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/*****************************************************************************
Copyright (c) 2007, 2009, Innobase Oy. 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., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 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 "univ.i"
#include "ha0storage.h"
#include "hash0hash.h"
#include "mem0mem.h"
/** Hash storage for strings */
struct ha_storage_struct {
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 */
typedef struct ha_storage_node_struct ha_storage_node_t;
/** Objects of this type are stored in ha_storage_struct */
struct ha_storage_node_struct {
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 = 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;
hash_table_clear(temp_storage.hash);
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 */
{
/* order is important because the pointer storage->hash is
within the heap */
hash_table_free(storage->hash);
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) * hash_get_n_cells(storage->hash);
return(ret);
}
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