opt_range.cc
上传用户:tsgydb
上传日期:2007-04-14
资源大小:10674k
文件大小:67k
- /* 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);
- /***************************************************************************
- ** 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(¶m,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(¶m,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+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(¶m,(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 (!(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++=' '; // 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] == ' ';)
- *--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)
- flag|= UNIQUE_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)
- {
- KEY *key=head->key_info+index;
- return ((key->flags & HA_NOSAME) &&
- key->key_length == tmp->min_length);
- }
- }
- 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 (;;)
- {
- if (range)
- { // Already read through key
- int result=((range->flag & EQ_RANGE) ?
- file->index_next_same(record, (byte*) range->min_key,
- range->min_length) :
- file->index_next(record));
- if (!result && !cmp_next(*it.ref()))
- DBUG_RETURN(0);
- }
- 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 (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)))
- {
- 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