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-rw-r--r--mysql/mysys/mf_keycaches.c363
1 files changed, 0 insertions, 363 deletions
diff --git a/mysql/mysys/mf_keycaches.c b/mysql/mysys/mf_keycaches.c
deleted file mode 100644
index 8622105..0000000
--- a/mysql/mysys/mf_keycaches.c
+++ /dev/null
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-/* Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved.
-
- 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
- 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 02110-1301 USA */
-
-/*
- Handling of multiple key caches
-
- The idea is to have a thread safe hash on the table name,
- with a default key cache value that is returned if the table name is not in
- the cache.
-*/
-
-#include "mysys_priv.h"
-#include <keycache.h>
-#include <hash.h>
-#include <m_string.h>
-
-/*****************************************************************************
- General functions to handle SAFE_HASH objects.
-
- A SAFE_HASH object is used to store the hash, the lock and default value
- needed by the rest of the key cache code.
- This is a separate struct to make it easy to later reuse the code for other
- purposes
-
- All entries are linked in a list to allow us to traverse all elements
- and delete selected ones. (HASH doesn't allow any easy ways to do this).
-*****************************************************************************/
-
-/*
- Struct to store a key and pointer to object
-*/
-
-typedef struct st_safe_hash_entry
-{
- uchar *key;
- uint length;
- uchar *data;
- struct st_safe_hash_entry *next, **prev;
-} SAFE_HASH_ENTRY;
-
-
-typedef struct st_safe_hash_with_default
-{
- mysql_rwlock_t lock;
- HASH hash;
- uchar *default_value;
- SAFE_HASH_ENTRY *root;
-} SAFE_HASH;
-
-
-/*
- Free a SAFE_HASH_ENTRY
-
- This function is called by the hash object on delete
-*/
-
-static void safe_hash_entry_free(SAFE_HASH_ENTRY *entry)
-{
- DBUG_ENTER("free_assign_entry");
- my_free(entry);
- DBUG_VOID_RETURN;
-}
-
-
-/* Get key and length for a SAFE_HASH_ENTRY */
-
-static uchar *safe_hash_entry_get(SAFE_HASH_ENTRY *entry, size_t *length,
- my_bool not_used MY_ATTRIBUTE((unused)))
-{
- *length=entry->length;
- return (uchar*) entry->key;
-}
-
-
-/*
- Init a SAFE_HASH object
-
- SYNOPSIS
- safe_hash_init()
- hash safe_hash handler
- elements Expected max number of elements
- default_value default value
-
- NOTES
- In case of error we set hash->default_value to 0 to allow one to call
- safe_hash_free on an object that couldn't be initialized.
-
- RETURN
- 0 ok
- 1 error
-*/
-
-static my_bool safe_hash_init(SAFE_HASH *hash, uint elements,
- uchar *default_value)
-{
- DBUG_ENTER("safe_hash");
- if (my_hash_init(&hash->hash, &my_charset_bin, elements,
- 0, 0, (my_hash_get_key) safe_hash_entry_get,
- (void (*)(void*)) safe_hash_entry_free, 0,
- key_memory_SAFE_HASH_ENTRY))
- {
- hash->default_value= 0;
- DBUG_RETURN(1);
- }
- mysql_rwlock_init(key_SAFE_HASH_lock, &hash->lock);
- hash->default_value= default_value;
- hash->root= 0;
- DBUG_RETURN(0);
-}
-
-
-/*
- Free a SAFE_HASH object
-
- NOTES
- This is safe to call on any object that has been sent to safe_hash_init()
-*/
-
-static void safe_hash_free(SAFE_HASH *hash)
-{
- /*
- Test if safe_hash_init succeeded. This will also guard us against multiple
- free calls.
- */
- if (hash->default_value)
- {
- my_hash_free(&hash->hash);
- mysql_rwlock_destroy(&hash->lock);
- hash->default_value=0;
- }
-}
-
-/*
- Return the value stored for a key or default value if no key
-*/
-
-static uchar *safe_hash_search(SAFE_HASH *hash, const uchar *key, uint length)
-{
- uchar *result;
- DBUG_ENTER("safe_hash_search");
- mysql_rwlock_rdlock(&hash->lock);
- result= my_hash_search(&hash->hash, key, length);
- mysql_rwlock_unlock(&hash->lock);
- if (!result)
- result= hash->default_value;
- else
- result= ((SAFE_HASH_ENTRY*) result)->data;
- DBUG_PRINT("exit",("data: 0x%lx", (long) result));
- DBUG_RETURN(result);
-}
-
-
-/*
- Associate a key with some data
-
- SYONOPSIS
- safe_hash_set()
- hash Hash handle
- key key (path to table etc..)
- length Length of key
- data data to to associate with the data
-
- NOTES
- This can be used both to insert a new entry and change an existing
- entry.
- If one associates a key with the default key cache, the key is deleted
-
- RETURN
- 0 ok
- 1 error (Can only be EOM). In this case my_message() is called.
-*/
-
-static my_bool safe_hash_set(SAFE_HASH *hash, const uchar *key, uint length,
- uchar *data)
-{
- SAFE_HASH_ENTRY *entry;
- my_bool error= 0;
- DBUG_ENTER("safe_hash_set");
- DBUG_PRINT("enter",("key: %.*s data: 0x%lx", length, key, (long) data));
-
- mysql_rwlock_wrlock(&hash->lock);
- entry= (SAFE_HASH_ENTRY*) my_hash_search(&hash->hash, key, length);
-
- if (data == hash->default_value)
- {
- /*
- The key is to be associated with the default entry. In this case
- we can just delete the entry (if it existed) from the hash as a
- search will return the default entry
- */
- if (!entry) /* nothing to do */
- goto end;
- /* unlink entry from list */
- if ((*entry->prev= entry->next))
- entry->next->prev= entry->prev;
- my_hash_delete(&hash->hash, (uchar*) entry);
- goto end;
- }
- if (entry)
- {
- /* Entry existed; Just change the pointer to point at the new data */
- entry->data= data;
- }
- else
- {
- if (!(entry= (SAFE_HASH_ENTRY *) my_malloc(key_memory_SAFE_HASH_ENTRY,
- sizeof(*entry) + length,
- MYF(MY_WME))))
- {
- error= 1;
- goto end;
- }
- entry->key= (uchar*) (entry +1);
- memcpy((char*) entry->key, (char*) key, length);
- entry->length= length;
- entry->data= data;
- /* Link entry to list */
- if ((entry->next= hash->root))
- entry->next->prev= &entry->next;
- entry->prev= &hash->root;
- hash->root= entry;
- if (my_hash_insert(&hash->hash, (uchar*) entry))
- {
- /* This can only happen if hash got out of memory */
- my_free(entry);
- error= 1;
- goto end;
- }
- }
-
-end:
- mysql_rwlock_unlock(&hash->lock);
- DBUG_RETURN(error);
-}
-
-
-/*
- Change all entres with one data value to another data value
-
- SYONOPSIS
- safe_hash_change()
- hash Hash handle
- old_data Old data
- new_data Change all 'old_data' to this
-
- NOTES
- We use the linked list to traverse all elements in the hash as
- this allows us to delete elements in the case where 'new_data' is the
- default value.
-*/
-
-static void safe_hash_change(SAFE_HASH *hash, uchar *old_data, uchar *new_data)
-{
- SAFE_HASH_ENTRY *entry, *next;
- DBUG_ENTER("safe_hash_set");
-
- mysql_rwlock_wrlock(&hash->lock);
-
- for (entry= hash->root ; entry ; entry= next)
- {
- next= entry->next;
- if (entry->data == old_data)
- {
- if (new_data == hash->default_value)
- {
- if ((*entry->prev= entry->next))
- entry->next->prev= entry->prev;
- my_hash_delete(&hash->hash, (uchar*) entry);
- }
- else
- entry->data= new_data;
- }
- }
-
- mysql_rwlock_unlock(&hash->lock);
- DBUG_VOID_RETURN;
-}
-
-
-/*****************************************************************************
- Functions to handle the key cache objects
-*****************************************************************************/
-
-/* Variable to store all key cache objects */
-static SAFE_HASH key_cache_hash;
-
-
-my_bool multi_keycache_init(void)
-{
- return safe_hash_init(&key_cache_hash, 16, (uchar*) dflt_key_cache);
-}
-
-
-void multi_keycache_free(void)
-{
- safe_hash_free(&key_cache_hash);
-}
-
-/*
- Get a key cache to be used for a specific table.
-
- SYNOPSIS
- multi_key_cache_search()
- key key to find (usually table path)
- uint length Length of key.
-
- NOTES
- This function is coded in such a way that we will return the
- default key cache even if one never called multi_keycache_init.
- This will ensure that it works with old MyISAM clients.
-
- RETURN
- key cache to use
-*/
-
-KEY_CACHE *multi_key_cache_search(uchar *key, uint length)
-{
- if (!key_cache_hash.hash.records)
- return dflt_key_cache;
- return (KEY_CACHE*) safe_hash_search(&key_cache_hash, key, length);
-}
-
-
-/*
- Assosiate a key cache with a key
-
-
- SYONOPSIS
- multi_key_cache_set()
- key key (path to table etc..)
- length Length of key
- key_cache cache to assococite with the table
-
- NOTES
- This can be used both to insert a new entry and change an existing
- entry
-*/
-
-
-my_bool multi_key_cache_set(const uchar *key, uint length,
- KEY_CACHE *key_cache)
-{
- return safe_hash_set(&key_cache_hash, key, length, (uchar*) key_cache);
-}
-
-
-void multi_key_cache_change(KEY_CACHE *old_data,
- KEY_CACHE *new_data)
-{
- safe_hash_change(&key_cache_hash, (uchar*) old_data, (uchar*) new_data);
-}
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