sbin/hammer/misc.c

   1 /*
   2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sbin/hammer/misc.c,v 1.5 2008/06/26 04:07:57 dillon Exp $
  35  */
  36
  37 #include "hammer.h"
  38
  39 /*
  40  * (taken from /usr/src/sys/vfs/hammer/hammer_btree.c)
  41  *
  42  * Compare two B-Tree elements, return -N, 0, or +N (e.g. similar to strcmp).
  43  *
  44  * Note that for this particular function a return value of -1, 0, or +1
  45  * can denote a match if delete_tid is otherwise discounted.  A delete_tid
  46  * of zero is considered to be 'infinity' in comparisons.
  47  *
  48  * See also hammer_rec_rb_compare() and hammer_rec_cmp() in hammer_object.c.
  49  */
  50 int
  51 hammer_btree_cmp(hammer_base_elm_t key1, hammer_base_elm_t key2)
  52 {
  53         if (key1->localization < key2->localization)
  54                 return(-5);
  55         if (key1->localization > key2->localization)
  56                 return(5);
  57
  58         if (key1->obj_id < key2->obj_id)
  59                 return(-4);
  60         if (key1->obj_id > key2->obj_id)
  61                 return(4);
  62
  63         if (key1->rec_type < key2->rec_type)
  64                 return(-3);
  65         if (key1->rec_type > key2->rec_type)
  66                 return(3);
  67
  68         if (key1->key < key2->key)
  69                 return(-2);
  70         if (key1->key > key2->key)
  71                 return(2);
  72
  73         if (key1->create_tid == 0) {
  74                 if (key2->create_tid == 0)
  75                         return(0);
  76                 return(1);
  77         }
  78         if (key2->create_tid == 0)
  79                 return(-1);
  80         if (key1->create_tid < key2->create_tid)
  81                 return(-1);
  82         if (key1->create_tid > key2->create_tid)
  83                 return(1);
  84         return(0);
  85 }
  86
  87 void
  88 hammer_key_beg_init(hammer_base_elm_t base)
  89 {
  90         bzero(base, sizeof(*base));
  91
  92         base->localization = HAMMER_MIN_LOCALIZATION;
  93         base->obj_id = HAMMER_MIN_OBJID;
  94         base->key = HAMMER_MIN_KEY;
  95         base->create_tid = 1;
  96         base->rec_type = HAMMER_MIN_RECTYPE;
  97 }
  98
  99 void
 100 hammer_key_end_init(hammer_base_elm_t base)
 101 {
 102         bzero(base, sizeof(*base));
 103
 104         base->localization = HAMMER_MAX_LOCALIZATION;
 105         base->obj_id = HAMMER_MAX_OBJID;
 106         base->key = HAMMER_MAX_KEY;
 107         base->create_tid = HAMMER_MAX_TID;
 108         base->rec_type = HAMMER_MAX_RECTYPE;
 109 }
 110
 111 int
 112 hammer_crc_test_leaf(void *data, hammer_btree_leaf_elm_t leaf)
 113 {
 114         hammer_crc_t crc;
 115
 116         if (leaf->data_len == 0) {
 117                 crc = 0;
 118         } else {
 119                 switch(leaf->base.rec_type) {
 120                 case HAMMER_RECTYPE_INODE:
 121                         if (leaf->data_len != sizeof(struct hammer_inode_data))
 122                                 return(0);
 123                         crc = crc32(data, HAMMER_INODE_CRCSIZE);
 124                         break;
 125                 default:
 126                         crc = crc32(data, leaf->data_len);
 127                         break;
 128                 }
 129         }
 130         return (leaf->data_crc == crc);
 131 }
 132