1/** @file midl.h
2 * @brief LMDB ID List header file.
3 *
4 * This file was originally part of back-bdb but has been
5 * modified for use in libmdb. Most of the macros defined
6 * in this file are unused, just left over from the original.
7 *
8 * This file is only used internally in libmdb and its definitions
9 * are not exposed publicly.
10 */
11/* $OpenLDAP$ */
12/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
13 *
14 * Copyright 2000-2019 The OpenLDAP Foundation.
15 * Portions Copyright 2001-2019 Howard Chu, Symas Corp.
16 * All rights reserved.
17 *
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted only as authorized by the OpenLDAP
20 * Public License.
21 *
22 * A copy of this license is available in the file LICENSE in the
23 * top-level directory of the distribution or, alternatively, at
24 * <http://www.OpenLDAP.org/license.html>.
25 */
26
27#ifndef _MDB_MIDL_H_
28#define _MDB_MIDL_H_
29
30#include "lmdb.h"
31
32#ifdef __cplusplus
33extern "C" {
34#endif
35
36/** @defgroup internal LMDB Internals
37 * @{
38 */
39
40/** @defgroup idls ID List Management
41 * @{
42 */
43 /** A generic unsigned ID number. These were entryIDs in back-bdb.
44 * Preferably it should have the same size as a pointer.
45 */
46typedef mdb_size_t MDB_ID;
47
48 /** An IDL is an ID List, a sorted array of IDs. The first
49 * element of the array is a counter for how many actual
50 * IDs are in the list. In the original back-bdb code, IDLs are
51 * sorted in ascending order. For libmdb IDLs are sorted in
52 * descending order.
53 */
54typedef MDB_ID *MDB_IDL;
55
56/* IDL sizes - likely should be even bigger
57 * limiting factors: sizeof(ID), thread stack size
58 */
59#define MDB_IDL_LOGN 16 /* DB_SIZE is 2^16, UM_SIZE is 2^17 */
60#define MDB_IDL_DB_SIZE (1<<MDB_IDL_LOGN)
61#define MDB_IDL_UM_SIZE (1<<(MDB_IDL_LOGN+1))
62
63#define MDB_IDL_DB_MAX (MDB_IDL_DB_SIZE-1)
64#define MDB_IDL_UM_MAX (MDB_IDL_UM_SIZE-1)
65
66#define MDB_IDL_SIZEOF(ids) (((ids)[0]+1) * sizeof(MDB_ID))
67#define MDB_IDL_IS_ZERO(ids) ( (ids)[0] == 0 )
68#define MDB_IDL_CPY( dst, src ) (memcpy( dst, src, MDB_IDL_SIZEOF( src ) ))
69#define MDB_IDL_FIRST( ids ) ( (ids)[1] )
70#define MDB_IDL_LAST( ids ) ( (ids)[(ids)[0]] )
71
72 /** Current max length of an #mdb_midl_alloc()ed IDL */
73#define MDB_IDL_ALLOCLEN( ids ) ( (ids)[-1] )
74
75 /** Append ID to IDL. The IDL must be big enough. */
76#define mdb_midl_xappend(idl, id) do { \
77 MDB_ID *xidl = (idl), xlen = ++(xidl[0]); \
78 xidl[xlen] = (id); \
79 } while (0)
80
81 /** Search for an ID in an IDL.
82 * @param[in] ids The IDL to search.
83 * @param[in] id The ID to search for.
84 * @return The index of the first ID greater than or equal to \b id.
85 */
86unsigned mdb_midl_search( MDB_IDL ids, MDB_ID id );
87
88 /** Allocate an IDL.
89 * Allocates memory for an IDL of the given size.
90 * @return IDL on success, NULL on failure.
91 */
92MDB_IDL mdb_midl_alloc(int num);
93
94 /** Free an IDL.
95 * @param[in] ids The IDL to free.
96 */
97void mdb_midl_free(MDB_IDL ids);
98
99 /** Shrink an IDL.
100 * Return the IDL to the default size if it has grown larger.
101 * @param[in,out] idp Address of the IDL to shrink.
102 */
103void mdb_midl_shrink(MDB_IDL *idp);
104
105 /** Make room for num additional elements in an IDL.
106 * @param[in,out] idp Address of the IDL.
107 * @param[in] num Number of elements to make room for.
108 * @return 0 on success, ENOMEM on failure.
109 */
110int mdb_midl_need(MDB_IDL *idp, unsigned num);
111
112 /** Append an ID onto an IDL.
113 * @param[in,out] idp Address of the IDL to append to.
114 * @param[in] id The ID to append.
115 * @return 0 on success, ENOMEM if the IDL is too large.
116 */
117int mdb_midl_append( MDB_IDL *idp, MDB_ID id );
118
119 /** Append an IDL onto an IDL.
120 * @param[in,out] idp Address of the IDL to append to.
121 * @param[in] app The IDL to append.
122 * @return 0 on success, ENOMEM if the IDL is too large.
123 */
124int mdb_midl_append_list( MDB_IDL *idp, MDB_IDL app );
125
126 /** Append an ID range onto an IDL.
127 * @param[in,out] idp Address of the IDL to append to.
128 * @param[in] id The lowest ID to append.
129 * @param[in] n Number of IDs to append.
130 * @return 0 on success, ENOMEM if the IDL is too large.
131 */
132int mdb_midl_append_range( MDB_IDL *idp, MDB_ID id, unsigned n );
133
134 /** Merge an IDL onto an IDL. The destination IDL must be big enough.
135 * @param[in] idl The IDL to merge into.
136 * @param[in] merge The IDL to merge.
137 */
138void mdb_midl_xmerge( MDB_IDL idl, MDB_IDL merge );
139
140 /** Sort an IDL.
141 * @param[in,out] ids The IDL to sort.
142 */
143void mdb_midl_sort( MDB_IDL ids );
144
145 /** An ID2 is an ID/pointer pair.
146 */
147typedef struct MDB_ID2 {
148 MDB_ID mid; /**< The ID */
149 void *mptr; /**< The pointer */
150} MDB_ID2;
151
152 /** An ID2L is an ID2 List, a sorted array of ID2s.
153 * The first element's \b mid member is a count of how many actual
154 * elements are in the array. The \b mptr member of the first element is unused.
155 * The array is sorted in ascending order by \b mid.
156 */
157typedef MDB_ID2 *MDB_ID2L;
158
159 /** Search for an ID in an ID2L.
160 * @param[in] ids The ID2L to search.
161 * @param[in] id The ID to search for.
162 * @return The index of the first ID2 whose \b mid member is greater than or equal to \b id.
163 */
164unsigned mdb_mid2l_search( MDB_ID2L ids, MDB_ID id );
165
166
167 /** Insert an ID2 into a ID2L.
168 * @param[in,out] ids The ID2L to insert into.
169 * @param[in] id The ID2 to insert.
170 * @return 0 on success, -1 if the ID was already present in the ID2L.
171 */
172int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id );
173
174 /** Append an ID2 into a ID2L.
175 * @param[in,out] ids The ID2L to append into.
176 * @param[in] id The ID2 to append.
177 * @return 0 on success, -2 if the ID2L is too big.
178 */
179int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id );
180
181#ifdef MDB_VL32
182typedef struct MDB_ID3 {
183 MDB_ID mid; /**< The ID */
184 void *mptr; /**< The pointer */
185 unsigned int mcnt; /**< Number of pages */
186 unsigned int mref; /**< Refcounter */
187} MDB_ID3;
188
189typedef MDB_ID3 *MDB_ID3L;
190
191unsigned mdb_mid3l_search( MDB_ID3L ids, MDB_ID id );
192int mdb_mid3l_insert( MDB_ID3L ids, MDB_ID3 *id );
193
194#endif /* MDB_VL32 */
195/** @} */
196/** @} */
197#ifdef __cplusplus
198}
199#endif
200#endif /* _MDB_MIDL_H_ */
201