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 } 132 133