +} + +/* + Handle optimize/analyze/check/repair of one partition + + SYNOPSIS + handle_opt_part() + thd Thread object + check_opt Options + file Handler object of partition + flag Optimize/Analyze/Check/Repair flag + + RETURN VALUE + >0 Failure + 0 Success +*/ + +static int handle_opt_part(THD *thd, HA_CHECK_OPT *check_opt, + handler *file, uint flag) +{ + int error; + DBUG_ENTER("handle_opt_part"); + DBUG_PRINT("enter", ("flag = %u", flag)); + + if (flag == OPTIMIZE_PARTS) + error= file->ha_optimize(thd, check_opt); + else if (flag == ANALYZE_PARTS) + error= file->ha_analyze(thd, check_opt); + else if (flag == CHECK_PARTS) + error= file->ha_check(thd, check_opt); + else if (flag == REPAIR_PARTS) + error= file->ha_repair(thd, check_opt); + else + { + DBUG_ASSERT(FALSE); + error= 1; + } + if (error == HA_ADMIN_ALREADY_DONE) + error= 0; + DBUG_RETURN(error); +} + + +/* + print a message row formatted for ANALYZE/CHECK/OPTIMIZE/REPAIR TABLE + (modelled after mi_check_print_msg) + TODO: move this into the handler, or rewrite mysql_admin_table. +*/ +static bool print_admin_msg(THD* thd, const char* msg_type, + const char* db_name, const char* table_name, + const char* op_name, const char *fmt, ...) +{ + va_list args; + Protocol *protocol= thd->protocol; + uint length, msg_length; + char msgbuf[MI_MAX_MSG_BUF]; + char name[NAME_LEN*2+2]; + + va_start(args, fmt); + msg_length= my_vsnprintf(msgbuf, sizeof(msgbuf), fmt, args); + va_end(args); + msgbuf[sizeof(msgbuf) - 1] = 0; // healthy paranoia + + + if (!thd->vio_ok()) + { + sql_print_error(msgbuf); + return TRUE; + } + + length=(uint) (strxmov(name, db_name, ".", table_name,NullS) - name); + /* + TODO: switch from protocol to push_warning here. The main reason we didn't + it yet is parallel repair. Due to following trace: + mi_check_print_msg/push_warning/sql_alloc/my_pthread_getspecific_ptr. + + Also we likely need to lock mutex here (in both cases with protocol and + push_warning). + */ + DBUG_PRINT("info",("print_admin_msg: %s, %s, %s, %s", name, op_name, + msg_type, msgbuf)); + protocol->prepare_for_resend(); + protocol->store(name, length, system_charset_info); + protocol->store(op_name, system_charset_info); + protocol->store(msg_type, system_charset_info); + protocol->store(msgbuf, msg_length, system_charset_info); + if (protocol->write()) + { + sql_print_error("Failed on my_net_write, writing to stderr instead: %s\n", + msgbuf); + return TRUE; + } + return FALSE; +} + + +/* + Handle optimize/analyze/check/repair of partitions + + SYNOPSIS + handle_opt_partitions() + thd Thread object + check_opt Options + flag Optimize/Analyze/Check/Repair flag + all_parts All partitions or only a subset + + RETURN VALUE + >0 Failure + 0 Success +*/ + +int ha_partition::handle_opt_partitions(THD *thd, HA_CHECK_OPT *check_opt, + uint flag, bool all_parts) +{ + List_iterator<partition_element> part_it(m_part_info->partitions); + uint no_parts= m_part_info->no_parts; + uint no_subparts= m_part_info->no_subparts; + uint i= 0; + int error; + DBUG_ENTER("ha_partition::handle_opt_partitions"); + DBUG_PRINT("enter", ("all_parts %u, flag= %u", all_parts, flag)); + + do + { + partition_element *part_elem= part_it++; + /* + when ALTER TABLE <CMD> PARTITION ... + it should only do named partitions, otherwise all partitions + */ + if (all_parts || + part_elem->part_state == PART_CHANGED) + { + if (m_is_sub_partitioned) + { + List_iterator<partition_element> subpart_it(part_elem->subpartitions); + partition_element *sub_elem; + uint j= 0, part; + do + { + sub_elem= subpart_it++; + part= i * no_subparts + j; + DBUG_PRINT("info", ("Optimize subpartition %u (%s)", + part, sub_elem->partition_name)); +#ifdef NOT_USED + if (print_admin_msg(thd, "note", table_share->db.str, table->alias, + opt_op_name[flag], + "Start to operate on subpartition %s", + sub_elem->partition_name)) + DBUG_RETURN(HA_ADMIN_INTERNAL_ERROR); +#endif + if ((error= handle_opt_part(thd, check_opt, m_file[part], flag))) + { + /* print a line which partition the error belongs to */ + if (error != HA_ADMIN_NOT_IMPLEMENTED && + error != HA_ADMIN_ALREADY_DONE && + error != HA_ADMIN_TRY_ALTER) + { + print_admin_msg(thd, "error", table_share->db.str, table->alias, + opt_op_name[flag], + "Subpartition %s returned error", + sub_elem->partition_name); + } + DBUG_RETURN(error); + } + } while (++j < no_subparts); + } + else + { + DBUG_PRINT("info", ("Optimize partition %u (%s)", i, + part_elem->partition_name)); +#ifdef NOT_USED + if (print_admin_msg(thd, "note", table_share->db.str, table->alias, + opt_op_name[flag], + "Start to operate on partition %s", + part_elem->partition_name)) + DBUG_RETURN(HA_ADMIN_INTERNAL_ERROR); +#endif + if ((error= handle_opt_part(thd, check_opt, m_file[i], flag))) + { + /* print a line which partition the error belongs to */ + if (error != HA_ADMIN_NOT_IMPLEMENTED && + error != HA_ADMIN_ALREADY_DONE && + error != HA_ADMIN_TRY_ALTER) + { + print_admin_msg(thd, "error", table_share->db.str, table->alias, + opt_op_name[flag], "Partition %s returned error", + part_elem->partition_name); + } + DBUG_RETURN(error); + } + } + } + } while (++i < no_parts); + DBUG_RETURN(FALSE); +} + + +/** + @brief Check and repair the table if neccesary + + @param thd Thread object + + @retval TRUE Error/Not supported + @retval FALSE Success +*/ + +bool ha_partition::check_and_repair(THD *thd) +{ + handler **file= m_file; + DBUG_ENTER("ha_partition::check_and_repair"); + + do + { + if ((*file)->ha_check_and_repair(thd)) + DBUG_RETURN(TRUE); + } while (*(++file)); + DBUG_RETURN(FALSE); +} + + +/** + @breif Check if the table can be automatically repaired + + @retval TRUE Can be auto repaired + @retval FALSE Cannot be auto repaired +*/ + +bool ha_partition::auto_repair() const +{ + DBUG_ENTER("ha_partition::auto_repair"); + + /* + As long as we only support one storage engine per table, + we can use the first partition for this function. + */ + DBUG_RETURN(m_file[0]->auto_repair()); +} + + +/** + @breif Check if the table is crashed + + @retval TRUE Crashed + @retval FALSE Not crashed +*/ + +bool ha_partition::is_crashed() const +{ + handler **file= m_file; + DBUG_ENTER("ha_partition::is_crashed"); + + do + { + if ((*file)->is_crashed()) + DBUG_RETURN(TRUE); + } while (*(++file)); + DBUG_RETURN(FALSE); +} + + +/* + Prepare by creating a new partition + + SYNOPSIS + prepare_new_partition() + table Table object + create_info Create info from CREATE TABLE + file Handler object of new partition + part_name partition name + + RETURN VALUE + >0 Error + 0 Success +*/ + +int ha_partition::prepare_new_partition(TABLE *tbl, + HA_CREATE_INFO *create_info, + handler *file, const char *part_name, + partition_element *p_elem) +{ + int error; + bool create_flag= FALSE; + DBUG_ENTER("prepare_new_partition"); + + if ((error= set_up_table_before_create(tbl, part_name, create_info, + 0, p_elem))) + goto error; + if ((error= file->ha_create(part_name, tbl, create_info))) + goto error; + create_flag= TRUE; + if ((error= file->ha_open(tbl, part_name, m_mode, m_open_test_lock))) + goto error; + /* + Note: if you plan to add another call that may return failure, + better to do it before external_lock() as cleanup_new_partition() + assumes that external_lock() is last call that may fail here. + Otherwise see description for cleanup_new_partition(). + */ + if ((error= file->ha_external_lock(current_thd, m_lock_type))) + goto error; + + DBUG_RETURN(0); +error: + if (create_flag) + VOID(file->ha_delete_table(part_name)); + DBUG_RETURN(error); +} + + +/* + Cleanup by removing all created partitions after error + + SYNOPSIS + cleanup_new_partition() + part_count Number of partitions to remove + + RETURN VALUE + NONE + + DESCRIPTION + This function is called immediately after prepare_new_partition() in + case the latter fails. + + In prepare_new_partition() last call that may return failure is + external_lock(). That means if prepare_new_partition() fails, + partition does not have external lock. Thus no need to call + external_lock(F_UNLCK) here. + + TODO: + We must ensure that in the case that we get an error during the process + that we call external_lock with F_UNLCK, close the table and delete the + table in the case where we have been successful with prepare_handler. + We solve this by keeping an array of successful calls to prepare_handler + which can then be used to undo the call. +*/ + +void ha_partition::cleanup_new_partition(uint part_count) +{ + handler **save_m_file= m_file; + DBUG_ENTER("ha_partition::cleanup_new_partition"); + + if (m_added_file && m_added_file[0]) + { + m_file= m_added_file; + m_added_file= NULL; + + /* delete_table also needed, a bit more complex */ + close(); + + m_added_file= m_file; + m_file= save_m_file; + } + DBUG_VOID_RETURN; +} + +/* + Implement the partition changes defined by ALTER TABLE of partitions + + SYNOPSIS + change_partitions() + create_info HA_CREATE_INFO object describing all + fields and indexes in table + path Complete path of db and table name + out: copied Output parameter where number of copied + records are added + out: deleted Output parameter where number of deleted + records are added + pack_frm_data Reference to packed frm file + pack_frm_len Length of packed frm file + + RETURN VALUE + >0 Failure + 0 Success + + DESCRIPTION + Add and copy if needed a number of partitions, during this operation + no other operation is ongoing in the server. This is used by + ADD PARTITION all types as well as by REORGANIZE PARTITION. For + one-phased implementations it is used also by DROP and COALESCE + PARTITIONs. + One-phased implementation needs the new frm file, other handlers will + get zero length and a NULL reference here. +*/ + +int ha_partition::change_partitions(HA_CREATE_INFO *create_info, + const char *path, + ulonglong *copied, + ulonglong *deleted, + const uchar *pack_frm_data + __attribute__((unused)), + size_t pack_frm_len + __attribute__((unused))) +{ + List_iterator<partition_element> part_it(m_part_info->partitions); + List_iterator <partition_element> t_it(m_part_info->temp_partitions); + char part_name_buff[FN_REFLEN]; + uint no_parts= m_part_info->partitions.elements; + uint no_subparts= m_part_info->no_subparts; + uint i= 0; + uint no_remain_partitions, part_count, orig_count; + handler **new_file_array; + int error= 1; + bool first; + uint temp_partitions= m_part_info->temp_partitions.elements; + THD *thd= current_thd; + DBUG_ENTER("ha_partition::change_partitions"); + + /* + Assert that it works without HA_FILE_BASED and lower_case_table_name = 2. + We use m_file[0] as long as all partitions have the same storage engine. + */ + DBUG_ASSERT(!strcmp(path, get_canonical_filename(m_file[0], path, + part_name_buff))); + m_reorged_parts= 0; + if (!m_part_info->is_sub_partitioned()) + no_subparts= 1; + + /* + Step 1: + Calculate number of reorganised partitions and allocate space for + their handler references. + */ + if (temp_partitions) + { + m_reorged_parts= temp_partitions * no_subparts; + } + else + { + do + { + partition_element *part_elem= part_it++; + if (part_elem->part_state == PART_CHANGED || + part_elem->part_state == PART_REORGED_DROPPED) + { + m_reorged_parts+= no_subparts; + } + } while (++i < no_parts); + } + if (m_reorged_parts && + !(m_reorged_file= (handler**)sql_calloc(sizeof(handler*)* + (m_reorged_parts + 1)))) + { + mem_alloc_error(sizeof(handler*)*(m_reorged_parts+1)); + DBUG_RETURN(ER_OUTOFMEMORY); + } + + /* + Step 2: + Calculate number of partitions after change and allocate space for + their handler references. + */ + no_remain_partitions= 0; + if (temp_partitions) + { + no_remain_partitions= no_parts * no_subparts; + } + else + { + part_it.rewind(); + i= 0; + do + { + partition_element *part_elem= part_it++; + if (part_elem->part_state == PART_NORMAL || + part_elem->part_state == PART_TO_BE_ADDED || + part_elem->part_state == PART_CHANGED) + { + no_remain_partitions+= no_subparts; + } + } while (++i < no_parts); + } + if (!(new_file_array= (handler**)sql_calloc(sizeof(handler*)* + (2*(no_remain_partitions + 1))))) + { + mem_alloc_error(sizeof(handler*)*2*(no_remain_partitions+1)); + DBUG_RETURN(ER_OUTOFMEMORY); + } + m_added_file= &new_file_array[no_remain_partitions + 1]; + + /* + Step 3: + Fill m_reorged_file with handler references and NULL at the end + */ + if (m_reorged_parts) + { + i= 0; + part_count= 0; + first= TRUE; + part_it.rewind(); + do + { + partition_element *part_elem= part_it++; + if (part_elem->part_state == PART_CHANGED || + part_elem->part_state == PART_REORGED_DROPPED) + { + memcpy((void*)&m_reorged_file[part_count], + (void*)&m_file[i*no_subparts], + sizeof(handler*)*no_subparts); + part_count+= no_subparts; + } + else if (first && temp_partitions && + part_elem->part_state == PART_TO_BE_ADDED) + { + /* + When doing an ALTER TABLE REORGANIZE PARTITION a number of + partitions is to be reorganised into a set of new partitions. + The reorganised partitions are in this case in the temp_partitions + list. We copy all of them in one batch and thus we only do this + until we find the first partition with state PART_TO_BE_ADDED + since this is where the new partitions go in and where the old + ones used to be. + */ + first= FALSE; + DBUG_ASSERT(((i*no_subparts) + m_reorged_parts) <= m_file_tot_parts); + memcpy((void*)m_reorged_file, &m_file[i*no_subparts], + sizeof(handler*)*m_reorged_parts); + } + } while (++i < no_parts); + } + + /* + Step 4: + Fill new_array_file with handler references. Create the handlers if + needed. + */ + i= 0; + part_count= 0; + orig_count= 0; + first= TRUE; + part_it.rewind(); + do + { + partition_element *part_elem= part_it++; + if (part_elem->part_state == PART_NORMAL) + { + DBUG_ASSERT(orig_count + no_subparts <= m_file_tot_parts); + memcpy((void*)&new_file_array[part_count], (void*)&m_file[orig_count], + sizeof(handler*)*no_subparts); + part_count+= no_subparts; + orig_count+= no_subparts; + } + else if (part_elem->part_state == PART_CHANGED || + part_elem->part_state == PART_TO_BE_ADDED) + { + uint j= 0; + do + { + if (!(new_file_array[part_count++]= + get_new_handler(table->s, + thd->mem_root, + part_elem->engine_type))) + { + mem_alloc_error(sizeof(handler)); + DBUG_RETURN(ER_OUTOFMEMORY); + } + } while (++j < no_subparts); + if (part_elem->part_state == PART_CHANGED) + orig_count+= no_subparts; + else if (temp_partitions && first) + { + orig_count+= (no_subparts * temp_partitions); + first= FALSE; + } + } + } while (++i < no_parts); + first= FALSE; + /* + Step 5: + Create the new partitions and also open, lock and call external_lock + on them to prepare them for copy phase and also for later close + calls + */ + i= 0; + part_count= 0; + part_it.rewind(); + do + { + partition_element *part_elem= part_it++; + if (part_elem->part_state == PART_TO_BE_ADDED || + part_elem->part_state == PART_CHANGED) + { + /* + A new partition needs to be created PART_TO_BE_ADDED means an + entirely new partition and PART_CHANGED means a changed partition + that will still exist with either more or less data in it. + */ + uint name_variant= NORMAL_PART_NAME; + if (part_elem->part_state == PART_CHANGED || + (part_elem->part_state == PART_TO_BE_ADDED && temp_partitions)) + name_variant= TEMP_PART_NAME; + if (m_part_info->is_sub_partitioned()) + { + List_iterator<partition_element> sub_it(part_elem->subpartitions); + uint j= 0, part; + do + { + partition_element *sub_elem= sub_it++; + create_subpartition_name(part_name_buff, path, + part_elem->partition_name, + sub_elem->partition_name, + name_variant); + part= i * no_subparts + j; + DBUG_PRINT("info", ("Add subpartition %s", part_name_buff)); + if ((error= prepare_new_partition(table, create_info, + new_file_array[part], + (const char *)part_name_buff, + sub_elem))) + { + cleanup_new_partition(part_count); + DBUG_RETURN(error); + } + m_added_file[part_count++]= new_file_array[part]; + } while (++j < no_subparts); + } + else + { + create_partition_name(part_name_buff, path, + part_elem->partition_name, name_variant, + TRUE); + DBUG_PRINT("info", ("Add partition %s", part_name_buff)); + if ((error= prepare_new_partition(table, create_info, + new_file_array[i], + (const char *)part_name_buff, + part_elem))) + { + cleanup_new_partition(part_count); + DBUG_RETURN(error); + } + m_added_file[part_count++]= new_file_array[i]; + } + } + } while (++i < no_parts); + + /* + Step 6: + State update to prepare for next write of the frm file. + */ + i= 0; + part_it.rewind(); + do + { + partition_element *part_elem= part_it++; + if (part_elem->part_state == PART_TO_BE_ADDED) + part_elem->part_state= PART_IS_ADDED; + else if (part_elem->part_state == PART_CHANGED) + part_elem->part_state= PART_IS_CHANGED; + else if (part_elem->part_state == PART_REORGED_DROPPED) + part_elem->part_state= PART_TO_BE_DROPPED; + } while (++i < no_parts); + for (i= 0; i < temp_partitions; i++) + { + partition_element *part_elem= t_it++; + DBUG_ASSERT(part_elem->part_state == PART_TO_BE_REORGED); + part_elem->part_state= PART_TO_BE_DROPPED; + } + m_new_file= new_file_array; + DBUG_RETURN(copy_partitions(copied, deleted)); +} + + +/* + Copy partitions as part of ALTER TABLE of partitions + + SYNOPSIS + copy_partitions() + out:copied Number of records copied + out:deleted Number of records deleted + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + change_partitions has done all the preparations, now it is time to + actually copy the data from the reorganised partitions to the new + partitions. +*/ + +int ha_partition::copy_partitions(ulonglong *copied, ulonglong *deleted) +{ + uint reorg_part= 0; + int result= 0; + longlong func_value; + DBUG_ENTER("ha_partition::copy_partitions"); + + if (m_part_info->linear_hash_ind) + { + if (m_part_info->part_type == HASH_PARTITION) + set_linear_hash_mask(m_part_info, m_part_info->no_parts); + else + set_linear_hash_mask(m_part_info, m_part_info->no_subparts); + } + + while (reorg_part < m_reorged_parts) + { + handler *file= m_reorged_file[reorg_part]; + uint32 new_part; + + late_extra_cache(reorg_part); + if ((result= file->ha_rnd_init(1))) + goto error; + while (TRUE) + { + if ((result= file->rnd_next(m_rec0))) + { + if (result == HA_ERR_RECORD_DELETED) + continue; //Probably MyISAM + if (result != HA_ERR_END_OF_FILE) + goto error; + /* + End-of-file reached, break out to continue with next partition or + end the copy process. + */ + break; + } + /* Found record to insert into new handler */ + if (m_part_info->get_partition_id(m_part_info, &new_part, + &func_value)) + { + /* + This record is in the original table but will not be in the new + table since it doesn't fit into any partition any longer due to + changed partitioning ranges or list values. + */ + deleted++; + } + else + { + THD *thd= ha_thd(); + /* Copy record to new handler */ + copied++; + tmp_disable_binlog(thd); /* Do not replicate the low-level changes. */ + result= m_new_file[new_part]->ha_write_row(m_rec0); + reenable_binlog(thd); + if (result) + goto error; + } + } + late_extra_no_cache(reorg_part); + file->ha_rnd_end(); + reorg_part++; + } + DBUG_RETURN(FALSE); +error: + DBUG_RETURN(result); +} + + +/* + Update create info as part of ALTER TABLE + + SYNOPSIS + update_create_info() + create_info Create info from ALTER TABLE + + RETURN VALUE + NONE + + DESCRIPTION + Method empty so far +*/ + +void ha_partition::update_create_info(HA_CREATE_INFO *create_info) +{ + info(HA_STATUS_AUTO); + + if (!(create_info->used_fields & HA_CREATE_USED_AUTO)) + create_info->auto_increment_value= stats.auto_increment_value; + + create_info->data_file_name= create_info->index_file_name = NULL; + return; +} + + +void ha_partition::change_table_ptr(TABLE *table_arg, TABLE_SHARE *share) +{ + handler **file_array= m_file; + table= table_arg; + table_share= share; + do + { + (*file_array)->change_table_ptr(table_arg, share); + } while (*(++file_array)); + if (m_added_file && m_added_file[0]) + { + /* if in middle of a drop/rename etc */ + file_array= m_added_file; + do + { + (*file_array)->change_table_ptr(table_arg, share); + } while (*(++file_array)); + } +} + +/* + Change comments specific to handler + + SYNOPSIS + update_table_comment() + comment Original comment + + RETURN VALUE + new comment + + DESCRIPTION + No comment changes so far +*/ + +char *ha_partition::update_table_comment(const char *comment) +{ + return (char*) comment; /* Nothing to change */ +} + + + +/* + Handle delete, rename and create table + + SYNOPSIS + del_ren_cre_table() + from Full path of old table + to Full path of new table + table_arg Table object + create_info Create info + + RETURN VALUE + >0 Error + 0 Success + + DESCRIPTION + Common routine to handle delete_table and rename_table. + The routine uses the partition handler file to get the + names of the partition instances. Both these routines + are called after creating the handler without table + object and thus the file is needed to discover the + names of the partitions and the underlying storage engines. +*/ + +uint ha_partition::del_ren_cre_table(const char *from, + const char *to, + TABLE *table_arg, + HA_CREATE_INFO *create_info) +{ + int save_error= 0; + int error; + char from_buff[FN_REFLEN], to_buff[FN_REFLEN], from_lc_buff[FN_REFLEN], + to_lc_buff[FN_REFLEN]; + char *name_buffer_ptr; + const char *from_path; + const char *to_path= NULL; + uint i; + handler **file, **abort_file; + DBUG_ENTER("del_ren_cre_table()"); + + if (get_from_handler_file(from, current_thd->mem_root)) + DBUG_RETURN(TRUE); + DBUG_ASSERT(m_file_buffer); + DBUG_PRINT("enter", ("from: (%s) to: (%s)", from, to)); + name_buffer_ptr= m_name_buffer_ptr; + file= m_file; + /* + Since ha_partition has HA_FILE_BASED, it must alter underlying table names + if they do not have HA_FILE_BASED and lower_case_table_names == 2. + See Bug#37402, for Mac OS X. + The appended #P#<partname>[#SP#<subpartname>] will remain in current case. + Using the first partitions handler, since mixing handlers is not allowed. + */ + from_path= get_canonical_filename(*file, from, from_lc_buff); + if (to != NULL) + to_path= get_canonical_filename(*file, to, to_lc_buff); + i= 0; + do + { + create_partition_name(from_buff, from_path, name_buffer_ptr, + NORMAL_PART_NAME, FALSE); + + if (to != NULL) + { // Rename branch + create_partition_name(to_buff, to_path, name_buffer_ptr, + NORMAL_PART_NAME, FALSE); + error= (*file)->ha_rename_table(from_buff, to_buff); + } + else if (table_arg == NULL) // delete branch + error= (*file)->ha_delete_table(from_buff); + else + { + if ((error= set_up_table_before_create(table_arg, from_buff, + create_info, i, NULL)) || + ((error= (*file)->ha_create(from_buff, table_arg, create_info)))) + goto create_error; + } + name_buffer_ptr= strend(name_buffer_ptr) + 1; + if (error) + save_error= error; + i++; + } while (*(++file)); + DBUG_RETURN(save_error); +create_error: + name_buffer_ptr= m_name_buffer_ptr; + for (abort_file= file, file= m_file; file < abort_file; file++) + { + create_partition_name(from_buff, from_path, name_buffer_ptr, NORMAL_PART_NAME, + FALSE); + VOID((*file)->ha_delete_table((const char*) from_buff)); + name_buffer_ptr= strend(name_buffer_ptr) + 1; + } + DBUG_RETURN(error); +} + +/* + Find partition based on partition id + + SYNOPSIS + find_partition_element() + part_id Partition id of partition looked for + + RETURN VALUE + >0 Reference to partition_element + 0 Partition not found +*/ + +partition_element *ha_partition::find_partition_element(uint part_id) +{ + uint i; + uint curr_part_id= 0; + List_iterator_fast <partition_element> part_it(m_part_info->partitions); + + for (i= 0; i < m_part_info->no_parts; i++) + { + partition_element *part_elem; + part_elem= part_it++; + if (m_is_sub_partitioned) + { + uint j; + List_iterator_fast <partition_element> sub_it(part_elem->subpartitions); + for (j= 0; j < m_part_info->no_subparts; j++) + { + part_elem= sub_it++; + if (part_id == curr_part_id++) + return part_elem; + } + } + else if (part_id == curr_part_id++) + return part_elem; + } + DBUG_ASSERT(0); + my_error(ER_OUT_OF_RESOURCES, MYF(0)); + current_thd->fatal_error(); // Abort + return NULL; +} + + +/* + Set up table share object before calling create on underlying handler + + SYNOPSIS + set_up_table_before_create() + table Table object + info Create info + part_id Partition id of partition to set-up + + RETURN VALUE + TRUE Error + FALSE Success + + DESCRIPTION + Set up + 1) Comment on partition + 2) MAX_ROWS, MIN_ROWS on partition + 3) Index file name on partition + 4) Data file name on partition +*/ + +int ha_partition::set_up_table_before_create(TABLE *tbl, + const char *partition_name_with_path, + HA_CREATE_INFO *info, + uint part_id, + partition_element *part_elem) +{ + int error= 0; + const char *partition_name; + THD *thd= current_thd; + DBUG_ENTER("set_up_table_before_create"); + + if (!part_elem) + { + part_elem= find_partition_element(part_id); + if (!part_elem) + DBUG_RETURN(1); // Fatal error + } + tbl->s->max_rows= part_elem->part_max_rows; + tbl->s->min_rows= part_elem->part_min_rows; + partition_name= strrchr(partition_name_with_path, FN_LIBCHAR); + if ((part_elem->index_file_name && + (error= append_file_to_dir(thd, + (const char**)&part_elem->index_file_name, + partition_name+1))) || + (part_elem->data_file_name && + (error= append_file_to_dir(thd, + (const char**)&part_elem->data_file_name, + partition_name+1)))) + { + DBUG_RETURN(error); + } + info->index_file_name= part_elem->index_file_name; + info->data_file_name= part_elem->data_file_name; + DBUG_RETURN(0); +} + + +/* + Add two names together + + SYNOPSIS + name_add() + out:dest Destination string + first_name First name + sec_name Second name + + RETURN VALUE + >0 Error + 0 Success + + DESCRIPTION + Routine used to add two names with '_' in between then. Service routine + to create_handler_file + Include the NULL in the count of characters since it is needed as separator + between the partition names. +*/ + +static uint name_add(char *dest, const char *first_name, const char *sec_name) +{ + return (uint) (strxmov(dest, first_name, "#SP#", sec_name, NullS) -dest) + 1; +} + + +/* + Create the special .par file + + SYNOPSIS + create_handler_file() + name Full path of table name + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + Method used to create handler file with names of partitions, their + engine types and the number of partitions. +*/ + +bool ha_partition::create_handler_file(const char *name) +{ + partition_element *part_elem, *subpart_elem; + uint i, j, part_name_len, subpart_name_len; + uint tot_partition_words, tot_name_len, no_parts; + uint tot_parts= 0; + uint tot_len_words, tot_len_byte, chksum, tot_name_words; + char *name_buffer_ptr; + uchar *file_buffer, *engine_array; + bool result= TRUE; + char file_name[FN_REFLEN]; + char part_name[FN_REFLEN]; + char subpart_name[FN_REFLEN]; + File file; + List_iterator_fast <partition_element> part_it(m_part_info->partitions); + DBUG_ENTER("create_handler_file"); + + no_parts= m_part_info->partitions.elements; + DBUG_PRINT("info", ("table name = %s, no_parts = %u", name, + no_parts)); + tot_name_len= 0; + for (i= 0; i < no_parts; i++) + { + part_elem= part_it++; + if (part_elem->part_state != PART_NORMAL && + part_elem->part_state != PART_TO_BE_ADDED && + part_elem->part_state != PART_CHANGED) + continue; + tablename_to_filename(part_elem->partition_name, part_name, + FN_REFLEN); + part_name_len= strlen(part_name); + if (!m_is_sub_partitioned) + { + tot_name_len+= part_name_len + 1; + tot_parts++; + } + else + { + List_iterator_fast <partition_element> sub_it(part_elem->subpartitions); + for (j= 0; j < m_part_info->no_subparts; j++) + { + subpart_elem= sub_it++; + tablename_to_filename(subpart_elem->partition_name, + subpart_name, + FN_REFLEN); + subpart_name_len= strlen(subpart_name); + tot_name_len+= part_name_len + subpart_name_len + 5; + tot_parts++; + } + } + } + /* + File format: + Length in words 4 byte + Checksum 4 byte + Total number of partitions 4 byte + Array of engine types n * 4 bytes where + n = (m_tot_parts + 3)/4 + Length of name part in bytes 4 bytes + Name part m * 4 bytes where + m = ((length_name_part + 3)/4)*4 + + All padding bytes are zeroed + */ + tot_partition_words= (tot_parts + 3) / 4; + tot_name_words= (tot_name_len + 3) / 4; + tot_len_words= 4 + tot_partition_words + tot_name_words; + tot_len_byte= 4 * tot_len_words; + if (!(file_buffer= (uchar *) my_malloc(tot_len_byte, MYF(MY_ZEROFILL)))) + DBUG_RETURN(TRUE); + engine_array= (file_buffer + 12); + name_buffer_ptr= (char*) (file_buffer + ((4 + tot_partition_words) * 4)); + part_it.rewind(); + for (i= 0; i < no_parts; i++) + { + part_elem= part_it++; + if (part_elem->part_state != PART_NORMAL && + part_elem->part_state != PART_TO_BE_ADDED && + part_elem->part_state != PART_CHANGED) + continue; + if (!m_is_sub_partitioned) + { + tablename_to_filename(part_elem->partition_name, part_name, FN_REFLEN); + name_buffer_ptr= strmov(name_buffer_ptr, part_name)+1; + *engine_array= (uchar) ha_legacy_type(part_elem->engine_type); + DBUG_PRINT("info", ("engine: %u", *engine_array)); + engine_array++; + } + else + { + List_iterator_fast <partition_element> sub_it(part_elem->subpartitions); + for (j= 0; j < m_part_info->no_subparts; j++) + { + subpart_elem= sub_it++; + tablename_to_filename(part_elem->partition_name, part_name, + FN_REFLEN); + tablename_to_filename(subpart_elem->partition_name, subpart_name, + FN_REFLEN); + name_buffer_ptr+= name_add(name_buffer_ptr, + part_name, + subpart_name); + *engine_array= (uchar) ha_legacy_type(subpart_elem->engine_type); + DBUG_PRINT("info", ("engine: %u", *engine_array)); + engine_array++; + } + } + } + chksum= 0; + int4store(file_buffer, tot_len_words); + int4store(file_buffer + 8, tot_parts); + int4store(file_buffer + 12 + (tot_partition_words * 4), tot_name_len); + for (i= 0; i < tot_len_words; i++) + chksum^= uint4korr(file_buffer + 4 * i); + int4store(file_buffer + 4, chksum); + /* + Remove .frm extension and replace with .par + Create and write and close file + to be used at open, delete_table and rename_table + */ + fn_format(file_name, name, "", ha_par_ext, MY_APPEND_EXT); + if ((file= my_create(file_name, CREATE_MODE, O_RDWR | O_TRUNC, + MYF(MY_WME))) >= 0) + { + result= my_write(file, (uchar *) file_buffer, tot_len_byte, + MYF(MY_WME | MY_NABP)) != 0; + VOID(my_close(file, MYF(0))); + } + else + result= TRUE; + my_free((char*) file_buffer, MYF(0)); + DBUG_RETURN(result); +} + +/* + Clear handler variables and free some memory + + SYNOPSIS + clear_handler_file() + + RETURN VALUE + NONE +*/ + +void ha_partition::clear_handler_file() +{ + if (m_engine_array) + plugin_unlock_list(NULL, m_engine_array, m_tot_parts); + my_free((char*) m_file_buffer, MYF(MY_ALLOW_ZERO_PTR)); + my_free((char*) m_engine_array, MYF(MY_ALLOW_ZERO_PTR)); + m_file_buffer= NULL; + m_engine_array= NULL; +} + +/* + Create underlying handler objects + + SYNOPSIS + create_handlers() + mem_root Allocate memory through this + + RETURN VALUE + TRUE Error + FALSE Success +*/ + +bool ha_partition::create_handlers(MEM_ROOT *mem_root) +{ + uint i; + uint alloc_len= (m_tot_parts + 1) * sizeof(handler*); + handlerton *hton0; + DBUG_ENTER("create_handlers"); + + if (!(m_file= (handler **) alloc_root(mem_root, alloc_len))) + DBUG_RETURN(TRUE); + m_file_tot_parts= m_tot_parts; + bzero((char*) m_file, alloc_len); + for (i= 0; i < m_tot_parts; i++) + { + handlerton *hton= plugin_data(m_engine_array[i], handlerton*); + if (!(m_file[i]= get_new_handler(table_share, mem_root, + hton))) + DBUG_RETURN(TRUE); + DBUG_PRINT("info", ("engine_type: %u", hton->db_type)); + } + /* For the moment we only support partition over the same table engine */ + hton0= plugin_data(m_engine_array[0], handlerton*); + if (hton0 == myisam_hton) + { + DBUG_PRINT("info", ("MyISAM")); + m_myisam= TRUE; + } + /* INNODB may not be compiled in... */ + else if (ha_legacy_type(hton0) == DB_TYPE_INNODB) + { + DBUG_PRINT("info", ("InnoDB")); + m_innodb= TRUE; + } + DBUG_RETURN(FALSE); +} + +/* + Create underlying handler objects from partition info + + SYNOPSIS + new_handlers_from_part_info() + mem_root Allocate memory through this + + RETURN VALUE + TRUE Error + FALSE Success +*/ + +bool ha_partition::new_handlers_from_part_info(MEM_ROOT *mem_root) +{ + uint i, j, part_count; + partition_element *part_elem; + uint alloc_len= (m_tot_parts + 1) * sizeof(handler*); + List_iterator_fast <partition_element> part_it(m_part_info->partitions); + DBUG_ENTER("ha_partition::new_handlers_from_part_info"); + + if (!(m_file= (handler **) alloc_root(mem_root, alloc_len))) + { + mem_alloc_error(alloc_len); + goto error_end; + } + m_file_tot_parts= m_tot_parts; + bzero((char*) m_file, alloc_len); + DBUG_ASSERT(m_part_info->no_parts > 0); + + i= 0; + part_count= 0; + /* + Don't know the size of the underlying storage engine, invent a number of + bytes allocated for error message if allocation fails + */ + do + { + part_elem= part_it++; + if (m_is_sub_partitioned) + { + for (j= 0; j < m_part_info->no_subparts; j++) + { + if (!(m_file[part_count++]= get_new_handler(table_share, mem_root, + part_elem->engine_type))) + goto error; + DBUG_PRINT("info", ("engine_type: %u", + (uint) ha_legacy_type(part_elem->engine_type))); + } + } + else + { + if (!(m_file[part_count++]= get_new_handler(table_share, mem_root, + part_elem->engine_type))) + goto error; + DBUG_PRINT("info", ("engine_type: %u", + (uint) ha_legacy_type(part_elem->engine_type))); + } + } while (++i < m_part_info->no_parts); + if (part_elem->engine_type == myisam_hton) + { + DBUG_PRINT("info", ("MyISAM")); + m_myisam= TRUE; + } + DBUG_RETURN(FALSE); +error: + mem_alloc_error(sizeof(handler)); +error_end: + DBUG_RETURN(TRUE); +} + + +/* + Get info about partition engines and their names from the .par file + + SYNOPSIS + get_from_handler_file() + name Full path of table name + mem_root Allocate memory through this + + RETURN VALUE + TRUE Error + FALSE Success + + DESCRIPTION + Open handler file to get partition names, engine types and number of + partitions. +*/ + +bool ha_partition::get_from_handler_file(const char *name, MEM_ROOT *mem_root) +{ + char buff[FN_REFLEN], *address_tot_name_len; + File file; + char *file_buffer, *name_buffer_ptr; + handlerton **engine_array; + uint i, len_bytes, len_words, tot_partition_words, tot_name_words, chksum; + DBUG_ENTER("ha_partition::get_from_handler_file"); + DBUG_PRINT("enter", ("table name: '%s'", name)); + + if (m_file_buffer) + DBUG_RETURN(FALSE); + fn_format(buff, name, "", ha_par_ext, MY_APPEND_EXT); + + /* Following could be done with my_stat to read in whole file */ + if ((file= my_open(buff, O_RDONLY | O_SHARE, MYF(0))) < 0) + DBUG_RETURN(TRUE); + if (my_read(file, (uchar *) & buff[0], 8, MYF(MY_NABP))) + goto err1; + len_words= uint4korr(buff); + len_bytes= 4 * len_words; + if (!(file_buffer= (char*) my_malloc(len_bytes, MYF(0)))) + goto err1; + VOID(my_seek(file, 0, MY_SEEK_SET, MYF(0))); + if (my_read(file, (uchar *) file_buffer, len_bytes, MYF(MY_NABP))) + goto err2; + + chksum= 0; + for (i= 0; i < len_words; i++) + chksum ^= uint4korr((file_buffer) + 4 * i); + if (chksum) + goto err2; + m_tot_parts= uint4korr((file_buffer) + 8); + DBUG_PRINT("info", ("No of parts = %u", m_tot_parts)); + tot_partition_words= (m_tot_parts + 3) / 4; + engine_array= (handlerton **) my_alloca(m_tot_parts * sizeof(handlerton*)); + for (i= 0; i < m_tot_parts; i++) + engine_array[i]= ha_resolve_by_legacy_type(current_thd, + (enum legacy_db_type) + *(uchar *) ((file_buffer) + 12 + i)); + address_tot_name_len= file_buffer + 12 + 4 * tot_partition_words; + tot_name_words= (uint4korr(address_tot_name_len) + 3) / 4; + if (len_words != (tot_partition_words + tot_name_words + 4)) + goto err3; + name_buffer_ptr= file_buffer + 16 + 4 * tot_partition_words; + VOID(my_close(file, MYF(0))); + m_file_buffer= file_buffer; // Will be freed in clear_handler_file() + m_name_buffer_ptr= name_buffer_ptr; + + if (!(m_engine_array= (plugin_ref*) + my_malloc(m_tot_parts * sizeof(plugin_ref), MYF(MY_WME)))) + goto err3; + + for (i= 0; i < m_tot_parts; i++) + m_engine_array[i]= ha_lock_engine(NULL, engine_array[i]); + + my_afree((gptr) engine_array); + + if (!m_file && create_handlers(mem_root)) + { + clear_handler_file(); + DBUG_RETURN(TRUE); + } + DBUG_RETURN(FALSE); + +err3: + my_afree((gptr) engine_array); +err2: + my_free(file_buffer, MYF(0)); +err1: + VOID(my_close(file, MYF(0))); + DBUG_RETURN(TRUE); +} + + +/**************************************************************************** + MODULE open/close object +****************************************************************************/ +/* + Open handler object + + SYNOPSIS + open() + name Full path of table name + mode Open mode flags + test_if_locked ? + + RETURN VALUE + >0 Error + 0 Success + + DESCRIPTION + Used for opening tables. The name will be the name of the file. + A table is opened when it needs to be opened. For instance + when a request comes in for a select on the table (tables are not + open and closed for each request, they are cached). + + Called from handler.cc by handler::ha_open(). The server opens all tables + by calling ha_open() which then calls the handler specific open(). +*/ + +int ha_partition::open(const char *name, int mode, uint test_if_locked) +{ + char *name_buffer_ptr= m_name_buffer_ptr; + int error; + uint alloc_len; + handler **file; + char name_buff[FN_REFLEN]; + DBUG_ENTER("ha_partition::open"); + + ref_length= 0; + m_mode= mode; + m_open_test_lock= test_if_locked; + m_part_field_array= m_part_info->full_part_field_array; + if (get_from_handler_file(name, &table->mem_root)) + DBUG_RETURN(1); + m_start_key.length= 0; + m_rec0= table->record[0]; + m_rec_length= table->s->reclength; + alloc_len= m_tot_parts * (m_rec_length + PARTITION_BYTES_IN_POS); + alloc_len+= table->s->max_key_length; + if (!m_ordered_rec_buffer) + { + if (!(m_ordered_rec_buffer= (uchar*)my_malloc(alloc_len, MYF(MY_WME)))) + { + DBUG_RETURN(1); + } + { + /* + We set-up one record per partition and each record has 2 bytes in + front where the partition id is written. This is used by ordered + index_read. + We also set-up a reference to the first record for temporary use in + setting up the scan. + */ + char *ptr= (char*)m_ordered_rec_buffer; + uint i= 0; + do + { + int2store(ptr, i); + ptr+= m_rec_length + PARTITION_BYTES_IN_POS; + } while (++i < m_tot_parts); + m_start_key.key= (const uchar*)ptr; + } + } + + /* Initialise the bitmap we use to determine what partitions are used */ + if (!is_clone) + { + if (bitmap_init(&(m_part_info->used_partitions), NULL, m_tot_parts, TRUE)) + DBUG_RETURN(1); + bitmap_set_all(&(m_part_info->used_partitions)); + } + + /* Recalculate table flags as they may change after open */ + m_table_flags= m_file[0]->ha_table_flags(); + file= m_file; + do + { + create_partition_name(name_buff, name, name_buffer_ptr, NORMAL_PART_NAME, + FALSE); + if ((error= (*file)->ha_open(table, (const char*) name_buff, mode, + test_if_locked))) + goto err_handler; + m_no_locks+= (*file)->lock_count(); + name_buffer_ptr+= strlen(name_buffer_ptr) + 1; + set_if_bigger(ref_length, ((*file)->ref_length)); + m_table_flags&= (*file)->ha_table_flags(); + } while (*(++file)); + m_table_flags&= ~(HA_CAN_GEOMETRY | HA_CAN_FULLTEXT | HA_DUPLICATE_POS | + HA_CAN_SQL_HANDLER | HA_CAN_INSERT_DELAYED); + m_table_flags|= HA_FILE_BASED | HA_REC_NOT_IN_SEQ; + key_used_on_scan= m_file[0]->key_used_on_scan; + implicit_emptied= m_file[0]->implicit_emptied; + /* + Add 2 bytes for partition id in position ref length. + ref_length=max_in_all_partitions(ref_length) + PARTITION_BYTES_IN_POS + */ + ref_length+= PARTITION_BYTES_IN_POS; + m_ref_length= ref_length; + /* + Release buffer read from .par file. It will not be reused again after + being opened once. + */ + clear_handler_file(); + /* + Initialise priority queue, initialised to reading forward. + */ + if ((error= init_queue(&m_queue, m_tot_parts, (uint) PARTITION_BYTES_IN_POS, + 0, key_rec_cmp, (void*)this))) + goto err_handler; + + /* + Some handlers update statistics as part of the open call. This will in + some cases corrupt the statistics of the partition handler and thus + to ensure we have correct statistics we call info from open after + calling open on all individual handlers. + */ + info(HA_STATUS_VARIABLE | HA_STATUS_CONST); + DBUG_RETURN(0); + +err_handler: + while (file-- != m_file) + (*file)->close(); + if (!is_clone) + bitmap_free(&(m_part_info->used_partitions)); + + DBUG_RETURN(error); +} + +handler *ha_partition::clone(MEM_ROOT *mem_root) +{ + handler *new_handler= get_new_handler(table->s, mem_root, + table->s->db_type()); + ((ha_partition*)new_handler)->m_part_info= m_part_info; + ((ha_partition*)new_handler)->is_clone= TRUE; + if (new_handler && !new_handler->ha_open(table, + table->s->normalized_path.str, + table->db_stat, + HA_OPEN_IGNORE_IF_LOCKED)) + return new_handler; + return NULL; +} + + +/* + Close handler object + + SYNOPSIS + close() + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + Called from sql_base.cc, sql_select.cc, and table.cc. + In sql_select.cc it is only used to close up temporary tables or during + the process where a temporary table is converted over to being a + myisam table. + For sql_base.cc look at close_data_tables(). +*/ + +int ha_partition::close(void) +{ + bool first= TRUE; + handler **file; + DBUG_ENTER("ha_partition::close"); + + delete_queue(&m_queue); + if (!is_clone) + bitmap_free(&(m_part_info->used_partitions)); + file= m_file; + +repeat: + do + { + (*file)->close(); + } while (*(++file)); + + if (first && m_added_file && m_added_file[0]) + { + file= m_added_file; + first= FALSE; + goto repeat; + } + + DBUG_RETURN(0); +} + +/**************************************************************************** + MODULE start/end statement +****************************************************************************/ +/* + A number of methods to define various constants for the handler. In + the case of the partition handler we need to use some max and min + of the underlying handlers in most cases. +*/ + +/* + Set external locks on table + + SYNOPSIS + external_lock() + thd Thread object + lock_type Type of external lock + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + First you should go read the section "locking functions for mysql" in + lock.cc to understand this. + This create a lock on the table. If you are implementing a storage engine + that can handle transactions look at ha_berkeley.cc to see how you will + want to go about doing this. Otherwise you should consider calling + flock() here. + Originally this method was used to set locks on file level to enable + several MySQL Servers to work on the same data. For transactional + engines it has been "abused" to also mean start and end of statements + to enable proper rollback of statements and transactions. When LOCK + TABLES has been issued the start_stmt method takes over the role of + indicating start of statement but in this case there is no end of + statement indicator(?). + + Called from lock.cc by lock_external() and unlock_external(). Also called + from sql_table.cc by copy_data_between_tables(). +*/ + +int ha_partition::external_lock(THD *thd, int lock_type) +{ + bool first= TRUE; + uint error; + handler **file; + DBUG_ENTER("ha_partition::external_lock"); + + file= m_file; + m_lock_type= lock_type; + +repeat: + do + { + DBUG_PRINT("info", ("external_lock(thd, %d) iteration %d", + lock_type, (int) (file - m_file))); + if ((error= (*file)->ha_external_lock(thd, lock_type))) + { + if (F_UNLCK != lock_type) + goto err_handler; + } + } while (*(++file)); + + if (first && m_added_file && m_added_file[0]) + { + DBUG_ASSERT(lock_type == F_UNLCK); + file= m_added_file; + first= FALSE; + goto repeat; + } + DBUG_RETURN(0); + +err_handler: + while (file-- != m_file) + { + (*file)->ha_external_lock(thd, F_UNLCK); + } + DBUG_RETURN(error); +} + + +/* + Get the lock(s) for the table and perform conversion of locks if needed + + SYNOPSIS + store_lock() + thd Thread object + to Lock object array + lock_type Table lock type + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + The idea with handler::store_lock() is the following: + + The statement decided which locks we should need for the table + for updates/deletes/inserts we get WRITE locks, for SELECT... we get + read locks. + + Before adding the lock into the table lock handler (see thr_lock.c) + mysqld calls store lock with the requested locks. Store lock can now + modify a write lock to a read lock (or some other lock), ignore the + lock (if we don't want to use MySQL table locks at all) or add locks + for many tables (like we do when we are using a MERGE handler). + + Berkeley DB for partition changes all WRITE locks to TL_WRITE_ALLOW_WRITE + (which signals that we are doing WRITES, but we are still allowing other + reader's and writer's. + + When releasing locks, store_lock() is also called. In this case one + usually doesn't have to do anything. + + store_lock is called when holding a global mutex to ensure that only + one thread at a time changes the locking information of tables. + + In some exceptional cases MySQL may send a request for a TL_IGNORE; + This means that we are requesting the same lock as last time and this + should also be ignored. (This may happen when someone does a flush + table when we have opened a part of the tables, in which case mysqld + closes and reopens the tables and tries to get the same locks as last + time). In the future we will probably try to remove this. + + Called from lock.cc by get_lock_data(). +*/ + +THR_LOCK_DATA **ha_partition::store_lock(THD *thd, + THR_LOCK_DATA **to, + enum thr_lock_type lock_type) +{ + handler **file; + DBUG_ENTER("ha_partition::store_lock"); + file= m_file; + do + { + DBUG_PRINT("info", ("store lock %d iteration", (int) (file - m_file))); + to= (*file)->store_lock(thd, to, lock_type); + } while (*(++file)); + DBUG_RETURN(to); +} + +/* + Start a statement when table is locked + + SYNOPSIS + start_stmt() + thd Thread object + lock_type Type of external lock + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + This method is called instead of external lock when the table is locked + before the statement is executed. +*/ + +int ha_partition::start_stmt(THD *thd, thr_lock_type lock_type) +{ + int error= 0; + handler **file; + DBUG_ENTER("ha_partition::start_stmt"); + + file= m_file; + do + { + if ((error= (*file)->start_stmt(thd, lock_type))) + break; + } while (*(++file)); + DBUG_RETURN(error); +} + + +/* + Get number of lock objects returned in store_lock + + SYNOPSIS + lock_count() + + RETURN VALUE + Number of locks returned in call to store_lock + + DESCRIPTION + Returns the number of store locks needed in call to store lock. + We return number of partitions since we call store_lock on each + underlying handler. Assists the above functions in allocating + sufficient space for lock structures. +*/ + +uint ha_partition::lock_count() const +{ + DBUG_ENTER("ha_partition::lock_count"); + DBUG_PRINT("info", ("m_no_locks %d", m_no_locks)); + DBUG_RETURN(m_no_locks); +} + + +/* + Unlock last accessed row + + SYNOPSIS + unlock_row() + + RETURN VALUE + NONE + + DESCRIPTION + Record currently processed was not in the result set of the statement + and is thus unlocked. Used for UPDATE and DELETE queries. +*/ + +void ha_partition::unlock_row() +{ + m_file[m_last_part]->unlock_row(); + return; +} + + +/**************************************************************************** + MODULE change record +****************************************************************************/ + +/* + Insert a row to the table + + SYNOPSIS + write_row() + buf The row in MySQL Row Format + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + write_row() inserts a row. buf() is a byte array of data, normally + record[0]. + + You can use the field information to extract the data from the native byte + array type. + + Example of this would be: + for (Field **field=table->field ; *field ; field++) + { + ... + } + + See ha_tina.cc for a variant of extracting all of the data as strings. + ha_berkeley.cc has a variant of how to store it intact by "packing" it + for ha_berkeley's own native storage type. + + Called from item_sum.cc, item_sum.cc, sql_acl.cc, sql_insert.cc, + sql_insert.cc, sql_select.cc, sql_table.cc, sql_udf.cc, and sql_update.cc. + + ADDITIONAL INFO: + + We have to set timestamp fields and auto_increment fields, because those + may be used in determining which partition the row should be written to. +*/ + +int ha_partition::write_row(uchar * buf) +{ + uint32 part_id; + int error; + longlong func_value; + bool autoincrement_lock= FALSE; + my_bitmap_map *old_map; + THD *thd= ha_thd(); + timestamp_auto_set_type orig_timestamp_type= table->timestamp_field_type; +#ifdef NOT_NEEDED + uchar *rec0= m_rec0; +#endif + DBUG_ENTER("ha_partition::write_row"); + DBUG_ASSERT(buf == m_rec0); + + /* If we have a timestamp column, update it to the current time */ + if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT) + table->timestamp_field->set_time(); + table->timestamp_field_type= TIMESTAMP_NO_AUTO_SET; + + /* + If we have an auto_increment column and we are writing a changed row + or a new row, then update the auto_increment value in the record. + */ + if (table->next_number_field && buf == table->record[0]) + { + /* + Some engines (InnoDB for example) can change autoincrement + counter only after 'table->write_row' operation. + So if another thread gets inside the ha_partition::write_row + before it is complete, it gets same auto_increment value, + which means DUP_KEY error (bug #27405) + Here we separate the access using table_share->mutex, and + use autoincrement_lock variable to avoid unnecessary locks. + Probably not an ideal solution. + */ + if (table_share->tmp_table == NO_TMP_TABLE) + { + /* + Bug#30878 crash when alter table from non partitioned table + to partitioned. + Checking if tmp table then there is no need to lock, + and the table_share->mutex may not be initialised. + */ + autoincrement_lock= TRUE; + pthread_mutex_lock(&table_share->mutex); + } + error= update_auto_increment(); + + /* + If we have failed to set the auto-increment value for this row, + it is highly likely that we will not be able to insert it into + the correct partition. We must check and fail if neccessary. + */ + if (error) + goto exit; + } + + old_map= dbug_tmp_use_all_columns(table, table->read_set); +#ifdef NOT_NEEDED + if (likely(buf == rec0)) +#endif + error= m_part_info->get_partition_id(m_part_info, &part_id, + &func_value); +#ifdef NOT_NEEDED + else + { + set_field_ptr(m_part_field_array, buf, rec0); + error= m_part_info->get_partition_id(m_part_info, &part_id, + &func_value); + set_field_ptr(m_part_field_array, rec0, buf); + } +#endif + dbug_tmp_restore_column_map(table->read_set, old_map); + if (unlikely(error)) + { + m_part_info->err_value= func_value; + goto exit; + } + m_last_part= part_id; + DBUG_PRINT("info", ("Insert in partition %d", part_id)); + tmp_disable_binlog(thd); /* Do not replicate the low-level changes. */ + error= m_file[part_id]->ha_write_row(buf); + reenable_binlog(thd); +exit: + table->timestamp_field_type= orig_timestamp_type; + if (autoincrement_lock) + pthread_mutex_unlock(&table_share->mutex); + DBUG_RETURN(error); +} + + +/* + Update an existing row + + SYNOPSIS + update_row() + old_data Old record in MySQL Row Format + new_data New record in MySQL Row Format + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + Yes, update_row() does what you expect, it updates a row. old_data will + have the previous row record in it, while new_data will have the newest + data in it. + Keep in mind that the server can do updates based on ordering if an + ORDER BY clause was used. Consecutive ordering is not guarenteed. + + Currently new_data will not have an updated auto_increament record, or + and updated timestamp field. You can do these for partition by doing these: + if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE) + table->timestamp_field->set_time(); + if (table->next_number_field && record == table->record[0]) + update_auto_increment(); + + Called from sql_select.cc, sql_acl.cc, sql_update.cc, and sql_insert.cc. + new_data is always record[0] + old_data is normally record[1] but may be anything +*/ + +int ha_partition::update_row(const uchar *old_data, uchar *new_data) +{ + THD *thd= ha_thd(); + uint32 new_part_id, old_part_id; + int error= 0; + longlong func_value; + timestamp_auto_set_type orig_timestamp_type= table->timestamp_field_type; + DBUG_ENTER("ha_partition::update_row"); + + /* + We need to set timestamp field once before we calculate + the partition. Then we disable timestamp calculations + inside m_file[*]->update_row() methods + */ + if (orig_timestamp_type & TIMESTAMP_AUTO_SET_ON_UPDATE) + table->timestamp_field->set_time(); + table->timestamp_field_type= TIMESTAMP_NO_AUTO_SET; + + if ((error= get_parts_for_update(old_data, new_data, table->record[0], + m_part_info, &old_part_id, &new_part_id, + &func_value))) + { + m_part_info->err_value= func_value; + goto exit; + } + + /* + TODO: + set_internal_auto_increment= + max(set_internal_auto_increment, new_data->auto_increment) + */ + m_last_part= new_part_id; + if (new_part_id == old_part_id) + { + DBUG_PRINT("info", ("Update in partition %d", new_part_id)); + tmp_disable_binlog(thd); /* Do not replicate the low-level changes. */ + error= m_file[new_part_id]->ha_update_row(old_data, new_data); + reenable_binlog(thd); + goto exit; + } + else + { + DBUG_PRINT("info", ("Update from partition %d to partition %d", + old_part_id, new_part_id)); + tmp_disable_binlog(thd); /* Do not replicate the low-level changes. */ + error= m_file[new_part_id]->ha_write_row(new_data); + reenable_binlog(thd); + if (error) + goto exit; + + tmp_disable_binlog(thd); /* Do not replicate the low-level changes. */ + error= m_file[old_part_id]->ha_delete_row(old_data); + reenable_binlog(thd); + if (error) + { +#ifdef IN_THE_FUTURE + (void) m_file[new_part_id]->delete_last_inserted_row(new_data); +#endif + goto exit; + } + } + +exit: + table->timestamp_field_type= orig_timestamp_type; + DBUG_RETURN(error); +} + + +/* + Remove an existing row + + SYNOPSIS + delete_row + buf Deleted row in MySQL Row Format + + RETURN VALUE + >0 Error Code + 0 Success + + DESCRIPTION + This will delete a row. buf will contain a copy of the row to be deleted. + The server will call this right after the current row has been read + (from either a previous rnd_xxx() or index_xxx() call). + If you keep a pointer to the last row or can access a primary key it will + make doing the deletion quite a bit easier. + Keep in mind that the server does no guarentee consecutive deletions. + ORDER BY clauses can be used. + + Called in sql_acl.cc and sql_udf.cc to manage internal table information. + Called in sql_delete.cc, sql_insert.cc, and sql_select.cc. In sql_select + it is used for removing duplicates while in insert it is used for REPLACE + calls. + + buf is either record[0] or record[1] +*/ + +int ha_partition::delete_row(const uchar *buf) +{ + uint32 part_id; + int error; + THD *thd= ha_thd(); + DBUG_ENTER("ha_partition::delete_row"); + + if ((error= get_part_for_delete(buf, m_rec0, m_part_info, &part_id))) + { + DBUG_RETURN(error); + } + m_last_part= part_id; + tmp_disable_binlog(thd); + error= m_file[part_id]->ha_delete_row(buf); + reenable_binlog(thd); + DBUG_RETURN(error); +} + + +/* + Delete all rows in a table + + SYNOPSIS + delete_all_rows() + + RETURN VALUE + >0 Error Code + 0 Success + + DESCRIPTION + Used to delete all rows in a table. Both for cases of truncate and + for cases where the optimizer realizes that all rows will be + removed as a result of a SQL statement. + + Called from item_sum.cc by Item_func_group_concat::clear(), + Item_sum_count_distinct::clear(), and Item_func_group_concat::clear(). + Called from sql_delete.cc by mysql_delete(). + Called from sql_select.cc by JOIN::reinit(). + Called from sql_union.cc by st_select_lex_unit::exec(). +*/ + +int ha_partition::delete_all_rows() +{ + int error; + handler **file; + DBUG_ENTER("ha_partition::delete_all_rows"); + + file= m_file; + do + { + if ((error= (*file)->ha_delete_all_rows())) + DBUG_RETURN(error); + } while (*(++file)); + DBUG_RETURN(0); +} + + +/* + Start a large batch of insert rows + + SYNOPSIS + start_bulk_insert() + rows Number of rows to insert + + RETURN VALUE + NONE + + DESCRIPTION + rows == 0 means we will probably insert many rows +*/ + +void ha_partition::start_bulk_insert(ha_rows rows) +{ + handler **file; + DBUG_ENTER("ha_partition::start_bulk_insert"); + + rows= rows ? rows/m_tot_parts + 1 : 0; + file= m_file; + do + { + (*file)->ha_start_bulk_insert(rows); + } while (*(++file)); + DBUG_VOID_RETURN; +} + + +/* + Finish a large batch of insert rows + + SYNOPSIS + end_bulk_insert() + + RETURN VALUE + >0 Error code + 0 Success +*/ + +int ha_partition::end_bulk_insert() +{ + int error= 0; + handler **file; + DBUG_ENTER("ha_partition::end_bulk_insert"); + + file= m_file; + do + { + int tmp; + if ((tmp= (*file)->ha_end_bulk_insert())) + error= tmp; + } while (*(++file)); + DBUG_RETURN(error); +} + + +/**************************************************************************** + MODULE full table scan +****************************************************************************/ +/* + Initialize engine for random reads + + SYNOPSIS + ha_partition::rnd_init() + scan 0 Initialize for random reads through rnd_pos() + 1 Initialize for random scan through rnd_next() + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + rnd_init() is called when the server wants the storage engine to do a + table scan or when the server wants to access data through rnd_pos. + + When scan is used we will scan one handler partition at a time. + When preparing for rnd_pos we will init all handler partitions. + No extra cache handling is needed when scannning is not performed. + + Before initialising we will call rnd_end to ensure that we clean up from + any previous incarnation of a table scan. + Called from filesort.cc, records.cc, sql_handler.cc, sql_select.cc, + sql_table.cc, and sql_update.cc. +*/ + +int ha_partition::rnd_init(bool scan) +{ + int error; + uint i= 0; + uint32 part_id; + DBUG_ENTER("ha_partition::rnd_init"); + + /* + For operations that may need to change data, we may need to extend + read_set. + */ + if (m_lock_type == F_WRLCK) + { + /* + If write_set contains any of the fields used in partition and + subpartition expression, we need to set all bits in read_set because + the row may need to be inserted in a different [sub]partition. In + other words update_row() can be converted into write_row(), which + requires a complete record. + */ + if (bitmap_is_overlapping(&m_part_info->full_part_field_set, + table->write_set)) + bitmap_set_all(table->read_set); + else + { + /* + Some handlers only read fields as specified by the bitmap for the + read set. For partitioned handlers we always require that the + fields of the partition functions are read such that we can + calculate the partition id to place updated and deleted records. + */ + bitmap_union(table->read_set, &m_part_info->full_part_field_set); + } + } + + /* Now we see what the index of our first important partition is */ + DBUG_PRINT("info", ("m_part_info->used_partitions: 0x%lx", + (long) m_part_info->used_partitions.bitmap)); + part_id= bitmap_get_first_set(&(m_part_info->used_partitions)); + DBUG_PRINT("info", ("m_part_spec.start_part %d", part_id)); + + if (MY_BIT_NONE == part_id) + { + error= 0; + goto err1; + } + + /* + We have a partition and we are scanning with rnd_next + so we bump our cache + */ + DBUG_PRINT("info", ("rnd_init on partition %d", part_id)); + if (scan) + { + /* + rnd_end() is needed for partitioning to reset internal data if scan + is already in use + */ + rnd_end(); + late_extra_cache(part_id); + if ((error= m_file[part_id]->ha_rnd_init(scan))) + goto err; + } + else + { + for (i= part_id; i < m_tot_parts; i++) + { + if (bitmap_is_set(&(m_part_info->used_partitions), i)) + { + if ((error= m_file[i]->ha_rnd_init(scan))) + goto err; + } + } + } + m_scan_value= scan; + m_part_spec.start_part= part_id; + m_part_spec.end_part= m_tot_parts - 1; + DBUG_PRINT("info", ("m_scan_value=%d", m_scan_value)); + DBUG_RETURN(0); + +err: + while ((int)--i >= (int)part_id) + { + if (bitmap_is_set(&(m_part_info->used_partitions), i)) + m_file[i]->ha_rnd_end(); + } +err1: + m_scan_value= 2; + m_part_spec.start_part= NO_CURRENT_PART_ID; + DBUG_RETURN(error); +} + + +/* + End of a table scan + + SYNOPSIS + rnd_end() + + RETURN VALUE + >0 Error code + 0 Success +*/ + +int ha_partition::rnd_end() +{ + handler **file; + DBUG_ENTER("ha_partition::rnd_end"); + switch (m_scan_value) { + case 2: // Error + break; + case 1: + if (NO_CURRENT_PART_ID != m_part_spec.start_part) // Table scan + { + late_extra_no_cache(m_part_spec.start_part); + m_file[m_part_spec.start_part]->ha_rnd_end(); + } + break; + case 0: + file= m_file; + do + { + if (bitmap_is_set(&(m_part_info->used_partitions), (file - m_file))) + (*file)->ha_rnd_end(); + } while (*(++file)); + break; + } + m_scan_value= 2; + m_part_spec.start_part= NO_CURRENT_PART_ID; + DBUG_RETURN(0); +} + +/* + read next row during full table scan (scan in random row order) + + SYNOPSIS + rnd_next() + buf buffer that should be filled with data + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + This is called for each row of the table scan. When you run out of records + you should return HA_ERR_END_OF_FILE. + The Field structure for the table is the key to getting data into buf + in a manner that will allow the server to understand it. + + Called from filesort.cc, records.cc, sql_handler.cc, sql_select.cc, + sql_table.cc, and sql_update.cc. +*/ + +int ha_partition::rnd_next(uchar *buf) +{ + handler *file; + int result= HA_ERR_END_OF_FILE; + uint part_id= m_part_spec.start_part; + DBUG_ENTER("ha_partition::rnd_next"); + + if (NO_CURRENT_PART_ID == part_id) + { + /* + The original set of partitions to scan was empty and thus we report + the result here. + */ + goto end; + } + + DBUG_ASSERT(m_scan_value == 1); + file= m_file[part_id]; + + while (TRUE) + { + int result= file->rnd_next(buf); + if (!result) + { + m_last_part= part_id; + m_part_spec.start_part= part_id; + table->status= 0; + DBUG_RETURN(0); + } + + /* + if we get here, then the current partition rnd_next returned failure + */ + if (result == HA_ERR_RECORD_DELETED) + continue; // Probably MyISAM + + if (result != HA_ERR_END_OF_FILE) + goto end_dont_reset_start_part; // Return error + + /* End current partition */ + late_extra_no_cache(part_id); + DBUG_PRINT("info", ("rnd_end on partition %d", part_id)); + if ((result= file->ha_rnd_end())) + break; + + /* Shift to next partition */ + while (++part_id < m_tot_parts && + !bitmap_is_set(&(m_part_info->used_partitions), part_id)) + ; + if (part_id >= m_tot_parts) + { + result= HA_ERR_END_OF_FILE; + break; + } + file= m_file[part_id]; + DBUG_PRINT("info", ("rnd_init on partition %d", part_id)); + if ((result= file->ha_rnd_init(1))) + break; + late_extra_cache(part_id); + } + +end: + m_part_spec.start_part= NO_CURRENT_PART_ID; +end_dont_reset_start_part: + table->status= STATUS_NOT_FOUND; + DBUG_RETURN(result); +} + + +/* + Save position of current row + + SYNOPSIS + position() + record Current record in MySQL Row Format + + RETURN VALUE + NONE + + DESCRIPTION + position() is called after each call to rnd_next() if the data needs + to be ordered. You can do something like the following to store + the position: + ha_store_ptr(ref, ref_length, current_position); + + The server uses ref to store data. ref_length in the above case is + the size needed to store current_position. ref is just a byte array + that the server will maintain. If you are using offsets to mark rows, then + current_position should be the offset. If it is a primary key like in + BDB, then it needs to be a primary key. + + Called from filesort.cc, sql_select.cc, sql_delete.cc and sql_update.cc. +*/ + +void ha_partition::position(const uchar *record) +{ + handler *file= m_file[m_last_part]; + DBUG_ENTER("ha_partition::position"); + + file->position(record); + int2store(ref, m_last_part); + memcpy((ref + PARTITION_BYTES_IN_POS), file->ref, + (ref_length - PARTITION_BYTES_IN_POS)); + +#ifdef SUPPORTING_PARTITION_OVER_DIFFERENT_ENGINES +#ifdef HAVE_purify + bzero(ref + PARTITION_BYTES_IN_POS + ref_length, + max_ref_length-ref_length); +#endif /* HAVE_purify */ +#endif + DBUG_VOID_RETURN; +} + + +void ha_partition::column_bitmaps_signal() +{ + handler::column_bitmaps_signal(); + bitmap_union(table->read_set, &m_part_info->full_part_field_set); +} + + +/* + Read row using position + + SYNOPSIS + rnd_pos() + out:buf Row read in MySQL Row Format + position Position of read row + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + This is like rnd_next, but you are given a position to use + to determine the row. The position will be of the type that you stored in + ref. You can use ha_get_ptr(pos,ref_length) to retrieve whatever key + or position you saved when position() was called. + Called from filesort.cc records.cc sql_insert.cc sql_select.cc + sql_update.cc. +*/ + +int ha_partition::rnd_pos(uchar * buf, uchar *pos) +{ + uint part_id; + handler *file; + DBUG_ENTER("ha_partition::rnd_pos"); + + part_id= uint2korr((const uchar *) pos); + DBUG_ASSERT(part_id < m_tot_parts); + file= m_file[part_id]; + m_last_part= part_id; + DBUG_RETURN(file->rnd_pos(buf, (pos + PARTITION_BYTES_IN_POS))); +} + + +/* + Read row using position using given record to find + + SYNOPSIS + rnd_pos_by_record() + record Current record in MySQL Row Format + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + this works as position()+rnd_pos() functions, but does some extra work, + calculating m_last_part - the partition to where the 'record' + should go. + + called from replication (log_event.cc) +*/ + +int ha_partition::rnd_pos_by_record(uchar *record) +{ + DBUG_ENTER("ha_partition::rnd_pos_by_record"); + + if (unlikely(get_part_for_delete(record, m_rec0, m_part_info, &m_last_part))) + DBUG_RETURN(1); + + DBUG_RETURN(handler::rnd_pos_by_record(record)); +} + + +/**************************************************************************** + MODULE index scan +****************************************************************************/ +/* + Positions an index cursor to the index specified in the handle. Fetches the + row if available. If the key value is null, begin at the first key of the + index. + + There are loads of optimisations possible here for the partition handler. + The same optimisations can also be checked for full table scan although + only through conditions and not from index ranges. + Phase one optimisations: + Check if the fields of the partition function are bound. If so only use + the single partition it becomes bound to. + Phase two optimisations: + If it can be deducted through range or list partitioning that only a + subset of the partitions are used, then only use those partitions. +*/ + +/* + Initialise handler before start of index scan + + SYNOPSIS + index_init() + inx Index number + sorted Is rows to be returned in sorted order + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + index_init is always called before starting index scans (except when + starting through index_read_idx and using read_range variants). +*/ + +int ha_partition::index_init(uint inx, bool sorted) +{ + int error= 0; + handler **file; + DBUG_ENTER("ha_partition::index_init"); + + active_index= inx; + m_part_spec.start_part= NO_CURRENT_PART_ID; + m_start_key.length= 0; + m_ordered= sorted; + m_curr_key_info= table->key_info+inx; + /* + Some handlers only read fields as specified by the bitmap for the + read set. For partitioned handlers we always require that the + fields of the partition functions are read such that we can + calculate the partition id to place updated and deleted records. + But this is required for operations that may need to change data only. + */ + if (m_lock_type == F_WRLCK) + bitmap_union(table->read_set, &m_part_info->full_part_field_set); + else if (sorted) + { + /* + An ordered scan is requested. We must make sure all fields of the + used index are in the read set, as partitioning requires them for + sorting (see ha_partition::handle_ordered_index_scan). + + The SQL layer may request an ordered index scan without having index + fields in the read set when + - it needs to do an ordered scan over an index prefix. + - it evaluates ORDER BY with SELECT COUNT(*) FROM t1. + + TODO: handle COUNT(*) queries via unordered scan. + */ + uint i; + for (i= 0; i < m_curr_key_info->key_parts; i++) + bitmap_set_bit(table->read_set, + m_curr_key_info->key_part[i].field->field_index); + } + file= m_file; + do + { + /* TODO RONM: Change to index_init() when code is stable */ + if (bitmap_is_set(&(m_part_info->used_partitions), (file - m_file))) + if ((error= (*file)->ha_index_init(inx, sorted))) + { + DBUG_ASSERT(0); // Should never happen + break; + } + } while (*(++file)); + DBUG_RETURN(error); +} + + +/* + End of index scan + + SYNOPSIS + index_end() + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + index_end is called at the end of an index scan to clean up any + things needed to clean up. +*/ + +int ha_partition::index_end() +{ + int error= 0; + handler **file; + DBUG_ENTER("ha_partition::index_end"); + + active_index= MAX_KEY; + m_part_spec.start_part= NO_CURRENT_PART_ID; + file= m_file; + do + { + int tmp; + /* TODO RONM: Change to index_end() when code is stable */ + if (bitmap_is_set(&(m_part_info->used_partitions), (file - m_file))) + if ((tmp= (*file)->ha_index_end())) + error= tmp; + } while (*(++file)); + DBUG_RETURN(error); +} + + +/* + Read one record in an index scan and start an index scan + + SYNOPSIS + index_read() + buf Read row in MySQL Row Format + key Key parts in consecutive order + key_len Total length of key parts + find_flag What type of key condition is used + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + index_read starts a new index scan using a start key. The MySQL Server + will check the end key on its own. Thus to function properly the + partitioned handler need to ensure that it delivers records in the sort + order of the MySQL Server. + index_read can be restarted without calling index_end on the previous + index scan and without calling index_init. In this case the index_read + is on the same index as the previous index_scan. This is particularly + used in conjuntion with multi read ranges. +*/ + +int ha_partition::index_read_map(uchar *buf, const uchar *key, + key_part_map keypart_map, + enum ha_rkey_function find_flag) +{ + DBUG_ENTER("ha_partition::index_read_map"); + + end_range= 0; + m_index_scan_type= partition_index_read; + DBUG_RETURN(common_index_read(buf, key, keypart_map, find_flag)); +} + + +/* + Common routine for a number of index_read variants + + SYNOPSIS + common_index_read + + see index_read for rest +*/ + +int ha_partition::common_index_read(uchar *buf, const uchar *key, + key_part_map keypart_map, + enum ha_rkey_function find_flag) +{ + int error; + bool reverse_order= FALSE; + uint key_len= calculate_key_len(table, active_index, key, keypart_map); + DBUG_ENTER("ha_partition::common_index_read"); + + memcpy((void*)m_start_key.key, key, key_len); + m_start_key.keypart_map= keypart_map; + m_start_key.length= key_len; + m_start_key.flag= find_flag; + + if ((error= partition_scan_set_up(buf, TRUE))) + { + DBUG_RETURN(error); + } + if (find_flag == HA_READ_PREFIX_LAST || + find_flag == HA_READ_PREFIX_LAST_OR_PREV || + find_flag == HA_READ_BEFORE_KEY) + { + reverse_order= TRUE; + m_ordered_scan_ongoing= TRUE; + } + if (!m_ordered_scan_ongoing || + (find_flag == HA_READ_KEY_EXACT && + (key_len >= m_curr_key_info->key_length || + key_len == 0))) + { + /* + We use unordered index scan either when read_range is used and flag + is set to not use ordered or when an exact key is used and in this + case all records will be sorted equal and thus the sort order of the + resulting records doesn't matter. + We also use an unordered index scan when the number of partitions to + scan is only one. + The unordered index scan will use the partition set created. + Need to set unordered scan ongoing since we can come here even when + it isn't set. + */ + m_ordered_scan_ongoing= FALSE; + error= handle_unordered_scan_next_partition(buf); + } + else + { + /* + In all other cases we will use the ordered index scan. This will use + the partition set created by the get_partition_set method. + */ + error= handle_ordered_index_scan(buf, reverse_order); + } + DBUG_RETURN(error); +} + + +/* + Start an index scan from leftmost record and return first record + + SYNOPSIS + index_first() + buf Read row in MySQL Row Format + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + index_first() asks for the first key in the index. + This is similar to index_read except that there is no start key since + the scan starts from the leftmost entry and proceeds forward with + index_next. + + Called from opt_range.cc, opt_sum.cc, sql_handler.cc, + and sql_select.cc. +*/ + +int ha_partition::index_first(uchar * buf) +{ + DBUG_ENTER("ha_partition::index_first"); + + end_range= 0; + m_index_scan_type= partition_index_first; + DBUG_RETURN(common_first_last(buf)); +} + + +/* + Start an index scan from rightmost record and return first record + + SYNOPSIS + index_last() + buf Read row in MySQL Row Format + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + index_last() asks for the last key in the index. + This is similar to index_read except that there is no start key since + the scan starts from the rightmost entry and proceeds forward with + index_prev. + + Called from opt_range.cc, opt_sum.cc, sql_handler.cc, + and sql_select.cc. +*/ + +int ha_partition::index_last(uchar * buf) +{ + DBUG_ENTER("ha_partition::index_last"); + + m_index_scan_type= partition_index_last; + DBUG_RETURN(common_first_last(buf)); +} + +/* + Common routine for index_first/index_last + + SYNOPSIS + common_index_first_last + + see index_first for rest +*/ + +int ha_partition::common_first_last(uchar *buf) +{ + int error; + + if ((error= partition_scan_set_up(buf, FALSE))) + return error; + if (!m_ordered_scan_ongoing && + m_index_scan_type != partition_index_last) + return handle_unordered_scan_next_partition(buf); + return handle_ordered_index_scan(buf, FALSE); +} + + +/* + Read last using key + + SYNOPSIS + index_read_last() + buf Read row in MySQL Row Format + key Key + keypart_map Which part of key is used + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + This is used in join_read_last_key to optimise away an ORDER BY. + Can only be used on indexes supporting HA_READ_ORDER +*/ + +int ha_partition::index_read_last_map(uchar *buf, const uchar *key, + key_part_map keypart_map) +{ + DBUG_ENTER("ha_partition::index_read_last"); + + m_ordered= TRUE; // Safety measure + end_range= 0; + m_index_scan_type= partition_index_read_last; + DBUG_RETURN(common_index_read(buf, key, keypart_map, HA_READ_PREFIX_LAST)); +} + + +/* + Read next record in a forward index scan + + SYNOPSIS + index_next() + buf Read row in MySQL Row Format + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + Used to read forward through the index. +*/ + +int ha_partition::index_next(uchar * buf) +{ + DBUG_ENTER("ha_partition::index_next"); + + /* + TODO(low priority): + If we want partition to work with the HANDLER commands, we + must be able to do index_last() -> index_prev() -> index_next() + */ + DBUG_ASSERT(m_index_scan_type != partition_index_last); + if (!m_ordered_scan_ongoing) + { + DBUG_RETURN(handle_unordered_next(buf, FALSE)); + } + DBUG_RETURN(handle_ordered_next(buf, FALSE)); +} + + +/* + Read next record special + + SYNOPSIS + index_next_same() + buf Read row in MySQL Row Format + key Key + keylen Length of key + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + This routine is used to read the next but only if the key is the same + as supplied in the call. +*/ + +int ha_partition::index_next_same(uchar *buf, const uchar *key, uint keylen) +{ + DBUG_ENTER("ha_partition::index_next_same"); + + DBUG_ASSERT(keylen == m_start_key.length); + DBUG_ASSERT(m_index_scan_type != partition_index_last); + if (!m_ordered_scan_ongoing) + DBUG_RETURN(handle_unordered_next(buf, TRUE)); + DBUG_RETURN(handle_ordered_next(buf, TRUE)); +} + + +/* + Read next record when performing index scan backwards + + SYNOPSIS + index_prev() + buf Read row in MySQL Row Format + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + Used to read backwards through the index. +*/ + +int ha_partition::index_prev(uchar * buf) +{ + DBUG_ENTER("ha_partition::index_prev"); + + /* TODO: read comment in index_next */ + DBUG_ASSERT(m_index_scan_type != partition_index_first); + DBUG_RETURN(handle_ordered_prev(buf)); +} + + +/* + Start a read of one range with start and end key + + SYNOPSIS + read_range_first() + start_key Specification of start key + end_key Specification of end key + eq_range_arg Is it equal range + sorted Should records be returned in sorted order + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + We reimplement read_range_first since we don't want the compare_key + check at the end. This is already performed in the partition handler. + read_range_next is very much different due to that we need to scan + all underlying handlers. +*/ + +int ha_partition::read_range_first(const key_range *start_key, + const key_range *end_key, + bool eq_range_arg, bool sorted) +{ + int error; + DBUG_ENTER("ha_partition::read_range_first"); + + m_ordered= sorted; + eq_range= eq_range_arg; + end_range= 0; + if (end_key) + { + end_range= &save_end_range; + save_end_range= *end_key; + key_compare_result_on_equal= + ((end_key->flag == HA_READ_BEFORE_KEY) ? 1 : + (end_key->flag == HA_READ_AFTER_KEY) ? -1 : 0); + } + range_key_part= m_curr_key_info->key_part; + + if (!start_key) // Read first record + { + if (m_ordered) + m_index_scan_type= partition_index_first; + else + m_index_scan_type= partition_index_first_unordered; + error= common_first_last(m_rec0); + } + else + { + m_index_scan_type= partition_index_read; + error= common_index_read(m_rec0, + start_key->key, + start_key->keypart_map, start_key->flag); + } + DBUG_RETURN(error); +} + + +/* + Read next record in read of a range with start and end key + + SYNOPSIS + read_range_next() + + RETURN VALUE + >0 Error code + 0 Success +*/ + +int ha_partition::read_range_next() +{ + DBUG_ENTER("ha_partition::read_range_next"); + + if (m_ordered) + { + DBUG_RETURN(handler::read_range_next()); + } + DBUG_RETURN(handle_unordered_next(m_rec0, eq_range)); +} + + +/* + Common routine to set up scans + + SYNOPSIS + buf Buffer to later return record in + idx_read_flag Is it index scan + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + This is where we check which partitions to actually scan if not all + of them +*/ + +int ha_partition::partition_scan_set_up(uchar * buf, bool idx_read_flag) +{ + DBUG_ENTER("ha_partition::partition_scan_set_up"); + + if (idx_read_flag) + get_partition_set(table,buf,active_index,&m_start_key,&m_part_spec); + else + { + m_part_spec.start_part= 0; + m_part_spec.end_part= m_tot_parts - 1; + } + if (m_part_spec.start_part > m_part_spec.end_part) + { + /* + We discovered a partition set but the set was empty so we report + key not found. + */ + DBUG_PRINT("info", ("scan with no partition to scan")); + DBUG_RETURN(HA_ERR_END_OF_FILE); + } + if (m_part_spec.start_part == m_part_spec.end_part) + { + /* + We discovered a single partition to scan, this never needs to be + performed using the ordered index scan. + */ + DBUG_PRINT("info", ("index scan using the single partition %d", + m_part_spec.start_part)); + m_ordered_scan_ongoing= FALSE; + } + else + { + /* + Set m_ordered_scan_ongoing according how the scan should be done + Only exact partitions are discovered atm by get_partition_set. + Verify this, also bitmap must have at least one bit set otherwise + the result from this table is the empty set. + */ + uint start_part= bitmap_get_first_set(&(m_part_info->used_partitions)); + if (start_part == MY_BIT_NONE) + { + DBUG_PRINT("info", ("scan with no partition to scan")); + DBUG_RETURN(HA_ERR_END_OF_FILE); + } + if (start_part > m_part_spec.start_part) + m_part_spec.start_part= start_part; + DBUG_ASSERT(m_part_spec.start_part < m_tot_parts); + m_ordered_scan_ongoing= m_ordered; + } + DBUG_ASSERT(m_part_spec.start_part < m_tot_parts && + m_part_spec.end_part < m_tot_parts); + DBUG_RETURN(0); +} + + +/**************************************************************************** + Unordered Index Scan Routines +****************************************************************************/ +/* + Common routine to handle index_next with unordered results + + SYNOPSIS + handle_unordered_next() + out:buf Read row in MySQL Row Format + next_same Called from index_next_same + + RETURN VALUE + HA_ERR_END_OF_FILE End of scan + 0 Success + other Error code + + DESCRIPTION + These routines are used to scan partitions without considering order. + This is performed in two situations. + 1) In read_multi_range this is the normal case + 2) When performing any type of index_read, index_first, index_last where + all fields in the partition function is bound. In this case the index + scan is performed on only one partition and thus it isn't necessary to + perform any sort. +*/ + +int ha_partition::handle_unordered_next(uchar *buf, bool is_next_same) +{ + handler *file= m_file[m_part_spec.start_part]; + int error; + DBUG_ENTER("ha_partition::handle_unordered_next"); + + /* + We should consider if this should be split into two functions as + next_same is alwas a local constant + */ + if (is_next_same) + { + if (!(error= file->index_next_same(buf, m_start_key.key, + m_start_key.length))) + { + m_last_part= m_part_spec.start_part; + DBUG_RETURN(0); + } + } + else if (!(error= file->index_next(buf))) + { + if (!(file->index_flags(active_index, 0, 1) & HA_READ_ORDER) || + compare_key(end_range) <= 0) + { + m_last_part= m_part_spec.start_part; + DBUG_RETURN(0); // Row was in range + } + error= HA_ERR_END_OF_FILE; + } + + if (error == HA_ERR_END_OF_FILE) + { + m_part_spec.start_part++; // Start using next part + error= handle_unordered_scan_next_partition(buf); + } + DBUG_RETURN(error); +} + + +/* + Handle index_next when changing to new partition + + SYNOPSIS + handle_unordered_scan_next_partition() + buf Read row in MySQL Row Format + + RETURN VALUE + HA_ERR_END_OF_FILE End of scan + 0 Success + other Error code + + DESCRIPTION + This routine is used to start the index scan on the next partition. + Both initial start and after completing scan on one partition. +*/ + +int ha_partition::handle_unordered_scan_next_partition(uchar * buf) +{ + uint i; + DBUG_ENTER("ha_partition::handle_unordered_scan_next_partition"); + + for (i= m_part_spec.start_part; i <= m_part_spec.end_part; i++) + { + int error; + handler *file; + + if (!(bitmap_is_set(&(m_part_info->used_partitions), i))) + continue; + file= m_file[i]; + m_part_spec.start_part= i; + switch (m_index_scan_type) { + case partition_index_read: + DBUG_PRINT("info", ("index_read on partition %d", i)); + error= file->index_read_map(buf, m_start_key.key, + m_start_key.keypart_map, + m_start_key.flag); + break; + case partition_index_first: + DBUG_PRINT("info", ("index_first on partition %d", i)); + error= file->index_first(buf); + break; + case partition_index_first_unordered: + /* + We perform a scan without sorting and this means that we + should not use the index_first since not all handlers + support it and it is also unnecessary to restrict sort + order. + */ + DBUG_PRINT("info", ("read_range_first on partition %d", i)); + table->record[0]= buf; + error= file->read_range_first(0, end_range, eq_range, 0); + table->record[0]= m_rec0; + break; + default: + DBUG_ASSERT(FALSE); + DBUG_RETURN(1); + } + if (!error) + { + if (!(file->index_flags(active_index, 0, 1) & HA_READ_ORDER) || + compare_key(end_range) <= 0) + { + m_last_part= i; + DBUG_RETURN(0); + } + error= HA_ERR_END_OF_FILE; + } + if ((error != HA_ERR_END_OF_FILE) && (error != HA_ERR_KEY_NOT_FOUND)) + DBUG_RETURN(error); + DBUG_PRINT("info", ("HA_ERR_END_OF_FILE on partition %d", i)); + } + m_part_spec.start_part= NO_CURRENT_PART_ID; + DBUG_RETURN(HA_ERR_END_OF_FILE); +} + + +/* + Common routine to start index scan with ordered results + + SYNOPSIS + handle_ordered_index_scan() + out:buf Read row in MySQL Row Format + + RETURN VALUE + HA_ERR_END_OF_FILE End of scan + 0 Success + other Error code + + DESCRIPTION + This part contains the logic to handle index scans that require ordered + output. This includes all except those started by read_range_first with + the flag ordered set to FALSE. Thus most direct index_read and all + index_first and index_last. + + We implement ordering by keeping one record plus a key buffer for each + partition. Every time a new entry is requested we will fetch a new + entry from the partition that is currently not filled with an entry. + Then the entry is put into its proper sort position. + + Returning a record is done by getting the top record, copying the + record to the request buffer and setting the partition as empty on + entries. +*/ + +int ha_partition::handle_ordered_index_scan(uchar *buf, bool reverse_order) +{ + uint i; + uint j= 0; + bool found= FALSE; + DBUG_ENTER("ha_partition::handle_ordered_index_scan"); + + m_top_entry= NO_CURRENT_PART_ID; + queue_remove_all(&m_queue); + + DBUG_PRINT("info", ("m_part_spec.start_part %d", m_part_spec.start_part)); + for (i= m_part_spec.start_part; i <= m_part_spec.end_part; i++) + { + if (!(bitmap_is_set(&(m_part_info->used_partitions), i))) + continue; + uchar *rec_buf_ptr= rec_buf(i); + int error; + handler *file= m_file[i]; + + switch (m_index_scan_type) { + case partition_index_read: + error= file->index_read_map(rec_buf_ptr, + m_start_key.key, + m_start_key.keypart_map, + m_start_key.flag); + break; + case partition_index_first: + error= file->index_first(rec_buf_ptr); + reverse_order= FALSE; + break; + case partition_index_last: + error= file->index_last(rec_buf_ptr); + reverse_order= TRUE; + break; + case partition_index_read_last: + error= file->index_read_last_map(rec_buf_ptr, + m_start_key.key, + m_start_key.keypart_map); + reverse_order= TRUE; + break; + default: + DBUG_ASSERT(FALSE); + DBUG_RETURN(HA_ERR_END_OF_FILE); + } + if (!error) + { + found= TRUE; + /* + Initialise queue without order first, simply insert + */ + queue_element(&m_queue, j++)= (uchar*)queue_buf(i); + } + else if (error != HA_ERR_KEY_NOT_FOUND && error != HA_ERR_END_OF_FILE) + { + DBUG_RETURN(error); + } + } + if (found) + { + /* + We found at least one partition with data, now sort all entries and + after that read the first entry and copy it to the buffer to return in. + */ + queue_set_max_at_top(&m_queue, reverse_order); + queue_set_cmp_arg(&m_queue, (void*)m_curr_key_info); + m_queue.elements= j; + queue_fix(&m_queue); + return_top_record(buf); + table->status= 0; + DBUG_PRINT("info", ("Record returned from partition %d", m_top_entry)); + DBUG_RETURN(0); + } + DBUG_RETURN(HA_ERR_END_OF_FILE); +} + + +/* + Return the top record in sort order + + SYNOPSIS + return_top_record() + out:buf Row returned in MySQL Row Format + + RETURN VALUE + NONE +*/ + +void ha_partition::return_top_record(uchar *buf) +{ + uint part_id; + uchar *key_buffer= queue_top(&m_queue); + uchar *rec_buffer= key_buffer + PARTITION_BYTES_IN_POS; + + part_id= uint2korr(key_buffer); + memcpy(buf, rec_buffer, m_rec_length); + m_last_part= part_id; + m_top_entry= part_id; +} + + +/* + Common routine to handle index_next with ordered results + + SYNOPSIS + handle_ordered_next() + out:buf Read row in MySQL Row Format + next_same Called from index_next_same + + RETURN VALUE + HA_ERR_END_OF_FILE End of scan + 0 Success + other Error code +*/ + +int ha_partition::handle_ordered_next(uchar *buf, bool is_next_same) +{ + int error; + uint part_id= m_top_entry; + handler *file= m_file[part_id]; + DBUG_ENTER("ha_partition::handle_ordered_next"); + + if (!is_next_same) + error= file->index_next(rec_buf(part_id)); + else + error= file->index_next_same(rec_buf(part_id), m_start_key.key, + m_start_key.length); + if (error) + { + if (error == HA_ERR_END_OF_FILE) + { + /* Return next buffered row */ + queue_remove(&m_queue, (uint) 0); + if (m_queue.elements) + { + DBUG_PRINT("info", ("Record returned from partition %u (2)", + m_top_entry)); + return_top_record(buf); + table->status= 0; + error= 0; + } + } + DBUG_RETURN(error); + } + queue_replaced(&m_queue); + return_top_record(buf); + DBUG_PRINT("info", ("Record returned from partition %u", m_top_entry)); + DBUG_RETURN(0); +} + + +/* + Common routine to handle index_prev with ordered results + + SYNOPSIS + handle_ordered_prev() + out:buf Read row in MySQL Row Format + + RETURN VALUE + HA_ERR_END_OF_FILE End of scan + 0 Success + other Error code +*/ + +int ha_partition::handle_ordered_prev(uchar *buf) +{ + int error; + uint part_id= m_top_entry; + handler *file= m_file[part_id]; + DBUG_ENTER("ha_partition::handle_ordered_prev"); + + if ((error= file->index_prev(rec_buf(part_id)))) + { + if (error == HA_ERR_END_OF_FILE) + { + queue_remove(&m_queue, (uint) 0); + if (m_queue.elements) + { + return_top_record(buf); + DBUG_PRINT("info", ("Record returned from partition %d (2)", + m_top_entry)); + error= 0; + table->status= 0; + } + } + DBUG_RETURN(error); + } + queue_replaced(&m_queue); + return_top_record(buf); + DBUG_PRINT("info", ("Record returned from partition %d", m_top_entry)); + DBUG_RETURN(0); +} + + +/**************************************************************************** + MODULE information calls +****************************************************************************/ + +/* + These are all first approximations of the extra, info, scan_time + and read_time calls +*/ + +/* + General method to gather info from handler + + SYNOPSIS + info() + flag Specifies what info is requested + + RETURN VALUE + NONE + + DESCRIPTION + ::info() is used to return information to the optimizer. + Currently this table handler doesn't implement most of the fields + really needed. SHOW also makes use of this data + Another note, if your handler doesn't proved exact record count, + you will probably want to have the following in your code: + if (records < 2) + records = 2; + The reason is that the server will optimize for cases of only a single + record. If in a table scan you don't know the number of records + it will probably be better to set records to two so you can return + as many records as you need. + + Along with records a few more variables you may wish to set are: + records + deleted + data_file_length + index_file_length + delete_length + check_time + Take a look at the public variables in handler.h for more information. + + Called in: + filesort.cc + ha_heap.cc + item_sum.cc + opt_sum.cc + sql_delete.cc + sql_delete.cc + sql_derived.cc + sql_select.cc + sql_select.cc + sql_select.cc + sql_select.cc + sql_select.cc + sql_show.cc + sql_show.cc + sql_show.cc + sql_show.cc + sql_table.cc + sql_union.cc + sql_update.cc + + Some flags that are not implemented + HA_STATUS_POS: + This parameter is never used from the MySQL Server. It is checked in a + place in MyISAM so could potentially be used by MyISAM specific + programs. + HA_STATUS_NO_LOCK: + This is declared and often used. It's only used by MyISAM. + It means that MySQL doesn't need the absolute latest statistics + information. This may save the handler from doing internal locks while + retrieving statistics data. +*/ + +int ha_partition::info(uint flag) +{ + handler *file, **file_array; + DBUG_ENTER("ha_partition:info"); + + if (flag & HA_STATUS_AUTO) + { + ulonglong auto_increment_value= 0; + DBUG_PRINT("info", ("HA_STATUS_AUTO")); + file_array= m_file; + do + { + file= *file_array; + file->info(HA_STATUS_AUTO); + set_if_bigger(auto_increment_value, file->stats.auto_increment_value); + } while (*(++file_array)); + stats.auto_increment_value= auto_increment_value; + } + if (flag & HA_STATUS_VARIABLE) + { + DBUG_PRINT("info", ("HA_STATUS_VARIABLE")); + /* + Calculates statistical variables + records: Estimate of number records in table + We report sum (always at least 2) + deleted: Estimate of number holes in the table due to + deletes + We report sum + data_file_length: Length of data file, in principle bytes in table + We report sum + index_file_length: Length of index file, in principle bytes in + indexes in the table + We report sum + delete_length: Length of free space easily used by new records in table + We report sum + mean_record_length:Mean record length in the table + We calculate this + check_time: Time of last check (only applicable to MyISAM) + We report last time of all underlying handlers + */ + stats.records= 0; + stats.deleted= 0; + stats.data_file_length= 0; + stats.index_file_length= 0; + stats.check_time= 0; + stats.delete_length= 0; + file_array= m_file; + do + { + if (bitmap_is_set(&(m_part_info->used_partitions), (file_array - m_file))) + { + file= *file_array; + file->info(HA_STATUS_VARIABLE); + stats.records+= file->stats.records; + stats.deleted+= file->stats.deleted; + stats.data_file_length+= file->stats.data_file_length; + stats.index_file_length+= file->stats.index_file_length; + stats.delete_length+= file->stats.delete_length; + if (file->stats.check_time > stats.check_time) + stats.check_time= file->stats.check_time; + } + } while (*(++file_array)); + if (stats.records < 2 && + !(m_table_flags & HA_STATS_RECORDS_IS_EXACT)) + stats.records= 2; + if (stats.records > 0) + stats.mean_rec_length= (ulong) (stats.data_file_length / stats.records); + else + stats.mean_rec_length= 1; //? What should we set here + } + if (flag & HA_STATUS_CONST) + { + DBUG_PRINT("info", ("HA_STATUS_CONST")); + /* + Recalculate loads of constant variables. MyISAM also sets things + directly on the table share object. + + Check whether this should be fixed since handlers should not + change things directly on the table object. + + Monty comment: This should NOT be changed! It's the handlers + responsibility to correct table->s->keys_xxxx information if keys + have been disabled. + + The most important parameters set here is records per key on + all indexes. block_size and primar key ref_length. + + For each index there is an array of rec_per_key. + As an example if we have an index with three attributes a,b and c + we will have an array of 3 rec_per_key. + rec_per_key[0] is an estimate of number of records divided by + number of unique values of the field a. + rec_per_key[1] is an estimate of the number of records divided + by the number of unique combinations of the fields a and b. + rec_per_key[2] is an estimate of the number of records divided + by the number of unique combinations of the fields a,b and c. + + Many handlers only set the value of rec_per_key when all fields + are bound (rec_per_key[2] in the example above). + + If the handler doesn't support statistics, it should set all of the + above to 0. + + We will allow the first handler to set the rec_per_key and use + this as an estimate on the total table. + + max_data_file_length: Maximum data file length + We ignore it, is only used in + SHOW TABLE STATUS + max_index_file_length: Maximum index file length + We ignore it since it is never used + block_size: Block size used + We set it to the value of the first handler + ref_length: We set this to the value calculated + and stored in local object + create_time: Creation time of table + Set by first handler + + So we calculate these constants by using the variables on the first + handler. + */ + + file= m_file[0]; + file->info(HA_STATUS_CONST); + stats.create_time= file->stats.create_time; + ref_length= m_ref_length; + } + if (flag & HA_STATUS_ERRKEY) + { + handler *file= m_file[m_last_part]; + DBUG_PRINT("info", ("info: HA_STATUS_ERRKEY")); + /* + This flag is used to get index number of the unique index that + reported duplicate key + We will report the errkey on the last handler used and ignore the rest + */ + file->info(HA_STATUS_ERRKEY); + if (file->errkey != (uint) -1) + errkey= file->errkey; + } + if (flag & HA_STATUS_TIME) + { + DBUG_PRINT("info", ("info: HA_STATUS_TIME")); + /* + This flag is used to set the latest update time of the table. + Used by SHOW commands + We will report the maximum of these times + */ + stats.update_time= 0; + file_array= m_file; + do + { + file= *file_array; + file->info(HA_STATUS_TIME); + if (file->stats.update_time > stats.update_time) + stats.update_time= file->stats.update_time; + } while (*(++file_array)); + } + DBUG_RETURN(0); +} + + +void ha_partition::get_dynamic_partition_info(PARTITION_INFO *stat_info, + uint part_id) +{ + handler *file= m_file[part_id]; + file->info(HA_STATUS_CONST | HA_STATUS_TIME | HA_STATUS_VARIABLE | + HA_STATUS_NO_LOCK); + + stat_info->records= file->stats.records; + stat_info->mean_rec_length= file->stats.mean_rec_length; + stat_info->data_file_length= file->stats.data_file_length; + stat_info->max_data_file_length= file->stats.max_data_file_length; + stat_info->index_file_length= file->stats.index_file_length; + stat_info->delete_length= file->stats.delete_length; + stat_info->create_time= file->stats.create_time; + stat_info->update_time= file->stats.update_time; + stat_info->check_time= file->stats.check_time; + stat_info->check_sum= 0; + if (file->ha_table_flags() & HA_HAS_CHECKSUM) + stat_info->check_sum= file->checksum(); + return; +} + + +/* + General function to prepare handler for certain behavior + + SYNOPSIS + extra() + operation Operation type for extra call + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + extra() is called whenever the server wishes to send a hint to + the storage engine. The MyISAM engine implements the most hints. + + We divide the parameters into the following categories: + 1) Parameters used by most handlers + 2) Parameters used by some non-MyISAM handlers + 3) Parameters used only by MyISAM + 4) Parameters only used by temporary tables for query processing + 5) Parameters only used by MyISAM internally + 6) Parameters not used at all + 7) Parameters only used by federated tables for query processing + 8) Parameters only used by NDB + + The partition handler need to handle category 1), 2) and 3). + + 1) Parameters used by most handlers + ----------------------------------- + HA_EXTRA_RESET: + This option is used by most handlers and it resets the handler state + to the same state as after an open call. This includes releasing + any READ CACHE or WRITE CACHE or other internal buffer used. + + It is called from the reset method in the handler interface. There are + three instances where this is called. + 1) After completing a INSERT ... SELECT ... query the handler for the + table inserted into is reset + 2) It is called from close_thread_table which in turn is called from + close_thread_tables except in the case where the tables are locked + in which case ha_commit_stmt is called instead. + It is only called from here if refresh_version hasn't changed and the + table is not an old table when calling close_thread_table. + close_thread_tables is called from many places as a general clean up + function after completing a query. + 3) It is called when deleting the QUICK_RANGE_SELECT object if the + QUICK_RANGE_SELECT object had its own handler object. It is called + immediatley before close of this local handler object. + HA_EXTRA_KEYREAD: + HA_EXTRA_NO_KEYREAD: + These parameters are used to provide an optimisation hint to the handler. + If HA_EXTRA_KEYREAD is set it is enough to read the index fields, for + many handlers this means that the index-only scans can be used and it + is not necessary to use the real records to satisfy this part of the + query. Index-only scans is a very important optimisation for disk-based + indexes. For main-memory indexes most indexes contain a reference to the + record and thus KEYREAD only says that it is enough to read key fields. + HA_EXTRA_NO_KEYREAD disables this for the handler, also HA_EXTRA_RESET + will disable this option. + The handler will set HA_KEYREAD_ONLY in its table flags to indicate this + feature is supported. + HA_EXTRA_FLUSH: + Indication to flush tables to disk, is supposed to be used to + ensure disk based tables are flushed at end of query execution. + Currently is never used. + + 2) Parameters used by some non-MyISAM handlers + ---------------------------------------------- + HA_EXTRA_KEYREAD_PRESERVE_FIELDS: + This is a strictly InnoDB feature that is more or less undocumented. + When it is activated InnoDB copies field by field from its fetch + cache instead of all fields in one memcpy. Have no idea what the + purpose of this is. + Cut from include/my_base.h: + When using HA_EXTRA_KEYREAD, overwrite only key member fields and keep + other fields intact. When this is off (by default) InnoDB will use memcpy + to overwrite entire row. + HA_EXTRA_IGNORE_DUP_KEY: + HA_EXTRA_NO_IGNORE_DUP_KEY: + Informs the handler to we will not stop the transaction if we get an + duplicate key errors during insert/upate. + Always called in pair, triggered by INSERT IGNORE and other similar + SQL constructs. + Not used by MyISAM. + + 3) Parameters used only by MyISAM + --------------------------------- + HA_EXTRA_NORMAL: + Only used in MyISAM to reset quick mode, not implemented by any other + handler. Quick mode is also reset in MyISAM by HA_EXTRA_RESET. + + It is called after completing a successful DELETE query if the QUICK + option is set. + + HA_EXTRA_QUICK: + When the user does DELETE QUICK FROM table where-clause; this extra + option is called before the delete query is performed and + HA_EXTRA_NORMAL is called after the delete query is completed. + Temporary tables used internally in MySQL always set this option + + The meaning of quick mode is that when deleting in a B-tree no merging + of leafs is performed. This is a common method and many large DBMS's + actually only support this quick mode since it is very difficult to + merge leaves in a tree used by many threads concurrently. + + HA_EXTRA_CACHE: + This flag is usually set with extra_opt along with a cache size. + The size of this buffer is set by the user variable + record_buffer_size. The value of this cache size is the amount of + data read from disk in each fetch when performing a table scan. + This means that before scanning a table it is normal to call + extra with HA_EXTRA_CACHE and when the scan is completed to call + HA_EXTRA_NO_CACHE to release the cache memory. + + Some special care is taken when using this extra parameter since there + could be a write ongoing on the table in the same statement. In this + one has to take special care since there might be a WRITE CACHE as + well. HA_EXTRA_CACHE specifies using a READ CACHE and using + READ CACHE and WRITE CACHE at the same time is not possible. + + Only MyISAM currently use this option. + + It is set when doing full table scans using rr_sequential and + reset when completing such a scan with end_read_record + (resetting means calling extra with HA_EXTRA_NO_CACHE). + + It is set in filesort.cc for MyISAM internal tables and it is set in + a multi-update where HA_EXTRA_CACHE is called on a temporary result + table and after that ha_rnd_init(0) on table to be updated + and immediately after that HA_EXTRA_NO_CACHE on table to be updated. + + Apart from that it is always used from init_read_record but not when + used from UPDATE statements. It is not used from DELETE statements + with ORDER BY and LIMIT but it is used in normal scan loop in DELETE + statements. The reason here is that DELETE's in MyISAM doesn't move + existings data rows. + + It is also set in copy_data_between_tables when scanning the old table + to copy over to the new table. + And it is set in join_init_read_record where quick objects are used + to perform a scan on the table. In this case the full table scan can + even be performed multiple times as part of the nested loop join. + + For purposes of the partition handler it is obviously necessary to have + special treatment of this extra call. If we would simply pass this + extra call down to each handler we would allocate + cache size * no of partitions amount of memory and this is not + necessary since we will only scan one partition at a time when doing + full table scans. + + Thus we treat it by first checking whether we have MyISAM handlers in + the table, if not we simply ignore the call and if we have we will + record the call but will not call any underlying handler yet. Then + when performing the sequential scan we will check this recorded value + and call extra_opt whenever we start scanning a new partition. + + monty: Neads to be fixed so that it's passed to all handlers when we + move to another partition during table scan. + + HA_EXTRA_NO_CACHE: + When performing a UNION SELECT HA_EXTRA_NO_CACHE is called from the + flush method in the select_union class. + It is used to some extent when insert delayed inserts. + See HA_EXTRA_RESET_STATE for use in conjunction with delete_all_rows(). + + It should be ok to call HA_EXTRA_NO_CACHE on all underlying handlers + if they are MyISAM handlers. Other handlers we can ignore the call + for. If no cache is in use they will quickly return after finding + this out. And we also ensure that all caches are disabled and no one + is left by mistake. + In the future this call will probably be deleted an we will instead call + ::reset(); + + HA_EXTRA_WRITE_CACHE: + See above, called from various places. It is mostly used when we + do INSERT ... SELECT + No special handling to save cache space is developed currently. + + HA_EXTRA_PREPARE_FOR_UPDATE: + This is called as part of a multi-table update. When the table to be + updated is also scanned then this informs MyISAM handler to drop any + caches if dynamic records are used (fixed size records do not care + about this call). We pass this along to all underlying MyISAM handlers + and ignore it for the rest. + + HA_EXTRA_PREPARE_FOR_DROP: + Only used by MyISAM, called in preparation for a DROP TABLE. + It's used mostly by Windows that cannot handle dropping an open file. + On other platforms it has the same effect as HA_EXTRA_FORCE_REOPEN. + + HA_EXTRA_PREPARE_FOR_RENAME: + Informs the handler we are about to attempt a rename of the table. + + HA_EXTRA_READCHECK: + HA_EXTRA_NO_READCHECK: + Only one call to HA_EXTRA_NO_READCHECK from ha_open where it says that + this is not needed in SQL. The reason for this call is that MyISAM sets + the READ_CHECK_USED in the open call so the call is needed for MyISAM + to reset this feature. + The idea with this parameter was to inform of doing/not doing a read + check before applying an update. Since SQL always performs a read before + applying the update No Read Check is needed in MyISAM as well. + + This is a cut from Docs/myisam.txt + Sometimes you might want to force an update without checking whether + another user has changed the record since you last read it. This is + somewhat dangerous, so it should ideally not be used. That can be + accomplished by wrapping the mi_update() call in two calls to mi_extra(), + using these functions: + HA_EXTRA_NO_READCHECK=5 No readcheck on update + HA_EXTRA_READCHECK=6 Use readcheck (def) + + HA_EXTRA_FORCE_REOPEN: + Only used by MyISAM, called when altering table, closing tables to + enforce a reopen of the table files. + + 4) Parameters only used by temporary tables for query processing + ---------------------------------------------------------------- + HA_EXTRA_RESET_STATE: + Same as reset() except that buffers are not released. If there is + a READ CACHE it is reinit'ed. A cache is reinit'ed to restart reading + or to change type of cache between READ CACHE and WRITE CACHE. + + This extra function is always called immediately before calling + delete_all_rows on the handler for temporary tables. + There are cases however when HA_EXTRA_RESET_STATE isn't called in + a similar case for a temporary table in sql_union.cc and in two other + cases HA_EXTRA_NO_CACHE is called before and HA_EXTRA_WRITE_CACHE + called afterwards. + The case with HA_EXTRA_NO_CACHE and HA_EXTRA_WRITE_CACHE means + disable caching, delete all rows and enable WRITE CACHE. This is + used for temporary tables containing distinct sums and a + functional group. + + The only case that delete_all_rows is called on non-temporary tables + is in sql_delete.cc when DELETE FROM table; is called by a user. + In this case no special extra calls are performed before or after this + call. + + The partition handler should not need to bother about this one. It + should never be called. + + HA_EXTRA_NO_ROWS: + Don't insert rows indication to HEAP and MyISAM, only used by temporary + tables used in query processing. + Not handled by partition handler. + + 5) Parameters only used by MyISAM internally + -------------------------------------------- + HA_EXTRA_REINIT_CACHE: + This call reinitialises the READ CACHE described above if there is one + and otherwise the call is ignored. + + We can thus safely call it on all underlying handlers if they are + MyISAM handlers. It is however never called so we don't handle it at all. + HA_EXTRA_FLUSH_CACHE: + Flush WRITE CACHE in MyISAM. It is only from one place in the code. + This is in sql_insert.cc where it is called if the table_flags doesn't + contain HA_DUPLICATE_POS. The only handler having the HA_DUPLICATE_POS + set is the MyISAM handler and so the only handler not receiving this + call is MyISAM. + Thus in effect this call is called but never used. Could be removed + from sql_insert.cc + HA_EXTRA_NO_USER_CHANGE: + Only used by MyISAM, never called. + Simulates lock_type as locked. + HA_EXTRA_WAIT_LOCK: + HA_EXTRA_WAIT_NOLOCK: + Only used by MyISAM, called from MyISAM handler but never from server + code on top of the handler. + Sets lock_wait on/off + HA_EXTRA_NO_KEYS: + Only used MyISAM, only used internally in MyISAM handler, never called + from server level. + HA_EXTRA_KEYREAD_CHANGE_POS: + HA_EXTRA_REMEMBER_POS: + HA_EXTRA_RESTORE_POS: + HA_EXTRA_PRELOAD_BUFFER_SIZE: + HA_EXTRA_CHANGE_KEY_TO_DUP: + HA_EXTRA_CHANGE_KEY_TO_UNIQUE: + Only used by MyISAM, never called. + + 6) Parameters not used at all + ----------------------------- + HA_EXTRA_KEY_CACHE: + HA_EXTRA_NO_KEY_CACHE: + This parameters are no longer used and could be removed. + + 7) Parameters only used by federated tables for query processing + ---------------------------------------------------------------- + HA_EXTRA_INSERT_WITH_UPDATE: + Inform handler that an "INSERT...ON DUPLICATE KEY UPDATE" will be + executed. This condition is unset by HA_EXTRA_NO_IGNORE_DUP_KEY. + + 8) Parameters only used by NDB + ------------------------------ + HA_EXTRA_DELETE_CANNOT_BATCH: + HA_EXTRA_UPDATE_CANNOT_BATCH: + Inform handler that delete_row()/update_row() cannot batch deletes/updates + and should perform them immediately. This may be needed when table has + AFTER DELETE/UPDATE triggers which access to subject table. + These flags are reset by the handler::extra(HA_EXTRA_RESET) call. +*/ + +int ha_partition::extra(enum ha_extra_function operation) +{ + DBUG_ENTER("ha_partition:extra"); + DBUG_PRINT("info", ("operation: %d", (int) operation)); + + switch (operation) { + /* Category 1), used by most handlers */ + case HA_EXTRA_KEYREAD: + case HA_EXTRA_NO_KEYREAD: + case HA_EXTRA_FLUSH: + DBUG_RETURN(loop_extra(operation)); + + /* Category 2), used by non-MyISAM handlers */ + case HA_EXTRA_IGNORE_DUP_KEY: + case HA_EXTRA_NO_IGNORE_DUP_KEY: + case HA_EXTRA_KEYREAD_PRESERVE_FIELDS: + { + if (!m_myisam) + DBUG_RETURN(loop_extra(operation)); + break; + } + + /* Category 3), used by MyISAM handlers */ + case HA_EXTRA_PREPARE_FOR_RENAME: + DBUG_RETURN(prepare_for_rename()); + break; + case HA_EXTRA_NORMAL: + case HA_EXTRA_QUICK: + case HA_EXTRA_NO_READCHECK: + case HA_EXTRA_PREPARE_FOR_UPDATE: + case HA_EXTRA_FORCE_REOPEN: + case HA_EXTRA_PREPARE_FOR_DROP: + case HA_EXTRA_FLUSH_CACHE: + { + if (m_myisam) + DBUG_RETURN(loop_extra(operation)); + break; + } + case HA_EXTRA_CACHE: + { + prepare_extra_cache(0); + break; + } + case HA_EXTRA_NO_CACHE: + case HA_EXTRA_WRITE_CACHE: + { + m_extra_cache= FALSE; + m_extra_cache_size= 0; + DBUG_RETURN(loop_extra(operation)); + } + case HA_EXTRA_IGNORE_NO_KEY: + case HA_EXTRA_NO_IGNORE_NO_KEY: + { + /* + Ignore as these are specific to NDB for handling + idempotency + */ + break; + } + case HA_EXTRA_WRITE_CAN_REPLACE: + case HA_EXTRA_WRITE_CANNOT_REPLACE: + { + /* + Informs handler that write_row() can replace rows which conflict + with row being inserted by PK/unique key without reporting error + to the SQL-layer. + + This optimization is not safe for partitioned table in general case + since we may have to put new version of row into partition which is + different from partition in which old version resides (for example + when we partition by non-PK column or by some column which is not + part of unique key which were violated). + And since NDB which is the only engine at the moment that supports + this optimization handles partitioning on its own we simple disable + it here. (BTW for NDB this optimization is safe since it supports + only KEY partitioning and won't use this optimization for tables + which have additional unique constraints). + */ + break; + } + /* Category 7), used by federated handlers */ + case HA_EXTRA_INSERT_WITH_UPDATE: + DBUG_RETURN(loop_extra(operation)); + /* Category 8) Parameters only used by NDB */ + case HA_EXTRA_DELETE_CANNOT_BATCH: + case HA_EXTRA_UPDATE_CANNOT_BATCH: + { + /* Currently only NDB use the *_CANNOT_BATCH */ + break; + } + default: + { + /* Temporary crash to discover what is wrong */ + DBUG_ASSERT(0); + break; + } + } + DBUG_RETURN(0); +} + + +/* + Special extra call to reset extra parameters + + SYNOPSIS + reset() + + RETURN VALUE + >0 Error code + 0 Success + + DESCRIPTION + Called at end of each statement to reste buffers +*/ + +int ha_partition::reset(void) +{ + int result= 0, tmp; + handler **file; + DBUG_ENTER("ha_partition::reset"); + if (m_part_info) + bitmap_set_all(&m_part_info->used_partitions); + file= m_file; + do + { + if ((tmp= (*file)->ha_reset())) + result= tmp; + } while (*(++file)); + DBUG_RETURN(result); +} + +/* + Special extra method for HA_EXTRA_CACHE with cachesize as extra parameter + + SYNOPSIS + extra_opt() + operation Must be HA_EXTRA_CACHE + cachesize Size of cache in full table scan + + RETURN VALUE + >0 Error code + 0 Success +*/ + +int ha_partition::extra_opt(enum ha_extra_function operation, ulong cachesize) +{ + DBUG_ENTER("ha_partition::extra_opt()"); + + DBUG_ASSERT(HA_EXTRA_CACHE == operation); + prepare_extra_cache(cachesize); + DBUG_RETURN(0); +} + + +/* + Call extra on handler with HA_EXTRA_CACHE and cachesize + + SYNOPSIS + prepare_extra_cache() + cachesize Size of cache for full table scan + + RETURN VALUE + NONE +*/ + +void ha_partition::prepare_extra_cache(uint cachesize) +{ + DBUG_ENTER("ha_partition::prepare_extra_cache()"); + + m_extra_cache= TRUE; + m_extra_cache_size= cachesize; + if (m_part_spec.start_part != NO_CURRENT_PART_ID) + { + late_extra_cache(m_part_spec.start_part); + } + DBUG_VOID_RETURN; +} + + +/* + Prepares our new and reorged handlers for rename or delete + + SYNOPSIS + prepare_for_delete() + + RETURN VALUE + >0 Error code + 0 Success +*/ + +int ha_partition::prepare_for_rename() +{ + int result= 0, tmp; + handler **file; + DBUG_ENTER("ha_partition::prepare_for_rename()"); + + if (m_new_file != NULL) + { + for (file= m_new_file; *file; file++) + if ((tmp= (*file)->extra(HA_EXTRA_PREPARE_FOR_RENAME))) + result= tmp; + for (file= m_reorged_file; *file; file++) + if ((tmp= (*file)->extra(HA_EXTRA_PREPARE_FOR_RENAME))) + result= tmp; + DBUG_RETURN(result); + } + + DBUG_RETURN(loop_extra(HA_EXTRA_PREPARE_FOR_RENAME)); +} + +/* + Call extra on all partitions + + SYNOPSIS + loop_extra() + operation extra operation type + + RETURN VALUE + >0 Error code + 0 Success +*/ + +int ha_partition::loop_extra(enum ha_extra_function operation) +{ + int result= 0, tmp; + handler **file; + DBUG_ENTER("ha_partition::loop_extra()"); + + /* + TODO, 5.2: this is where you could possibly add optimisations to add the bitmap + _if_ a SELECT. + */ + for (file= m_file; *file; file++) + { + if ((tmp= (*file)->extra(operation))) + result= tmp; + } + DBUG_RETURN(result); +} + + +/* + Call extra(HA_EXTRA_CACHE) on next partition_id + + SYNOPSIS + late_extra_cache() + partition_id Partition id to call extra on + + RETURN VALUE + NONE +*/ + +void ha_partition::late_extra_cache(uint partition_id) +{ + handler *file; + DBUG_ENTER("ha_partition::late_extra_cache"); + + if (!m_extra_cache) + DBUG_VOID_RETURN; + file= m_file[partition_id]; + if (m_extra_cache_size == 0) + VOID(file->extra(HA_EXTRA_CACHE)); + else + VOID(file->extra_opt(HA_EXTRA_CACHE, m_extra_cache_size)); + DBUG_VOID_RETURN; +} + + +/* + Call extra(HA_EXTRA_NO_CACHE) on next partition_id + + SYNOPSIS + late_extra_no_cache() + partition_id Partition id to call extra on + + RETURN VALUE + NONE +*/ + +void ha_partition::late_extra_no_cache(uint partition_id) +{ + handler *file; + DBUG_ENTER("ha_partition::late_extra_no_cache"); + + if (!m_extra_cache) + DBUG_VOID_RETURN; + file= m_file[partition_id]; + VOID(file->extra(HA_EXTRA_NO_CACHE)); + DBUG_VOID_RETURN; +} + + +/**************************************************************************** + MODULE optimiser support +****************************************************************************/ + +/* + Get keys to use for scanning + + SYNOPSIS + keys_to_use_for_scanning() + + RETURN VALUE + key_map of keys usable for scanning +*/ + +const key_map *ha_partition::keys_to_use_for_scanning() +{ + DBUG_ENTER("ha_partition::keys_to_use_for_scanning"); + + DBUG_RETURN(m_file[0]->keys_to_use_for_scanning()); +} + + +/* + Return time for a scan of the table + + SYNOPSIS + scan_time() + + RETURN VALUE + time for scan +*/ + +double ha_partition::scan_time() +{ + double scan_time= 0; + handler **file; + DBUG_ENTER("ha_partition::scan_time"); + + for (file= m_file; *file; file++) + if (bitmap_is_set(&(m_part_info->used_partitions), (file - m_file))) + scan_time+= (*file)->scan_time(); + DBUG_RETURN(scan_time); +} + + +/* + Get time to read + + SYNOPSIS + read_time() + index Index number used + ranges Number of ranges + rows Number of rows + + RETURN VALUE + time for read + + DESCRIPTION + This will be optimised later to include whether or not the index can + be used with partitioning. To achieve we need to add another parameter + that specifies how many of the index fields that are bound in the ranges. + Possibly added as a new call to handlers. +*/ + +double ha_partition::read_time(uint index, uint ranges, ha_rows rows) +{ + DBUG_ENTER("ha_partition::read_time"); + + DBUG_RETURN(m_file[0]->read_time(index, ranges, rows)); +} + +/* + Find number of records in a range + + SYNOPSIS + records_in_range() + inx Index number + min_key Start of range + max_key End of range + + RETURN VALUE + Number of rows in range + + DESCRIPTION + Given a starting key, and an ending key estimate the number of rows that + will exist between the two. end_key may be empty which in case determine + if start_key matches any rows. + + Called from opt_range.cc by check_quick_keys(). + + monty: MUST be called for each range and added. + Note that MySQL will assume that if this returns 0 there is no + matching rows for the range! +*/ + +ha_rows ha_partition::records_in_range(uint inx, key_range *min_key, + key_range *max_key) +{ + handler **file; + ha_rows in_range= 0; + DBUG_ENTER("ha_partition::records_in_range"); + + file= m_file; + do + { + if (bitmap_is_set(&(m_part_info->used_partitions), (file - m_file))) + { + ha_rows tmp_in_range= (*file)->records_in_range(inx, min_key, max_key); + if (tmp_in_range == HA_POS_ERROR) + DBUG_RETURN(tmp_in_range); + in_range+= tmp_in_range; + } + } while (*(++file)); + DBUG_RETURN(in_range); +} + + +/* + Estimate upper bound of number of rows + + SYNOPSIS + estimate_rows_upper_bound() + + RETURN VALUE + Number of rows +*/ + +ha_rows ha_partition::estimate_rows_upper_bound() +{ + ha_rows rows, tot_rows= 0; + handler **file; + DBUG_ENTER("ha_partition::estimate_rows_upper_bound"); + + file= m_file; + do + { + if (bitmap_is_set(&(m_part_info->used_partitions), (file - m_file))) + { + rows= (*file)->estimate_rows_upper_bound(); + if (rows == HA_POS_ERROR) + DBUG_RETURN(HA_POS_ERROR); + tot_rows+= rows; + } + } while (*(++file)); + DBUG_RETURN(tot_rows); +} + + +/** + Number of rows in table. see handler.h + + SYNOPSIS + records() + + RETURN VALUE + Number of total rows in a partitioned table. +*/ + +ha_rows ha_partition::records() +{ + ha_rows rows, tot_rows= 0; + handler **file; + DBUG_ENTER("ha_partition::records"); + + file= m_file; + do + { + rows= (*file)->records(); + if (rows == HA_POS_ERROR) + DBUG_RETURN(HA_POS_ERROR); + tot_rows+= rows; + } while (*(++file)); + DBUG_RETURN(tot_rows); +} + + +/* + Is it ok to switch to a new engine for this table + + SYNOPSIS + can_switch_engine() + + RETURN VALUE + TRUE Ok + FALSE Not ok + + DESCRIPTION + Used to ensure that tables with foreign key constraints are not moved + to engines without foreign key support. +*/ + +bool ha_partition::can_switch_engines() +{ + handler **file; + DBUG_ENTER("ha_partition::can_switch_engines"); + + file= m_file; + do + { + if (!(*file)->can_switch_engines()) + DBUG_RETURN(FALSE); + } while (*(++file)); + DBUG_RETURN(TRUE); +} + + +/* + Is table cache supported + + SYNOPSIS + table_cache_type() + +*/ + +uint8 ha_partition::table_cache_type() +{ + DBUG_ENTER("ha_partition::table_cache_type"); + + DBUG_RETURN(m_file[0]->table_cache_type()); +} + + +/**************************************************************************** + MODULE print messages +****************************************************************************/ + +const char *ha_partition::index_type(uint inx) +{ + DBUG_ENTER("ha_partition::index_type"); + + DBUG_RETURN(m_file[0]->index_type(inx)); +} + + +enum row_type ha_partition::get_row_type() const +{ + handler **file; + enum row_type type= (*m_file)->get_row_type(); + + for (file= m_file, file++; *file; file++) + { + enum row_type part_type= (*file)->get_row_type(); + if (part_type != type) + return ROW_TYPE_NOT_USED; + } + + return type; +} + + +void ha_partition::print_error(int error, myf errflag) +{ + DBUG_ENTER("ha_partition::print_error"); + + /* Should probably look for my own errors first */ + DBUG_PRINT("enter", ("error: %d", error)); + + if (error == HA_ERR_NO_PARTITION_FOUND) + m_part_info->print_no_partition_found(table); + else + m_file[m_last_part]->print_error(error, errflag); + DBUG_VOID_RETURN; +} + + +bool ha_partition::get_error_message(int error, String *buf) +{ + DBUG_ENTER("ha_partition::get_error_message"); + + /* Should probably look for my own errors first */ + DBUG_RETURN(m_file[m_last_part]->get_error_message(error, buf)); +} + + +/**************************************************************************** + MODULE handler characteristics +****************************************************************************/ +/* + If frm_error() is called then we will use this to to find out what file + extensions exist for the storage engine. This is also used by the default + rename_table and delete_table method in handler.cc. +*/ + +static const char *ha_partition_ext[]= +{ + ha_par_ext, NullS +}; + +const char **ha_partition::bas_ext() const +{ return ha_partition_ext; } + + +uint ha_partition::min_of_the_max_uint( + uint (handler::*operator_func)(void) const) const +{ + handler **file; + uint min_of_the_max= ((*m_file)->*operator_func)(); + + for (file= m_file+1; *file; file++) + { + uint tmp= ((*file)->*operator_func)(); + set_if_smaller(min_of_the_max, tmp); + } + return min_of_the_max; +} + + +uint ha_partition::max_supported_key_parts() const +{ + return min_of_the_max_uint(&handler::max_supported_key_parts); +} + + +uint ha_partition::max_supported_key_length() const +{ + return min_of_the_max_uint(&handler::max_supported_key_length); +} + + +uint ha_partition::max_supported_key_part_length() const +{ + return min_of_the_max_uint(&handler::max_supported_key_part_length); +} + + +uint ha_partition::max_supported_record_length() const +{ + return min_of_the_max_uint(&handler::max_supported_record_length); +} + + +uint ha_partition::max_supported_keys() const +{ + return min_of_the_max_uint(&handler::max_supported_keys); +} + + +uint ha_partition::extra_rec_buf_length() const +{ + handler **file; + uint max= (*m_file)->extra_rec_buf_length(); + + for (file= m_file, file++; *file; file++) + if (max < (*file)->extra_rec_buf_length()) + max= (*file)->extra_rec_buf_length(); + return max; +} + + +uint ha_partition::min_record_length(uint options) const +{ + handler **file; + uint max= (*m_file)->min_record_length(options); + + for (file= m_file, file++; *file; file++) + if (max < (*file)->min_record_length(options)) + max= (*file)->min_record_length(options); + return max; +} + + +/**************************************************************************** + MODULE compare records +****************************************************************************/ +/* + Compare two positions + + SYNOPSIS + cmp_ref() + ref1 First position + ref2 Second position + + RETURN VALUE + <0 ref1 < ref2 + 0 Equal + >0 ref1 > ref2 + + DESCRIPTION + We get two references and need to check if those records are the same. + If they belong to different partitions we decide that they are not + the same record. Otherwise we use the particular handler to decide if + they are the same. Sort in partition id order if not equal. +*/ + +int ha_partition::cmp_ref(const uchar *ref1, const uchar *ref2) +{ + uint part_id; + my_ptrdiff_t diff1, diff2; + handler *file; + DBUG_ENTER("ha_partition::cmp_ref"); + + if ((ref1[0] == ref2[0]) && (ref1[1] == ref2[1])) + { + part_id= uint2korr(ref1); + file= m_file[part_id]; + DBUG_ASSERT(part_id < m_tot_parts); + DBUG_RETURN(file->cmp_ref((ref1 + PARTITION_BYTES_IN_POS), + (ref2 + PARTITION_BYTES_IN_POS))); + } + diff1= ref2[1] - ref1[1]; + diff2= ref2[0] - ref1[0]; + if (diff1 > 0) + { + DBUG_RETURN(-1); + } + if (diff1 < 0) + { + DBUG_RETURN(+1); + } + if (diff2 > 0) + { + DBUG_RETURN(-1); + } + DBUG_RETURN(+1); +} + + +/**************************************************************************** + MODULE auto increment +****************************************************************************/ + +void ha_partition::restore_auto_increment(ulonglong) +{ + DBUG_ENTER("ha_partition::restore_auto_increment"); + + DBUG_VOID_RETURN; +} + + +/* + This method is called by update_auto_increment which in turn is called + by the individual handlers as part of write_row. We will always let + the first handler keep track of the auto increment value for all + partitions. +*/ + +void ha_partition::get_auto_increment(ulonglong offset, ulonglong increment, + ulonglong nb_desired_values, + ulonglong *first_value, + ulonglong *nb_reserved_values) +{ + ulonglong first_value_part, last_value_part, nb_reserved_values_part, + last_value= ~ (ulonglong) 0; + handler **pos, **end; + bool retry= TRUE; + DBUG_ENTER("ha_partition::get_auto_increment"); + +again: + for (pos=m_file, end= m_file+ m_tot_parts; pos != end ; pos++) + { + first_value_part= *first_value; + (*pos)->get_auto_increment(offset, increment, nb_desired_values, + &first_value_part, &nb_reserved_values_part); + if (first_value_part == ~(ulonglong)(0)) // error in one partition + { + *first_value= first_value_part; + sql_print_error("Partition failed to reserve auto_increment value"); + DBUG_VOID_RETURN; + } + /* + Partition has reserved an interval. Intersect it with the intervals + already reserved for the previous partitions. + */ + last_value_part= (nb_reserved_values_part == ULONGLONG_MAX) ? + ULONGLONG_MAX : (first_value_part + nb_reserved_values_part * increment); + set_if_bigger(*first_value, first_value_part); + set_if_smaller(last_value, last_value_part); + } + if (last_value < *first_value) /* empty intersection, error */ + { + /* + When we have an empty intersection, it means that one or more + partitions may have a significantly different autoinc next value. + We should not fail here - it just means that we should try to + find a new reservation making use of the current *first_value + wbich should now be compatible with all partitions. + */ + if (retry) + { + retry= FALSE; + last_value= ~ (ulonglong) 0; + release_auto_increment(); + goto again; + } + /* + We should not get here. + */ + sql_print_error("Failed to calculate auto_increment value for partition"); + + *first_value= ~(ulonglong)(0); + } + if (increment) // If not check for values + *nb_reserved_values= (last_value == ULONGLONG_MAX) ? + ULONGLONG_MAX : ((last_value - *first_value) / increment); + DBUG_VOID_RETURN; +} + +void ha_partition::release_auto_increment() +{ + DBUG_ENTER("ha_partition::release_auto_increment"); + + for (uint i= 0; i < m_tot_parts; i++) + { + m_file[i]->ha_release_auto_increment(); + } + DBUG_VOID_RETURN; +} + +/**************************************************************************** + MODULE initialise handler for HANDLER call +****************************************************************************/ + +void ha_partition::init_table_handle_for_HANDLER() +{ + return; +} + + +/**************************************************************************** + MODULE enable/disable indexes +****************************************************************************/ + +/* + Disable indexes for a while + SYNOPSIS + disable_indexes() + mode Mode + RETURN VALUES + 0 Success + != 0 Error +*/ + +int ha_partition::disable_indexes(uint mode) +{ + handler **file; + int error= 0; + + for (file= m_file; *file; file++) + { + if ((error= (*file)->ha_disable_indexes(mode))) + break; + } + return error; +} + + +/* + Enable indexes again + SYNOPSIS + enable_indexes() + mode Mode + RETURN VALUES + 0 Success + != 0 Error +*/ + +int ha_partition::enable_indexes(uint mode) +{ + handler **file; + int error= 0; + + for (file= m_file; *file; file++) + { + if ((error= (*file)->ha_enable_indexes(mode))) + break; + } + return error; +} + + +/* + Check if indexes are disabled + SYNOPSIS + indexes_are_disabled() + + RETURN VALUES + 0 Indexes are enabled + != 0 Indexes are disabled +*/ + +int ha_partition::indexes_are_disabled(void) +{ + handler **file; + int error= 0; + + for (file= m_file; *file; file++) + { + if ((error= (*file)->indexes_are_disabled())) + break; + } + return error; +} + + +/**************************************************************************** + MODULE Partition Share +****************************************************************************/ +/* + Service routines for ... methods. +------------------------------------------------------------------------- + Variables for partition share methods. A hash used to track open tables. + A mutex for the hash table and an init variable to check if hash table + is initialised. + There is also a constant ending of the partition handler file name. +*/ + +#ifdef NOT_USED +static HASH partition_open_tables; +static pthread_mutex_t partition_mutex; +static int partition_init= 0; + + +/* + Function we use in the creation of our hash to get key. +*/ + +static uchar *partition_get_key(PARTITION_SHARE *share, size_t *length, + my_bool not_used __attribute__ ((unused))) +{ + *length= share->table_name_length; + return (uchar *) share->table_name; +} + +/* + Example of simple lock controls. The "share" it creates is structure we + will pass to each partition handler. Do you have to have one of these? + Well, you have pieces that are used for locking, and they are needed to + function. +*/ + +static PARTITION_SHARE *get_share(const char *table_name, TABLE *table) +{ + PARTITION_SHARE *share; + uint length; + char *tmp_name; + + /* + So why does this exist? There is no way currently to init a storage + engine. + Innodb and BDB both have modifications to the server to allow them to + do this. Since you will not want to do this, this is probably the next + best method. + */ + if (!partition_init) + { + /* Hijack a mutex for init'ing the storage engine */ + pthread_mutex_lock(&LOCK_mysql_create_db); + if (!partition_init) + { + partition_init++; + VOID(pthread_mutex_init(&partition_mutex, MY_MUTEX_INIT_FAST)); + (void) hash_init(&partition_open_tables, system_charset_info, 32, 0, 0, + (hash_get_key) partition_get_key, 0, 0); + } + pthread_mutex_unlock(&LOCK_mysql_create_db); + } + pthread_mutex_lock(&partition_mutex); + length= (uint) strlen(table_name); + + if (!(share= (PARTITION_SHARE *) hash_search(&partition_open_tables, + (uchar *) table_name, length))) + { + if (!(share= (PARTITION_SHARE *) + my_multi_malloc(MYF(MY_WME | MY_ZEROFILL), + &share, (uint) sizeof(*share), + &tmp_name, (uint) length + 1, NullS))) + { + pthread_mutex_unlock(&partition_mutex); + return NULL; + } + + share->use_count= 0; + share->table_name_length= length; + share->table_name= tmp_name; + strmov(share->table_name, table_name); + if (my_hash_insert(&partition_open_tables, (uchar *) share)) + goto error; + thr_lock_init(&share->lock); + pthread_mutex_init(&share->mutex, MY_MUTEX_INIT_FAST); + } + share->use_count++; + pthread_mutex_unlock(&partition_mutex); + + return share; + +error: + pthread_mutex_unlock(&partition_mutex); + my_free((uchar*) share, MYF(0)); + + return NULL; +} + + +/* + Free lock controls. We call this whenever we close a table. If the table + had the last reference to the share then we free memory associated with + it. +*/ + +static int free_share(PARTITION_SHARE *share) +{ + pthread_mutex_lock(&partition_mutex); + if (!--share->use_count) + { + hash_delete(&partition_open_tables, (uchar *) share); + thr_lock_delete(&share->lock); + pthread_mutex_destroy(&share->mutex); + my_free((uchar*) share, MYF(0)); + } + pthread_mutex_unlock(&partition_mutex); + + return 0; +} +#endif /* NOT_USED */ + +struct st_mysql_storage_engine partition_storage_engine= +{ MYSQL_HANDLERTON_INTERFACE_VERSION }; + +mysql_declare_plugin(partition) +{ + MYSQL_STORAGE_ENGINE_PLUGIN, + &partition_storage_engine, + "partition", + "Mikael Ronstrom, MySQL AB", + "Partition Storage Engine Helper", + PLUGIN_LICENSE_GPL, + partition_initialize, /* Plugin Init */ + NULL, /* Plugin Deinit */ + 0x0100, /* 1.0 */ + NULL, /* status variables */ + NULL, /* system variables */ + NULL /* config options */ +} +mysql_declare_plugin_end; + +#endif |