nostrdb

an unfairly fast embedded nostr database backed by lmdb
git clone git://jb55.com/nostrdb
Log | Files | Refs | Submodules | README | LICENSE

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_ */