mirror of
https://github.com/MariaDB/server.git
synced 2025-01-16 20:12:31 +01:00
142 lines
4.1 KiB
C++
142 lines
4.1 KiB
C++
/*****************************************************************************
|
|
|
|
Copyright (c) 2007, 2013, 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 Street, Fifth Floor, Boston, MA 02110-1335 USA
|
|
|
|
*****************************************************************************/
|
|
|
|
/**************************************************//**
|
|
@file include/ha0storage.ic
|
|
Hash storage.
|
|
Provides a data structure that stores chunks of data in
|
|
its own storage, avoiding duplicates.
|
|
|
|
Created September 24, 2007 Vasil Dimov
|
|
*******************************************************/
|
|
|
|
#include "hash0hash.h"
|
|
#include "mem0mem.h"
|
|
|
|
/** Hash storage for strings */
|
|
struct ha_storage_t {
|
|
mem_heap_t* heap; /*!< memory heap from which memory is
|
|
allocated */
|
|
hash_table_t hash; /*!< hash table used to avoid
|
|
duplicates */
|
|
};
|
|
|
|
/** Objects of this type are stored in ha_storage_t */
|
|
struct ha_storage_node_t {
|
|
ulint data_len;/*!< length of the data */
|
|
const void* data; /*!< pointer to data */
|
|
ha_storage_node_t* next; /*!< next node in hash chain */
|
|
};
|
|
|
|
/*******************************************************************//**
|
|
Creates a hash storage. If any of the parameters is 0, then a default
|
|
value is used.
|
|
@return own: hash storage */
|
|
UNIV_INLINE
|
|
ha_storage_t*
|
|
ha_storage_create(
|
|
/*==============*/
|
|
ulint initial_heap_bytes, /*!< in: initial heap's size */
|
|
ulint initial_hash_cells) /*!< in: initial number of cells
|
|
in the hash table */
|
|
{
|
|
ha_storage_t* storage;
|
|
mem_heap_t* heap;
|
|
|
|
if (initial_heap_bytes == 0) {
|
|
|
|
initial_heap_bytes = HA_STORAGE_DEFAULT_HEAP_BYTES;
|
|
}
|
|
|
|
if (initial_hash_cells == 0) {
|
|
|
|
initial_hash_cells = HA_STORAGE_DEFAULT_HASH_CELLS;
|
|
}
|
|
|
|
/* we put "storage" within "storage->heap" */
|
|
|
|
heap = mem_heap_create(sizeof(ha_storage_t)
|
|
+ initial_heap_bytes);
|
|
|
|
storage = (ha_storage_t*) mem_heap_alloc(heap,
|
|
sizeof(ha_storage_t));
|
|
|
|
storage->heap = heap;
|
|
storage->hash.create(initial_hash_cells);
|
|
|
|
return(storage);
|
|
}
|
|
|
|
/*******************************************************************//**
|
|
Empties a hash storage, freeing memory occupied by data chunks.
|
|
This invalidates any pointers previously returned by ha_storage_put().
|
|
The hash storage is not invalidated itself and can be used again. */
|
|
UNIV_INLINE
|
|
void
|
|
ha_storage_empty(
|
|
/*=============*/
|
|
ha_storage_t** storage) /*!< in/out: hash storage */
|
|
{
|
|
ha_storage_t temp_storage;
|
|
|
|
temp_storage.heap = (*storage)->heap;
|
|
temp_storage.hash = (*storage)->hash;
|
|
|
|
temp_storage.hash.clear();
|
|
mem_heap_empty(temp_storage.heap);
|
|
|
|
*storage = (ha_storage_t*) mem_heap_alloc(temp_storage.heap,
|
|
sizeof(ha_storage_t));
|
|
|
|
(*storage)->heap = temp_storage.heap;
|
|
(*storage)->hash = temp_storage.hash;
|
|
}
|
|
|
|
/*******************************************************************//**
|
|
Frees a hash storage and everything it contains, it cannot be used after
|
|
this call.
|
|
This invalidates any pointers previously returned by ha_storage_put(). */
|
|
UNIV_INLINE
|
|
void
|
|
ha_storage_free(
|
|
/*============*/
|
|
ha_storage_t* storage) /*!< in, own: hash storage */
|
|
{
|
|
storage->hash.free();
|
|
mem_heap_free(storage->heap);
|
|
}
|
|
|
|
/*******************************************************************//**
|
|
Gets the size of the memory used by a storage.
|
|
@return bytes used */
|
|
UNIV_INLINE
|
|
ulint
|
|
ha_storage_get_size(
|
|
/*================*/
|
|
const ha_storage_t* storage) /*!< in: hash storage */
|
|
{
|
|
ulint ret;
|
|
|
|
ret = mem_heap_get_size(storage->heap);
|
|
|
|
/* this assumes hash->heap and hash->heaps are NULL */
|
|
ret += sizeof(hash_table_t);
|
|
ret += sizeof(hash_cell_t) * storage->hash.n_cells;
|
|
|
|
return(ret);
|
|
}
|