2 * @brief LMDB ID List header file.
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.
8 * This file is only used internally in libmdb and its definitions
9 * are not exposed publicly.
12 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
14 * Copyright 2000-2014 The OpenLDAP Foundation.
15 * All rights reserved.
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted only as authorized by the OpenLDAP
21 * A copy of this license is available in the file LICENSE in the
22 * top-level directory of the distribution or, alternatively, at
23 * <http://www.OpenLDAP.org/license.html>.
35 /** @defgroup internal LMDB Internals
39 /** @defgroup idls ID List Management
42 /** A generic unsigned ID number. These were entryIDs in back-bdb.
43 * Preferably it should have the same size as a pointer.
45 typedef size_t MDB_ID;
47 /** An IDL is an ID List, a sorted array of IDs. The first
48 * element of the array is a counter for how many actual
49 * IDs are in the list. In the original back-bdb code, IDLs are
50 * sorted in ascending order. For libmdb IDLs are sorted in
53 typedef MDB_ID *MDB_IDL;
55 /* IDL sizes - likely should be even bigger
56 * limiting factors: sizeof(ID), thread stack size
59 #define MDB_IDL_LOGN 10 /* DB_SIZE is 2^16, UM_SIZE is 2^17 */
61 #define MDB_IDL_LOGN 16 /* DB_SIZE is 2^16, UM_SIZE is 2^17 */
63 #define MDB_IDL_DB_SIZE (1<<MDB_IDL_LOGN)
64 #define MDB_IDL_UM_SIZE (1<<(MDB_IDL_LOGN+1))
66 #define MDB_IDL_DB_MAX (MDB_IDL_DB_SIZE-1)
67 #define MDB_IDL_UM_MAX (MDB_IDL_UM_SIZE-1)
69 #define MDB_IDL_SIZEOF(ids) (((ids)[0]+1) * sizeof(MDB_ID))
70 #define MDB_IDL_IS_ZERO(ids) ( (ids)[0] == 0 )
71 #define MDB_IDL_CPY( dst, src ) (memcpy( dst, src, MDB_IDL_SIZEOF( src ) ))
72 #define MDB_IDL_FIRST( ids ) ( (ids)[1] )
73 #define MDB_IDL_LAST( ids ) ( (ids)[(ids)[0]] )
75 /** Current max length of an #mdb_midl_alloc()ed IDL */
76 #define MDB_IDL_ALLOCLEN( ids ) ( (ids)[-1] )
78 /** Append ID to IDL. The IDL must be big enough. */
79 #define mdb_midl_xappend(idl, id) do { \
80 MDB_ID *xidl = (idl), xlen = ++(xidl[0]); \
84 /** Search for an ID in an IDL.
85 * @param[in] ids The IDL to search.
86 * @param[in] id The ID to search for.
87 * @return The index of the first ID greater than or equal to \b id.
89 unsigned mdb_midl_search( MDB_IDL ids, MDB_ID id );
92 * Allocates memory for an IDL of the given size.
93 * @return IDL on success, NULL on failure.
95 MDB_IDL mdb_midl_alloc(int num);
98 * @param[in] ids The IDL to free.
100 void mdb_midl_free(MDB_IDL ids);
103 * Return the IDL to the default size if it has grown larger.
104 * @param[in,out] idp Address of the IDL to shrink.
105 * @return 0 on no change, non-zero if shrunk.
107 int mdb_midl_shrink(MDB_IDL *idp);
109 /** Make room for num additional elements in an IDL.
110 * @param[in,out] idp Address of the IDL.
111 * @param[in] num Number of elements to make room for.
112 * @return 0 on success, ENOMEM on failure.
114 int mdb_midl_need(MDB_IDL *idp, unsigned num);
116 /** Append an ID onto an IDL.
117 * @param[in,out] idp Address of the IDL to append to.
118 * @param[in] id The ID to append.
119 * @return 0 on success, ENOMEM if the IDL is too large.
121 int mdb_midl_append( MDB_IDL *idp, MDB_ID id );
123 /** Append an IDL onto an IDL.
124 * @param[in,out] idp Address of the IDL to append to.
125 * @param[in] app The IDL to append.
126 * @return 0 on success, ENOMEM if the IDL is too large.
128 int mdb_midl_append_list( MDB_IDL *idp, MDB_IDL app );
130 /** Append an ID range onto an IDL.
131 * @param[in,out] idp Address of the IDL to append to.
132 * @param[in] id The lowest ID to append.
133 * @param[in] n Number of IDs to append.
134 * @return 0 on success, ENOMEM if the IDL is too large.
136 int mdb_midl_append_range( MDB_IDL *idp, MDB_ID id, unsigned n );
138 /** Merge an IDL onto an IDL. The destination IDL must be big enough.
139 * @param[in] idl The IDL to merge into.
140 * @param[in] merge The IDL to merge.
142 void mdb_midl_xmerge( MDB_IDL idl, MDB_IDL merge );
145 * @param[in,out] ids The IDL to sort.
147 void mdb_midl_sort( MDB_IDL ids );
149 /** An ID2 is an ID/pointer pair.
151 typedef struct MDB_ID2 {
152 MDB_ID mid; /**< The ID */
153 void *mptr; /**< The pointer */
156 /** An ID2L is an ID2 List, a sorted array of ID2s.
157 * The first element's \b mid member is a count of how many actual
158 * elements are in the array. The \b mptr member of the first element is unused.
159 * The array is sorted in ascending order by \b mid.
161 typedef MDB_ID2 *MDB_ID2L;
163 /** Search for an ID in an ID2L.
164 * @param[in] ids The ID2L to search.
165 * @param[in] id The ID to search for.
166 * @return The index of the first ID2 whose \b mid member is greater than or equal to \b id.
168 unsigned mdb_mid2l_search( MDB_ID2L ids, MDB_ID id );
171 /** Insert an ID2 into a ID2L.
172 * @param[in,out] ids The ID2L to insert into.
173 * @param[in] id The ID2 to insert.
174 * @return 0 on success, -1 if the ID was already present in the ID2L.
176 int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id );
178 /** Append an ID2 into a ID2L.
179 * @param[in,out] ids The ID2L to append into.
180 * @param[in] id The ID2 to append.
181 * @return 0 on success, -2 if the ID2L is too big.
183 int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id );
190 #endif /* _MDB_MIDL_H_ */