1 /*- 2 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 3 * Redistribution and use in source and binary forms, with or without 4 * modification, are permitted provided that the following conditions 5 * are met: 6 * 1. Redistributions of source code must retain the above copyright 7 * notice, this list of conditions and the following disclaimer. 8 * 2. Redistributions in binary form must reproduce the above copyright 9 * notice, this list of conditions and the following disclaimer in the 10 * documentation and/or other materials provided with the distribution. 11 * 4. Neither the name of the University nor the names of its contributors 12 * may be used to endorse or promote products derived from this software 13 * without specific prior written permission. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 21 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 24 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 /* 29 * The radix bitmap structure is ported from FreeBSD. 30 */ 31 32 33 #ifndef _KERNEL_UTIL_RADIX_BITMAP_H 34 #define _KERNEL_UTIL_RADIX_BITMAP_H 35 36 37 #include <SupportDefs.h> 38 39 40 typedef uint32 radix_slot_t; 41 typedef uint32 bitmap_t; 42 43 typedef struct radix_node { 44 union { 45 bitmap_t bitmap; // bitmap for the slots if we are a leaf 46 int32 available; // available slots under us if we are not a leaf 47 } u; 48 int32 big_hint; // the biggest continuous slots under us 49 } radix_node; 50 51 // Bitmap which uses radix tree for hinting. 52 // The radix tree is stored in an array. 53 typedef struct radix_bitmap { 54 radix_slot_t free_slots; // # of free slots 55 radix_slot_t radix; // coverage radix 56 radix_slot_t skip; // starting skip 57 radix_node *root; // root of radix tree, actually it is an array 58 radix_slot_t root_size; // size of the array(# of nodes in the tree) 59 } radix_bitmap; 60 61 62 #define BITMAP_RADIX (sizeof(radix_slot_t) * 8) 63 #define NODE_RADIX 16 64 65 #define RADIX_SLOT_NONE ((radix_slot_t)-1) 66 67 68 extern radix_bitmap *radix_bitmap_create(uint32 slots); 69 extern radix_slot_t radix_bitmap_alloc(radix_bitmap *bmp, uint32 count); 70 extern void radix_bitmap_dealloc(radix_bitmap *bmp, radix_slot_t slotIndex, 71 uint32 count); 72 extern void radix_bitmap_destroy(radix_bitmap *bmp); 73 74 #endif // _KERNEL_UTIL_RADIX_BITMAP_H 75 76