Drizzled Public API Documentation

drizzled::Cursor Class Reference

#include <cursor.h>

Inheritance diagram for drizzled::Cursor:
drizzled::SEAPITesterCursor FunctionCursor ha_heap ha_innobase ha_myisam HailDBCursor TableProtoTesterCursor

List of all members.

Public Types

enum  { NONE = 0, INDEX, RND }

Public Member Functions

plugin::StorageEnginegetEngine () const
TableSharegetShare ()
TablegetTable () const
uint64_t getNextInsertId ()
uint64_t getAutoIncrement ()
 Cursor (plugin::StorageEngine &engine_arg, Table &share_arg)
virtual Cursorclone (memory::Root *mem_root)
int ha_open (const identifier::Table &identifier, int mode, int test_if_locked)
int startIndexScan (uint32_t idx, bool sorted) __attribute__((warn_unused_result))
int endIndexScan ()
int startTableScan (bool scan) __attribute__((warn_unused_result))
int endTableScan ()
int ha_reset ()
int ha_index_or_rnd_end ()
int ha_external_lock (Session *session, int lock_type)
int insertRecord (unsigned char *buf) __attribute__((warn_unused_result))
int updateRecord (const unsigned char *old_data, unsigned char *new_data) __attribute__((warn_unused_result))
int deleteRecord (const unsigned char *buf) __attribute__((warn_unused_result))
void ha_release_auto_increment ()
int ha_check (Session *session, HA_CHECK_OPT *check_opt)
void ha_start_bulk_insert (ha_rows rows)
int ha_end_bulk_insert ()
int ha_delete_all_rows ()
int ha_reset_auto_increment (uint64_t value)
int ha_analyze (Session *session, HA_CHECK_OPT *check_opt)
int ha_disable_indexes (uint32_t mode)
int ha_enable_indexes (uint32_t mode)
int ha_discard_or_import_tablespace (bool discard)
void closeMarkForDelete (const char *name)
void adjust_next_insert_id_after_explicit_value (uint64_t nr)
int update_auto_increment ()
virtual double scan_time (void)
virtual double read_time (uint32_t, uint32_t ranges, ha_rows rows)
virtual double index_only_read_time (uint32_t keynr, double records)
virtual ha_rows multi_range_read_info_const (uint32_t keyno, RANGE_SEQ_IF *seq, void *seq_init_param, uint32_t n_ranges, uint32_t *bufsz, uint32_t *flags, optimizer::CostVector *cost)
virtual int multi_range_read_info (uint32_t keyno, uint32_t n_ranges, uint32_t keys, uint32_t *bufsz, uint32_t *flags, optimizer::CostVector *cost)
virtual int multi_range_read_init (RANGE_SEQ_IF *seq, void *seq_init_param, uint32_t n_ranges, uint32_t mode)
virtual int multi_range_read_next (char **range_info)
virtual const key_map * keys_to_use_for_scanning ()
bool has_transactions ()
virtual bool is_fatal_error (int error, uint32_t flags)
virtual ha_rows records ()
virtual uint64_t tableSize ()
virtual uint64_t rowSize ()
virtual ha_rows estimate_rows_upper_bound ()
virtual const char * index_type (uint32_t)
uint32_t get_index (void) const
virtual int close (void)=0
virtual int index_read_map (unsigned char *buf, const unsigned char *key, key_part_map keypart_map, enum ha_rkey_function find_flag)
 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.
virtual int index_read_idx_map (unsigned char *buf, uint32_t index, const unsigned char *key, key_part_map keypart_map, enum ha_rkey_function find_flag)
 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.
virtual int index_next (unsigned char *) __attribute__((warn_unused_result))
virtual int index_prev (unsigned char *)
virtual int index_first (unsigned char *)
virtual int index_last (unsigned char *)
virtual int index_next_same (unsigned char *, const unsigned char *, uint32_t)
virtual int index_read_last_map (unsigned char *buf, const unsigned char *key, key_part_map keypart_map)
 The following functions works like index_read, but it find the last row with the current key value or prefix.
virtual int read_range_first (const key_range *start_key, const key_range *end_key, bool eq_range, bool sorted)
virtual int read_range_next ()
int compare_key (key_range *range)
virtual int rnd_next (unsigned char *)=0
virtual int rnd_pos (unsigned char *, unsigned char *)=0
virtual int read_first_row (unsigned char *buf, uint32_t primary_key)
virtual int rnd_same (unsigned char *, uint32_t)
virtual ha_rows records_in_range (uint32_t, key_range *, key_range *)
virtual void position (const unsigned char *record)=0
virtual int info (uint32_t)=0
virtual uint32_t calculate_key_hash_value (Field **)
virtual int extra (enum ha_extra_function)
virtual int extra_opt (enum ha_extra_function operation, uint32_t)
virtual bool was_semi_consistent_read ()
virtual void try_semi_consistent_read (bool)
virtual void unlock_row (void)
virtual void get_auto_increment (uint64_t offset, uint64_t increment, uint64_t nb_desired_values, uint64_t *first_value, uint64_t *nb_reserved_values)=0
void set_next_insert_id (uint64_t id)
void restore_auto_increment (uint64_t prev_insert_id)
virtual int indexes_are_disabled (void)
virtual void append_create_info (String *)
virtual char * get_foreign_key_create_info (void)
virtual bool can_switch_engines (void)
virtual int get_foreign_key_list (Session *, List< ForeignKeyInfo > *)
virtual uint32_t referenced_by_foreign_key ()
virtual void free_foreign_key_create_info (char *)
virtual THR_LOCK_DATA ** store_lock (Session *, THR_LOCK_DATA **to, enum thr_lock_type)
virtual bool primary_key_is_clustered ()
virtual int cmp_ref (const unsigned char *ref1, const unsigned char *ref2)
virtual bool isOrdered (void)

Public Attributes

unsigned char * ref
unsigned char * dup_ref
ha_statistics stats
range_seq_t mrr_iter
RANGE_SEQ_IF mrr_funcs
uint32_t ranges_in_seq
bool mrr_is_output_sorted
bool mrr_have_range
bool eq_range
KEY_MULTI_RANGE mrr_cur_range
key_range save_end_range
key_rangeend_range
KeyPartInforange_key_part
int key_compare_result_on_equal
uint32_t errkey
uint32_t key_used_on_scan
uint32_t active_index
uint32_t ref_length
enum drizzled::Cursor:: { ... }  inited
bool locked
uint64_t next_insert_id
uint64_t insert_id_for_cur_row
Discrete_interval auto_inc_interval_for_cur_row

Protected Member Functions

void ha_statistic_increment (uint64_t system_status_var::*offset) const
void ** ha_data (Session *) const

Protected Attributes

ha_rows estimation_rows_to_insert

Private Member Functions

uint32_t calculate_key_len (uint32_t key_position, key_part_map keypart_map_arg)
void setTransactionReadWrite ()
virtual int open (const char *, int, uint32_t)
virtual int doOpen (const identifier::Table &identifier, int mode, uint32_t test_if_locked)
virtual int doStartIndexScan (uint32_t idx, bool)
virtual int doEndIndexScan ()
virtual int doStartTableScan (bool scan) __attribute__((warn_unused_result))=0
virtual int doEndTableScan ()
virtual int doInsertRecord (unsigned char *)
virtual int doUpdateRecord (const unsigned char *, unsigned char *)
virtual int doDeleteRecord (const unsigned char *)
virtual int reset ()
virtual int external_lock (Session *, int)
virtual void release_auto_increment (void)
virtual int check (Session *)
virtual void start_bulk_insert (ha_rows)
virtual int end_bulk_insert (void)
virtual int index_read (unsigned char *, const unsigned char *, uint32_t, enum ha_rkey_function)
virtual int index_read_last (unsigned char *, const unsigned char *, uint32_t)
virtual int delete_all_rows (void)
virtual int reset_auto_increment (uint64_t)
virtual int analyze (Session *)
virtual int disable_indexes (uint32_t)
virtual int enable_indexes (uint32_t)
virtual int discard_or_import_tablespace (bool)
virtual void drop_table (const char *name)

Private Attributes

Tabletable
plugin::StorageEngineengine

Friends

class SEAPITesterCursor

Detailed Description

The Cursor class is the interface for dynamically loadable storage engines. Do not add ifdefs and take care when adding or changing virtual functions to avoid vtable confusion

Functions in this class accept and return table columns data. Two data representation formats are used: 1. TableRecordFormat - Used to pass [partial] table records to/from storage engine

2. KeyTupleFormat - used to pass index search tuples (aka "keys") to storage engine. See optimizer/range.cc for description of this format.

TableRecordFormat ================= [Warning: this description is work in progress and may be incomplete] The table record is stored in a fixed-size buffer:

record: null_bytes, column1_data, column2_data, ...

The offsets of the parts of the buffer are also fixed: every column has an offset to its column{i}_data, and if it is nullable it also has its own bit in null_bytes.

The record buffer only includes data about columns that are marked in the relevant column set (table->read_set and/or table->write_set, depending on the situation). <not-sure>It could be that it is required that null bits of non-present columns are set to 1</not-sure>

VARIOUS EXCEPTIONS AND SPECIAL CASES

f the table has no nullable columns, then null_bytes is still present, its length is one byte <not-sure> which must be set to 0xFF at all times. </not-sure>

For blob columns (see Field_blob), the record buffer stores length of the data, following by memory pointer to the blob data. The pointer is owned by the storage engine and is valid until the next operation.

If a blob column has NULL value, then its length and blob data pointer must be set to 0.

Definition at line 136 of file cursor.h.


Member Function Documentation

virtual bool drizzled::Cursor::can_switch_engines ( void  ) [inline, virtual]

used in ALTER Table; if changing storage engine is allowed. e.g. not be allowed if table has foreign key constraints in engine.

Reimplemented in ha_innobase.

Definition at line 463 of file cursor.h.

Referenced by drizzled::internal_alter_table().

virtual int drizzled::Cursor::check ( Session ) [inline, private, virtual]

admin commands - called from mysql_admin_table

Reimplemented in ha_innobase.

Definition at line 587 of file cursor.h.

void drizzled::Cursor::closeMarkForDelete ( const char *  name)

Drop table in the engine: public interface.

See also:
Cursor::drop_table()

Definition at line 799 of file cursor.cc.

References setTransactionReadWrite().

int drizzled::Cursor::compare_key ( key_range range)

Compare if found key (in row) is over max-value.

Parameters:
rangerange to compare to row. May be 0 for no range

key.cc::key_cmp()

Returns:
The return value is SIGN(key_in_row - range_key):
  • 0 : Key is equal to range or 'range' == 0 (no range)
  • -1 : Key is less than range
  • 1 : Key is larger than range

Definition at line 1256 of file cursor.cc.

References drizzled::key_cmp().

Referenced by read_range_first(), and read_range_next().

virtual int drizzled::Cursor::delete_all_rows ( void  ) [inline, private, virtual]

This is called to delete all rows in a table If the Cursor don't support this, then this function will return HA_ERR_WRONG_COMMAND and MySQL will delete the rows one by one.

Reimplemented in HailDBCursor, ha_innobase, ha_heap, and ha_myisam.

Definition at line 604 of file cursor.h.

Referenced by ha_delete_all_rows().

virtual int drizzled::Cursor::doStartTableScan ( bool  scan) [private, pure virtual]

doStartTableScan() can be called two times without doEndTableScan() in between (it only makes sense if scan=1). then the second call should prepare for the new table scan (e.g if rnd_init allocates the cursor, second call should position it to the start of the table, no need to deallocate and allocate it again

Implemented in FunctionCursor, HailDBCursor, ha_innobase, ha_heap, ha_myisam, drizzled::SEAPITesterCursor, and TableProtoTesterCursor.

virtual ha_rows drizzled::Cursor::estimate_rows_upper_bound ( void  ) [inline, virtual]

Return upper bound of current number of records in the table (max. of how many records one will retrieve when doing a full table scan) If upper bound is not known, HA_POS_ERROR should be returned as a max possible upper bound.

Reimplemented in FunctionCursor, and ha_innobase.

Definition at line 318 of file cursor.h.

Referenced by drizzled::FileSort::run().

virtual int drizzled::Cursor::external_lock ( Session ,
int   
) [inline, private, virtual]

Is not invoked for non-transactional temporary tables.

Tells the storage engine that we intend to read or write data from the table. This call is prefixed with a call to Cursor::store_lock() and is invoked only for those Cursor instances that stored the lock.

Calls to rnd_init/index_init are prefixed with this call. When table IO is complete, we call external_lock(F_UNLCK). A storage engine writer should expect that each call to ::external_lock(F_[RD|WR]LOCK is followed by a call to ::external_lock(F_UNLCK). If it is not, it is a bug in MySQL.

The name and signature originate from the first implementation in MyISAM, which would call fcntl to set/clear an advisory lock on the data file in this method.

Parameters:
lock_typeF_RDLCK, F_WRLCK, F_UNLCK
Returns:
non-0 in case of failure, 0 in case of success. When lock_type is F_UNLCK, the return value is ignored.

Reimplemented in HailDBCursor, ha_innobase, ha_myisam, and drizzled::SEAPITesterCursor.

Definition at line 581 of file cursor.h.

Referenced by ha_external_lock().

virtual char* drizzled::Cursor::get_foreign_key_create_info ( void  ) [inline, virtual]

If index == MAX_KEY then a check for table is made and if index < MAX_KEY then a check is made if the table has foreign keys and if a foreign key uses this index (and thus the index cannot be dropped).

Parameters:
indexIndex to check if foreign key uses it
Return values:
trueForeign key defined on table or index
falseNo foreign key defined

Reimplemented in ha_innobase.

Definition at line 458 of file cursor.h.

virtual int drizzled::Cursor::get_foreign_key_list ( Session ,
List< ForeignKeyInfo > *   
) [inline, virtual]

used in REPLACE; is > 0 if table is referred by a FOREIGN KEY

Reimplemented in ha_innobase.

Definition at line 465 of file cursor.h.

uint64_t drizzled::Cursor::getAutoIncrement ( ) [inline]

Used by SHOW TABLE STATUS to get the current auto_inc from the engine

Definition at line 208 of file cursor.h.

int drizzled::Cursor::ha_analyze ( Session session,
HA_CHECK_OPT check_opt 
)

Analyze table: public interface.

See also:
Cursor::analyze()

Definition at line 741 of file cursor.cc.

References setTransactionReadWrite().

int drizzled::Cursor::ha_check ( Session session,
HA_CHECK_OPT check_opt 
)

to be actually called to get 'check()' functionality

Performs checks upon the table.

Parameters:
sessionthread doing CHECK Table operation
check_optoptions from the parser
Return values:
HA_ADMIN_OKSuccessful upgrade
HA_ADMIN_NEEDS_UPGRADETable has structures requiring upgrade
HA_ADMIN_NEEDS_ALTERTable has structures requiring ALTER Table
HA_ADMIN_NOT_IMPLEMENTED

Definition at line 645 of file cursor.cc.

int drizzled::Cursor::ha_delete_all_rows ( )

Delete all rows: public interface.

See also:
Cursor::delete_all_rows()
Note:

This is now equalivalent to TRUNCATE TABLE.

Trigger post-truncate notification to plugins...

Todo:
Make TransactionServices generic to AfterTriggerServices or similar...

Definition at line 696 of file cursor.cc.

References delete_all_rows(), drizzled::Table::in_use, setTransactionReadWrite(), drizzled::TransactionServices::singleton(), and drizzled::TransactionServices::truncateTable().

Referenced by drizzled::select_union::cleanup(), and drizzled::delete_query().

int drizzled::Cursor::ha_disable_indexes ( uint32_t  mode)

Disable indexes: public interface.

See also:
Cursor::disable_indexes()

Definition at line 755 of file cursor.cc.

References setTransactionReadWrite().

Referenced by drizzled::alter_table_manage_keys(), and drizzled::internal_alter_table().

int drizzled::Cursor::ha_discard_or_import_tablespace ( bool  discard)

Discard or import tablespace: public interface.

See also:
Cursor::discard_or_import_tablespace()

Definition at line 785 of file cursor.cc.

References setTransactionReadWrite().

int drizzled::Cursor::ha_enable_indexes ( uint32_t  mode)

Enable indexes: public interface.

See also:
Cursor::enable_indexes()

Definition at line 770 of file cursor.cc.

References setTransactionReadWrite().

Referenced by drizzled::alter_table_manage_keys(), and drizzled::internal_alter_table().

int drizzled::Cursor::ha_external_lock ( Session session,
int  lock_type 
)

These functions represent the public interface to *users* of the Cursor class, hence they are *not* virtual. For the inheritance interface, see the (private) functions doInsertRecord(), doUpdateRecord(), and doDeleteRecord() below.

Definition at line 1387 of file cursor.cc.

References external_lock(), and next_insert_id.

int drizzled::Cursor::ha_open ( const identifier::Table identifier,
int  mode,
int  test_if_locked 
)

Open database-Cursor.

Try O_RDONLY if cannot open as O_RDWR Don't wait for locks if not HA_OPEN_WAIT_IF_LOCKED is set

Definition at line 223 of file cursor.cc.

References drizzled::Table::db_stat, and ref_length.

void drizzled::Cursor::ha_release_auto_increment ( )

Reserves an interval of auto_increment values from the Cursor.

offset and increment means that we want values to be of the form offset + N * increment, where N>=0 is integer. If the function sets *first_value to ~(uint64_t)0 it means an error. If the function sets *nb_reserved_values to UINT64_MAX it means it has reserved to "positive infinite".

Parameters:
offset
increment
nb_desired_valueshow many values we want
first_value(OUT) the first value reserved by the Cursor
nb_reserved_values(OUT) how many values the Cursor reserved

Definition at line 608 of file cursor.cc.

References auto_inc_interval_for_cur_row, drizzled::Session::auto_inc_intervals_forced, drizzled::Table::in_use, insert_id_for_cur_row, and next_insert_id.

Referenced by drizzled::insert_query().

int drizzled::Cursor::ha_reset ( )

Check Cursor usage and reset state of file to after 'open'

Definition at line 1449 of file cursor.cc.

References reset().

Referenced by drizzled::Session::free_cached_table(), and drizzled::Session::mark_used_tables_as_free_for_reuse().

int drizzled::Cursor::ha_reset_auto_increment ( uint64_t  value)

Reset auto increment: public interface.

See also:
Cursor::reset_auto_increment()

Definition at line 726 of file cursor.cc.

References reset_auto_increment(), and setTransactionReadWrite().

Referenced by drizzled::delete_query().

double drizzled::Cursor::index_only_read_time ( uint32_t  keynr,
double  key_records 
) [virtual]

Calculate cost of 'index only' scan for given index and number of records

Parameters:
keynrIndex number
recordsEstimated number of records to be retrieved
Note:
It is assumed that we will read trough the whole key range and that all key blocks are half full (normally things are much better). It is also assumed that each time we read the next key from the index, the Cursor performs a random seek, thus the cost is proportional to the number of blocks read.
Todo:
Consider joining this function and Cursor::read_time() into one Cursor::read_time(keynr, records, ranges, bool index_only) function.
Returns:
Estimated cost of 'index only' scan

Definition at line 882 of file cursor.cc.

References drizzled::Table::key_info, and ref_length.

Referenced by drizzled::best_access_path(), multi_range_read_info(), and multi_range_read_info_const().

bool drizzled::Cursor::is_fatal_error ( int  error,
uint32_t  flags 
) [virtual]

This method is used to analyse the error to see whether the error is ignorable or not, certain handlers can have more error that are ignorable than others. E.g. the partition Cursor can get inserts into a range where there is no partition and this is an ignorable error. HA_ERR_FOUND_DUP_UNIQUE is a special case in MyISAM that means the same thing as HA_ERR_FOUND_DUP_KEY but can in some cases lead to a slightly different error message.

Definition at line 197 of file cursor.cc.

Referenced by drizzled::update_query().

int drizzled::Cursor::multi_range_read_info ( uint32_t  keyno,
uint32_t  n_ranges,
uint32_t  n_rows,
uint32_t *  bufsz,
uint32_t *  flags,
optimizer::CostVector cost 
) [virtual]

Get cost and other information about MRR scan over some sequence of ranges

Calculate estimated cost and other information about an MRR scan for some sequence of ranges.

The ranges themselves will be known only at execution phase. When this function is called we only know number of ranges and a (rough) E(records) within those ranges.

Currently this function is only called for "n-keypart singlepoint" ranges, i.e. each range is "keypart1=someconst1 AND ... AND keypartN=someconstN"

The flags parameter is a combination of those flags: HA_MRR_SORTED, HA_MRR_INDEX_ONLY, HA_MRR_NO_ASSOCIATION, HA_MRR_LIMITS.

Parameters:
keynoIndex number
n_rangesEstimated number of ranges (i.e. intervals) in the range sequence.
n_rowsEstimated total number of records contained within all of the ranges
bufszINOUT IN: Size of the buffer available for use OUT: Size of the buffer that will be actually used, or 0 if buffer is not needed.
flagsINOUT A combination of HA_MRR_* flags
costOUT Estimated cost of MRR access
Return values:
0OK, *cost contains cost of the scan, *bufsz and *flags contain scan parameters.
otherError or can't perform the requested scan

Definition at line 1014 of file cursor.cc.

References index_only_read_time().

ha_rows drizzled::Cursor::multi_range_read_info_const ( uint32_t  keyno,
RANGE_SEQ_IF seq,
void *  seq_init_param,
uint32_t  n_ranges,
uint32_t *  bufsz,
uint32_t *  flags,
optimizer::CostVector cost 
) [virtual]

Get cost and other information about MRR scan over a known list of ranges

Calculate estimated cost and other information about an MRR scan for given sequence of ranges.

Parameters:
keynoIndex number
seqRange sequence to be traversed
seq_init_paramFirst parameter for seq->init()
n_ranges_argNumber of ranges in the sequence, or 0 if the caller can't efficiently determine it
bufszINOUT IN: Size of the buffer available for use OUT: Size of the buffer that is expected to be actually used, or 0 if buffer is not needed.
flagsINOUT A combination of HA_MRR_* flags
costOUT Estimated cost of MRR access
Note:
This method (or an overriding one in a derived class) must check for session->getKilled() and return HA_POS_ERROR if it is not zero. This is required for a user to be able to interrupt the calculation by killing the connection/query.
Return values:
HA_POS_ERRORError or the engine is unable to perform the requested scan. Values of OUT parameters are undefined.
otherOK, *cost contains cost of the scan, *bufsz and *flags contain scan parameters.

Definition at line 927 of file cursor.cc.

References index_only_read_time(), and TIME_FOR_COMPARE.

int drizzled::Cursor::multi_range_read_init ( RANGE_SEQ_IF seq_funcs,
void *  seq_init_param,
uint32_t  n_ranges,
uint32_t  mode 
) [virtual]

Initialize the MRR scan

Initialize the MRR scan. This function may do heavyweight scan initialization like row prefetching/sorting/etc (NOTE: but better not do it here as we may not need it, e.g. if we never satisfy WHERE clause on previous tables. For many implementations it would be natural to do such initializations in the first multi_read_range_next() call)

mode is a combination of the following flags: HA_MRR_SORTED, HA_MRR_INDEX_ONLY, HA_MRR_NO_ASSOCIATION

Parameters:
seqRange sequence to be traversed
seq_init_paramFirst parameter for seq->init()
n_rangesNumber of ranges in the sequence
modeFlags, see the description section for the details
bufINOUT: memory buffer to be used
Note:
One must have called doStartIndexScan() before calling this function. Several multi_range_read_init() calls may be made in course of one query.

Until WL#2623 is done (see its text, section 3.2), the following will also hold: The caller will guarantee that if "seq->init == mrr_ranges_array_init" then seq_init_param is an array of n_ranges KEY_MULTI_RANGE structures. This property will only be used by NDB Cursor until WL#2623 is done.

Buffer memory management is done according to the following scenario: The caller allocates the buffer and provides it to the callee by filling the members of HANDLER_BUFFER structure. The callee consumes all or some fraction of the provided buffer space, and sets the HANDLER_BUFFER members accordingly. The callee may use the buffer memory until the next multi_range_read_init() call is made, all records have been read, or until doEndIndexScan() call is made, whichever comes first.

Return values:
0OK
1Error

Definition at line 1075 of file cursor.cc.

References mrr_have_range, and mrr_iter.

int drizzled::Cursor::multi_range_read_next ( char **  range_info) [virtual]

Get next record in MRR scan

Default MRR implementation: read the next record

Parameters:
range_infoOUT Undefined if HA_MRR_NO_ASSOCIATION flag is in effect Otherwise, the opaque value associated with the range that contains the returned record.
Return values:
0OK
otherError code

Definition at line 1100 of file cursor.cc.

References mrr_cur_range, mrr_have_range, mrr_iter, read_range_first(), read_range_next(), and was_semi_consistent_read().

int drizzled::Cursor::read_first_row ( unsigned char *  buf,
uint32_t  primary_key 
) [virtual]

Read first row (only) from a table.

This is never called for InnoDB tables, as these table types has the HA_STATS_RECORDS_IS_EXACT set.

Definition at line 266 of file cursor.cc.

int drizzled::Cursor::read_range_first ( const key_range start_key,
const key_range end_key,
bool  eq_range_arg,
bool  sorted 
) [virtual]

Read first row between two ranges.

Parameters:
start_keyStart key. Is 0 if no min range
end_keyEnd key. Is 0 if no max range
eq_range_argSet to 1 if start_key == end_key
sortedSet to 1 if result should be sorted per key
Note:
Record is read into table->getInsertRecord()
Return values:
0Found row
HA_ERR_END_OF_FILENo rows in range
\::Error code

Reimplemented in ha_innobase, and ha_myisam.

Definition at line 1176 of file cursor.cc.

References compare_key(), index_read_map(), drizzled::Table::key_info, and save_end_range.

Referenced by multi_range_read_next().

int drizzled::Cursor::read_range_next ( ) [virtual]

Read next row between two endpoints.

Note:
Record is read into table->getInsertRecord()
Return values:
0Found row
HA_ERR_END_OF_FILENo rows in range
\::Error code

Reimplemented in ha_innobase, and ha_myisam.

Definition at line 1223 of file cursor.cc.

References compare_key().

Referenced by multi_range_read_next().

ha_rows drizzled::Cursor::records ( ) [virtual]

Number of rows in table. It will only be called if (table_flags() & (HA_HAS_RECORDS | HA_STATS_RECORDS_IS_EXACT)) != 0

Definition at line 208 of file cursor.cc.

virtual int drizzled::Cursor::reset ( void  ) [inline, private, virtual]

Reset state of file to after 'open'. This function is called after every statement for all tables used by that statement.

Reimplemented in FunctionCursor, HailDBCursor, ha_innobase, ha_heap, ha_myisam, and drizzled::SEAPITesterCursor.

Definition at line 557 of file cursor.h.

Referenced by ha_reset().

virtual int drizzled::Cursor::reset_auto_increment ( uint64_t  ) [inline, private, virtual]

Reset the auto-increment counter to the given value, i.e. the next row inserted will get the given value. This is called e.g. after TRUNCATE is emulated by doing a 'DELETE FROM t'. HA_ERR_WRONG_COMMAND is returned by storage engines that don't support this operation.

Reimplemented in ha_innobase, ha_heap, and ha_myisam.

Definition at line 612 of file cursor.h.

Referenced by ha_reset_auto_increment().

void drizzled::Cursor::setTransactionReadWrite ( ) [inline, private]
virtual THR_LOCK_DATA** drizzled::Cursor::store_lock ( Session ,
THR_LOCK_DATA **  to,
enum thr_lock_type   
) [inline, virtual]

Is not invoked for non-transactional temporary tables.

Note:
store_lock() can return more than one lock if the table is MERGE or partitioned.
that one can NOT rely on table->in_use in store_lock(). It may refer to a different thread if called from abortLockForThread().
If the table is MERGE, store_lock() can return less locks than lock_count() claimed. This can happen when the MERGE children are not attached when this is called from another thread.

Reimplemented in ha_innobase, and drizzled::SEAPITesterCursor.

Definition at line 483 of file cursor.h.

Referenced by drizzled::Session::get_lock_data().

virtual void drizzled::Cursor::try_semi_consistent_read ( bool  ) [inline, virtual]

Tell the engine whether it should avoid unnecessary lock waits. If yes, in an UPDATE or DELETE, if the row under the cursor was locked by another transaction, the engine may try an optimistic read of the last committed row value under the cursor.

Reimplemented in ha_innobase.

Definition at line 416 of file cursor.h.

Referenced by drizzled::update_query().

virtual bool drizzled::Cursor::was_semi_consistent_read ( void  ) [inline, virtual]

In an UPDATE or DELETE, if the row under the cursor was locked by another transaction, and the engine used an optimistic read of the last committed row value under the cursor, then the engine returns 1 from this function. MySQL must NOT try to update this optimistic value. If the optimistic value does not match the WHERE condition, MySQL can decide to skip over this row. Currently only works for InnoDB. This can be used to avoid unnecessary lock waits.

If this method returns nonzero, it will also signal the storage engine that the next read will be a locking re-read of the row.

Reimplemented in ha_innobase.

Definition at line 409 of file cursor.h.

Referenced by multi_range_read_next(), and drizzled::update_query().


Member Data Documentation

Interval returned by get_auto_increment() and being consumed by the inserter.

Definition at line 224 of file cursor.h.

Referenced by ha_release_auto_increment().

insert id for the current row (*autogenerated*; if not autogenerated, it's 0). At first successful insertion, this variable is stored into Session::first_successful_insert_id_in_cur_stmt.

Definition at line 219 of file cursor.h.

Referenced by ha_release_auto_increment().

Current range (the one we're now returning rows from)

Definition at line 175 of file cursor.h.

Referenced by multi_range_read_next().

true <=> we're currently traversing a range in mrr_cur_range.

Definition at line 170 of file cursor.h.

Referenced by multi_range_read_init(), and multi_range_read_next().

MultiRangeRead-related members:

Definition at line 162 of file cursor.h.

Referenced by multi_range_read_init(), and multi_range_read_next().

next_insert_id is the next value which should be inserted into the auto_increment column: in a inserting-multi-row statement (like INSERT SELECT), for the first row where the autoinc value is not specified by the statement, get_auto_increment() called and asked to generate a value, next_insert_id is set to the next value, then for all other rows next_insert_id is used (and increased each time) without calling get_auto_increment().

Definition at line 199 of file cursor.h.

Referenced by ha_external_lock(), and ha_release_auto_increment().

The following are for read_range()

Definition at line 178 of file cursor.h.

Referenced by read_range_first().


The documentation for this class was generated from the following files: