midl.h (5711B)
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 2000-2021 The OpenLDAP Foundation. 15 * Portions Copyright 2001-2021 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 <stddef.h> 31 32 #ifdef __cplusplus 33 extern "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 */ 46 typedef 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 */ 54 typedef 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 */ 86 unsigned 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 */ 92 MDB_IDL mdb_midl_alloc(int num); 93 94 /** Free an IDL. 95 * @param[in] ids The IDL to free. 96 */ 97 void 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 */ 103 void 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 */ 110 int 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 */ 117 int 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 */ 124 int 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 */ 132 int 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 */ 138 void mdb_midl_xmerge( MDB_IDL idl, MDB_IDL merge ); 139 140 /** Sort an IDL. 141 * @param[in,out] ids The IDL to sort. 142 */ 143 void mdb_midl_sort( MDB_IDL ids ); 144 145 /** An ID2 is an ID/pointer pair. 146 */ 147 typedef 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 */ 157 typedef 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 */ 164 unsigned 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 */ 172 int 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 */ 179 int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id ); 180 181 /** @} */ 182 /** @} */ 183 #ifdef __cplusplus 184 } 185 #endif 186 #endif /* _MDB_MIDL_H_ */