core/rangelist.h

   1 /*
   2  * Copyright (c) 2001-2014 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 #ifndef _HFS_RANGELIST_H_
  29 #define _HFS_RANGELIST_H_
  30
  31 #include <sys/appleapiopts.h>
  32
  33 #ifdef KERNEL
  34 #ifdef __APPLE_API_PRIVATE
  35 #include <sys/types.h>
  36 #include <sys/queue.h>
  37
  38 enum rl_overlaptype {
  39     RL_NOOVERLAP = 0,           /* 0 */
  40     RL_MATCHINGOVERLAP,         /* 1 */
  41     RL_OVERLAPCONTAINSRANGE,    /* 2 */
  42     RL_OVERLAPISCONTAINED,      /* 3 */
  43     RL_OVERLAPSTARTSBEFORE,     /* 4 */
  44     RL_OVERLAPENDSAFTER         /* 5 */
  45 };
  46
  47 #define RL_INFINITY INT64_MAX
  48
  49 TAILQ_HEAD(rl_head, rl_entry);
  50
  51 struct rl_entry {
  52     TAILQ_ENTRY(rl_entry) rl_link;
  53     off_t rl_start;
  54     off_t rl_end;
  55 };
  56
  57 __BEGIN_DECLS
  58 void rl_init(struct rl_head *rangelist);
  59 void rl_add(off_t start, off_t end, struct rl_head *rangelist);
  60 void rl_remove(off_t start, off_t end, struct rl_head *rangelist);
  61 void rl_remove_all(struct rl_head *rangelist);
  62 enum rl_overlaptype rl_scan(struct rl_head *rangelist,
  63                                                         off_t start,
  64                                                         off_t end,
  65                                                         struct rl_entry **overlap);
  66 enum rl_overlaptype rl_overlap(const struct rl_entry *range,
  67                                                            off_t start, off_t end);
  68
  69 static __attribute__((pure)) inline
  70 off_t rl_len(const struct rl_entry *range)
  71 {
  72         return range->rl_end - range->rl_start + 1;
  73 }
  74
  75 void rl_subtract(struct rl_entry *a, const struct rl_entry *b);
  76
  77 static inline struct rl_entry rl_make(off_t start, off_t end)
  78 {
  79         return (struct rl_entry){ .rl_start = start, .rl_end = end };
  80 }
  81
  82 __END_DECLS
  83
  84 #endif /* __APPLE_API_PRIVATE */
  85 #endif /* KERNEL */
  86 #endif /* ! _HFS_RANGELIST_H_ */