/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 1996-2017. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* %CopyrightEnd%
*/
/*
** General hash and index functions
** The idea behind this file was to capture the
** way Atom,Export and Module table was implemented
*/
#ifndef __INDEX_H__
#define __INDEX_H__
#include "hash.h"
#include "erl_alloc.h"
typedef struct index_slot
{
HashBucket bucket;
int index;
} IndexSlot;
typedef struct index_table
{
Hash htable; /* Mapping obj -> index */
ErtsAlcType_t type;
int size; /* Allocated size */
int limit; /* Max size */
int entries; /* Number of entries */
IndexSlot*** seg_table; /* Mapping index -> obj */
} IndexTable;
#define INDEX_PAGE_SHIFT 10
#define INDEX_PAGE_SIZE (1 << INDEX_PAGE_SHIFT)
#define INDEX_PAGE_MASK ((1 << INDEX_PAGE_SHIFT)-1)
IndexTable *erts_index_init(ErtsAlcType_t,IndexTable*,char*,int,int,HashFunctions);
void index_info(fmtfn_t, void *, IndexTable*);
int index_table_sz(IndexTable *);
int index_get(IndexTable*, void*);
IndexSlot* index_put_entry(IndexTable*, void*);
void erts_index_merge(Hash*, IndexTable*);
/* Erase all entries with index 'ix' and higher
*/
void index_erase_latest_from(IndexTable*, Uint ix);
ERTS_GLB_INLINE int index_put(IndexTable*, void*);
ERTS_GLB_INLINE IndexSlot* erts_index_lookup(IndexTable*, Uint);
ERTS_GLB_INLINE int erts_index_num_entries(IndexTable* t);
#if ERTS_GLB_INLINE_INCL_FUNC_DEF
ERTS_GLB_INLINE int index_put(IndexTable* t, void* tmpl)
{
return index_put_entry(t, tmpl)->index;
}
ERTS_GLB_INLINE IndexSlot*
erts_index_lookup(IndexTable* t, Uint ix)
{
return t->seg_table[ix>>INDEX_PAGE_SHIFT][ix&INDEX_PAGE_MASK];
}
ERTS_GLB_INLINE int erts_index_num_entries(IndexTable* t)
{
int ret = t->entries;
/*
* Do a read barrier here to allow lock free iteration
* on tables where entries are never erased.
* index_put_entry() does matching write barrier.
*/
ERTS_THR_READ_MEMORY_BARRIER;
return ret;
}
#endif
#endif
