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WL#2126 - Multi_read_range.

Browse source 
Added the required structures and functions for
handing over multiple key ranges to the table handler.


include/my_base.h:
  WL#2126 - Multi_read_range.
  Moved key range flags from sql/opt_range.h to here.
  Added the multi-range structure.
sql/handler.cc:
  WL#2126 - Multi_read_range.
  Added the new table handler methods.
sql/handler.h:
  WL#2126 - Multi_read_range.
  Added a new table flag.
  Added a declaration for the handler buffer.
  Added new elements to class handler.
  Added new function declarations.
sql/mysqld.cc:
  WL#2126 - Multi_read_range.
  Added an option to set new system variable 'multi_range_count'.
sql/opt_range.cc:
  WL#2126 - Multi_read_range.
  Added initialization for the new class members.
  Added initialization for the extended get_next().
  Added de-initialization for the allocated buffers.
  Added a buffer allocation method.
  Added an inner loop to collect multiple ranges.
  Adapted range collection loops to the new initialization.
sql/opt_range.h:
  WL#2126 - Multi_read_range.
  Moved key range flags from here to include/my_base.h.
  Added new elements to class QUICK_RANGE_SELECT.
  Added a copy constructor.
sql/records.cc:
  WL#2126 - Multi_read_range.
  Added a call of the allocation method.
sql/set_var.cc:
  WL#2126 - Multi_read_range.
  Added the new system variable 'multi_range_count'.
sql/sql_class.h:
  WL#2126 - Multi_read_range.
  Added the new system variable 'multi_range_count'.
This commit is contained in:
unknown 2004-12-23 21:45:10 +01:00
parent dd6981f4d0
commit 8d11c01c59
9 changed files with 406 additions and 68 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
include/my_base.h
View file

@ -370,6 +370,15 @@ enum data_file_type {
/* For key ranges */
#define NO_MIN_RANGE 1
#define NO_MAX_RANGE 2
#define NEAR_MIN 4
#define NEAR_MAX 8
#define UNIQUE_RANGE 16
#define EQ_RANGE 32
#define NULL_RANGE 64
#define GEOM_FLAG 128
typedef struct st_key_range
{
const byte *key;
@ -377,6 +386,14 @@ typedef struct st_key_range
enum ha_rkey_function flag;
} key_range;
typedef struct st_key_multi_range
{
key_range start_key;
key_range end_key;
char *ptr; /* Free to use by caller (ptr to row etc) */
uint range_flag; /* key range flags see above */
} KEY_MULTI_RANGE;
/* For number of records */
#ifdef BIG_TABLES

125
sql/handler.cc
View file

@ -1685,6 +1685,131 @@ int ha_table_exists(THD* thd, const char* db, const char* name)
#endif
/*
Read the first row of a multi-range set.
SYNOPSIS
read_multi_range_first()
found_range_p Returns a pointer to the element in 'ranges' that
corresponds to the returned row.
ranges An array of KEY_MULTI_RANGE range descriptions.
range_count Number of ranges in 'ranges'.
sorted If result should be sorted per key.
buffer A HANDLER_BUFFER for internal handler usage.
NOTES
Record is read into table->record[0].
*found_range_p returns a valid value only if read_multi_range_first()
returns 0.
Sorting is done within each range. If you want an overall sort, enter
'ranges' with sorted ranges.
RETURN
0 OK, found a row
HA_ERR_END_OF_FILE No rows in range
# Error code
*/
int handler::read_multi_range_first(KEY_MULTI_RANGE **found_range_p,
KEY_MULTI_RANGE *ranges, uint range_count,
bool sorted, HANDLER_BUFFER *buffer)
{
int result= HA_ERR_END_OF_FILE;
DBUG_ENTER("handler::read_multi_range_first");
multi_range_sorted= sorted;
multi_range_buffer= buffer;
for (multi_range_curr= ranges, multi_range_end= ranges + range_count;
multi_range_curr < multi_range_end;
multi_range_curr++)
{
result= read_range_first(multi_range_curr->start_key.length ?
&multi_range_curr->start_key : 0,
multi_range_curr->end_key.length ?
&multi_range_curr->end_key : 0,
test(multi_range_curr->range_flag & EQ_RANGE),
multi_range_sorted);
if (result != HA_ERR_END_OF_FILE)
break;
}
*found_range_p= multi_range_curr;
DBUG_PRINT("exit",("result %d", result));
DBUG_RETURN(result);
}
/*
Read the next row of a multi-range set.
SYNOPSIS
read_multi_range_next()
found_range_p Returns a pointer to the element in 'ranges' that
corresponds to the returned row.
NOTES
Record is read into table->record[0].
*found_range_p returns a valid value only if read_multi_range_next()
returns 0.
RETURN
0 OK, found a row
HA_ERR_END_OF_FILE No (more) rows in range
# Error code
*/
int handler::read_multi_range_next(KEY_MULTI_RANGE **found_range_p)
{
int result;
DBUG_ENTER("handler::read_multi_range_next");
/* We should not be called after the last call returned EOF. */
DBUG_ASSERT(multi_range_curr < multi_range_end);
do
{
/* Save a call if there can be only one row in range. */
if (multi_range_curr->range_flag != (UNIQUE_RANGE | EQ_RANGE))
{
result= read_range_next();
/* On success or non-EOF errors jump to the end. */
if (result != HA_ERR_END_OF_FILE)
break;
}
else
{
/*
We need to set this for the last range only, but checking this
condition is more expensive than just setting the result code.
*/
result= HA_ERR_END_OF_FILE;
}
/* Try the next range(s) until one matches a record. */
for (multi_range_curr++;
multi_range_curr < multi_range_end;
multi_range_curr++)
{
result= read_range_first(multi_range_curr->start_key.length ?
&multi_range_curr->start_key : 0,
multi_range_curr->end_key.length ?
&multi_range_curr->end_key : 0,
test(multi_range_curr->range_flag & EQ_RANGE),
multi_range_sorted);
if (result != HA_ERR_END_OF_FILE)
break;
}
}
while ((result == HA_ERR_END_OF_FILE) &&
(multi_range_curr < multi_range_end));
*found_range_p= multi_range_curr;
DBUG_PRINT("exit",("handler::read_multi_range_next: result %d", result));
DBUG_RETURN(result);
}
/*
Read first row between two ranges.
Store ranges for future calls to read_range_next

26
sql/handler.h
View file

@ -76,6 +76,7 @@
#define HA_FILE_BASED (1 << 26)
#define HA_NO_VARCHAR (1 << 27)
#define HA_CAN_BIT_FIELD (1 << 28) /* supports bit fields */
#define HA_NEED_READ_RANGE_BUFFER (1 << 29) /* for read_multi_range */
/* bits in index_flags(index_number) for what you can do with index */
@ -276,6 +277,21 @@ typedef struct st_ha_check_opt
} HA_CHECK_OPT;
/*
This is a buffer area that the handler can use to store rows.
'end_of_used_area' should be kept updated after calls to
read-functions so that other parts of the code can use the
remaining area (until next read calls is issued).
*/
typedef struct st_handler_buffer
{
const byte *buffer; /* Buffer one can start using */
const byte *buffer_end; /* End of buffer */
byte *end_of_used_area; /* End of area that was used by handler */
} HANDLER_BUFFER;
class handler :public Sql_alloc
{
protected:
@ -310,6 +326,12 @@ public:
time_t check_time;
time_t update_time;
/* The following are for read_multi_range */
bool multi_range_sorted;
KEY_MULTI_RANGE *multi_range_curr;
KEY_MULTI_RANGE *multi_range_end;
HANDLER_BUFFER *multi_range_buffer;
/* The following are for read_range() */
key_range save_end_range, *end_range;
KEY_PART_INFO *range_key_part;
@ -421,6 +443,10 @@ public:
virtual int index_next_same(byte *buf, const byte *key, uint keylen);
virtual int index_read_last(byte * buf, const byte * key, uint key_len)
{ return (my_errno=HA_ERR_WRONG_COMMAND); }
virtual int read_multi_range_first(KEY_MULTI_RANGE **found_range_p,
KEY_MULTI_RANGE *ranges, uint range_count,
bool sorted, HANDLER_BUFFER *buffer);
virtual int read_multi_range_next(KEY_MULTI_RANGE **found_range_p);
virtual int read_range_first(const key_range *start_key,
const key_range *end_key,
bool eq_range, bool sorted);

7
sql/mysqld.cc
View file

@ -4141,7 +4141,7 @@ enum options_mysqld
OPT_MAX_SEEKS_FOR_KEY, OPT_MAX_TMP_TABLES, OPT_MAX_USER_CONNECTIONS,
OPT_MAX_LENGTH_FOR_SORT_DATA,
OPT_MAX_WRITE_LOCK_COUNT, OPT_BULK_INSERT_BUFFER_SIZE,
OPT_MAX_ERROR_COUNT, OPT_MYISAM_DATA_POINTER_SIZE,
OPT_MAX_ERROR_COUNT, OPT_MULTI_RANGE_COUNT, OPT_MYISAM_DATA_POINTER_SIZE,
OPT_MYISAM_BLOCK_SIZE, OPT_MYISAM_MAX_EXTRA_SORT_FILE_SIZE,
OPT_MYISAM_MAX_SORT_FILE_SIZE, OPT_MYISAM_SORT_BUFFER_SIZE,
OPT_NET_BUFFER_LENGTH, OPT_NET_RETRY_COUNT,
@ -5137,6 +5137,11 @@ The minimum value for this variable is 4096.",
"After this many write locks, allow some read locks to run in between.",
(gptr*) &max_write_lock_count, (gptr*) &max_write_lock_count, 0, GET_ULONG,
REQUIRED_ARG, ~0L, 1, ~0L, 0, 1, 0},
{"multi_range_count", OPT_MULTI_RANGE_COUNT,
"Number of key ranges to request at once.",
(gptr*) &global_system_variables.multi_range_count,
(gptr*) &max_system_variables.multi_range_count, 0,
GET_ULONG, REQUIRED_ARG, 256, 1, ~0L, 0, 1, 0},
{"myisam_block_size", OPT_MYISAM_BLOCK_SIZE,
"Block size to be used for MyISAM index pages.",
(gptr*) &opt_myisam_block_size,

241
sql/opt_range.cc
View file

@ -712,7 +712,7 @@ QUICK_SELECT_I::QUICK_SELECT_I()
QUICK_RANGE_SELECT::QUICK_RANGE_SELECT(THD *thd, TABLE *table, uint key_nr,
bool no_alloc, MEM_ROOT *parent_alloc)
:dont_free(0),error(0),free_file(0),cur_range(NULL),range(0)
:dont_free(0),error(0),free_file(0),cur_range(NULL),range(0),in_range(0)
{
sorted= 0;
index= key_nr;
@ -720,6 +720,13 @@ QUICK_RANGE_SELECT::QUICK_RANGE_SELECT(THD *thd, TABLE *table, uint key_nr,
key_part_info= head->key_info[index].key_part;
my_init_dynamic_array(&ranges, sizeof(QUICK_RANGE*), 16, 16);
/* 'thd' is not accessible in QUICK_RANGE_SELECT::get_next_init(). */
multi_range_bufsiz= thd->variables.read_rnd_buff_size;
multi_range_count= thd->variables.multi_range_count;
multi_range_length= 0;
multi_range= NULL;
multi_range_buff= NULL;
if (!no_alloc && !parent_alloc)
{
// Allocates everything through the internal memroot
@ -736,6 +743,10 @@ QUICK_RANGE_SELECT::QUICK_RANGE_SELECT(THD *thd, TABLE *table, uint key_nr,
int QUICK_RANGE_SELECT::init()
{
DBUG_ENTER("QUICK_RANGE_SELECT::init");
if ((error= get_next_init()))
DBUG_RETURN(error);
if (file->inited == handler::NONE)
DBUG_RETURN(error= file->ha_index_init(index));
error= 0;
@ -771,6 +782,10 @@ QUICK_RANGE_SELECT::~QUICK_RANGE_SELECT()
delete_dynamic(&ranges); /* ranges are allocated in alloc */
free_root(&alloc,MYF(0));
}
if (multi_range)
my_free((char*) multi_range, MYF(0));
if (multi_range_buff)
my_free((char*) multi_range_buff, MYF(0));
DBUG_VOID_RETURN;
}
@ -5872,58 +5887,178 @@ int QUICK_ROR_UNION_SELECT::get_next()
DBUG_RETURN(error);
}
/* get next possible record using quick-struct */
/*
Initialize data structures needed by get_next().
SYNOPSIS
QUICK_RANGE_SELECT::get_next_init()
DESCRIPTION
This is called from get_next() at its first call for an object.
It allocates memory buffers and sets size variables.
RETURN
0 OK.
!= 0 Error.
*/
int QUICK_RANGE_SELECT::get_next_init(void)
{
uint mrange_bufsiz;
byte *mrange_buff;
DBUG_ENTER("QUICK_RANGE_SELECT::get_next_init");
/* Do not allocate the buffers twice. */
if (multi_range_length)
{
DBUG_ASSERT(multi_range_length == min(multi_range_count, ranges.elements));
DBUG_RETURN(0);
}
/* If the ranges are not yet initialized, wait for the next call. */
if (! ranges.elements)
{
DBUG_RETURN(0);
}
/*
Allocate the ranges array.
*/
multi_range_length= min(multi_range_count, ranges.elements);
DBUG_ASSERT(multi_range_length > 0);
while (multi_range_length && ! (multi_range= (KEY_MULTI_RANGE*)
my_malloc(multi_range_length *
sizeof(KEY_MULTI_RANGE),
MYF(MY_WME))))
{
/* Try to shrink the buffers until it is 0. */
multi_range_length/= 2;
}
if (! multi_range)
{
multi_range_length= 0;
DBUG_RETURN(HA_ERR_OUT_OF_MEM);
}
/*
Allocate the handler buffer if necessary.
*/
if (file->table_flags() & HA_NEED_READ_RANGE_BUFFER)
{
mrange_bufsiz= min(multi_range_bufsiz,
QUICK_SELECT_I::records * head->reclength);
while (mrange_bufsiz &&
! my_multi_malloc(MYF(MY_WME),
&multi_range_buff, sizeof(*multi_range_buff),
&mrange_buff, mrange_bufsiz,
NullS))
{
/* Try to shrink the buffers until both are 0. */
mrange_bufsiz/= 2;
}
if (! multi_range_buff)
{
my_free((char*) multi_range, MYF(0));
multi_range= NULL;
multi_range_length= 0;
DBUG_RETURN(HA_ERR_OUT_OF_MEM);
}
/* Initialize the handler buffer. */
multi_range_buff->buffer= mrange_buff;
multi_range_buff->buffer_end= mrange_buff + mrange_bufsiz;
multi_range_buff->end_of_used_area= mrange_buff;
}
/* Initialize the current QUICK_RANGE pointer. */
cur_range= (QUICK_RANGE**) ranges.buffer;
DBUG_RETURN(0);
}
/*
Get next possible record using quick-struct.
SYNOPSIS
QUICK_RANGE_SELECT::get_next()
NOTES
Record is read into table->record[0]
RETURN
0 Found row
HA_ERR_END_OF_FILE No (more) rows in range
# Error code
*/
int QUICK_RANGE_SELECT::get_next()
{
int result;
KEY_MULTI_RANGE *mrange;
key_range *start_key;
key_range *end_key;
DBUG_ENTER("QUICK_RANGE_SELECT::get_next");
DBUG_ASSERT(multi_range_length && multi_range &&
(cur_range >= (QUICK_RANGE**) ranges.buffer) &&
(cur_range <= (QUICK_RANGE**) ranges.buffer + ranges.elements));
for (;;)
{
int result;
key_range start_key, end_key;
if (range)
if (in_range)
{
// Already read through key
result= file->read_range_next();
/* We did already start to read this key. */
result= file->read_multi_range_next(&mrange);
if (result != HA_ERR_END_OF_FILE)
{
in_range= ! result;
DBUG_RETURN(result);
}
}
if (!cur_range)
range= *(cur_range= (QUICK_RANGE**) ranges.buffer);
else
range=
(cur_range == ((QUICK_RANGE**) ranges.buffer + ranges.elements - 1)) ?
(QUICK_RANGE*) 0 : *(++cur_range);
uint count= min(multi_range_length, ranges.elements -
(cur_range - (QUICK_RANGE**) ranges.buffer));
if (count == 0)
{
/* Ranges have already been used up before. None is left for read. */
in_range= FALSE;
DBUG_RETURN(HA_ERR_END_OF_FILE);
}
KEY_MULTI_RANGE *mrange_slot, *mrange_end;
for (mrange_slot= multi_range, mrange_end= mrange_slot+count;
mrange_slot < mrange_end;
mrange_slot++)
{
start_key= &mrange_slot->start_key;
end_key= &mrange_slot->end_key;
range= *(cur_range++);
if (!range)
DBUG_RETURN(HA_ERR_END_OF_FILE); // All ranges used
start_key->key= (const byte*) range->min_key;
start_key->length= range->min_length;
start_key->flag= ((range->flag & NEAR_MIN) ? HA_READ_AFTER_KEY :
(range->flag & EQ_RANGE) ?
HA_READ_KEY_EXACT : HA_READ_KEY_OR_NEXT);
end_key->key= (const byte*) range->max_key;
end_key->length= range->max_length;
/*
We use HA_READ_AFTER_KEY here because if we are reading on a key
prefix. We want to find all keys with this prefix.
*/
end_key->flag= (range->flag & NEAR_MAX ? HA_READ_BEFORE_KEY :
HA_READ_AFTER_KEY);
start_key.key= (const byte*) range->min_key;
start_key.length= range->min_length;
start_key.flag= ((range->flag & NEAR_MIN) ? HA_READ_AFTER_KEY :
(range->flag & EQ_RANGE) ?
HA_READ_KEY_EXACT : HA_READ_KEY_OR_NEXT);
end_key.key= (const byte*) range->max_key;
end_key.length= range->max_length;
/*
We use READ_AFTER_KEY here because if we are reading on a key
prefix we want to find all keys with this prefix
*/
end_key.flag= (range->flag & NEAR_MAX ? HA_READ_BEFORE_KEY :
HA_READ_AFTER_KEY);
result= file->read_range_first(range->min_length ? &start_key : 0,
range->max_length ? &end_key : 0,
test(range->flag & EQ_RANGE),
sorted);
if (range->flag == (UNIQUE_RANGE | EQ_RANGE))
range=0; // Stop searching
mrange_slot->range_flag= range->flag;
}
result= file->read_multi_range_first(&mrange, multi_range, count,
sorted, multi_range_buff);
if (result != HA_ERR_END_OF_FILE)
{
in_range= ! result;
DBUG_RETURN(result);
range=0; // No matching rows; go to next range
}
in_range= FALSE; /* No matching rows; go to next set of ranges. */
}
}
@ -5974,15 +6109,14 @@ int QUICK_RANGE_SELECT::get_next_prefix(uint prefix_length, byte *cur_prefix)
DBUG_RETURN(result);
}
if (!cur_range)
range= *(cur_range= (QUICK_RANGE**) ranges.buffer); /* First range. */
else
range=
(cur_range == ((QUICK_RANGE**) ranges.buffer + ranges.elements - 1)) ?
(QUICK_RANGE*) 0 : *(++cur_range); /* Next range. */
if (!range)
DBUG_RETURN(HA_ERR_END_OF_FILE); // All ranges used
uint count= ranges.elements - (cur_range - (QUICK_RANGE**) ranges.buffer);
if (count == 0)
{
/* Ranges have already been used up before. None is left for read. */
range= 0;
DBUG_RETURN(HA_ERR_END_OF_FILE);
}
range= *(cur_range++);
start_key.key= (const byte*) range->min_key;
start_key.length= min(range->min_length, prefix_length);
@ -6030,15 +6164,14 @@ int QUICK_RANGE_SELECT_GEOM::get_next()
DBUG_RETURN(result);
}
if (!cur_range)
range= *(cur_range= (QUICK_RANGE**) ranges.buffer);
else
range=
(cur_range == ((QUICK_RANGE**) ranges.buffer + ranges.elements - 1)) ?
(QUICK_RANGE*) 0 : *(++cur_range);
if (!range)
DBUG_RETURN(HA_ERR_END_OF_FILE); // All ranges used
uint count= ranges.elements - (cur_range - (QUICK_RANGE**) ranges.buffer);
if (count == 0)
{
/* Ranges have already been used up before. None is left for read. */
range= 0;
DBUG_RETURN(HA_ERR_END_OF_FILE);
}
range= *(cur_range++);
result= file->index_read(record,
(byte*) range->min_key,

47
sql/opt_range.h
View file

@ -24,16 +24,6 @@
#pragma interface /* gcc class implementation */
#endif
#define NO_MIN_RANGE 1
#define NO_MAX_RANGE 2
#define NEAR_MIN 4
#define NEAR_MAX 8
#define UNIQUE_RANGE 16
#define EQ_RANGE 32
#define NULL_RANGE 64
#define GEOM_FLAG 128
typedef struct st_key_part {
uint16 key,part, store_length, length;
uint8 null_bit;
@ -135,9 +125,24 @@ public:
*/
virtual int reset(void) = 0;
/*
Initialize get_next() for row retrieval.
SYNOPSIS
get_next_init()
get_next_init() must be called before the first get_next().
If get_next_init() call fails get_next() must not be called.
RETURN
0 OK
other Error code
*/
virtual int get_next_init() { return false; }
virtual int get_next() = 0; /* get next record to retrieve */
/* Range end should be called when we have looped over the whole index */
virtual void range_end() {}
virtual int get_next() = 0; /* get next record to retrieve */
virtual bool reverse_sorted() = 0;
virtual bool unique_key_range() { return false; }
@ -236,6 +241,14 @@ protected:
closed no later then this quick select is deleted.
*/
bool free_file;
bool in_range;
uint multi_range_count; /* copy from thd->variables.multi_range_count */
uint multi_range_length; /* the allocated length for the array */
uint multi_range_bufsiz; /* copy from thd->variables.read_rnd_buff_size */
KEY_MULTI_RANGE *multi_range; /* the multi-range array (allocated and
freed by QUICK_RANGE_SELECT) */
HANDLER_BUFFER *multi_range_buff; /* the handler buffer (allocated and
freed by QUICK_RANGE_SELECT) */
protected:
friend class TRP_ROR_INTERSECT;
@ -270,18 +283,19 @@ public:
MEM_ROOT *parent_alloc=NULL);
~QUICK_RANGE_SELECT();
int init();
int reset(void)
{
next=0;
range= NULL;
cur_range= NULL;
cur_range= (QUICK_RANGE**) ranges.buffer;
/*
Note: in opt_range.cc there are places where it is assumed that this
function always succeeds
*/
return 0;
}
int init();
int get_next_init(void);
int get_next();
void range_end();
int get_next_prefix(uint prefix_length, byte *cur_prefix);
@ -296,6 +310,13 @@ public:
#ifndef DBUG_OFF
void dbug_dump(int indent, bool verbose);
#endif
QUICK_RANGE_SELECT(const QUICK_RANGE_SELECT& org) : QUICK_SELECT_I()
{
bcopy(&org, this, sizeof(*this));
multi_range_length= 0;
multi_range= NULL;
multi_range_buff= NULL;
}
};

8
sql/records.cc
View file

@ -100,11 +100,19 @@ void init_read_record(READ_RECORD *info,THD *thd, TABLE *table,
}
else if (select && select->quick)
{
int error;
DBUG_PRINT("info",("using rr_quick"));
if (!table->file->inited)
table->file->ha_index_init(select->quick->index);
info->read_record=rr_quick;
if ((error= select->quick->get_next_init()))
{
/* Cannot return error code here. Instead print to error log. */
table->file->print_error(error,MYF(ME_NOREFRESH));
thd->fatal_error();
}
}
else if (table->sort.record_pointers)
{

2
sql/set_var.cc
View file

@ -259,6 +259,8 @@ sys_var_thd_ulong sys_max_tmp_tables("max_tmp_tables",
&SV::max_tmp_tables);
sys_var_long_ptr sys_max_write_lock_count("max_write_lock_count",
&max_write_lock_count);
sys_var_thd_ulong sys_multi_range_count("multi_range_count",
&SV::multi_range_count);
sys_var_long_ptr sys_myisam_data_pointer_size("myisam_data_pointer_size",
&myisam_data_pointer_size);
sys_var_thd_ulonglong sys_myisam_max_extra_sort_file_size("myisam_max_extra_sort_file_size", &SV::myisam_max_extra_sort_file_size, fix_myisam_max_extra_sort_file_size, 1);

1
sql/sql_class.h
View file

@ -388,6 +388,7 @@ struct system_variables
ulong max_sort_length;
ulong max_tmp_tables;
ulong max_insert_delayed_threads;
ulong multi_range_count;
ulong myisam_repair_threads;
ulong myisam_sort_buff_size;
ulong net_buffer_length;