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			947 lines
		
	
	
	
		
			25 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			947 lines
		
	
	
	
		
			25 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Copyright (c) 2000, 2010, Oracle and/or its affiliates.
 | |
|    Copyright (c) 2011, 2020, MariaDB Corporation.
 | |
| 
 | |
|    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; version 2 of the License.
 | |
| 
 | |
|    This program is distributed in the hope that it will be useful,
 | |
|    but WITHOUT ANY WARRANTY; without even the implied warranty of
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|    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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
 | |
| 
 | |
| /* The hash functions used for saveing keys */
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| /* One of key_length or key_length_offset must be given */
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| /* Key length of 0 isn't allowed */
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| 
 | |
| #include "mysys_priv.h"
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| #include <m_string.h>
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| #include <m_ctype.h>
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| #include "hash.h"
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| 
 | |
| #define NO_RECORD	~((my_hash_value_type) 0)
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| #define LOWFIND 1
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| #define LOWUSED 2
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| #define HIGHFIND 4
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| #define HIGHUSED 8
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| 
 | |
| typedef struct st_hash_info {
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|   uint32 next;					/* index to next key */
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|   my_hash_value_type hash_nr;
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|   uchar *data;					/* data for current entry */
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| } HASH_LINK;
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| 
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| static uint my_hash_mask(my_hash_value_type hashnr,
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|                          size_t buffmax, size_t maxlength);
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| static void movelink(HASH_LINK *array,uint pos,uint next_link,uint newlink);
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| static int hashcmp(const HASH *hash, HASH_LINK *pos, const uchar *key,
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|                    size_t length);
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| 
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| my_hash_value_type my_hash_sort(CHARSET_INFO *cs, const uchar *key,
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|                                 size_t length)
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| {
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|   ulong nr1= 1, nr2= 4;
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|   my_ci_hash_sort(cs, (uchar*) key, length, &nr1, &nr2);
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|   return (my_hash_value_type) nr1;
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| }
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| 
 | |
| /**
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|   @brief Initialize the hash
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|   
 | |
|   @details
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| 
 | |
|   Initialize the hash, by defining and giving valid values for
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|   its elements. The failure to allocate memory for the
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|   hash->array element will not result in a fatal failure. The
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|   dynamic array that is part of the hash will allocate memory
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|   as required during insertion.
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| 
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|   @param[in]     psi_key      The key to register instrumented memory
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|   @param[in,out] hash         The hash that is initialized
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|   @param[in]     growth_size  size incrememnt for the underlying dynarray
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|   @param[in]     charset      The character set information
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|   @param[in]     size         The hash size
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|   @param[in]     key_offest   The key offset for the hash
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|   @param[in]     key_length   The length of the key used in
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|                               the hash
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|   @param[in]     get_key      get the key for the hash
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|   @param[in]     free_element pointer to the function that
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|                               does cleanup
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|   @param[in]     flags        flags set in the hash
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|   @return        indicates success or failure of initialization
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|     @retval 0 success
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|     @retval 1 failure
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| */
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| my_bool
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| my_hash_init2(PSI_memory_key psi_key, HASH *hash, size_t growth_size,
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|               CHARSET_INFO *charset, size_t size, size_t key_offset,
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|               size_t key_length, my_hash_get_key get_key,
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|               my_hash_function hash_function,
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|               void (*free_element)(void*), uint flags)
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| {
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|   my_bool res;
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|   DBUG_ENTER("my_hash_init2");
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|   DBUG_PRINT("enter",("hash:%p  size: %u", hash, (uint) size));
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| 
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|   hash->records=0;
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|   hash->key_offset=key_offset;
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|   hash->key_length=key_length;
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|   hash->blength=1;
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|   hash->get_key=get_key;
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|   hash->hash_function= hash_function ? hash_function : my_hash_sort;
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|   hash->free=free_element;
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|   hash->flags=flags;
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|   hash->charset=charset;
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|   res= init_dynamic_array2(psi_key, &hash->array, sizeof(HASH_LINK), NULL, size,
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|                            growth_size, MYF((flags & HASH_THREAD_SPECIFIC ?
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|                                              MY_THREAD_SPECIFIC : 0)));
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|   DBUG_RETURN(res);
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| }
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| 
 | |
| 
 | |
| /*
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|   Call hash->free on all elements in hash.
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| 
 | |
|   SYNOPSIS
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|     my_hash_free_elements()
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|     hash   hash table
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| 
 | |
|   NOTES:
 | |
|     Sets records to 0
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| */
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| 
 | |
| static inline void my_hash_free_elements(HASH *hash)
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| {
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|   uint records= hash->records;
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|   if (records == 0)
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|     return;
 | |
| 
 | |
|   /*
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|     Set records to 0 early to guard against anyone looking at the structure
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|     during the free process
 | |
|   */
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|   hash->records= 0;
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| 
 | |
|   if (hash->free)
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|   {
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|     HASH_LINK *data=dynamic_element(&hash->array,0,HASH_LINK*);
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|     HASH_LINK *end= data + records;
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|     do
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|     {
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|       (*hash->free)((data++)->data);
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|     } while (data < end);
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|   }
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| }
 | |
| 
 | |
| 
 | |
| /*
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|   Free memory used by hash.
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| 
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|   SYNOPSIS
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|     my_hash_free()
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|     hash   the hash to delete elements of
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| 
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|   NOTES: Hash can't be reused without calling my_hash_init again.
 | |
| */
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| 
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| void my_hash_free(HASH *hash)
 | |
| {
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|   DBUG_ENTER("my_hash_free");
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|   DBUG_PRINT("enter",("hash:%p  elements: %ld",
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|                       hash, hash->records));
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| 
 | |
|   my_hash_free_elements(hash);
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|   hash->free= 0;
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|   delete_dynamic(&hash->array);
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|   hash->blength= 0;
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|   DBUG_VOID_RETURN;
 | |
| }
 | |
| 
 | |
| 
 | |
| /*
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|   Delete all elements from the hash (the hash itself is to be reused).
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| 
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|   SYNOPSIS
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|     my_hash_reset()
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|     hash   the hash to delete elements of
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| */
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| 
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| void my_hash_reset(HASH *hash)
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| {
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|   DBUG_ENTER("my_hash_reset");
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|   DBUG_PRINT("enter",("hash:%p", hash));
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| 
 | |
|   my_hash_free_elements(hash);
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|   reset_dynamic(&hash->array);
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|   /* Set row pointers so that the hash can be reused at once */
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|   hash->blength= 1;
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|   DBUG_VOID_RETURN;
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| }
 | |
| 
 | |
| /* some helper functions */
 | |
| 
 | |
| /*
 | |
|   This function is char* instead of uchar* as HPUX11 compiler can't
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|   handle inline functions that are not defined as native types
 | |
| */
 | |
| 
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| static inline char*
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| my_hash_key(const HASH *hash, const uchar *record, size_t *length,
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|             my_bool first)
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| {
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|   if (hash->get_key)
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|     return (char*) (*hash->get_key)(record,length,first);
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|   *length=hash->key_length;
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|   return (char*) record+hash->key_offset;
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| }
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| 
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| 	/* Calculate pos according to keys */
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| 
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| static uint my_hash_mask(my_hash_value_type hashnr, size_t buffmax,
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|                          size_t maxlength)
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| {
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|   if ((hashnr & (buffmax-1)) < maxlength)
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|     return (uint) (hashnr & (buffmax-1));
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|   return (uint) (hashnr & ((buffmax >> 1) -1));
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| }
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| 
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| static inline uint my_hash_rec_mask(HASH_LINK *pos,
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|                                     size_t buffmax, size_t maxlength)
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| {
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|   return my_hash_mask(pos->hash_nr, buffmax, maxlength);
 | |
| }
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| 
 | |
| 
 | |
| 
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| /* for compilers which can not handle inline */
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| static
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| #if !defined(__USLC__) && !defined(__sgi)
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| inline
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| #endif
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| my_hash_value_type rec_hashnr(HASH *hash,const uchar *record)
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| {
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|   size_t length;
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|   uchar *key= (uchar*) my_hash_key(hash, record, &length, 0);
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|   return hash->hash_function(hash->charset, key, length);
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| }
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| 
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| 
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| uchar* my_hash_search(const HASH *hash, const uchar *key, size_t length)
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| {
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|   HASH_SEARCH_STATE state;
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|   return my_hash_first(hash, key, length, &state);
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| }
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| 
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| uchar* my_hash_search_using_hash_value(const HASH *hash, 
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|                                        my_hash_value_type hash_value,
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|                                        const uchar *key,
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|                                        size_t length)
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| {
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|   HASH_SEARCH_STATE state;
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|   return my_hash_first_from_hash_value(hash, hash_value,
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|                                        key, length, &state);
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| }
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| 
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| 
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| /*
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|   Search after a record based on a key
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| 
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|   NOTE
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|    Assigns the number of the found record to HASH_SEARCH_STATE state
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| */
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| 
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| uchar* my_hash_first(const HASH *hash, const uchar *key, size_t length,
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|                      HASH_SEARCH_STATE *current_record)
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| {
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|   uchar *res;
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|   DBUG_ASSERT(my_hash_inited(hash));
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| 
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|   res= my_hash_first_from_hash_value(hash,
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|                                      hash->hash_function(hash->charset, key,
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|                                                          length ? length :
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|                                                          hash->key_length),
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|                                      key, length, current_record);
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|   return res;
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| }
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| 
 | |
| 
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| uchar* my_hash_first_from_hash_value(const HASH *hash,
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|                                      my_hash_value_type hash_value,
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|                                      const uchar *key,
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|                                      size_t length,
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|                                      HASH_SEARCH_STATE *current_record)
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| {
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|   HASH_LINK *pos;
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|   DBUG_ENTER("my_hash_first_from_hash_value");
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| 
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|   if (hash->records)
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|   {
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|     uint flag= 1;
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|     uint idx= my_hash_mask(hash_value,
 | |
|                            hash->blength, hash->records);
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|     if (!length)
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|       length= hash->key_length; // length for fixed length keys or 0
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|     do
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|     {
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|       pos= dynamic_element(&hash->array,idx,HASH_LINK*);
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|       if (!hashcmp(hash,pos,key,length))
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|       {
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| 	DBUG_PRINT("exit",("found key at %d",idx));
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| 	*current_record= idx;
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| 	DBUG_RETURN (pos->data);
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|       }
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|       if (flag)
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|       {
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| 	flag=0;					/* Reset flag */
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| 	if (my_hash_rec_mask(pos, hash->blength, hash->records) != idx)
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| 	  break;				/* Wrong link */
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|       }
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|     }
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|     while ((idx=pos->next) != NO_RECORD);
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|   }
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|   *current_record= NO_RECORD;
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|   DBUG_RETURN(0);
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| }
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| 
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| 	/* Get next record with identical key */
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| 	/* Can only be called if previous calls was my_hash_search */
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| 
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| uchar* my_hash_next(const HASH *hash, const uchar *key, size_t length,
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|                     HASH_SEARCH_STATE *current_record)
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| {
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|   HASH_LINK *pos;
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|   uint idx;
 | |
| 
 | |
|   if (*current_record != NO_RECORD)
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|   {
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|     HASH_LINK *data=dynamic_element(&hash->array,0,HASH_LINK*);
 | |
|     if (!length)
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|       length= hash->key_length; // length for fixed length keys or 0
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|     for (idx=data[*current_record].next; idx != NO_RECORD ; idx=pos->next)
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|     {
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|       pos=data+idx;
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|       if (!hashcmp(hash,pos,key,length))
 | |
|       {
 | |
| 	*current_record= idx;
 | |
| 	return pos->data;
 | |
|       }
 | |
|     }
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|     *current_record= NO_RECORD;
 | |
|   }
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| 
 | |
| 	/* Change link from pos to new_link */
 | |
| 
 | |
| static void movelink(HASH_LINK *array,uint find,uint next_link,uint newlink)
 | |
| {
 | |
|   HASH_LINK *old_link;
 | |
|   do
 | |
|   {
 | |
|     old_link=array+next_link;
 | |
|   }
 | |
|   while ((next_link=old_link->next) != find);
 | |
|   old_link->next= newlink;
 | |
|   return;
 | |
| }
 | |
| 
 | |
| /*
 | |
|   Compare a key in a record to a whole key. Return 0 if identical
 | |
| 
 | |
|   SYNOPSIS
 | |
|     hashcmp()
 | |
|     hash   hash table
 | |
|     pos    position of hash record to use in comparison
 | |
|     key    key for comparison
 | |
|     length length of key
 | |
| 
 | |
|   NOTES:
 | |
|     length equal 0 can mean 2 things:
 | |
|       1) it is fixed key length hash (HASH::key_length != 0) and
 | |
|       default length should be taken in this case
 | |
|       2) it is really 0 length key for variable key length hash
 | |
|       (HASH::key_length == 0)
 | |
| 
 | |
|   RETURN
 | |
|     = 0  key of record == key
 | |
|     != 0 key of record != key
 | |
|  */
 | |
| 
 | |
| static int hashcmp(const HASH *hash, HASH_LINK *pos, const uchar *key,
 | |
|                    size_t length)
 | |
| {
 | |
|   size_t rec_keylength;
 | |
|   uchar *rec_key;
 | |
|   rec_key= (uchar*) my_hash_key(hash, pos->data, &rec_keylength, 1);
 | |
|   return (length != rec_keylength) ||
 | |
| 	  my_strnncoll(hash->charset, (uchar*) rec_key, rec_keylength,
 | |
| 		       (uchar*) key, rec_keylength);
 | |
| }
 | |
| 
 | |
| 
 | |
| /**
 | |
|    Write a hash-key to the hash-index
 | |
| 
 | |
|    @return
 | |
|    @retval  0  ok
 | |
|    @retval  1  Duplicate key or out of memory
 | |
| */
 | |
| 
 | |
| my_bool my_hash_insert(HASH *info, const uchar *record)
 | |
| {
 | |
|   int flag;
 | |
|   size_t idx, halfbuff, first_index;
 | |
|   size_t length;
 | |
|   my_hash_value_type current_hash_nr, UNINIT_VAR(rec_hash_nr),
 | |
|     UNINIT_VAR(rec2_hash_nr);
 | |
|   uchar *UNINIT_VAR(rec_data),*UNINIT_VAR(rec2_data), *key;
 | |
|   HASH_LINK *data,*empty,*UNINIT_VAR(gpos),*UNINIT_VAR(gpos2),*pos;
 | |
| 
 | |
|   key= (uchar*) my_hash_key(info, record, &length, 1);
 | |
|   current_hash_nr= info->hash_function(info->charset, key, length);
 | |
| 
 | |
|   if (info->flags & HASH_UNIQUE)
 | |
|   {
 | |
|     if (my_hash_search_using_hash_value(info, current_hash_nr, key, length))
 | |
|       return(TRUE);				/* Duplicate entry */
 | |
|   }
 | |
| 
 | |
|   flag=0;
 | |
|   if (!(empty=(HASH_LINK*) alloc_dynamic(&info->array)))
 | |
|     return(TRUE);				/* No more memory */
 | |
| 
 | |
|   data=dynamic_element(&info->array,0,HASH_LINK*);
 | |
|   halfbuff= info->blength >> 1;
 | |
| 
 | |
|   idx=first_index=info->records-halfbuff;
 | |
|   if (idx != info->records)				/* If some records */
 | |
|   {
 | |
|     do
 | |
|     {
 | |
|       my_hash_value_type hash_nr;
 | |
|       pos=data+idx;
 | |
|       hash_nr= pos->hash_nr;
 | |
|       if (flag == 0)				/* First loop; Check if ok */
 | |
| 	if (my_hash_mask(hash_nr, info->blength, info->records) != first_index)
 | |
| 	  break;
 | |
|       if (!(hash_nr & halfbuff))
 | |
|       {						/* Key will not move */
 | |
| 	if (!(flag & LOWFIND))
 | |
| 	{
 | |
| 	  if (flag & HIGHFIND)
 | |
| 	  {
 | |
| 	    flag= LOWFIND | HIGHFIND;
 | |
| 	    /* key shall be moved to the current empty position */
 | |
| 	    gpos= empty;
 | |
|             rec_data=    pos->data;
 | |
|             rec_hash_nr= pos->hash_nr;
 | |
| 	    empty=pos;				/* This place is now free */
 | |
| 	  }
 | |
| 	  else
 | |
| 	  {
 | |
| 	    flag= LOWFIND | LOWUSED;		/* key isn't changed */
 | |
| 	    gpos= pos;
 | |
|             rec_data=    pos->data;
 | |
|             rec_hash_nr= pos->hash_nr;
 | |
| 	  }
 | |
| 	}
 | |
| 	else
 | |
| 	{
 | |
| 	  if (!(flag & LOWUSED))
 | |
| 	  {
 | |
| 	    /* Change link of previous LOW-key */
 | |
| 	    gpos->data=    rec_data;
 | |
| 	    gpos->hash_nr= rec_hash_nr;
 | |
| 	    gpos->next=    (uint) (pos-data);
 | |
| 	    flag= (flag & HIGHFIND) | (LOWFIND | LOWUSED);
 | |
| 	  }
 | |
| 	  gpos= pos;
 | |
| 	  rec_data=    pos->data;
 | |
|           rec_hash_nr= pos->hash_nr;
 | |
| 	}
 | |
|       }
 | |
|       else
 | |
|       {						/* key will be moved */
 | |
| 	if (!(flag & HIGHFIND))
 | |
| 	{
 | |
| 	  flag= (flag & LOWFIND) | HIGHFIND;
 | |
| 	  /* key shall be moved to the last (empty) position */
 | |
| 	  gpos2= empty;
 | |
|           empty= pos;
 | |
| 	  rec2_data=    pos->data;
 | |
|           rec2_hash_nr= pos->hash_nr;
 | |
| 	}
 | |
| 	else
 | |
| 	{
 | |
| 	  if (!(flag & HIGHUSED))
 | |
| 	  {
 | |
| 	    /* Change link of previous hash-key and save */
 | |
| 	    gpos2->data=    rec2_data;
 | |
| 	    gpos2->hash_nr= rec2_hash_nr;
 | |
| 	    gpos2->next=    (uint) (pos-data);
 | |
| 	    flag= (flag & LOWFIND) | (HIGHFIND | HIGHUSED);
 | |
| 	  }
 | |
| 	  gpos2= pos;
 | |
| 	  rec2_data=    pos->data;
 | |
|           rec2_hash_nr= pos->hash_nr;
 | |
| 	}
 | |
|       }
 | |
|     }
 | |
|     while ((idx=pos->next) != NO_RECORD);
 | |
| 
 | |
|     if ((flag & (LOWFIND | LOWUSED)) == LOWFIND)
 | |
|     {
 | |
|       gpos->data=    rec_data;
 | |
|       gpos->hash_nr= rec_hash_nr;
 | |
|       gpos->next=    NO_RECORD;
 | |
|     }
 | |
|     if ((flag & (HIGHFIND | HIGHUSED)) == HIGHFIND)
 | |
|     {
 | |
|       gpos2->data=    rec2_data;
 | |
|       gpos2->hash_nr= rec2_hash_nr;
 | |
|       gpos2->next=    NO_RECORD;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   idx= my_hash_mask(current_hash_nr, info->blength, info->records + 1);
 | |
|   pos= data+idx;
 | |
|   /* Check if we are at the empty position */
 | |
|   if (pos == empty)
 | |
|   {
 | |
|     pos->next=NO_RECORD;
 | |
|   }
 | |
|   else
 | |
|   {
 | |
|     /* Move conflicting record to empty position (last) */
 | |
|     empty[0]= pos[0];
 | |
|     /* Check if the moved record was in same hash-nr family */
 | |
|     gpos= data + my_hash_rec_mask(pos, info->blength, info->records + 1);
 | |
|     if (pos == gpos)
 | |
|     {
 | |
|       /* Point to moved record */
 | |
|       pos->next= (uint32) (empty - data);
 | |
|     }
 | |
|     else
 | |
|     {
 | |
|       pos->next= NO_RECORD;
 | |
|       movelink(data,(uint) (pos-data),(uint) (gpos-data),(uint) (empty-data));
 | |
|     }
 | |
|   }
 | |
|   pos->data=    (uchar*) record;
 | |
|   pos->hash_nr= current_hash_nr;
 | |
|   if (++info->records == info->blength)
 | |
|     info->blength+= info->blength;
 | |
|   return(0);
 | |
| }
 | |
| 
 | |
| 
 | |
| /**
 | |
|    Remove one record from hash-table.
 | |
| 
 | |
|    @fn    hash_delete()
 | |
|    @param hash		Hash tree
 | |
|    @param record	Row to be deleted
 | |
| 
 | |
|    @notes
 | |
|    The record with the same record ptr is removed.
 | |
|    If there is a free-function it's called if record was found.
 | |
| 
 | |
|    hash->free() is guarantee to be called only after the row has been
 | |
|    deleted from the hash and the hash can be reused by other threads.
 | |
| 
 | |
|    @return
 | |
|    @retval  0  ok
 | |
|    @retval  1 Record not found
 | |
| */
 | |
| 
 | |
| my_bool my_hash_delete(HASH *hash, uchar *record)
 | |
| {
 | |
|   uint pos2,idx,empty_index;
 | |
|   my_hash_value_type pos_hashnr, lastpos_hashnr;
 | |
|   size_t blength;
 | |
|   HASH_LINK *data,*lastpos,*gpos,*pos,*pos3,*empty;
 | |
|   DBUG_ENTER("my_hash_delete");
 | |
|   if (!hash->records)
 | |
|     DBUG_RETURN(1);
 | |
| 
 | |
|   blength=hash->blength;
 | |
|   data=dynamic_element(&hash->array,0,HASH_LINK*);
 | |
|   /* Search after record with key */
 | |
|   pos= data + my_hash_mask(rec_hashnr(hash, record), blength, hash->records);
 | |
|   gpos = 0;
 | |
| 
 | |
|   while (pos->data != record)
 | |
|   {
 | |
|     gpos=pos;
 | |
|     if (pos->next == NO_RECORD)
 | |
|       DBUG_RETURN(1);			/* Key not found */
 | |
|     pos=data+pos->next;
 | |
|   }
 | |
| 
 | |
|   if ( --(hash->records) < hash->blength >> 1) hash->blength>>=1;
 | |
|   lastpos=data+hash->records;
 | |
| 
 | |
|   /* Remove link to record */
 | |
|   empty=pos; empty_index=(uint) (empty-data);
 | |
|   if (gpos)
 | |
|     gpos->next=pos->next;		/* unlink current ptr */
 | |
|   else if (pos->next != NO_RECORD)
 | |
|   {
 | |
|     empty=data+(empty_index=pos->next);
 | |
|     pos[0]= empty[0];
 | |
|   }
 | |
| 
 | |
|   if (empty == lastpos)		/* last key at wrong pos or no next link */
 | |
|     goto exit;
 | |
| 
 | |
|   /* Move the last key (lastpos) */
 | |
|   lastpos_hashnr= lastpos->hash_nr;
 | |
|   /* pos is where lastpos should be */
 | |
|   pos= data + my_hash_mask(lastpos_hashnr, hash->blength, hash->records);
 | |
|   if (pos == empty)			/* Move to empty position. */
 | |
|   {
 | |
|     empty[0]=lastpos[0];
 | |
|     goto exit;
 | |
|   }
 | |
|   pos_hashnr= pos->hash_nr;
 | |
|   /* pos3 is where the pos should be */
 | |
|   pos3= data + my_hash_mask(pos_hashnr, hash->blength, hash->records);
 | |
|   if (pos != pos3)
 | |
|   {					/* pos is on wrong posit */
 | |
|     empty[0]=pos[0];			/* Save it here */
 | |
|     pos[0]=lastpos[0];			/* This should be here */
 | |
|     movelink(data,(uint) (pos-data),(uint) (pos3-data),empty_index);
 | |
|     goto exit;
 | |
|   }
 | |
|   pos2= my_hash_mask(lastpos_hashnr, blength, hash->records + 1);
 | |
|   if (pos2 == my_hash_mask(pos_hashnr, blength, hash->records + 1))
 | |
|   {					/* Identical key-positions */
 | |
|     if (pos2 != hash->records)
 | |
|     {
 | |
|       empty[0]=lastpos[0];
 | |
|       movelink(data,(uint) (lastpos-data),(uint) (pos-data),empty_index);
 | |
|       goto exit;
 | |
|     }
 | |
|     idx= (uint) (pos-data);		/* Link pos->next after lastpos */
 | |
|   }
 | |
|   else idx= NO_RECORD;		/* Different positions merge */
 | |
| 
 | |
|   empty[0]=lastpos[0];
 | |
|   movelink(data,idx,empty_index,pos->next);
 | |
|   pos->next=empty_index;
 | |
| 
 | |
| exit:
 | |
|   (void) pop_dynamic(&hash->array);
 | |
|   if (hash->free)
 | |
|     (*hash->free)((uchar*) record);
 | |
|   DBUG_RETURN(0);
 | |
| }
 | |
| 
 | |
| 
 | |
| /**
 | |
|    Update keys when record has changed.
 | |
|    This is much more efficient than using a delete & insert.
 | |
| */
 | |
| 
 | |
| my_bool my_hash_update(HASH *hash, uchar *record, uchar *old_key,
 | |
|                        size_t old_key_length)
 | |
| {
 | |
|   uint new_index, new_pos_index, org_index, records, idx;
 | |
|   size_t length, empty, blength;
 | |
|   my_hash_value_type hash_nr;
 | |
|   HASH_LINK org_link,*data,*previous,*pos;
 | |
|   uchar *new_key;
 | |
|   DBUG_ENTER("my_hash_update");
 | |
| 
 | |
|   new_key= (uchar*) my_hash_key(hash, record, &length, 1);
 | |
|   hash_nr= hash->hash_function(hash->charset, new_key, length);
 | |
|   
 | |
|   if (HASH_UNIQUE & hash->flags)
 | |
|   {
 | |
|     HASH_SEARCH_STATE state;
 | |
|     uchar *found;
 | |
| 
 | |
|     if ((found= my_hash_first_from_hash_value(hash, hash_nr, new_key, length,
 | |
|                                               &state)))
 | |
|     {
 | |
|       do 
 | |
|       {
 | |
|         if (found != record)
 | |
|           DBUG_RETURN(1);		/* Duplicate entry */
 | |
|       } 
 | |
|       while ((found= my_hash_next(hash, new_key, length, &state)));
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   data=dynamic_element(&hash->array,0,HASH_LINK*);
 | |
|   blength=hash->blength; records=hash->records;
 | |
| 
 | |
|   /* Search after record with key */
 | |
| 
 | |
|   idx= my_hash_mask(hash->hash_function(hash->charset, old_key,
 | |
|                                         (old_key_length ? old_key_length :
 | |
|                                                           hash->key_length)),
 | |
|                     blength, records);
 | |
|   org_index= idx;
 | |
|   new_index= my_hash_mask(hash_nr, blength, records);
 | |
|   previous=0;
 | |
|   for (;;)
 | |
|   {
 | |
|     if ((pos= data+idx)->data == record)
 | |
|       break;
 | |
|     previous=pos;
 | |
|     if ((idx=pos->next) == NO_RECORD)
 | |
|       DBUG_RETURN(1);			/* Not found in links */
 | |
|   }
 | |
| 
 | |
|   if (org_index == new_index)
 | |
|   {
 | |
|     data[idx].hash_nr= hash_nr;         /* Hash number may have changed */
 | |
|     DBUG_RETURN(0);			/* Record is in right position */
 | |
|   }
 | |
| 
 | |
|   org_link= *pos;
 | |
|   empty=idx;
 | |
| 
 | |
|   /* Relink record from current chain */
 | |
| 
 | |
|   if (!previous)
 | |
|   {
 | |
|     if (pos->next != NO_RECORD)
 | |
|     {
 | |
|       empty=pos->next;
 | |
|       *pos= data[pos->next];
 | |
|     }
 | |
|   }
 | |
|   else
 | |
|     previous->next=pos->next;		/* unlink pos */
 | |
| 
 | |
|   /* Move data to correct position */
 | |
|   if (new_index == empty)
 | |
|   {
 | |
|     /*
 | |
|       At this point record is unlinked from the old chain, thus it holds
 | |
|       random position. By the chance this position is equal to position
 | |
|       for the first element in the new chain. That means updated record
 | |
|       is the only record in the new chain.
 | |
|     */
 | |
|     if (empty != idx)
 | |
|     {
 | |
|       /*
 | |
|         Record was moved while unlinking it from the old chain.
 | |
|         Copy data to a new position.
 | |
|       */
 | |
|       data[empty]= org_link;
 | |
|     }
 | |
|     data[empty].next= NO_RECORD;
 | |
|     data[empty].hash_nr= hash_nr;
 | |
|     DBUG_RETURN(0);
 | |
|   }
 | |
|   pos=data+new_index;
 | |
|   new_pos_index= my_hash_rec_mask(pos, blength, records);
 | |
|   if (new_index != new_pos_index)
 | |
|   {					/* Other record in wrong position */
 | |
|     data[empty]= *pos;
 | |
|     movelink(data,new_index,new_pos_index, (uint) empty);
 | |
|     org_link.next=NO_RECORD;
 | |
|     data[new_index]= org_link;
 | |
|     data[new_index].hash_nr= hash_nr;
 | |
|   }
 | |
|   else
 | |
|   {					/* Link in chain at right position */
 | |
|     org_link.next=data[new_index].next;
 | |
|     data[empty]=org_link;
 | |
|     data[empty].hash_nr= hash_nr;
 | |
|     data[new_index].next= (uint) empty;
 | |
|   }
 | |
|   DBUG_RETURN(0);
 | |
| }
 | |
| 
 | |
| 
 | |
| uchar *my_hash_element(HASH *hash, size_t idx)
 | |
| {
 | |
|   if (idx < hash->records)
 | |
|     return dynamic_element(&hash->array,idx,HASH_LINK*)->data;
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| 
 | |
| /*
 | |
|   Replace old row with new row.  This should only be used when key
 | |
|   isn't changed
 | |
| */
 | |
| 
 | |
| void my_hash_replace(HASH *hash, HASH_SEARCH_STATE *current_record,
 | |
|                      uchar *new_row)
 | |
| {
 | |
|   if (*current_record != NO_RECORD)            /* Safety */
 | |
|     dynamic_element(&hash->array, *current_record, HASH_LINK*)->data= new_row;
 | |
| }
 | |
| 
 | |
| 
 | |
| /**
 | |
|    Iterate over all elements in hash and call function with the element
 | |
| 
 | |
|    @param hash     hash array
 | |
|    @param action   function to call for each argument
 | |
|    @param argument second argument for call to action
 | |
| 
 | |
|    @notes
 | |
|    If one of functions calls returns 1 then the iteration aborts
 | |
| 
 | |
|    @retval 0  ok
 | |
|    @retval 1  iteration aborted becasue action returned 1
 | |
| */
 | |
| 
 | |
| my_bool my_hash_iterate(HASH *hash, my_hash_walk_action action, void *argument)
 | |
| {
 | |
|   uint records, i;
 | |
| 
 | |
|   records= hash->records;
 | |
| 
 | |
|   for (i= 0 ; i < records ; i++)
 | |
|   {
 | |
|     if ((*action)(dynamic_element(&hash->array, i, HASH_LINK *)->data,
 | |
|                   argument))
 | |
|       return 1;
 | |
|   }
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| 
 | |
| #if !defined(DBUG_OFF) || defined(MAIN)
 | |
| 
 | |
| my_bool my_hash_check(HASH *hash)
 | |
| {
 | |
|   int error;
 | |
|   uint i,rec_link,found,max_links,seek,links,idx;
 | |
|   uint records;
 | |
|   size_t blength;
 | |
|   HASH_LINK *data,*hash_info;
 | |
| 
 | |
|   records=hash->records; blength=hash->blength;
 | |
|   data=dynamic_element(&hash->array,0,HASH_LINK*);
 | |
|   error=0;
 | |
| 
 | |
|   for (i=found=max_links=seek=0 ; i < records ; i++)
 | |
|   {
 | |
|     size_t length;
 | |
|     uchar *key= (uchar*) my_hash_key(hash, data[i].data, &length, 0);
 | |
|     if (data[i].hash_nr != hash->hash_function(hash->charset, key, length))
 | |
|     {
 | |
|       DBUG_PRINT("error", ("record at %d has wrong hash", i));
 | |
|       error= 1;
 | |
|     }
 | |
| 
 | |
|     if (my_hash_rec_mask(data + i, blength, records) == i)
 | |
|     {
 | |
|       found++; seek++; links=1;
 | |
|       for (idx=data[i].next ;
 | |
| 	   idx != NO_RECORD && found < records + 1;
 | |
| 	   idx=hash_info->next)
 | |
|       {
 | |
| 	if (idx >= records)
 | |
| 	{
 | |
| 	  DBUG_PRINT("error",
 | |
| 		     ("Found pointer outside array to %d from link starting at %d",
 | |
| 		      idx,i));
 | |
| 	  error=1;
 | |
| 	}
 | |
| 	hash_info=data+idx;
 | |
| 	seek+= ++links;
 | |
| 	if ((rec_link= my_hash_rec_mask(hash_info,
 | |
|                                         blength, records)) != i)
 | |
| 	{
 | |
|           DBUG_PRINT("error", ("Record in wrong link at %d: Start %d  "
 | |
|                                "Record:%p  Record-link %d",
 | |
|                                idx, i, hash_info->data, rec_link));
 | |
| 	  error=1;
 | |
| 	}
 | |
| 	else
 | |
| 	  found++;
 | |
|       }
 | |
|       if (links > max_links) max_links=links;
 | |
|     }
 | |
|   }
 | |
|   if (found != records)
 | |
|   {
 | |
|     DBUG_PRINT("error",("Found %u of %u records", found, records));
 | |
|     error=1;
 | |
|   }
 | |
|   if (records)
 | |
|     DBUG_PRINT("info",
 | |
| 	       ("records: %u   seeks: %d   max links: %d   hitrate: %.2f",
 | |
| 		records,seek,max_links,(float) seek / (float) records));
 | |
|   DBUG_ASSERT(error == 0);
 | |
|   return error;
 | |
| }
 | |
| #endif
 | |
| 
 | |
| #ifdef MAIN
 | |
| 
 | |
| #define RECORDS 1000
 | |
| 
 | |
| const uchar *test_get_key(const void *data, size_t *length,
 | |
|                           my_bool not_used __attribute__((unused)))
 | |
| {
 | |
|   *length= 2;
 | |
|   return data;
 | |
| }
 | |
| 
 | |
| 
 | |
| int main(int argc __attribute__((unused)),char **argv __attribute__((unused)))
 | |
| {
 | |
|   uchar records[RECORDS][2], copy[2];
 | |
|   HASH hash_test;
 | |
|   uint i;
 | |
|   MY_INIT(argv[0]);
 | |
|   DBUG_PUSH("d:t:O,/tmp/test_hash.trace");
 | |
| 
 | |
|   printf("my_hash_init\n");
 | |
|   if (my_hash_init2(PSI_INSTRUMENT_ME, &hash_test, 100, &my_charset_bin, 20, 0,
 | |
|                     0, test_get_key, 0, 0, HASH_UNIQUE))
 | |
|   {
 | |
|     fprintf(stderr, "hash init failed\n");
 | |
|     exit(1);
 | |
|   }
 | |
| 
 | |
|   printf("my_hash_insert\n");
 | |
|   for (i= 0 ; i < RECORDS ; i++)
 | |
|   {
 | |
|     int2store(records[i],i);
 | |
|     my_hash_insert(&hash_test, records[i]);
 | |
|     my_hash_check(&hash_test);
 | |
|   }
 | |
|   printf("my_hash_update\n");
 | |
|   for (i= 0 ; i < RECORDS ; i+=2)
 | |
|   {
 | |
|     memcpy(copy, records[i], 2);
 | |
|     int2store(records[i],i + RECORDS);
 | |
|     if (my_hash_update(&hash_test, records[i], copy, 2))
 | |
|     {
 | |
|       fprintf(stderr, "hash update failed\n");
 | |
|       exit(1);
 | |
|     }
 | |
|     my_hash_check(&hash_test);
 | |
|   }
 | |
|   printf("my_hash_delete\n");
 | |
|   for (i= 0 ; i < RECORDS ; i++)
 | |
|   {
 | |
|     if (my_hash_delete(&hash_test, records[i]))
 | |
|     {
 | |
|       fprintf(stderr, "hash delete failed\n");
 | |
|       exit(1);
 | |
|     }
 | |
|     my_hash_check(&hash_test);
 | |
|   }
 | |
|   my_hash_free(&hash_test);
 | |
|   printf("ok\n");
 | |
|   my_end(MY_CHECK_ERROR);
 | |
|   return(0);
 | |
| }
 | |
| #endif /* MAIN */
 | 
