lib/util/idtree.h

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    very efficient functions to manage mapping a id (such as a fnum) to
   5    a pointer. This is used for fnum and search id allocation.
   6
   7    Copyright (C) Andrew Tridgell 2004
   8
   9    This code is derived from lib/idr.c in the 2.6 Linux kernel, which was
  10    written by Jim Houston jim.houston@ccur.com, and is
  11    Copyright (C) 2002 by Concurrent Computer Corporation
  12
  13    This program is free software; you can redistribute it and/or modify
  14    it under the terms of the GNU General Public License as published by
  15    the Free Software Foundation; either version 2 of the License, or
  16    (at your option) any later version.
  17
  18    This program is distributed in the hope that it will be useful,
  19    but WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21    GNU General Public License for more details.
  22
  23    You should have received a copy of the GNU General Public License
  24    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  25 */
  26
  27 #ifndef _SAMBA_IDTREE_H_
  28 #define _SAMBA_IDTREE_H_
  29
  30 #include <talloc.h>
  31
  32 struct idr_context;
  33
  34 /**
  35   initialise a idr tree. The context return value must be passed to
  36   all subsequent idr calls. To destroy the idr tree use talloc_free()
  37   on this context
  38  */
  39 struct idr_context *idr_init(TALLOC_CTX *mem_ctx);
  40
  41 /**
  42   allocate the next available id, and assign 'ptr' into its slot.
  43   you can retrieve later this pointer using idr_find()
  44 */
  45 int idr_get_new(struct idr_context *idp, void *ptr, int limit);
  46
  47 /**
  48    allocate a new id, giving the first available value greater than or
  49    equal to the given starting id
  50 */
  51 int idr_get_new_above(struct idr_context *idp, void *ptr, int starting_id, int limit);
  52
  53 /**
  54   allocate a new id randomly in the given range
  55 */
  56 int idr_get_new_random(struct idr_context *idp, void *ptr, int limit);
  57
  58 /**
  59   find a pointer value previously set with idr_get_new given an id
  60 */
  61 void *idr_find(struct idr_context *idp, int id);
  62
  63 /**
  64   remove an id from the idr tree
  65 */
  66 int idr_remove(struct idr_context *idp, int id);
  67
  68 #endif /* _SAMBA_IDTREE_H_ */