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mariadb/sql/opt_range.cc
unknown 94ab8e9c4c Fixed portability problems in mysqlcheck 
Docs/manual.texi:
  Updated TODO
client/mysqlcheck.c:
  Fixed portability problems
mysql-test/r/backup.result:
  Fixed output after format change for BACKUP TABLE
sql/ha_berkeley.cc:
  Added missing variable
sql/opt_range.cc:
  Small optimization when calculating key blocks
2001-04-21 03:03:08 +03:00

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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult 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; either version 2 of the License, or
(at your option) any later version.
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 */
/*
TODO:
Fix that MAYBE_KEY are stored in the tree so that we can detect use
of full hash keys for queries like:
select s.id, kws.keyword_id from sites as s,kws where s.id=kws.site_id and kws.keyword_id in (204,205);
*/
#ifdef __GNUC__
#pragma implementation // gcc: Class implementation
#endif
#include "mysql_priv.h"
#include <m_ctype.h>
#include <nisam.h>
#include "sql_select.h"
#ifndef EXTRA_DEBUG
#define test_rb_tree(A,B) {}
#define test_use_count(A) {}
#endif
static int sel_cmp(Field *f,char *a,char *b,uint8 a_flag,uint8 b_flag);
static char is_null_string[2]= {1,0};
class SEL_ARG :public Sql_alloc
{
public:
uint8 min_flag,max_flag,maybe_flag;
uint8 part; // Which key part
uint8 maybe_null;
uint16 elements; // Elements in tree
ulong use_count; // use of this sub_tree
Field *field;
char *min_value,*max_value; // Pointer to range
SEL_ARG *left,*right,*next,*prev,*parent,*next_key_part;
enum leaf_color { BLACK,RED } color;
enum Type { IMPOSSIBLE, MAYBE, MAYBE_KEY, KEY_RANGE } type;
SEL_ARG() {}
SEL_ARG(SEL_ARG &);
SEL_ARG(Field *,const char *,const char *);
SEL_ARG(Field *field, uint8 part, char *min_value, char *max_value,
uint8 min_flag, uint8 max_flag, uint8 maybe_flag);
SEL_ARG(enum Type type_arg)
:elements(1),use_count(1),left(0),next_key_part(0),type(type_arg) {}
inline bool is_same(SEL_ARG *arg)
{
if (type != arg->type)
return 0;
if (type != KEY_RANGE)
return 1;
return cmp_min_to_min(arg) == 0 && cmp_max_to_max(arg) == 0;
}
inline void merge_flags(SEL_ARG *arg) { maybe_flag|=arg->maybe_flag; }
inline void maybe_smaller() { maybe_flag=1; }
inline int cmp_min_to_min(SEL_ARG* arg)
{
return sel_cmp(field,min_value, arg->min_value, min_flag, arg->min_flag);
}
inline int cmp_min_to_max(SEL_ARG* arg)
{
return sel_cmp(field,min_value, arg->max_value, min_flag, arg->max_flag);
}
inline int cmp_max_to_max(SEL_ARG* arg)
{
return sel_cmp(field,max_value, arg->max_value, max_flag, arg->max_flag);
}
inline int cmp_max_to_min(SEL_ARG* arg)
{
return sel_cmp(field,max_value, arg->min_value, max_flag, arg->min_flag);
}
SEL_ARG *clone_and(SEL_ARG* arg)
{ // Get overlapping range
char *new_min,*new_max;
uint8 flag_min,flag_max;
if (cmp_min_to_min(arg) >= 0)
{
new_min=min_value; flag_min=min_flag;
}
else
{
new_min=arg->min_value; flag_min=arg->min_flag; /* purecov: deadcode */
}
if (cmp_max_to_max(arg) <= 0)
{
new_max=max_value; flag_max=max_flag;
}
else
{
new_max=arg->max_value; flag_max=arg->max_flag;
}
return new SEL_ARG(field, part, new_min, new_max, flag_min, flag_max,
test(maybe_flag && arg->maybe_flag));
}
SEL_ARG *clone_first(SEL_ARG *arg)
{ // min <= X < arg->min
return new SEL_ARG(field,part, min_value, arg->min_value,
min_flag, arg->min_flag & NEAR_MIN ? 0 : NEAR_MAX,
maybe_flag | arg->maybe_flag);
}
SEL_ARG *clone_last(SEL_ARG *arg)
{ // min <= X <= key_max
return new SEL_ARG(field, part, min_value, arg->max_value,
min_flag, arg->max_flag, maybe_flag | arg->maybe_flag);
}
SEL_ARG *clone(SEL_ARG *new_parent,SEL_ARG **next);
bool copy_min(SEL_ARG* arg)
{ // Get overlapping range
if (cmp_min_to_min(arg) > 0)
{
min_value=arg->min_value; min_flag=arg->min_flag;
if ((max_flag & (NO_MAX_RANGE | NO_MIN_RANGE)) ==
(NO_MAX_RANGE | NO_MIN_RANGE))
return 1; // Full range
}
maybe_flag|=arg->maybe_flag;
return 0;
}
bool copy_max(SEL_ARG* arg)
{ // Get overlapping range
if (cmp_max_to_max(arg) <= 0)
{
max_value=arg->max_value; max_flag=arg->max_flag;
if ((max_flag & (NO_MAX_RANGE | NO_MIN_RANGE)) ==
(NO_MAX_RANGE | NO_MIN_RANGE))
return 1; // Full range
}
maybe_flag|=arg->maybe_flag;
return 0;
}
void copy_min_to_min(SEL_ARG *arg)
{
min_value=arg->min_value; min_flag=arg->min_flag;
}
void copy_min_to_max(SEL_ARG *arg)
{
max_value=arg->min_value;
max_flag=arg->min_flag & NEAR_MIN ? 0 : NEAR_MAX;
}
void copy_max_to_min(SEL_ARG *arg)
{
min_value=arg->max_value;
min_flag=arg->max_flag & NEAR_MAX ? 0 : NEAR_MIN;
}
void store(uint length,char **min_key,uint min_key_flag,
char **max_key, uint max_key_flag)
{
if (!(min_flag & NO_MIN_RANGE) &&
!(min_key_flag & (NO_MIN_RANGE | NEAR_MIN)))
{
if (maybe_null && *min_value)
{
**min_key=1;
bzero(*min_key+1,length);
}
else
memcpy(*min_key,min_value,length+(int) maybe_null);
(*min_key)+= length+(int) maybe_null;
}
if (!(max_flag & NO_MAX_RANGE) &&
!(max_key_flag & (NO_MAX_RANGE | NEAR_MAX)))
{
if (maybe_null && *max_value)
{
**max_key=1;
bzero(*max_key+1,length);
}
else
memcpy(*max_key,max_value,length+(int) maybe_null);
(*max_key)+= length+(int) maybe_null;
}
}
void store_min_key(KEY_PART *key,char **range_key, uint *range_key_flag)
{
SEL_ARG *key_tree= first();
key_tree->store(key[key_tree->part].part_length,
range_key,*range_key_flag,range_key,NO_MAX_RANGE);
*range_key_flag|= key_tree->min_flag;
if (key_tree->next_key_part &&
key_tree->next_key_part->part == key_tree->part+1 &&
!(*range_key_flag & (NO_MIN_RANGE | NEAR_MIN)) &&
key_tree->next_key_part->type == SEL_ARG::KEY_RANGE)
key_tree->next_key_part->store_min_key(key,range_key, range_key_flag);
}
void store_max_key(KEY_PART *key,char **range_key, uint *range_key_flag)
{
SEL_ARG *key_tree= last();
key_tree->store(key[key_tree->part].part_length,
range_key, NO_MIN_RANGE, range_key,*range_key_flag);
(*range_key_flag)|= key_tree->max_flag;
if (key_tree->next_key_part &&
key_tree->next_key_part->part == key_tree->part+1 &&
!(*range_key_flag & (NO_MAX_RANGE | NEAR_MAX)) &&
key_tree->next_key_part->type == SEL_ARG::KEY_RANGE)
key_tree->next_key_part->store_max_key(key,range_key, range_key_flag);
}
SEL_ARG *insert(SEL_ARG *key);
SEL_ARG *tree_delete(SEL_ARG *key);
SEL_ARG *find_range(SEL_ARG *key);
SEL_ARG *rb_insert(SEL_ARG *leaf);
friend SEL_ARG *rb_delete_fixup(SEL_ARG *root,SEL_ARG *key, SEL_ARG *par);
#ifdef EXTRA_DEBUG
friend int test_rb_tree(SEL_ARG *element,SEL_ARG *parent);
void test_use_count(SEL_ARG *root);
#endif
SEL_ARG *first();
SEL_ARG *last();
void make_root();
inline bool simple_key()
{
return !next_key_part && elements == 1;
}
void increment_use_count(long count)
{
if (next_key_part)
{
next_key_part->use_count+=count;
count*= (next_key_part->use_count-count);
for (SEL_ARG *pos=next_key_part->first(); pos ; pos=pos->next)
if (pos->next_key_part)
pos->increment_use_count(count);
}
}
void free_tree()
{
for (SEL_ARG *pos=first(); pos ; pos=pos->next)
if (pos->next_key_part)
{
pos->next_key_part->use_count--;
pos->next_key_part->free_tree();
}
}
inline SEL_ARG **parent_ptr()
{
return parent->left == this ? &parent->left : &parent->right;
}
SEL_ARG *clone_tree();
};
class SEL_TREE :public Sql_alloc
{
public:
enum Type { IMPOSSIBLE, ALWAYS, MAYBE, KEY, KEY_SMALLER } type;
SEL_TREE(enum Type type_arg) :type(type_arg) {}
SEL_TREE() :type(KEY) { bzero((char*) keys,sizeof(keys));}
SEL_ARG *keys[MAX_KEY];
};
typedef struct st_qsel_param {
uint baseflag,keys,max_key_part;
table_map prev_tables,read_tables,current_table;
TABLE *table;
bool quick; // Don't calulate possible keys
KEY_PART *key_parts,*key_parts_end,*key[MAX_KEY];
uint real_keynr[MAX_KEY];
char min_key[MAX_KEY_LENGTH+MAX_FIELD_WIDTH],
max_key[MAX_KEY_LENGTH+MAX_FIELD_WIDTH];
} PARAM;
static SEL_TREE * get_mm_parts(PARAM *param,Field *field,
Item_func::Functype type,Item *value,
Item_result cmp_type);
static SEL_ARG *get_mm_leaf(Field *field,KEY_PART *key_part,
Item_func::Functype type,Item *value);
static bool like_range(const char *ptr,uint length,char wild_prefix,
uint field_length, char *min_str,char *max_str,
char max_sort_char,uint *min_length,uint *max_length);
static SEL_TREE *get_mm_tree(PARAM *param,COND *cond);
static ha_rows check_quick_select(PARAM *param,uint index,SEL_ARG *key_tree);
static ha_rows check_quick_keys(PARAM *param,uint index,SEL_ARG *key_tree,
char *min_key,uint min_key_flag,
char *max_key, uint max_key_flag);
static QUICK_SELECT *get_quick_select(PARAM *param,uint index,
SEL_ARG *key_tree);
#ifndef DBUG_OFF
static void print_quick(QUICK_SELECT *quick,key_map needed_reg);
#endif
static SEL_TREE *tree_and(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2);
static SEL_TREE *tree_or(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2);
static SEL_ARG *sel_add(SEL_ARG *key1,SEL_ARG *key2);
static SEL_ARG *key_or(SEL_ARG *key1,SEL_ARG *key2);
static SEL_ARG *key_and(SEL_ARG *key1,SEL_ARG *key2,uint clone_flag);
static bool get_range(SEL_ARG **e1,SEL_ARG **e2,SEL_ARG *root1);
static bool get_quick_keys(PARAM *param,QUICK_SELECT *quick,KEY_PART *key,
SEL_ARG *key_tree,char *min_key,uint min_key_flag,
char *max_key,uint max_key_flag);
static bool eq_tree(SEL_ARG* a,SEL_ARG *b);
static SEL_ARG null_element(SEL_ARG::IMPOSSIBLE);
static bool null_part_in_key(KEY_PART *key_part, const char *key, uint length);
/***************************************************************************
** Basic functions for SQL_SELECT and QUICK_SELECT
***************************************************************************/
/* make a select from mysql info
Error is set as following:
0 = ok
1 = Got some error (out of memory?)
*/
SQL_SELECT *make_select(TABLE *head, table_map const_tables,
table_map read_tables, COND *conds, int *error)
{
SQL_SELECT *select;
DBUG_ENTER("make_select");
*error=0;
if (!conds)
DBUG_RETURN(0);
if (!(select= new SQL_SELECT))
{
*error= 1;
DBUG_RETURN(0); /* purecov: inspected */
}
select->read_tables=read_tables;
select->const_tables=const_tables;
select->head=head;
select->cond=conds;
if (head->io_cache)
{
select->file= *head->io_cache;
select->records=(ha_rows) (select->file.end_of_file/
head->file->ref_length);
my_free((gptr) (head->io_cache),MYF(0));
head->io_cache=0;
}
DBUG_RETURN(select);
}
SQL_SELECT::SQL_SELECT() :quick(0),cond(0),free_cond(0)
{
quick_keys=0; needed_reg=0;
my_b_clear(&file);
}
SQL_SELECT::~SQL_SELECT()
{
delete quick;
if (free_cond)
delete cond;
close_cached_file(&file);
}
#undef index // Fix for Unixware 7
QUICK_SELECT::QUICK_SELECT(TABLE *table,uint key_nr,bool no_alloc)
:error(0),index(key_nr),max_used_key_length(0),head(table),
it(ranges),range(0)
{
if (!no_alloc)
{
init_sql_alloc(&alloc,1024,0); // Allocates everything here
my_pthread_setspecific_ptr(THR_MALLOC,&alloc);
}
else
bzero((char*) &alloc,sizeof(alloc));
file=head->file;
record=head->record[0];
init();
}
QUICK_SELECT::~QUICK_SELECT()
{
file->index_end();
free_root(&alloc,MYF(0));
}
int QUICK_SELECT::init()
{
return error=file->index_init(index);
}
QUICK_RANGE::QUICK_RANGE()
:min_key(0),max_key(0),min_length(0),max_length(0),
flag(NO_MIN_RANGE | NO_MAX_RANGE)
{}
SEL_ARG::SEL_ARG(SEL_ARG &arg) :Sql_alloc()
{
type=arg.type;
min_flag=arg.min_flag;
max_flag=arg.max_flag;
maybe_flag=arg.maybe_flag;
maybe_null=arg.maybe_null;
part=arg.part;
field=arg.field;
min_value=arg.min_value;
max_value=arg.max_value;
next_key_part=arg.next_key_part;
use_count=1; elements=1;
}
inline void SEL_ARG::make_root()
{
left=right= &null_element;
color=BLACK;
next=prev=0;
use_count=0; elements=1;
}
SEL_ARG::SEL_ARG(Field *f,const char *min_value_arg,const char *max_value_arg)
:min_flag(0), max_flag(0), maybe_flag(0), maybe_null(f->real_maybe_null()),
elements(1), use_count(1), field(f), min_value((char*) min_value_arg),
max_value((char*) max_value_arg), next(0),prev(0),
next_key_part(0),color(BLACK),type(KEY_RANGE)
{
left=right= &null_element;
}
SEL_ARG::SEL_ARG(Field *field_,uint8 part_,char *min_value_,char *max_value_,
uint8 min_flag_,uint8 max_flag_,uint8 maybe_flag_)
:min_flag(min_flag_),max_flag(max_flag_),maybe_flag(maybe_flag_),
part(part_),maybe_null(field_->real_maybe_null()), elements(1),use_count(1),
field(field_), min_value(min_value_), max_value(max_value_),
next(0),prev(0),next_key_part(0),color(BLACK),type(KEY_RANGE)
{
left=right= &null_element;
}
SEL_ARG *SEL_ARG::clone(SEL_ARG *new_parent,SEL_ARG **next_arg)
{
SEL_ARG *tmp;
if (type != KEY_RANGE)
{
tmp=new SEL_ARG(type);
tmp->prev= *next_arg; // Link into next/prev chain
(*next_arg)->next=tmp;
(*next_arg)= tmp;
}
else
{
tmp=new SEL_ARG(field,part, min_value,max_value,
min_flag, max_flag, maybe_flag);
tmp->parent=new_parent;
tmp->next_key_part=next_key_part;
if (left != &null_element)
tmp->left=left->clone(tmp,next_arg);
tmp->prev= *next_arg; // Link into next/prev chain
(*next_arg)->next=tmp;
(*next_arg)= tmp;
if (right != &null_element)
tmp->right=right->clone(tmp,next_arg);
}
increment_use_count(1);
return tmp;
}
SEL_ARG *SEL_ARG::first()
{
SEL_ARG *next_arg=this;
if (!next_arg->left)
return 0; // MAYBE_KEY
while (next_arg->left != &null_element)
next_arg=next_arg->left;
return next_arg;
}
SEL_ARG *SEL_ARG::last()
{
SEL_ARG *next_arg=this;
if (!next_arg->right)
return 0; // MAYBE_KEY
while (next_arg->right != &null_element)
next_arg=next_arg->right;
return next_arg;
}
/*
Check if a compare is ok, when one takes ranges in account
Returns -2 or 2 if the ranges where 'joined' like < 2 and >= 2
*/
static int sel_cmp(Field *field, char *a,char *b,uint8 a_flag,uint8 b_flag)
{
int cmp;
/* First check if there was a compare to a min or max element */
if (a_flag & (NO_MIN_RANGE | NO_MAX_RANGE))
{
if ((a_flag & (NO_MIN_RANGE | NO_MAX_RANGE)) ==
(b_flag & (NO_MIN_RANGE | NO_MAX_RANGE)))
return 0;
return (a_flag & NO_MIN_RANGE) ? -1 : 1;
}
if (b_flag & (NO_MIN_RANGE | NO_MAX_RANGE))
return (b_flag & NO_MIN_RANGE) ? 1 : -1;
if (field->real_maybe_null()) // If null is part of key
{
if (*a != *b)
{
return *a ? -1 : 1;
}
if (*a)
goto end; // NULL where equal
a++; b++; // Skipp NULL marker
}
cmp=field->key_cmp((byte*) a,(byte*) b);
if (cmp) return cmp < 0 ? -1 : 1; // The values differed
// Check if the compared equal arguments was defined with open/closed range
end:
if (a_flag & (NEAR_MIN | NEAR_MAX))
{
if ((a_flag & (NEAR_MIN | NEAR_MAX)) == (b_flag & (NEAR_MIN | NEAR_MAX)))
return 0;
if (!(b_flag & (NEAR_MIN | NEAR_MAX)))
return (a_flag & NEAR_MIN) ? 2 : -2;
return (a_flag & NEAR_MIN) ? 1 : -1;
}
if (b_flag & (NEAR_MIN | NEAR_MAX))
return (b_flag & NEAR_MIN) ? -2 : 2;
return 0; // The elements where equal
}
SEL_ARG *SEL_ARG::clone_tree()
{
SEL_ARG tmp_link,*next_arg,*root;
next_arg= &tmp_link;
root=clone((SEL_ARG *) 0, &next_arg);
next_arg->next=0; // Fix last link
tmp_link.next->prev=0; // Fix first link
root->use_count=0;
return root;
}
/*****************************************************************************
** Test if a key can be used in different ranges
** Returns:
** -1 if impossible select
** 0 if can't use quick_select
** 1 if found usable range
** Updates the following in the select parameter:
** needed_reg ; Bits for keys with may be used if all prev regs are read
** quick ; Parameter to use when reading records.
** In the table struct the following information is updated:
** quick_keys ; Which keys can be used
** quick_rows ; How many rows the key matches
*****************************************************************************/
int SQL_SELECT::test_quick_select(key_map keys_to_use, table_map prev_tables,
ha_rows limit, bool force_quick_range)
{
uint basflag;
uint idx;
double scan_time;
DBUG_ENTER("test_quick_select");
delete quick;
quick=0;
needed_reg=0; quick_keys=0;
if (!cond || (specialflag & SPECIAL_SAFE_MODE) && ! force_quick_range ||
!limit)
DBUG_RETURN(0); /* purecov: inspected */
if (!((basflag= head->file->option_flag()) & HA_KEYPOS_TO_RNDPOS) &&
keys_to_use == (uint) ~0 || !keys_to_use)
DBUG_RETURN(0); /* Not smart database */
records=head->file->records;
if (!records)
records++; /* purecov: inspected */
scan_time=(double) records / TIME_FOR_COMPARE+1;
read_time=(double) head->file->scan_time()+ scan_time + 1.0;
if (limit < records)
read_time=(double) records+scan_time+1; // Force to use index
else if (read_time <= 2.0 && !force_quick_range)
DBUG_RETURN(0); /* No nead for quick select */
DBUG_PRINT("info",("Time to scan table: %ld",(long) read_time));
keys_to_use&=head->keys_in_use_for_query;
if (keys_to_use)
{
MEM_ROOT *old_root,alloc;
SEL_TREE *tree;
KEY_PART *key_parts;
PARAM param;
/* set up parameter that is passed to all functions */
param.baseflag=basflag;
param.prev_tables=prev_tables | const_tables;
param.read_tables=read_tables;
param.current_table= head->map;
param.table=head;
param.keys=0;
current_thd->no_errors=1; // Don't warn about NULL
init_sql_alloc(&alloc,2048,0);
if (!(param.key_parts = (KEY_PART*) alloc_root(&alloc,
sizeof(KEY_PART)*
head->key_parts)))
{
current_thd->no_errors=0;
free_root(&alloc,MYF(0)); // Return memory & allocator
DBUG_RETURN(0); // Can't use range
}
key_parts= param.key_parts;
old_root=my_pthread_getspecific_ptr(MEM_ROOT*,THR_MALLOC);
my_pthread_setspecific_ptr(THR_MALLOC,&alloc);
for (idx=0 ; idx < head->keys ; idx++)
{
if (!(keys_to_use & ((key_map) 1L << idx)))
continue;
KEY *key_info= &head->key_info[idx];
if (key_info->flags & HA_FULLTEXT)
continue; // ToDo: ft-keys in non-ft ranges, if possible SerG
param.key[param.keys]=key_parts;
for (uint part=0 ; part < key_info->key_parts ; part++,key_parts++)
{
key_parts->key=param.keys;
key_parts->part=part;
key_parts->part_length= key_info->key_part[part].length;
key_parts->field= key_info->key_part[part].field;
key_parts->null_bit= key_info->key_part[part].null_bit;
if (key_parts->field->type() == FIELD_TYPE_BLOB)
key_parts->part_length+=HA_KEY_BLOB_LENGTH;
}
param.real_keynr[param.keys++]=idx;
}
param.key_parts_end=key_parts;
if ((tree=get_mm_tree(&param,cond)))
{
if (tree->type == SEL_TREE::IMPOSSIBLE)
{
records=0L; // Return -1 from this function
read_time= (double) HA_POS_ERROR;
}
else if (tree->type == SEL_TREE::KEY ||
tree->type == SEL_TREE::KEY_SMALLER)
{
SEL_ARG **key,**end,**best_key=0;
for (idx=0,key=tree->keys, end=key+param.keys ;
key != end ;
key++,idx++)
{
ha_rows found_records;
double found_read_time;
if (*key)
{
if ((*key)->type == SEL_ARG::MAYBE_KEY ||
(*key)->maybe_flag)
needed_reg|= (key_map) 1 << param.real_keynr[idx];
found_records=check_quick_select(&param,idx, *key);
if (found_records != HA_POS_ERROR && found_records > 2 &&
head->used_keys & ((table_map) 1 << param.real_keynr[idx]) &&
(head->file->option_flag() & HA_HAVE_KEY_READ_ONLY))
{
/*
** We can resolve this by only reading through this key
** Assume that we will read trough the whole key range
** and that all key blocks are half full (normally things are
** much better)
*/
uint keys_per_block= head->file->block_size/2/
(head->key_info[param.real_keynr[idx]].key_length+
head->file->ref_length) + 1;
found_read_time=((double) (found_records+keys_per_block-1)/
(double) keys_per_block);
}
else
found_read_time= head->file->read_time(found_records)+
(double) found_records / TIME_FOR_COMPARE;
if (read_time > found_read_time)
{
read_time=found_read_time;
records=found_records;
best_key=key;
}
}
}
if (best_key && records)
{
if ((quick=get_quick_select(&param,(uint) (best_key-tree->keys),
*best_key)))
{
quick->records=records;
quick->read_time=read_time;
}
}
}
}
free_root(&alloc,MYF(0)); // Return memory & allocator
my_pthread_setspecific_ptr(THR_MALLOC,old_root);
current_thd->no_errors=0;
}
DBUG_EXECUTE("info",print_quick(quick,needed_reg););
/*
Assume that if the user is using 'limit' we will only need to scan
limit rows if we are using a key
*/
DBUG_RETURN(records ? test(quick) : -1);
}
/* make a select tree of all keys in condition */
static SEL_TREE *get_mm_tree(PARAM *param,COND *cond)
{
SEL_TREE *tree=0;
DBUG_ENTER("get_mm_tree");
if (cond->type() == Item::COND_ITEM)
{
List_iterator<Item> li(*((Item_cond*) cond)->argument_list());
if (((Item_cond*) cond)->functype() == Item_func::COND_AND_FUNC)
{
tree=0;
Item *item;
while ((item=li++))
{
SEL_TREE *new_tree=get_mm_tree(param,item);
tree=tree_and(param,tree,new_tree);
if (tree && tree->type == SEL_TREE::IMPOSSIBLE)
break;
}
}
else
{ // COND OR
tree=get_mm_tree(param,li++);
if (tree)
{
Item *item;
while ((item=li++))
{
SEL_TREE *new_tree=get_mm_tree(param,item);
if (!new_tree)
DBUG_RETURN(0);
tree=tree_or(param,tree,new_tree);
if (!tree || tree->type == SEL_TREE::ALWAYS)
break;
}
}
}
DBUG_RETURN(tree);
}
/* Here when simple cond */
if (cond->const_item())
{
if (cond->val_int())
DBUG_RETURN(new SEL_TREE(SEL_TREE::ALWAYS));
DBUG_RETURN(new SEL_TREE(SEL_TREE::IMPOSSIBLE));
}
table_map ref_tables=cond->used_tables();
if (ref_tables & ~(param->prev_tables | param->read_tables |
param->current_table))
DBUG_RETURN(0); // Can't be calculated yet
if (cond->type() != Item::FUNC_ITEM)
{ // Should be a field
if (ref_tables & param->current_table)
DBUG_RETURN(0);
DBUG_RETURN(new SEL_TREE(SEL_TREE::MAYBE));
}
if (!(ref_tables & param->current_table))
DBUG_RETURN(new SEL_TREE(SEL_TREE::MAYBE)); // This may be false or true
Item_func *cond_func= (Item_func*) cond;
if (cond_func->select_optimize() == Item_func::OPTIMIZE_NONE)
DBUG_RETURN(0); // Can't be calculated
if (cond_func->functype() == Item_func::BETWEEN)
{
if (cond_func->arguments()[0]->type() == Item::FIELD_ITEM)
{
Field *field=((Item_field*) (cond_func->arguments()[0]))->field;
Item_result cmp_type=field->cmp_type();
tree= get_mm_parts(param,field,Item_func::GE_FUNC,
cond_func->arguments()[1],cmp_type);
DBUG_RETURN(tree_and(param,tree,
get_mm_parts(param, field,
Item_func::LE_FUNC,
cond_func->arguments()[2],cmp_type)));
}
DBUG_RETURN(0);
}
if (cond_func->functype() == Item_func::IN_FUNC)
{ // COND OR
Item_func_in *func=(Item_func_in*) cond_func;
if (func->key_item()->type() == Item::FIELD_ITEM)
{
Field *field=((Item_field*) (func->key_item()))->field;
Item_result cmp_type=field->cmp_type();
tree= get_mm_parts(param,field,Item_func::EQ_FUNC,
func->arguments()[0],cmp_type);
if (!tree)
DBUG_RETURN(tree); // Not key field
for (uint i=1 ; i < func->argument_count(); i++)
{
SEL_TREE *new_tree=get_mm_parts(param,field,Item_func::EQ_FUNC,
func->arguments()[i],cmp_type);
tree=tree_or(param,tree,new_tree);
}
DBUG_RETURN(tree);
}
DBUG_RETURN(0); // Can't optimize this IN
}
/* check field op const */
/* btw, ft_func's arguments()[0] isn't FIELD_ITEM. SerG*/
if (cond_func->arguments()[0]->type() == Item::FIELD_ITEM)
{
tree= get_mm_parts(param,
((Item_field*) (cond_func->arguments()[0]))->field,
cond_func->functype(),
cond_func->arg_count > 1 ? cond_func->arguments()[1] :
0,
((Item_field*) (cond_func->arguments()[0]))->field->
cmp_type());
}
/* check const op field */
if (!tree &&
cond_func->have_rev_func() &&
cond_func->arguments()[1]->type() == Item::FIELD_ITEM)
{
DBUG_RETURN(get_mm_parts(param,
((Item_field*)
(cond_func->arguments()[1]))->field,
((Item_bool_func2*) cond_func)->rev_functype(),
cond_func->arguments()[0],
((Item_field*)
(cond_func->arguments()[1]))->field->cmp_type()
));
}
DBUG_RETURN(tree);
}
static SEL_TREE *
get_mm_parts(PARAM *param,Field *field, Item_func::Functype type,Item *value,
Item_result cmp_type)
{
DBUG_ENTER("get_mm_parts");
if (field->table != param->table)
DBUG_RETURN(0);
KEY_PART *key_part = param->key_parts,*end=param->key_parts_end;
SEL_TREE *tree=0;
if (value &&
value->used_tables() & ~(param->prev_tables | param->read_tables))
DBUG_RETURN(0);
for ( ; key_part != end ; key_part++)
{
if (field->eq(key_part->field))
{
SEL_ARG *sel_arg=0;
if (!tree)
tree=new SEL_TREE();
if (!value || !(value->used_tables() & ~param->read_tables))
{
sel_arg=get_mm_leaf(key_part->field,key_part,type,value);
if (!sel_arg)
continue;
if (sel_arg->type == SEL_ARG::IMPOSSIBLE)
{
tree->type=SEL_TREE::IMPOSSIBLE;
DBUG_RETURN(tree);
}
}
else
sel_arg=new SEL_ARG(SEL_ARG::MAYBE_KEY);// This key may be used later
sel_arg->part=(uchar) key_part->part;
tree->keys[key_part->key]=sel_add(tree->keys[key_part->key],sel_arg);
}
}
DBUG_RETURN(tree);
}
static SEL_ARG *
get_mm_leaf(Field *field,KEY_PART *key_part,
Item_func::Functype type,Item *value)
{
uint maybe_null=(uint) field->real_maybe_null();
uint field_length=field->pack_length()+maybe_null;
SEL_ARG *tree;
DBUG_ENTER("get_mm_leaf");
if (type == Item_func::LIKE_FUNC)
{
bool like_error;
char buff1[MAX_FIELD_WIDTH],*min_str,*max_str;
String tmp(buff1,sizeof(buff1)),*res;
uint length,offset,min_length,max_length;
if (!field->optimize_range())
DBUG_RETURN(0); // Can't optimize this
if (!(res= value->val_str(&tmp)))
DBUG_RETURN(&null_element);
// Check if this was a function. This should have be optimized away
// in the sql_select.cc
if (res != &tmp)
{
tmp.copy(*res); // Get own copy
res= &tmp;
}
if (field->cmp_type() != STRING_RESULT)
DBUG_RETURN(0); // Can only optimize strings
offset=maybe_null;
length=key_part->part_length;
if (field->type() == FIELD_TYPE_BLOB)
{
offset+=HA_KEY_BLOB_LENGTH;
field_length=key_part->part_length-HA_KEY_BLOB_LENGTH;
}
else
{
if (length < field_length)
length=field_length; // Only if overlapping key
else
field_length=length;
}
length+=offset;
if (!(min_str= (char*) sql_alloc(length*2)))
DBUG_RETURN(0);
max_str=min_str+length;
if (maybe_null)
max_str[0]= min_str[0]=0;
if (field->binary())
like_error=like_range(res->ptr(),res->length(),wild_prefix,field_length,
min_str+offset,max_str+offset,(char) 255,
&min_length,&max_length);
else
{
#ifdef USE_STRCOLL
if (use_strcoll(default_charset_info))
like_error= my_like_range(default_charset_info,
res->ptr(),res->length(),wild_prefix,
field_length, min_str+maybe_null,
max_str+maybe_null,&min_length,&max_length);
else
#endif
like_error=like_range(res->ptr(),res->length(),wild_prefix,
field_length,
min_str+offset,max_str+offset,
max_sort_char,&min_length,&max_length);
}
if (like_error) // Can't optimize with LIKE
DBUG_RETURN(0);
if (offset != maybe_null) // Blob
{
int2store(min_str+maybe_null,min_length);
int2store(max_str+maybe_null,max_length);
}
DBUG_RETURN(new SEL_ARG(field,min_str,max_str));
}
if (!value) // IS NULL or IS NOT NULL
{
if (field->table->outer_join) // Can't use a key on this
DBUG_RETURN(0);
if (!maybe_null) // Not null field
DBUG_RETURN(type == Item_func::ISNULL_FUNC ? &null_element : 0);
tree=new SEL_ARG(field,is_null_string,is_null_string);
if (!tree)
DBUG_RETURN(0);
if (type == Item_func::ISNOTNULL_FUNC)
{
tree->min_flag=NEAR_MIN; /* IS NOT NULL -> X > NULL */
tree->max_flag=NO_MAX_RANGE;
}
DBUG_RETURN(tree);
}
if (!field->optimize_range() && type != Item_func::EQ_FUNC &&
type != Item_func::EQUAL_FUNC)
DBUG_RETURN(0); // Can't optimize this
/* We can't always use indexes when comparing a string index to a number */
/* cmp_type() is checked to allow compare of dates to numbers */
if (field->result_type() == STRING_RESULT &&
value->result_type() != STRING_RESULT &&
field->cmp_type() != value->result_type())
DBUG_RETURN(0);
if (value->save_in_field(field))
{
if (type == Item_func::EQUAL_FUNC)
{
/* convert column_name <=> NULL -> column_name IS NULL */
char *str= (char*) sql_alloc(1); // Get local copy of key
if (!*str)
DBUG_RETURN(0);
*str = 1;
DBUG_RETURN(new SEL_ARG(field,str,str));
}
DBUG_RETURN(&null_element); // NULL is never true
}
// Get local copy of key
char *str= (char*) sql_alloc(key_part->part_length+maybe_null);
if (!str)
DBUG_RETURN(0);
if (maybe_null)
*str=0; // Not NULL
field->get_key_image(str+maybe_null,key_part->part_length);
if (!(tree=new SEL_ARG(field,str,str)))
DBUG_RETURN(0);
switch (type) {
case Item_func::LT_FUNC:
if (field_is_equal_to_item(field,value))
tree->max_flag=NEAR_MAX;
/* fall through */
case Item_func::LE_FUNC:
if (!maybe_null)
tree->min_flag=NO_MIN_RANGE; /* From start */
else
{ // > NULL
tree->min_value=is_null_string;
tree->min_flag=NEAR_MIN;
}
break;
case Item_func::GT_FUNC:
if (field_is_equal_to_item(field,value))
tree->min_flag=NEAR_MIN;
/* fall through */
case Item_func::GE_FUNC:
tree->max_flag=NO_MAX_RANGE;
break;
default:
break;
}
DBUG_RETURN(tree);
}
/*
** Calculate min_str and max_str that ranges a LIKE string.
** Arguments:
** ptr Pointer to LIKE string.
** ptr_length Length of LIKE string.
** escape Escape character in LIKE. (Normally '\').
** All escape characters should be removed from min_str and max_str
** res_length Length of min_str and max_str.
** min_str Smallest case sensitive string that ranges LIKE.
** Should be space padded to res_length.
** max_str Largest case sensitive string that ranges LIKE.
** Normally padded with the biggest character sort value.
**
** The function should return 0 if ok and 1 if the LIKE string can't be
** optimized !
*/
static bool like_range(const char *ptr,uint ptr_length,char escape,
uint res_length, char *min_str,char *max_str,
char max_sort_chr, uint *min_length, uint *max_length)
{
const char *end=ptr+ptr_length;
char *min_org=min_str;
char *min_end=min_str+res_length;
for (; ptr != end && min_str != min_end ; ptr++)
{
if (*ptr == escape && ptr+1 != end)
{
ptr++; // Skipp escape
*min_str++= *max_str++ = *ptr;
continue;
}
if (*ptr == wild_one) // '_' in SQL
{
*min_str++='\0'; // This should be min char
*max_str++=max_sort_chr;
continue;
}
if (*ptr == wild_many) // '%' in SQL
{
*min_length= (uint) (min_str - min_org);
*max_length=res_length;
do {
*min_str++ = ' '; // Because if key compression
*max_str++ = max_sort_chr;
} while (min_str != min_end);
return 0;
}
*min_str++= *max_str++ = *ptr;
}
*min_length= *max_length = (uint) (min_str - min_org);
/* Temporary fix for handling wild_one at end of string (key compression) */
for (char *tmp= min_str ; tmp > min_org && tmp[-1] == '\0';)
*--tmp=' ';
while (min_str != min_end)
*min_str++ = *max_str++ = ' '; // Because if key compression
return 0;
}
/******************************************************************************
** Tree manipulation functions
** If tree is 0 it means that the condition can't be tested. It refers
** to a non existent table or to a field in current table with isn't a key.
** The different tree flags:
** IMPOSSIBLE: Condition is never true
** ALWAYS: Condition is always true
** MAYBE: Condition may exists when tables are read
** MAYBE_KEY: Condition refers to a key that may be used in join loop
** KEY_RANGE: Condition uses a key
******************************************************************************/
/*
** Add a new key test to a key when scanning through all keys
** This will never be called for same key parts.
*/
static SEL_ARG *
sel_add(SEL_ARG *key1,SEL_ARG *key2)
{
SEL_ARG *root,**key_link;
if (!key1)
return key2;
if (!key2)
return key1;
key_link= &root;
while (key1 && key2)
{
if (key1->part < key2->part)
{
*key_link= key1;
key_link= &key1->next_key_part;
key1=key1->next_key_part;
}
else
{
*key_link= key2;
key_link= &key2->next_key_part;
key2=key2->next_key_part;
}
}
*key_link=key1 ? key1 : key2;
return root;
}
#define CLONE_KEY1_MAYBE 1
#define CLONE_KEY2_MAYBE 2
#define swap_clone_flag(A) ((A & 1) << 1) | ((A & 2) >> 1)
static SEL_TREE *
tree_and(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2)
{
DBUG_ENTER("tree_and");
if (!tree1)
DBUG_RETURN(tree2);
if (!tree2)
DBUG_RETURN(tree1);
if (tree1->type == SEL_TREE::IMPOSSIBLE || tree2->type == SEL_TREE::ALWAYS)
DBUG_RETURN(tree1);
if (tree2->type == SEL_TREE::IMPOSSIBLE || tree1->type == SEL_TREE::ALWAYS)
DBUG_RETURN(tree2);
if (tree1->type == SEL_TREE::MAYBE)
{
if (tree2->type == SEL_TREE::KEY)
tree2->type=SEL_TREE::KEY_SMALLER;
DBUG_RETURN(tree2);
}
if (tree2->type == SEL_TREE::MAYBE)
{
tree1->type=SEL_TREE::KEY_SMALLER;
DBUG_RETURN(tree1);
}
/* Join the trees key per key */
SEL_ARG **key1,**key2,**end;
for (key1= tree1->keys,key2= tree2->keys,end=key1+param->keys ;
key1 != end ; key1++,key2++)
{
uint flag=0;
if (*key1 || *key2)
{
if (*key1 && !(*key1)->simple_key())
flag|=CLONE_KEY1_MAYBE;
if (*key2 && !(*key2)->simple_key())
flag|=CLONE_KEY2_MAYBE;
*key1=key_and(*key1,*key2,flag);
if ((*key1)->type == SEL_ARG::IMPOSSIBLE)
{
tree1->type= SEL_TREE::IMPOSSIBLE;
break;
}
#ifdef EXTRA_DEBUG
(*key1)->test_use_count(*key1);
#endif
}
}
DBUG_RETURN(tree1);
}
static SEL_TREE *
tree_or(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2)
{
DBUG_ENTER("tree_or");
if (!tree1 || !tree2)
DBUG_RETURN(0);
if (tree1->type == SEL_TREE::IMPOSSIBLE || tree2->type == SEL_TREE::ALWAYS)
DBUG_RETURN(tree2);
if (tree2->type == SEL_TREE::IMPOSSIBLE || tree1->type == SEL_TREE::ALWAYS)
DBUG_RETURN(tree1);
if (tree1->type == SEL_TREE::MAYBE)
DBUG_RETURN(tree1); // Can't use this
if (tree2->type == SEL_TREE::MAYBE)
DBUG_RETURN(tree2);
/* Join the trees key per key */
SEL_ARG **key1,**key2,**end;
SEL_TREE *result=0;
for (key1= tree1->keys,key2= tree2->keys,end=key1+param->keys ;
key1 != end ; key1++,key2++)
{
*key1=key_or(*key1,*key2);
if (*key1)
{
result=tree1; // Added to tree1
#ifdef EXTRA_DEBUG
(*key1)->test_use_count(*key1);
#endif
}
}
DBUG_RETURN(result);
}
/* And key trees where key1->part < key2 -> part */
static SEL_ARG *
and_all_keys(SEL_ARG *key1,SEL_ARG *key2,uint clone_flag)
{
SEL_ARG *next;
ulong use_count=key1->use_count;
if (key1->elements != 1)
{
key2->use_count+=key1->elements-1;
key2->increment_use_count((int) key1->elements-1);
}
if (key1->type == SEL_ARG::MAYBE_KEY)
{
key1->left= &null_element; key1->next=0;
}
for (next=key1->first(); next ; next=next->next)
{
if (next->next_key_part)
{
SEL_ARG *tmp=key_and(next->next_key_part,key2,clone_flag);
if (tmp && tmp->type == SEL_ARG::IMPOSSIBLE)
{
key1=key1->tree_delete(next);
continue;
}
next->next_key_part=tmp;
if (use_count)
next->increment_use_count(use_count);
}
else
next->next_key_part=key2;
}
if (!key1)
return &null_element; // Impossible ranges
key1->use_count++;
return key1;
}
static SEL_ARG *
key_and(SEL_ARG *key1,SEL_ARG *key2,uint clone_flag)
{
if (!key1)
return key2;
if (!key2)
return key1;
if (key1->part != key2->part)
{
if (key1->part > key2->part)
{
swap(SEL_ARG *,key1,key2);
clone_flag=swap_clone_flag(clone_flag);
}
// key1->part < key2->part
key1->use_count--;
if (key1->use_count > 0)
key1=key1->clone_tree();
return and_all_keys(key1,key2,clone_flag);
}
if (((clone_flag & CLONE_KEY2_MAYBE) &&
!(clone_flag & CLONE_KEY1_MAYBE)) ||
key1->type == SEL_ARG::MAYBE_KEY)
{ // Put simple key in key2
swap(SEL_ARG *,key1,key2);
clone_flag=swap_clone_flag(clone_flag);
}
// If one of the key is MAYBE_KEY then the found region may be smaller
if (key2->type == SEL_ARG::MAYBE_KEY)
{
if (key1->use_count > 1)
{
key1->use_count--;
key1=key1->clone_tree();
key1->use_count++;
}
if (key1->type == SEL_ARG::MAYBE_KEY)
{ // Both are maybe key
key1->next_key_part=key_and(key1->next_key_part,key2->next_key_part,
clone_flag);
if (key1->next_key_part &&
key1->next_key_part->type == SEL_ARG::IMPOSSIBLE)
return key1;
}
else
{
key1->maybe_smaller();
if (key2->next_key_part)
return and_all_keys(key1,key2,clone_flag);
key2->use_count--; // Key2 doesn't have a tree
}
return key1;
}
key1->use_count--;
key2->use_count--;
SEL_ARG *e1=key1->first(), *e2=key2->first(), *new_tree=0;
while (e1 && e2)
{
int cmp=e1->cmp_min_to_min(e2);
if (cmp < 0)
{
if (get_range(&e1,&e2,key1))
continue;
}
else if (get_range(&e2,&e1,key2))
continue;
SEL_ARG *next=key_and(e1->next_key_part,e2->next_key_part,clone_flag);
e1->increment_use_count(1);
e2->increment_use_count(1);
if (!next || next->type != SEL_ARG::IMPOSSIBLE)
{
SEL_ARG *new_arg= e1->clone_and(e2);
new_arg->next_key_part=next;
if (!new_tree)
{
new_tree=new_arg;
}
else
new_tree=new_tree->insert(new_arg);
}
if (e1->cmp_max_to_max(e2) < 0)
e1=e1->next; // e1 can't overlapp next e2
else
e2=e2->next;
}
key1->free_tree();
key2->free_tree();
if (!new_tree)
return &null_element; // Impossible range
return new_tree;
}
static bool
get_range(SEL_ARG **e1,SEL_ARG **e2,SEL_ARG *root1)
{
(*e1)=root1->find_range(*e2); // first e1->min < e2->min
if ((*e1)->cmp_max_to_min(*e2) < 0)
{
if (!((*e1)=(*e1)->next))
return 1;
if ((*e1)->cmp_min_to_max(*e2) > 0)
{
(*e2)=(*e2)->next;
return 1;
}
}
return 0;
}
static SEL_ARG *
key_or(SEL_ARG *key1,SEL_ARG *key2)
{
if (!key1)
{
if (key2)
{
key2->use_count--;
key2->free_tree();
}
return 0;
}
else if (!key2)
{
key1->use_count--;
key1->free_tree();
return 0;
}
key1->use_count--;
key2->use_count--;
if (key1->part != key2->part)
{
key1->free_tree();
key2->free_tree();
return 0; // Can't optimize this
}
// If one of the key is MAYBE_KEY then the found region may be bigger
if (key1->type == SEL_ARG::MAYBE_KEY)
{
key2->free_tree();
key1->use_count++;
return key1;
}
if (key2->type == SEL_ARG::MAYBE_KEY)
{
key1->free_tree();
key2->use_count++;
return key2;
}
if (key1->use_count > 0)
{
if (key2->use_count == 0 || key1->elements > key2->elements)
{
swap(SEL_ARG *,key1,key2);
}
else
key1=key1->clone_tree();
}
// Add tree at key2 to tree at key1
bool key2_shared=key2->use_count != 0;
key1->maybe_flag|=key2->maybe_flag;
for (key2=key2->first(); key2; )
{
SEL_ARG *tmp=key1->find_range(key2); // Find key1.min <= key2.min
int cmp;
if (!tmp)
{
tmp=key1->first(); // tmp.min > key2.min
cmp= -1;
}
else if ((cmp=tmp->cmp_max_to_min(key2)) < 0)
{ // Found tmp.max < key2.min
SEL_ARG *next=tmp->next;
if (cmp == -2 && eq_tree(tmp->next_key_part,key2->next_key_part))
{
// Join near ranges like tmp.max < 0 and key2.min >= 0
SEL_ARG *key2_next=key2->next;
if (key2_shared)
{
key2=new SEL_ARG(*key2);
key2->increment_use_count(key1->use_count+1);
key2->next=key2_next; // New copy of key2
}
key2->copy_min(tmp);
if (!(key1=key1->tree_delete(tmp)))
{ // Only one key in tree
key1=key2;
key1->make_root();
key2=key2_next;
break;
}
}
if (!(tmp=next)) // tmp.min > key2.min
break; // Copy rest of key2
}
if (cmp < 0)
{ // tmp.min > key2.min
int tmp_cmp;
if ((tmp_cmp=tmp->cmp_min_to_max(key2)) > 0) // if tmp.min > key2.max
{
if (tmp_cmp == 2 && eq_tree(tmp->next_key_part,key2->next_key_part))
{ // ranges are connected
tmp->copy_min_to_min(key2);
key1->merge_flags(key2);
if (tmp->min_flag & NO_MIN_RANGE &&
tmp->max_flag & NO_MAX_RANGE)
{
if (key1->maybe_flag)
return new SEL_ARG(SEL_ARG::MAYBE_KEY);
return 0;
}
key2->increment_use_count(-1); // Free not used tree
key2=key2->next;
continue;
}
else
{
SEL_ARG *next=key2->next; // Keys are not overlapping
if (key2_shared)
{
key1=key1->insert(new SEL_ARG(*key2)); // Must make copy
key2->increment_use_count(key1->use_count+1);
}
else
key1=key1->insert(key2); // Will destroy key2_root
key2=next;
continue;
}
}
}
// tmp.max >= key2.min && tmp.min <= key.max (overlapping ranges)
if (eq_tree(tmp->next_key_part,key2->next_key_part))
{
if (tmp->is_same(key2))
{
tmp->merge_flags(key2); // Copy maybe flags
key2->increment_use_count(-1); // Free not used tree
}
else
{
SEL_ARG *last=tmp;
while (last->next && last->next->cmp_min_to_max(key2) <= 0 &&
eq_tree(last->next->next_key_part,key2->next_key_part))
{
SEL_ARG *save=last;
last=last->next;
key1=key1->tree_delete(save);
}
if (last->copy_min(key2) || last->copy_max(key2))
{ // Full range
key1->free_tree();
for (; key2 ; key2=key2->next)
key2->increment_use_count(-1); // Free not used tree
if (key1->maybe_flag)
return new SEL_ARG(SEL_ARG::MAYBE_KEY);
return 0;
}
}
key2=key2->next;
continue;
}
if (cmp >= 0 && tmp->cmp_min_to_min(key2) < 0)
{ // tmp.min <= x < key2.min
SEL_ARG *new_arg=tmp->clone_first(key2);
if ((new_arg->next_key_part= key1->next_key_part))
new_arg->increment_use_count(key1->use_count+1);
tmp->copy_min_to_min(key2);
key1=key1->insert(new_arg);
}
// tmp.min >= key2.min && tmp.min <= key2.max
SEL_ARG key(*key2); // Get copy we can modify
for (;;)
{
if (tmp->cmp_min_to_min(&key) > 0)
{ // key.min <= x < tmp.min
SEL_ARG *new_arg=key.clone_first(tmp);
if ((new_arg->next_key_part=key.next_key_part))
new_arg->increment_use_count(key1->use_count+1);
key1=key1->insert(new_arg);
}
if ((cmp=tmp->cmp_max_to_max(&key)) <= 0)
{ // tmp.min. <= x <= tmp.max
tmp->maybe_flag|= key.maybe_flag;
key.increment_use_count(key1->use_count+1);
tmp->next_key_part=key_or(tmp->next_key_part,key.next_key_part);
if (!cmp) // Key2 is ready
break;
key.copy_max_to_min(tmp);
if (!(tmp=tmp->next))
{
key1=key1->insert(new SEL_ARG(key));
key2=key2->next;
goto end;
}
if (tmp->cmp_min_to_max(&key) > 0)
{
key1=key1->insert(new SEL_ARG(key));
break;
}
}
else
{
SEL_ARG *new_arg=tmp->clone_last(&key); // tmp.min <= x <= key.max
tmp->copy_max_to_min(&key);
tmp->increment_use_count(key1->use_count+1);
new_arg->next_key_part=key_or(tmp->next_key_part,key.next_key_part);
key1=key1->insert(new_arg);
break;
}
}
key2=key2->next;
}
end:
while (key2)
{
SEL_ARG *next=key2->next;
if (key2_shared)
{
key2->increment_use_count(key1->use_count+1);
key1=key1->insert(new SEL_ARG(*key2)); // Must make copy
}
else
key1=key1->insert(key2); // Will destroy key2_root
key2=next;
}
key1->use_count++;
return key1;
}
/* Compare if two trees are equal */
static bool eq_tree(SEL_ARG* a,SEL_ARG *b)
{
if (a == b)
return 1;
if (!a || !b || !a->is_same(b))
return 0;
if (a->left != &null_element && b->left != &null_element)
{
if (!eq_tree(a->left,b->left))
return 0;
}
else if (a->left != &null_element || b->left != &null_element)
return 0;
if (a->right != &null_element && b->right != &null_element)
{
if (!eq_tree(a->right,b->right))
return 0;
}
else if (a->right != &null_element || b->right != &null_element)
return 0;
if (a->next_key_part != b->next_key_part)
{ // Sub range
if (!a->next_key_part != !b->next_key_part ||
!eq_tree(a->next_key_part, b->next_key_part))
return 0;
}
return 1;
}
SEL_ARG *
SEL_ARG::insert(SEL_ARG *key)
{
SEL_ARG *element,**par,*last_element;
LINT_INIT(par); LINT_INIT(last_element);
for (element= this; element != &null_element ; )
{
last_element=element;
if (key->cmp_min_to_min(element) > 0)
{
par= &element->right; element= element->right;
}
else
{
par = &element->left; element= element->left;
}
}
*par=key;
key->parent=last_element;
/* Link in list */
if (par == &last_element->left)
{
key->next=last_element;
if ((key->prev=last_element->prev))
key->prev->next=key;
last_element->prev=key;
}
else
{
if ((key->next=last_element->next))
key->next->prev=key;
key->prev=last_element;
last_element->next=key;
}
key->left=key->right= &null_element;
SEL_ARG *root=rb_insert(key); // rebalance tree
root->use_count=this->use_count; // copy root info
root->elements= this->elements+1;
root->maybe_flag=this->maybe_flag;
return root;
}
/*
** Find best key with min <= given key
** Because the call context this should never return 0 to get_range
*/
SEL_ARG *
SEL_ARG::find_range(SEL_ARG *key)
{
SEL_ARG *element=this,*found=0;
for (;;)
{
if (element == &null_element)
return found;
int cmp=element->cmp_min_to_min(key);
if (cmp == 0)
return element;
if (cmp < 0)
{
found=element;
element=element->right;
}
else
element=element->left;
}
}
/*
** Remove a element from the tree
** This also frees all sub trees that is used by the element
*/
SEL_ARG *
SEL_ARG::tree_delete(SEL_ARG *key)
{
enum leaf_color remove_color;
SEL_ARG *root,*nod,**par,*fix_par;
root=this; this->parent= 0;
/* Unlink from list */
if (key->prev)
key->prev->next=key->next;
if (key->next)
key->next->prev=key->prev;
key->increment_use_count(-1);
if (!key->parent)
par= &root;
else
par=key->parent_ptr();
if (key->left == &null_element)
{
*par=nod=key->right;
fix_par=key->parent;
if (nod != &null_element)
nod->parent=fix_par;
remove_color= key->color;
}
else if (key->right == &null_element)
{
*par= nod=key->left;
nod->parent=fix_par=key->parent;
remove_color= key->color;
}
else
{
SEL_ARG *tmp=key->next; // next bigger key (exist!)
nod= *tmp->parent_ptr()= tmp->right; // unlink tmp from tree
fix_par=tmp->parent;
if (nod != &null_element)
nod->parent=fix_par;
remove_color= tmp->color;
tmp->parent=key->parent; // Move node in place of key
(tmp->left=key->left)->parent=tmp;
if ((tmp->right=key->right) != &null_element)
tmp->right->parent=tmp;
tmp->color=key->color;
*par=tmp;
if (fix_par == key) // key->right == key->next
fix_par=tmp; // new parent of nod
}
if (root == &null_element)
return 0; // Maybe root later
if (remove_color == BLACK)
root=rb_delete_fixup(root,nod,fix_par);
test_rb_tree(root,root->parent);
root->use_count=this->use_count; // Fix root counters
root->elements=this->elements-1;
root->maybe_flag=this->maybe_flag;
return root;
}
/* Functions to fix up the tree after insert and delete */
static void left_rotate(SEL_ARG **root,SEL_ARG *leaf)
{
SEL_ARG *y=leaf->right;
leaf->right=y->left;
if (y->left != &null_element)
y->left->parent=leaf;
if (!(y->parent=leaf->parent))
*root=y;
else
*leaf->parent_ptr()=y;
y->left=leaf;
leaf->parent=y;
}
static void right_rotate(SEL_ARG **root,SEL_ARG *leaf)
{
SEL_ARG *y=leaf->left;
leaf->left=y->right;
if (y->right != &null_element)
y->right->parent=leaf;
if (!(y->parent=leaf->parent))
*root=y;
else
*leaf->parent_ptr()=y;
y->right=leaf;
leaf->parent=y;
}
SEL_ARG *
SEL_ARG::rb_insert(SEL_ARG *leaf)
{
SEL_ARG *y,*par,*par2,*root;
root= this; root->parent= 0;
leaf->color=RED;
while (leaf != root && (par= leaf->parent)->color == RED)
{ // This can't be root or 1 level under
if (par == (par2= leaf->parent->parent)->left)
{
y= par2->right;
if (y->color == RED)
{
par->color=BLACK;
y->color=BLACK;
leaf=par2;
leaf->color=RED; /* And the loop continues */
}
else
{
if (leaf == par->right)
{
left_rotate(&root,leaf->parent);
par=leaf; /* leaf is now parent to old leaf */
}
par->color=BLACK;
par2->color=RED;
right_rotate(&root,par2);
break;
}
}
else
{
y= par2->left;
if (y->color == RED)
{
par->color=BLACK;
y->color=BLACK;
leaf=par2;
leaf->color=RED; /* And the loop continues */
}
else
{
if (leaf == par->left)
{
right_rotate(&root,par);
par=leaf;
}
par->color=BLACK;
par2->color=RED;
left_rotate(&root,par2);
break;
}
}
}
root->color=BLACK;
test_rb_tree(root,root->parent);
return root;
}
SEL_ARG *rb_delete_fixup(SEL_ARG *root,SEL_ARG *key,SEL_ARG *par)
{
SEL_ARG *x,*w;
root->parent=0;
x= key;
while (x != root && x->color == SEL_ARG::BLACK)
{
if (x == par->left)
{
w=par->right;
if (w->color == SEL_ARG::RED)
{
w->color=SEL_ARG::BLACK;
par->color=SEL_ARG::RED;
left_rotate(&root,par);
w=par->right;
}
if (w->left->color == SEL_ARG::BLACK && w->right->color == SEL_ARG::BLACK)
{
w->color=SEL_ARG::RED;
x=par;
}
else
{
if (w->right->color == SEL_ARG::BLACK)
{
w->left->color=SEL_ARG::BLACK;
w->color=SEL_ARG::RED;
right_rotate(&root,w);
w=par->right;
}
w->color=par->color;
par->color=SEL_ARG::BLACK;
w->right->color=SEL_ARG::BLACK;
left_rotate(&root,par);
x=root;
break;
}
}
else
{
w=par->left;
if (w->color == SEL_ARG::RED)
{
w->color=SEL_ARG::BLACK;
par->color=SEL_ARG::RED;
right_rotate(&root,par);
w=par->left;
}
if (w->right->color == SEL_ARG::BLACK && w->left->color == SEL_ARG::BLACK)
{
w->color=SEL_ARG::RED;
x=par;
}
else
{
if (w->left->color == SEL_ARG::BLACK)
{
w->right->color=SEL_ARG::BLACK;
w->color=SEL_ARG::RED;
left_rotate(&root,w);
w=par->left;
}
w->color=par->color;
par->color=SEL_ARG::BLACK;
w->left->color=SEL_ARG::BLACK;
right_rotate(&root,par);
x=root;
break;
}
}
par=x->parent;
}
x->color=SEL_ARG::BLACK;
return root;
}
/* Test that the proporties for a red-black tree holds */
#ifdef EXTRA_DEBUG
int test_rb_tree(SEL_ARG *element,SEL_ARG *parent)
{
int count_l,count_r;
if (element == &null_element)
return 0; // Found end of tree
if (element->parent != parent)
{
sql_print_error("Wrong tree: Parent doesn't point at parent");
return -1;
}
if (element->color == SEL_ARG::RED &&
(element->left->color == SEL_ARG::RED ||
element->right->color == SEL_ARG::RED))
{
sql_print_error("Wrong tree: Found two red in a row");
return -1;
}
if (element->left == element->right && element->left != &null_element)
{ // Dummy test
sql_print_error("Wrong tree: Found right == left");
return -1;
}
count_l=test_rb_tree(element->left,element);
count_r=test_rb_tree(element->right,element);
if (count_l >= 0 && count_r >= 0)
{
if (count_l == count_r)
return count_l+(element->color == SEL_ARG::BLACK);
sql_print_error("Wrong tree: Incorrect black-count: %d - %d",
count_l,count_r);
}
return -1; // Error, no more warnings
}
static ulong count_key_part_usage(SEL_ARG *root, SEL_ARG *key)
{
ulong count= 0;
for (root=root->first(); root ; root=root->next)
{
if (root->next_key_part)
{
if (root->next_key_part == key)
count++;
if (root->next_key_part->part < key->part)
count+=count_key_part_usage(root->next_key_part,key);
}
}
return count;
}
void SEL_ARG::test_use_count(SEL_ARG *root)
{
if (this == root && use_count != 1)
{
sql_print_error("Use_count: Wrong count %lu for root",use_count);
return;
}
if (this->type != SEL_ARG::KEY_RANGE)
return;
uint e_count=0;
for (SEL_ARG *pos=first(); pos ; pos=pos->next)
{
e_count++;
if (pos->next_key_part)
{
ulong count=count_key_part_usage(root,pos->next_key_part);
if (count > pos->next_key_part->use_count)
{
sql_print_error("Use_count: Wrong count for key at %lx, %lu should be %lu",
pos,pos->next_key_part->use_count,count);
return;
}
pos->next_key_part->test_use_count(root);
}
}
if (e_count != elements)
sql_print_error("Wrong use count: %u for tree at %lx", e_count,
(gptr) this);
}
#endif
/*****************************************************************************
** Check how many records we will find by using the found tree
*****************************************************************************/
static ha_rows
check_quick_select(PARAM *param,uint idx,SEL_ARG *tree)
{
ha_rows records;
DBUG_ENTER("check_quick_select");
if (!tree)
DBUG_RETURN(HA_POS_ERROR); // Can't use it
if (tree->type == SEL_ARG::IMPOSSIBLE)
DBUG_RETURN(0L); // Impossible select. return
if (tree->type != SEL_ARG::KEY_RANGE || tree->part != 0)
DBUG_RETURN(HA_POS_ERROR); // Don't use tree
param->max_key_part=0;
records=check_quick_keys(param,idx,tree,param->min_key,0,param->max_key,0);
if (records != HA_POS_ERROR)
{
uint key=param->real_keynr[idx];
param->table->quick_keys|= (key_map) 1 << key;
param->table->quick_rows[key]=records;
param->table->quick_key_parts[key]=param->max_key_part+1;
}
DBUG_RETURN(records);
}
static ha_rows
check_quick_keys(PARAM *param,uint idx,SEL_ARG *key_tree,
char *min_key,uint min_key_flag, char *max_key,
uint max_key_flag)
{
ha_rows records=0,tmp;
param->max_key_part=max(param->max_key_part,key_tree->part);
if (key_tree->left != &null_element)
{
records=check_quick_keys(param,idx,key_tree->left,min_key,min_key_flag,
max_key,max_key_flag);
if (records == HA_POS_ERROR) // Impossible
return records;
}
uint tmp_min_flag,tmp_max_flag,keynr;
char *tmp_min_key=min_key,*tmp_max_key=max_key;
key_tree->store(param->key[idx][key_tree->part].part_length,
&tmp_min_key,min_key_flag,&tmp_max_key,max_key_flag);
uint min_key_length= (uint) (tmp_min_key- param->min_key);
uint max_key_length= (uint) (tmp_max_key- param->max_key);
if (key_tree->next_key_part &&
key_tree->next_key_part->part == key_tree->part+1 &&
key_tree->next_key_part->type == SEL_ARG::KEY_RANGE)
{ // const key as prefix
if (min_key_length == max_key_length &&
!memcmp(min_key,max_key, (uint) (tmp_max_key - max_key)) &&
!key_tree->min_flag && !key_tree->max_flag)
{
tmp=check_quick_keys(param,idx,key_tree->next_key_part,
tmp_min_key, min_key_flag | key_tree->min_flag,
tmp_max_key, max_key_flag | key_tree->max_flag);
goto end; // Ugly, but efficient
}
tmp_min_flag=key_tree->min_flag;
tmp_max_flag=key_tree->max_flag;
if (!tmp_min_flag)
key_tree->next_key_part->store_min_key(param->key[idx], &tmp_min_key,
&tmp_min_flag);
if (!tmp_max_flag)
key_tree->next_key_part->store_max_key(param->key[idx], &tmp_max_key,
&tmp_max_flag);
min_key_length= (uint) (tmp_min_key- param->min_key);
max_key_length= (uint) (tmp_max_key- param->max_key);
}
else
{
tmp_min_flag=min_key_flag | key_tree->min_flag;
tmp_max_flag=max_key_flag | key_tree->max_flag;
}
keynr=param->real_keynr[idx];
if (!tmp_min_flag && ! tmp_max_flag &&
(uint) key_tree->part+1 == param->table->key_info[keynr].key_parts &&
(param->table->key_info[keynr].flags & HA_NOSAME) &&
min_key_length == max_key_length &&
!memcmp(param->min_key,param->max_key,min_key_length))
tmp=1; // Max one record
else
tmp=param->table->file->
records_in_range((int) keynr,
(byte*) (!min_key_length ? NullS :
param->min_key),
min_key_length,
(tmp_min_flag & NEAR_MIN ?
HA_READ_AFTER_KEY : HA_READ_KEY_EXACT),
(byte*) (!max_key_length ? NullS :
param->max_key),
max_key_length,
(tmp_max_flag & NEAR_MAX ?
HA_READ_BEFORE_KEY : HA_READ_AFTER_KEY));
end:
if (tmp == HA_POS_ERROR) // Impossible range
return tmp;
records+=tmp;
if (key_tree->right != &null_element)
{
tmp=check_quick_keys(param,idx,key_tree->right,min_key,min_key_flag,
max_key,max_key_flag);
if (tmp == HA_POS_ERROR)
return tmp;
records+=tmp;
}
return records;
}
/****************************************************************************
** change a tree to a structure to be used by quick_select
** This uses it's own malloc tree
****************************************************************************/
static QUICK_SELECT *
get_quick_select(PARAM *param,uint idx,SEL_ARG *key_tree)
{
QUICK_SELECT *quick;
DBUG_ENTER("get_quick_select");
if ((quick=new QUICK_SELECT(param->table,param->real_keynr[idx])))
{
if (quick->error ||
get_quick_keys(param,quick,param->key[idx],key_tree,param->min_key,0,
param->max_key,0))
{
delete quick;
quick=0;
}
else
{
quick->key_parts=(KEY_PART*)
sql_memdup(param->key[idx],
sizeof(KEY_PART)*
param->table->key_info[param->real_keynr[idx]].key_parts);
}
}
DBUG_RETURN(quick);
}
/*
** Fix this to get all possible sub_ranges
*/
static bool
get_quick_keys(PARAM *param,QUICK_SELECT *quick,KEY_PART *key,
SEL_ARG *key_tree,char *min_key,uint min_key_flag,
char *max_key, uint max_key_flag)
{
QUICK_RANGE *range;
uint flag;
if (key_tree->left != &null_element)
{
if (get_quick_keys(param,quick,key,key_tree->left,
min_key,min_key_flag, max_key, max_key_flag))
return 1;
}
char *tmp_min_key=min_key,*tmp_max_key=max_key;
key_tree->store(key[key_tree->part].part_length,
&tmp_min_key,min_key_flag,&tmp_max_key,max_key_flag);
if (key_tree->next_key_part &&
key_tree->next_key_part->part == key_tree->part+1 &&
key_tree->next_key_part->type == SEL_ARG::KEY_RANGE)
{ // const key as prefix
if (!((tmp_min_key - min_key) != (tmp_max_key - max_key) ||
memcmp(min_key,max_key, (uint) (tmp_max_key - max_key)) ||
key_tree->min_flag || key_tree->max_flag))
{
if (get_quick_keys(param,quick,key,key_tree->next_key_part,
tmp_min_key, min_key_flag | key_tree->min_flag,
tmp_max_key, max_key_flag | key_tree->max_flag))
return 1;
goto end; // Ugly, but efficient
}
{
uint tmp_min_flag=key_tree->min_flag,tmp_max_flag=key_tree->max_flag;
if (!tmp_min_flag)
key_tree->next_key_part->store_min_key(key, &tmp_min_key,
&tmp_min_flag);
if (!tmp_max_flag)
key_tree->next_key_part->store_max_key(key, &tmp_max_key,
&tmp_max_flag);
flag=tmp_min_flag | tmp_max_flag;
}
}
else
flag=key_tree->min_flag | key_tree->max_flag;
/* Ensure that some part of min_key and max_key are used. If not,
regard this as no lower/upper range */
if (tmp_min_key != param->min_key)
flag&= ~NO_MIN_RANGE;
else
flag|= NO_MIN_RANGE;
if (tmp_max_key != param->max_key)
flag&= ~NO_MAX_RANGE;
else
flag|= NO_MAX_RANGE;
if (flag == 0)
{
uint length= (uint) (tmp_min_key - param->min_key);
if (length == (uint) (tmp_max_key - param->max_key) &&
!memcmp(param->min_key,param->max_key,length))
{
KEY *table_key=quick->head->key_info+quick->index;
flag=EQ_RANGE;
if (table_key->flags & HA_NOSAME && key->part == table_key->key_parts-1)
{
if (!(table_key->flags & HA_NULL_PART_KEY) ||
!null_part_in_key(key,
param->min_key,
(uint) (tmp_min_key - param->min_key)))
flag|= UNIQUE_RANGE;
else
flag|= NULL_RANGE;
}
}
}
/* Get range for retrieving rows in QUICK_SELECT::get_next */
range= new QUICK_RANGE(param->min_key,
(uint) (tmp_min_key - param->min_key),
param->max_key,
(uint) (tmp_max_key - param->max_key),
flag);
set_if_bigger(quick->max_used_key_length,range->min_length);
set_if_bigger(quick->max_used_key_length,range->max_length);
if (!range) // Not enough memory
return 1;
quick->ranges.push_back(range);
end:
if (key_tree->right != &null_element)
return get_quick_keys(param,quick,key,key_tree->right,
min_key,min_key_flag,
max_key,max_key_flag);
return 0;
}
/*
Return 1 if there is only one range and this uses the whole primary key
*/
bool QUICK_SELECT::unique_key_range()
{
if (ranges.elements == 1)
{
QUICK_RANGE *tmp;
if (((tmp=ranges.head())->flag & (EQ_RANGE | NULL_RANGE)) == EQ_RANGE)
{
KEY *key=head->key_info+index;
return ((key->flags & HA_NOSAME) &&
key->key_length == tmp->min_length);
}
}
return 0;
}
/* Returns true if any part of the key is NULL */
static bool null_part_in_key(KEY_PART *key_part, const char *key, uint length)
{
for (const char *end=key+length ;
key < end;
key+= key_part++->part_length)
{
if (key_part->null_bit)
{
if (*key++)
return 1;
}
}
return 0;
}
/****************************************************************************
** Create a QUICK RANGE based on a key
****************************************************************************/
QUICK_SELECT *get_quick_select_for_ref(TABLE *table, TABLE_REF *ref)
{
table->file->index_end(); // Remove old cursor
QUICK_SELECT *quick=new QUICK_SELECT(table, ref->key, 1);
KEY *key_info = &table->key_info[ref->key];
KEY_PART *key_part;
uint part;
if (!quick)
return 0;
QUICK_RANGE *range= new QUICK_RANGE();
if (!range || cp_buffer_from_ref(ref))
goto err;
range->min_key=range->max_key=(char*) ref->key_buff;
range->min_length=range->max_length=ref->key_length;
range->flag= ((ref->key_length == key_info->key_length &&
(key_info->flags & HA_NOSAME)) ? EQ_RANGE : 0);
if (!(quick->key_parts=key_part=(KEY_PART *)
sql_alloc(sizeof(KEY_PART)*ref->key_parts)))
goto err;
for (part=0 ; part < ref->key_parts ;part++,key_part++)
{
key_part->part=part;
key_part->field= key_info->key_part[part].field;
key_part->part_length= key_info->key_part[part].length;
if (key_part->field->type() == FIELD_TYPE_BLOB)
key_part->part_length+=HA_KEY_BLOB_LENGTH;
key_part->null_bit= key_info->key_part[part].null_bit;
}
if (!quick->ranges.push_back(range))
return quick;
err:
delete quick;
return 0;
}
/* get next possible record using quick-struct */
int QUICK_SELECT::get_next()
{
DBUG_ENTER("get_next");
for (;;)
{
int result;
if (range)
{ // Already read through key
result=((range->flag & EQ_RANGE) ?
file->index_next_same(record, (byte*) range->min_key,
range->min_length) :
file->index_next(record));
if (!result)
{
if (!cmp_next(*it.ref()))
DBUG_RETURN(0);
}
else if (result != HA_ERR_END_OF_FILE)
DBUG_RETURN(result);
}
if (!(range=it++))
DBUG_RETURN(HA_ERR_END_OF_FILE); // All ranges used
if (range->flag & NO_MIN_RANGE) // Read first record
{
int error;
if ((error=file->index_first(record)))
DBUG_RETURN(error); // Empty table
if (cmp_next(range) == 0)
DBUG_RETURN(0); // No matching records
range=0; // To next range
continue;
}
if ((result = file->index_read(record,(byte*) range->min_key,
range->min_length,
((range->flag & NEAR_MIN) ?
HA_READ_AFTER_KEY:
(range->flag & EQ_RANGE) ?
HA_READ_KEY_EXACT :
HA_READ_KEY_OR_NEXT))))
{
if (result != HA_ERR_KEY_NOT_FOUND)
DBUG_RETURN(result);
range=0; // Not found, to next range
continue;
}
if (cmp_next(range) == 0)
{
if (range->flag == (UNIQUE_RANGE | EQ_RANGE))
range=0; // Stop searching
DBUG_RETURN(0); // Found key is in range
}
range=0; // To next range
}
}
/* compare if found key is over max-value */
/* Returns 0 if key <= range->max_key */
int QUICK_SELECT::cmp_next(QUICK_RANGE *range)
{
if (range->flag & NO_MAX_RANGE)
return (0); /* key can't be to large */
KEY_PART *key_part=key_parts;
for (char *key=range->max_key, *end=key+range->max_length;
key < end;
key+= key_part++->part_length)
{
int cmp;
if (key_part->null_bit)
{
if (*key++)
{
if (!key_part->field->is_null())
return 1;
continue;
}
else if (key_part->field->is_null())
return 0;
}
if ((cmp=key_part->field->key_cmp((byte*) key, key_part->part_length)) < 0)
return 0;
if (cmp > 0)
return 1;
}
return (range->flag & NEAR_MAX) ? 1 : 0; // Exact match
}
/*****************************************************************************
** Print a quick range for debugging
** TODO:
** This should be changed to use a String to store each row instead
** of locking the DEBUG stream !
*****************************************************************************/
#ifndef DBUG_OFF
static void
print_key(KEY_PART *key_part,const char *key,uint used_length)
{
char buff[1024];
String tmp(buff,sizeof(buff));
for (uint length=0;
length < used_length ;
length+=key_part->part_length, key+=key_part->part_length, key_part++)
{
Field *field=key_part->field;
if (length != 0)
fputc('/',DBUG_FILE);
if (field->real_maybe_null())
{
length++; // null byte is not in part_length
if (*key++)
{
fwrite("NULL",sizeof(char),4,DBUG_FILE);
continue;
}
}
field->set_key_image((char*) key,key_part->part_length -
((field->type() == FIELD_TYPE_BLOB) ?
HA_KEY_BLOB_LENGTH : 0));
field->val_str(&tmp,&tmp);
fwrite(tmp.ptr(),sizeof(char),tmp.length(),DBUG_FILE);
}
}
static void print_quick(QUICK_SELECT *quick,key_map needed_reg)
{
QUICK_RANGE *range;
DBUG_ENTER("print_param");
if (! _db_on_ || !quick)
DBUG_VOID_RETURN;
List_iterator<QUICK_RANGE> li(quick->ranges);
DBUG_LOCK_FILE;
fprintf(DBUG_FILE,"Used quick_range on key: %d (other_keys: %lu):\n",
quick->index, (ulong) needed_reg);
while ((range=li++))
{
if (!(range->flag & NO_MIN_RANGE))
{
print_key(quick->key_parts,range->min_key,range->min_length);
if (range->flag & NEAR_MIN)
fputs(" < ",DBUG_FILE);
else
fputs(" <= ",DBUG_FILE);
}
fputs("X",DBUG_FILE);
if (!(range->flag & NO_MAX_RANGE))
{
if (range->flag & NEAR_MAX)
fputs(" < ",DBUG_FILE);
else
fputs(" <= ",DBUG_FILE);
print_key(quick->key_parts,range->max_key,range->max_length);
}
fputs("\n",DBUG_FILE);
}
DBUG_UNLOCK_FILE;
DBUG_VOID_RETURN;
}
#endif
/*****************************************************************************
** Instansiate templates
*****************************************************************************/
#ifdef __GNUC__
template class List<QUICK_RANGE>;
template class List_iterator<QUICK_RANGE>;
#endif
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