/** @file midl.h
* @brief LMDB ID List header file.
*
* This file was originally part of back-bdb but has been
* modified for use in libmdb. Most of the macros defined
* in this file are unused, just left over from the original.
*
* This file is only used internally in libmdb and its definitions
* are not exposed publicly.
*/
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 2000-2014 The OpenLDAP Foundation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in the file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*/
#ifndef _MDB_MIDL_H_
#define _MDB_MIDL_H_
#include <stddef.h>
#ifdef __cplusplus
extern "C" {
#endif
/** @defgroup internal LMDB Internals
* @{
*/
/** @defgroup idls ID List Management
* @{
*/
/** A generic unsigned ID number. These were entryIDs in back-bdb.
* Preferably it should have the same size as a pointer.
*/
typedef size_t MDB_ID;
/** An IDL is an ID List, a sorted array of IDs. The first
* element of the array is a counter for how many actual
* IDs are in the list. In the original back-bdb code, IDLs are
* sorted in ascending order. For libmdb IDLs are sorted in
* descending order.
*/
typedef MDB_ID *MDB_IDL;
/* IDL sizes - likely should be even bigger
* limiting factors: sizeof(ID), thread stack size
*/
#ifdef VL32
#define MDB_IDL_LOGN 10 /* DB_SIZE is 2^10, UM_SIZE is 2^11 */
#else
#define MDB_IDL_LOGN 16 /* DB_SIZE is 2^16, UM_SIZE is 2^17 */
#endif
#define MDB_IDL_DB_SIZE (1<<MDB_IDL_LOGN)
#define MDB_IDL_UM_SIZE (1<<(MDB_IDL_LOGN+1))
#define MDB_IDL_DB_MAX (MDB_IDL_DB_SIZE-1)
#define MDB_IDL_UM_MAX (MDB_IDL_UM_SIZE-1)
#define MDB_IDL_SIZEOF(ids) (((ids)[0]+1) * sizeof(MDB_ID))
#define MDB_IDL_IS_ZERO(ids) ( (ids)[0] == 0 )
#define MDB_IDL_CPY( dst, src ) (memcpy( dst, src, MDB_IDL_SIZEOF( src ) ))
#define MDB_IDL_FIRST( ids ) ( (ids)[1] )
#define MDB_IDL_LAST( ids ) ( (ids)[(ids)[0]] )
/** Current max length of an #mdb_midl_alloc()ed IDL */
#define MDB_IDL_ALLOCLEN( ids ) ( (ids)[-1] )
/** Append ID to IDL. The IDL must be big enough. */
#define mdb_midl_xappend(idl, id) do { \
MDB_ID *xidl = (idl), xlen = ++(xidl[0]); \
xidl[xlen] = (id); \
} while (0)
/** Search for an ID in an IDL.
* @param[in] ids The IDL to search.
* @param[in] id The ID to search for.
* @return The index of the first ID greater than or equal to \b id.
*/
unsigned mdb_midl_search( MDB_IDL ids, MDB_ID id );
/** Allocate an IDL.
* Allocates memory for an IDL of the given size.
* @return IDL on success, NULL on failure.
*/
MDB_IDL mdb_midl_alloc(int num);
/** Free an IDL.
* @param[in] ids The IDL to free.
*/
void mdb_midl_free(MDB_IDL ids);
/** Shrink an IDL.
* Return the IDL to the default size if it has grown larger.
* @param[in,out] idp Address of the IDL to shrink.
* @return 0 on no change, non-zero if shrunk.
*/
int mdb_midl_shrink(MDB_IDL *idp);
/** Make room for num additional elements in an IDL.
* @param[in,out] idp Address of the IDL.
* @param[in] num Number of elements to make room for.
* @return 0 on success, ENOMEM on failure.
*/
int mdb_midl_need(MDB_IDL *idp, unsigned num);
/** Append an ID onto an IDL.
* @param[in,out] idp Address of the IDL to append to.
* @param[in] id The ID to append.
* @return 0 on success, ENOMEM if the IDL is too large.
*/
int mdb_midl_append( MDB_IDL *idp, MDB_ID id );
/** Append an IDL onto an IDL.
* @param[in,out] idp Address of the IDL to append to.
* @param[in] app The IDL to append.
* @return 0 on success, ENOMEM if the IDL is too large.
*/
int mdb_midl_append_list( MDB_IDL *idp, MDB_IDL app );
/** Append an ID range onto an IDL.
* @param[in,out] idp Address of the IDL to append to.
* @param[in] id The lowest ID to append.
* @param[in] n Number of IDs to append.
* @return 0 on success, ENOMEM if the IDL is too large.
*/
int mdb_midl_append_range( MDB_IDL *idp, MDB_ID id, unsigned n );
/** Merge an IDL onto an IDL. The destination IDL must be big enough.
* @param[in] idl The IDL to merge into.
* @param[in] merge The IDL to merge.
*/
void mdb_midl_xmerge( MDB_IDL idl, MDB_IDL merge );
/** Sort an IDL.
* @param[in,out] ids The IDL to sort.
*/
void mdb_midl_sort( MDB_IDL ids );
/** An ID2 is an ID/pointer pair.
*/
typedef struct MDB_ID2 {
MDB_ID mid; /**< The ID */
void *mptr; /**< The pointer */
} MDB_ID2;
/** An ID2L is an ID2 List, a sorted array of ID2s.
* The first element's \b mid member is a count of how many actual
* elements are in the array. The \b mptr member of the first element is unused.
* The array is sorted in ascending order by \b mid.
*/
typedef MDB_ID2 *MDB_ID2L;
/** Search for an ID in an ID2L.
* @param[in] ids The ID2L to search.
* @param[in] id The ID to search for.
* @return The index of the first ID2 whose \b mid member is greater than or equal to \b id.
*/
unsigned mdb_mid2l_search( MDB_ID2L ids, MDB_ID id );
/** Insert an ID2 into a ID2L.
* @param[in,out] ids The ID2L to insert into.
* @param[in] id The ID2 to insert.
* @return 0 on success, -1 if the ID was already present in the ID2L.
*/
int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id );
/** Append an ID2 into a ID2L.
* @param[in,out] ids The ID2L to append into.
* @param[in] id The ID2 to append.
* @return 0 on success, -2 if the ID2L is too big.
*/
int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id );
/** @} */
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* _MDB_MIDL_H_ */
