1 /*
2 * linux/fs/hfsplus/brec.c
3 *
4 * Copyright (C) 2001
5 * Brad Boyer (flar@allandria.com)
6 * (C) 2003 Ardis Technologies <roman@ardistech.com>
7 *
8 * Handle individual btree records
9 */
10
11 #include "hfsplus_fs.h"
12 #include "hfsplus_raw.h"
13
14 /* Get the length and offset of the given record in the given node */
hfsplus_brec_lenoff(hfsplus_bnode * node,u16 rec,u16 * off)15 u16 hfsplus_brec_lenoff(hfsplus_bnode *node, u16 rec, u16 *off)
16 {
17 u16 retval[2];
18 u16 dataoff;
19
20 dataoff = node->tree->node_size - (rec + 2) * 2;
21 hfsplus_bnode_readbytes(node, retval, dataoff, 4);
22 *off = be16_to_cpu(retval[1]);
23 return be16_to_cpu(retval[0]) - *off;
24 }
25
26 /* Get the length of the key from a keyed record */
hfsplus_brec_keylen(hfsplus_bnode * node,u16 rec)27 u16 hfsplus_brec_keylen(hfsplus_bnode *node, u16 rec)
28 {
29 u16 klsz, retval, recoff;
30 unsigned char buf[2];
31
32 if ((node->kind != HFSPLUS_NODE_NDX)&&(node->kind != HFSPLUS_NODE_LEAF))
33 return 0;
34
35 klsz = (node->tree->attributes & HFSPLUS_TREE_BIGKEYS) ? 2 : 1;
36 if ((node->kind == HFSPLUS_NODE_NDX) &&
37 !(node->tree->attributes & HFSPLUS_TREE_VAR_NDXKEY_SIZE)) {
38 retval = node->tree->max_key_len;
39 } else {
40 recoff = hfsplus_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2);
41 if (!recoff)
42 return 0;
43 hfsplus_bnode_readbytes(node, buf, recoff, klsz);
44 if (klsz == 1)
45 retval = buf[0];
46 else
47 retval = be16_to_cpu(*(u16 *)buf);
48 }
49 return (retval + klsz + 1) & 0xFFFE;
50 }
51