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8fc8fa80899c66937979cd5b807766a40b74cd13
irix-657m-src/eoe/cmd/sss/ssdb/ssdbserver/sql/opt_range.cc
calmsacibis995 8fc8fa8089 Source code upload
2022-09-29 17:59:04 +03:00

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/* Copyright (C) 1979-1996 TcX AB & Monty Program KB & Detron HB
This software is distributed with NO WARRANTY OF ANY KIND. No author or
distributor accepts any responsibility for the consequences of using it, or
for whether it serves any particular purpose or works at all, unless he or
she says so in writing. Refer to the Free Public License (the "License")
for full details.
Every copy of this file must include a copy of the License, normally in a
plain ASCII text file named PUBLIC. The License grants you the right to
copy, modify and redistribute this file, but only under certain conditions
described in the License. Among other things, the License requires that
the copyright notice and this notice be preserved on all copies. */
#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 const uint NO_MIN_RANGE=1,NO_MAX_RANGE=2,NEAR_MIN=4,NEAR_MAX=8;
class SEL_ARG :public Sql_alloc
{
public:
uint8 min_flag,max_flag,maybe_flag;
uint8 part; // Which key part
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)
:use_count(1),type(type_arg),next_key_part(0),left(0),elements(1) {}
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; }
int cmp_min_to_min(SEL_ARG* arg)
{
return sel_cmp(field,min_value, arg->min_value, min_flag, arg->min_flag);
}
int cmp_min_to_max(SEL_ARG* arg)
{
return sel_cmp(field,min_value, arg->max_value, min_flag, arg->max_flag);
}
int cmp_max_to_max(SEL_ARG* arg)
{
return sel_cmp(field,max_value, arg->max_value, max_flag, arg->max_flag);
}
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)))
{
memcpy(*min_key,min_value,length);
(*min_key)+= length;
}
if (!(max_flag & NO_MAX_RANGE) &&
!(max_key_flag & (NO_MAX_RANGE | NEAR_MAX)))
{
memcpy(*max_key,max_value,length);
(*max_key)+= length;
}
}
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();
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,current_tablenr,keys;
table_map prev_tables,read_tables,current_table;
TABLE *table;
bool quick; // Don't calulate possible keys
KEY_PART key_parts[MAX_KEY*MAX_REF_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];
MEM_ROOT alloc;
} 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(PARAM *param,Field *field,KEY_PART *key_part,
Item_func::Functype type,Item *value,
Item_result cmp_type);
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);
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,table_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,uint index,
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);
/***************************************************************************
** Basic functions for SQL_SELECT and QUICK_SELECT
***************************************************************************/
SQL_SELECT::SQL_SELECT() :quick(0),cond(0),free_cond(0)
{
quick_keys=needed_reg=0;
my_b_clear(&file);
}
SQL_SELECT::~SQL_SELECT()
{
delete quick;
if (free_cond)
delete cond;
close_cacheed_file(&file);
}
#undef index // Fix or Unixware 7
QUICK_SELECT::QUICK_SELECT(TABLE *table,uint key_nr,bool no_alloc)
:next(0),head(table),index(key_nr),it(ranges)
{
if (!no_alloc)
{
init_sql_alloc(&alloc,1024); // Allocates everything here
my_pthread_setspecific_ptr(THR_MALLOC,&alloc);
}
else
bzero((char*) &alloc,sizeof(alloc));
next=0;
}
QUICK_SELECT::~QUICK_SELECT()
{
free_root(&alloc);
}
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;
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), elements(1), use_count(1),
field(f), min_value((char*) min_value_arg), max_value((char*) max_value_arg),
type(KEY_RANGE),color(BLACK),next(0),prev(0),next_key_part(0)
{
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_),elements(1),use_count(1),field(field_),
min_value(min_value_), max_value(max_value_),
type(KEY_RANGE),color(BLACK),next(0),prev(0),next_key_part(0)
{
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;
}
/*
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)
{
/* 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;
int cmp=field->cmp(a,b);
if (cmp) return cmp < 0 ? -1 : 1; // The values differed
/* Check if the compared equal arguments was defined with open/closed range */
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 link,*next_arg,*root;
next_arg= &link;
root=clone((SEL_ARG *) 0, &next_arg);
next_arg->next=0; // Fix last link
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 usably range
** Updates the folling 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)
{
PARAM param;
uint basflag;
DBUG_ENTER("test_quick_select");
delete quick;
quick=0;
needed_reg=quick_keys=0;
if (!cond || (specialflag & SPECIAL_SAFE_MODE) || !limit)
DBUG_RETURN(0); /* purecov: inspected */
if (!((basflag= head->db_capabilities) & HA_KEYPOS_TO_RNDPOS) &&
keys_to_use == (uint) ~0 || !keys_to_use)
DBUG_RETURN(0); /* Not smart database */
records=head->keyfile_info.records;
if (!records)
records++; /* purecov: inspected */
read_time=(ha_rows) (((head->keyfile_info.data_file_length)/IO_SIZE)+1+
records / TIME_FOR_COMPARE);
if (limit < records)
read_time=records+1; // Force to use index
else if (read_time < 2)
DBUG_RETURN(0); /* No nead for quick select */
DBUG_PRINT("info",("Time to scan table: %ld",(long) read_time));
/* set up parameter that is passed to all functions */
param.baseflag=basflag;
param.prev_tables=prev_tables;
param.read_tables=read_tables;
param.current_table= head->map;
param.current_tablenr= head->tablenr;
param.table=head;
current_thd->no_errors=1; // Don't warn about NULL
KEY_PART *key_parts=param.key_parts;
param.keys=0;
for (uint index=0 ; index < head->keys ; index++)
{
if (!(keys_to_use & ((key_map) 1L << index)))
continue;
KEY *key_info= &head->key_info[index];
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->length= key_info->key_part[part].length;
key_parts->field= key_info->key_part[part].field;
}
param.real_keynr[param.keys++]=index;
}
if (key_parts != param.key_parts) // If there is some usable key
{
param.key_parts_end=key_parts;
SEL_TREE *tree;
MEM_ROOT *old_root=my_pthread_getspecific_ptr(MEM_ROOT*,THR_MALLOC);
my_pthread_setspecific_ptr(THR_MALLOC,&param.alloc);
init_sql_alloc(&param.alloc,1024);
if ((tree=get_mm_tree(&param,cond)))
{
if (tree->type == SEL_TREE::IMPOSSIBLE)
{
records=0L; // Return -1 from this function
read_time=HA_POS_ERROR;
}
else if (tree->type == SEL_TREE::KEY)
{
SEL_ARG **key,**end,**best_key=0;
uint index;
for (index=0,key=tree->keys, end=key+param.keys ;
key != end ;
key++,index++)
{
ha_rows found_records,found_read_time;
if (*key)
{
if ((*key)->type == SEL_ARG::MAYBE_KEY ||
(*key)->maybe_flag)
needed_reg|= (table_map) 1 << param.real_keynr[index];
found_records=check_quick_select(&param,index, *key);
if (found_records != HA_POS_ERROR &&
head->used_keys & ((table_map) 1 << param.real_keynr[index]))
{
/*
** We can resolve this by only reading trough 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->keyfile_info.block_size/2/head->key_info[param.real_keynr[index]].key_length+1;
found_read_time=(found_records+keys_per_block-1)/keys_per_block+1;
}
else
found_read_time=found_records;
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_keys|= 1L << param.real_keynr[(uint) (best_key-tree->keys)];
quick->records=records;
quick->read_time=read_time;
}
}
}
}
free_root(&param.alloc); // Return memory & allocator
my_pthread_setspecific_ptr(THR_MALLOC,old_root);
}
current_thd->no_errors=0;
DBUG_EXECUTE("info",print_quick(quick,needed_reg););
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())
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 */
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->arguments()[1],
((Item_field*) (cond_func->arguments()[0]))->field->
cmp_type());
}
/* check const op field */
if (!tree &&
cond_func->arguments()[1]->type() == Item::FIELD_ITEM &&
cond_func->functype() != Item_func::LIKE_FUNC)
{
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->tablenr != param->current_tablenr)
DBUG_RETURN(0);
KEY_PART *key_part = param->key_parts,*end=param->key_parts_end;
SEL_TREE *tree=0;
if (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->used_tables() & ~param->read_tables))
{
sel_arg=get_mm_leaf(param,key_part->field,key_part,type,value,
cmp_type);
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(PARAM *param,Field *field,KEY_PART *key_part,
Item_func::Functype type,Item *value,Item_result cmp_type)
{
uint field_length=field->pack_length();
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;
if (!(res= value->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
if (!(min_str=sql_alloc(field_length*2)))
DBUG_RETURN(0);
max_str=min_str+field_length;
if (field->binary())
like_error=like_range(res->ptr(),res->length(),wild_prefix,field_length,
min_str,max_str,(char) 255);
else
#ifndef USE_STRCOLL
like_error=like_range(res->ptr(),res->length(),wild_prefix,field_length,
min_str,max_str,max_sort_char);
#else
like_error= my_like_range(res->ptr(),res->length(),wild_prefix,
field_length, min_str, max_str);
#endif
if (like_error) // Can't optimize with LIKE
DBUG_RETURN(0);
DBUG_RETURN(new SEL_ARG(field,min_str,max_str));
}
if (!field->optimize_range() && type != Item_func::EQ_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))
DBUG_RETURN(&null_element); // NULL is never true
char *str=sql_alloc(key_part->length); // Get local copy of key
if (!str)
DBUG_RETURN(0);
field->get_image(str,key_part->length);
if (!(tree=new SEL_ARG(field,str,str)))
DBUG_RETURN(0);
switch (type) {
case Item_func::LT_FUNC:
tree->max_flag=NEAR_MAX;
/* fall through */
case Item_func::LE_FUNC:
tree->min_flag=NO_MIN_RANGE; /* From start */
break;
case Item_func::GT_FUNC:
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_char)
{
const char *end=ptr+ptr_length;
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_char;
continue;
}
if (*ptr == wild_many) // '%' in SQL
{
do {
*min_str++ = ' '; // Because if key compression
*max_str++ = max_sort_char;
} while (min_str != min_end);
return 0;
}
*min_str++= *max_str++ = *ptr;
}
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,**link;
if (!key1)
return key2;
if (!key2)
return key1;
link= &root;
while (key1 && key2)
{
if (key1->part < key2->part)
{
*link= key1;
link= &key1->next_key_part;
key1=key1->next_key_part;
}
else
{
*link= key2;
link= &key2->next_key_part;
key2=key2->next_key_part;
}
}
*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)
{
if (!tree1)
return tree2;
if (!tree2)
return tree1;
if (tree1->type == SEL_TREE::IMPOSSIBLE || tree2->type == SEL_TREE::ALWAYS)
return tree1;
if (tree2->type == SEL_TREE::IMPOSSIBLE || tree1->type == SEL_TREE::ALWAYS)
return tree2;
if (tree1->type == SEL_TREE::MAYBE)
{
if (tree2->type == SEL_TREE::KEY)
tree2->type=SEL_TREE::KEY_SMALLER;
return tree2;
}
if (tree2->type == SEL_TREE::MAYBE)
{
tree1->type=SEL_TREE::KEY_SMALLER;
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
}
}
return tree1;
}
static SEL_TREE *
tree_or(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2)
{
if (!tree1 || !tree2)
return 0;
if (tree1->type == SEL_TREE::IMPOSSIBLE || tree2->type == SEL_TREE::ALWAYS)
return tree2;
if (tree2->type == SEL_TREE::IMPOSSIBLE || tree1->type == SEL_TREE::ALWAYS)
return tree1;
if (tree1->type == SEL_TREE::MAYBE)
return tree1; // Can't use this
if (tree2->type == SEL_TREE::MAYBE)
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
}
}
return result;
}
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 (!(clone_flag & CLONE_KEY2_MAYBE) && 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 (!(clone_flag & CLONE_KEY2_MAYBE) && 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 index,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
records=check_quick_keys(param,index,tree,param->min_key,0,param->max_key,0);
if (records != HA_POS_ERROR)
{
uint key=param->real_keynr[index];
param->table->quick_keys|= (key_map) 1L << key;
param->table->quick_rows[key]=records;
}
DBUG_RETURN(records);
}
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)
{
ha_rows records=0,tmp;
if (key_tree->left != &null_element)
{
records=check_quick_keys(param,index,key_tree->left,min_key,min_key_flag,
max_key,max_key_flag);
if (records == HA_POS_ERROR) // Impossible
return records;
}
if (key_tree->next_key_part &&
key_tree->next_key_part->part == key_tree->part+1 &&
!key_tree->min_flag &&
key_tree->next_key_part->type == SEL_ARG::KEY_RANGE)
{ // const key as prefix
char *tmp_min_key=min_key,*tmp_max_key=max_key;
key_tree->store(param->key[index][key_tree->part].length,
&tmp_min_key,min_key_flag,&tmp_max_key,max_key_flag);
tmp=check_quick_keys(param,index,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);
}
else
{
char *tmp_min_key=min_key,*tmp_max_key=max_key;
key_tree->store(param->key[index][key_tree->part].length,
&tmp_min_key,min_key_flag, &tmp_max_key,max_key_flag);
uint keynr=param->real_keynr[index];
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->min_flag && ! key_tree->max_flag &&
! min_key_flag && ! max_key_flag &&
(uint) key_tree->part+1 == param->table->key_info[keynr].key_parts &&
!param->table->key_info[keynr].dupp_key &&
min_key_length == (uint) (tmp_max_key- param->max_key) &&
!memcmp(param->min_key,param->max_key,min_key_length))
tmp=1; // Max one record
else
tmp=ni_records_in_range((N_INFO*) param->table->file,
(int) keynr,
(byte*) (!min_key_length ? NullS :
param->min_key),
min_key_length,
((key_tree->min_flag | min_key_flag) & NEAR_MIN ?
HA_READ_AFTER_KEY : HA_READ_KEY_EXACT),
(byte*) (!max_key_length ? NullS :
param->max_key),
max_key_length,
((key_tree->max_flag | max_key_flag) & NEAR_MAX ?
HA_READ_BEFORE_KEY : HA_READ_AFTER_KEY));
}
if (tmp == HA_POS_ERROR) // Impossible
return tmp;
records+=tmp;
if (key_tree->right != &null_element)
{
tmp=check_quick_keys(param,index,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 index,SEL_ARG *key_tree)
{
QUICK_SELECT *quick;
DBUG_ENTER("get_quick_select");
if ((quick=new QUICK_SELECT(param->table,param->real_keynr[index])))
{
if (get_quick_keys(param,quick,index,key_tree,param->min_key,0,
param->max_key,0))
{
delete quick;
quick=0;
}
else
{
quick->key_parts=(KEY_PART*)
sql_memdup(param->key[index],
sizeof(KEY_PART)*
param->table->key_info[param->real_keynr[index]].key_parts);
}
}
DBUG_RETURN(quick);
}
/*
** Fix this to get all possible sub_ranges
*/
static bool
get_quick_keys(PARAM *param,QUICK_SELECT *quick,uint index,
SEL_ARG *key_tree,char *min_key,uint min_key_flag,
char *max_key, uint max_key_flag)
{
if (key_tree->left != &null_element)
{
if (get_quick_keys(param,quick,index,key_tree->left,
min_key,min_key_flag, max_key, max_key_flag))
return 1;
}
if (key_tree->next_key_part &&
key_tree->next_key_part->part == key_tree->part+1 &&
!key_tree->min_flag &&
key_tree->next_key_part->type == SEL_ARG::KEY_RANGE)
{ // const key as prefix
char *tmp_min_key=min_key,*tmp_max_key=max_key;
key_tree->store(param->key[index][key_tree->part].length,
&tmp_min_key,min_key_flag,&tmp_max_key,max_key_flag);
if (get_quick_keys(param,quick,index,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;
}
else
{
char *tmp_min_key=min_key,*tmp_max_key=max_key;
key_tree->store(param->key[index][key_tree->part].length,
&tmp_min_key,min_key_flag, &tmp_max_key, max_key_flag);
uint flag=key_tree->min_flag | key_tree->max_flag;
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;
QUICK_RANGE *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);
if (!range) // Not enough memory
return 1;
quick->ranges.push_back(range);
}
if (key_tree->right != &null_element)
return get_quick_keys(param,quick,index,key_tree->right,
min_key,min_key_flag,
max_key,max_key_flag);
return 0;
}
/* get next possible record using quick-struct */
int QUICK_SELECT::get_next()
{
QUICK_RANGE *range;
DBUG_ENTER("get_next");
for (;;)
{
if (next == 1)
{ // Already read through key
if (ha_rnext(head,head->record[0],index) == 0 &&
cmp_next(*it.ref()) == 0)
DBUG_RETURN(0);
}
if (!(range=it++))
DBUG_RETURN(HA_ERR_END_OF_FILE); // All ranges used
next=1;
if (range->flag & NO_MIN_RANGE) // Read first record
{
int error;
if ((error=ha_rfirst(head,head->record[0],index)))
DBUG_RETURN(error); // Empty table
if (cmp_next(range) == 0)
DBUG_RETURN(0); // No matching records
next=0; // To next range
continue;
}
if (ha_rkey(head,head->record[0],index,(byte*) range->min_key,
range->min_length,
(!(range->flag & NEAR_MIN) ? HA_READ_KEY_OR_NEXT :
HA_READ_AFTER_KEY)))
continue;
if (cmp_next(range) == 0)
DBUG_RETURN(0); // Found key is in range
next=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++->length)
{
int cmp;
if ((cmp=key_part->field->cmp(key)) < 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++->length)
{
Field *field=key_part->field;
field->set_image((char*) key,key_part->length);
field->val_str(&tmp,&tmp);
if (length != 0)
fputc('/',DBUG_FILE);
fwrite(tmp.ptr(),sizeof(char),tmp.length(),DBUG_FILE);
key+=key_part->length;
}
}
extern "C" {
extern pthread_mutex_t THR_LOCK_dbug;
}
static void print_quick(QUICK_SELECT *quick,table_map needed_reg)
{
QUICK_RANGE *range;
DBUG_ENTER("print_param");
if (! _db_on_ || !quick)
DBUG_VOID_RETURN;
List_iterator<QUICK_RANGE> li(quick->ranges);
pthread_mutex_lock(&THR_LOCK_dbug);
fprintf(DBUG_FILE,"Used quck_range on key: %d (other_keys: %lu):\n",
quick->index, 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);
}
pthread_mutex_unlock(&THR_LOCK_dbug);
DBUG_VOID_RETURN;
}
#endif
/*****************************************************************************
** Instansiate templates
*****************************************************************************/
#ifdef __GNUC__
template class List<QUICK_RANGE>;
template class List_iterator<QUICK_RANGE>;
#endif
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