| 1 |
dpavlin |
1 |
/* |
| 2 |
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* libhfs - library for reading and writing Macintosh HFS volumes |
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* Copyright (C) 1996-1998 Robert Leslie |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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* |
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*/ |
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# ifdef HAVE_CONFIG_H |
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# include "config.h" |
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# endif |
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# include <stdlib.h> |
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# include <string.h> |
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# include <errno.h> |
| 28 |
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# include "libhfs.h" |
| 30 |
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# include "btree.h" |
| 31 |
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# include "data.h" |
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# include "file.h" |
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# include "block.h" |
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# include "node.h" |
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/* |
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* NAME: btree->getnode() |
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* DESCRIPTION: retrieve a numbered node from a B*-tree file |
| 39 |
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*/ |
| 40 |
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int bt_getnode(node *np, btree *bt, unsigned long nnum) |
| 41 |
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{ |
| 42 |
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block *bp = &np->data; |
| 43 |
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const byte *ptr; |
| 44 |
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int i; |
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np->bt = bt; |
| 47 |
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np->nnum = nnum; |
| 48 |
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# if 0 |
| 50 |
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fprintf(stderr, "BTREE: GET vol \"%s\" btree \"%s\" node %lu\n", |
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bt->f.vol->mdb.drVN, bt->f.name, np->nnum); |
| 52 |
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# endif |
| 53 |
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| 54 |
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/* verify the node exists and is marked as in-use */ |
| 55 |
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| 56 |
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if (nnum > 0 && nnum >= bt->hdr.bthNNodes) |
| 57 |
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ERROR(EIO, "read nonexistent b*-tree node"); |
| 58 |
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else if (bt->map && ! BMTST(bt->map, nnum)) |
| 59 |
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ERROR(EIO, "read unallocated b*-tree node"); |
| 60 |
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| 61 |
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if (f_getblock(&bt->f, nnum, bp) == -1) |
| 62 |
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goto fail; |
| 63 |
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ptr = *bp; |
| 65 |
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| 66 |
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d_fetchul(&ptr, &np->nd.ndFLink); |
| 67 |
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d_fetchul(&ptr, &np->nd.ndBLink); |
| 68 |
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d_fetchsb(&ptr, &np->nd.ndType); |
| 69 |
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d_fetchsb(&ptr, &np->nd.ndNHeight); |
| 70 |
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d_fetchuw(&ptr, &np->nd.ndNRecs); |
| 71 |
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d_fetchsw(&ptr, &np->nd.ndResv2); |
| 72 |
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| 73 |
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if (np->nd.ndNRecs > HFS_MAX_NRECS) |
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ERROR(EIO, "too many b*-tree node records"); |
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i = np->nd.ndNRecs + 1; |
| 77 |
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ptr = *bp + HFS_BLOCKSZ - (2 * i); |
| 79 |
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| 80 |
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while (i--) |
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d_fetchuw(&ptr, &np->roff[i]); |
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return 0; |
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fail: |
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return -1; |
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} |
| 88 |
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| 89 |
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/* |
| 90 |
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* NAME: btree->putnode() |
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* DESCRIPTION: store a numbered node into a B*-tree file |
| 92 |
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*/ |
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int bt_putnode(node *np) |
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{ |
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btree *bt = np->bt; |
| 96 |
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block *bp = &np->data; |
| 97 |
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byte *ptr; |
| 98 |
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int i; |
| 99 |
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| 100 |
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# if 0 |
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fprintf(stderr, "BTREE: PUT vol \"%s\" btree \"%s\" node %lu\n", |
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bt->f.vol->mdb.drVN, bt->f.name, np->nnum); |
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# endif |
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| 105 |
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/* verify the node exists and is marked as in-use */ |
| 106 |
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| 107 |
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if (np->nnum > 0 && np->nnum >= bt->hdr.bthNNodes) |
| 108 |
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ERROR(EIO, "write nonexistent b*-tree node"); |
| 109 |
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else if (bt->map && ! BMTST(bt->map, np->nnum)) |
| 110 |
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ERROR(EIO, "write unallocated b*-tree node"); |
| 111 |
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| 112 |
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ptr = *bp; |
| 113 |
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| 114 |
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d_storeul(&ptr, np->nd.ndFLink); |
| 115 |
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d_storeul(&ptr, np->nd.ndBLink); |
| 116 |
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d_storesb(&ptr, np->nd.ndType); |
| 117 |
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d_storesb(&ptr, np->nd.ndNHeight); |
| 118 |
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d_storeuw(&ptr, np->nd.ndNRecs); |
| 119 |
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d_storesw(&ptr, np->nd.ndResv2); |
| 120 |
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| 121 |
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if (np->nd.ndNRecs > HFS_MAX_NRECS) |
| 122 |
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ERROR(EIO, "too many b*-tree node records"); |
| 123 |
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| 124 |
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i = np->nd.ndNRecs + 1; |
| 125 |
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| 126 |
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ptr = *bp + HFS_BLOCKSZ - (2 * i); |
| 127 |
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| 128 |
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while (i--) |
| 129 |
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d_storeuw(&ptr, np->roff[i]); |
| 130 |
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| 131 |
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return f_putblock(&bt->f, np->nnum, bp); |
| 132 |
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| 133 |
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fail: |
| 134 |
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return -1; |
| 135 |
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} |
| 136 |
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| 137 |
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/* |
| 138 |
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* NAME: btree->readhdr() |
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* DESCRIPTION: read the header node of a B*-tree |
| 140 |
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*/ |
| 141 |
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int bt_readhdr(btree *bt) |
| 142 |
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{ |
| 143 |
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const byte *ptr; |
| 144 |
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byte *map = 0; |
| 145 |
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int i; |
| 146 |
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unsigned long nnum; |
| 147 |
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| 148 |
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if (bt_getnode(&bt->hdrnd, bt, 0) == -1) |
| 149 |
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goto fail; |
| 150 |
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| 151 |
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if (bt->hdrnd.nd.ndType != ndHdrNode || |
| 152 |
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bt->hdrnd.nd.ndNRecs != 3 || |
| 153 |
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bt->hdrnd.roff[0] != 0x00e || |
| 154 |
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bt->hdrnd.roff[1] != 0x078 || |
| 155 |
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bt->hdrnd.roff[2] != 0x0f8 || |
| 156 |
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bt->hdrnd.roff[3] != 0x1f8) |
| 157 |
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ERROR(EIO, "malformed b*-tree header node"); |
| 158 |
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| 159 |
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/* read header record */ |
| 160 |
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| 161 |
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ptr = HFS_NODEREC(bt->hdrnd, 0); |
| 162 |
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| 163 |
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d_fetchuw(&ptr, &bt->hdr.bthDepth); |
| 164 |
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d_fetchul(&ptr, &bt->hdr.bthRoot); |
| 165 |
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d_fetchul(&ptr, &bt->hdr.bthNRecs); |
| 166 |
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d_fetchul(&ptr, &bt->hdr.bthFNode); |
| 167 |
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d_fetchul(&ptr, &bt->hdr.bthLNode); |
| 168 |
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d_fetchuw(&ptr, &bt->hdr.bthNodeSize); |
| 169 |
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d_fetchuw(&ptr, &bt->hdr.bthKeyLen); |
| 170 |
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d_fetchul(&ptr, &bt->hdr.bthNNodes); |
| 171 |
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d_fetchul(&ptr, &bt->hdr.bthFree); |
| 172 |
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| 173 |
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for (i = 0; i < 76; ++i) |
| 174 |
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d_fetchsb(&ptr, &bt->hdr.bthResv[i]); |
| 175 |
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| 176 |
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if (bt->hdr.bthNodeSize != HFS_BLOCKSZ) |
| 177 |
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ERROR(EINVAL, "unsupported b*-tree node size"); |
| 178 |
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| 179 |
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/* read map record; construct btree bitmap */ |
| 180 |
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/* don't set bt->map until we're done, since getnode() checks it */ |
| 181 |
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| 182 |
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map = ALLOC(byte, HFS_MAP1SZ); |
| 183 |
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if (map == 0) |
| 184 |
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ERROR(ENOMEM, 0); |
| 185 |
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| 186 |
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memcpy(map, HFS_NODEREC(bt->hdrnd, 2), HFS_MAP1SZ); |
| 187 |
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bt->mapsz = HFS_MAP1SZ; |
| 188 |
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| 189 |
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/* read continuation map records, if any */ |
| 190 |
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| 191 |
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nnum = bt->hdrnd.nd.ndFLink; |
| 192 |
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| 193 |
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while (nnum) |
| 194 |
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{ |
| 195 |
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node n; |
| 196 |
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byte *newmap; |
| 197 |
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|
| 198 |
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if (bt_getnode(&n, bt, nnum) == -1) |
| 199 |
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goto fail; |
| 200 |
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| 201 |
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if (n.nd.ndType != ndMapNode || |
| 202 |
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n.nd.ndNRecs != 1 || |
| 203 |
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n.roff[0] != 0x00e || |
| 204 |
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n.roff[1] != 0x1fa) |
| 205 |
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ERROR(EIO, "malformed b*-tree map node"); |
| 206 |
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| 207 |
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newmap = REALLOC(map, byte, bt->mapsz + HFS_MAPXSZ); |
| 208 |
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if (newmap == 0) |
| 209 |
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ERROR(ENOMEM, 0); |
| 210 |
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| 211 |
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map = newmap; |
| 212 |
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| 213 |
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memcpy(map + bt->mapsz, HFS_NODEREC(n, 0), HFS_MAPXSZ); |
| 214 |
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bt->mapsz += HFS_MAPXSZ; |
| 215 |
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| 216 |
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nnum = n.nd.ndFLink; |
| 217 |
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} |
| 218 |
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| 219 |
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bt->map = map; |
| 220 |
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| 221 |
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return 0; |
| 222 |
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| 223 |
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fail: |
| 224 |
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FREE(map); |
| 225 |
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return -1; |
| 226 |
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} |
| 227 |
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| 228 |
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/* |
| 229 |
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* NAME: btree->writehdr() |
| 230 |
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* DESCRIPTION: write the header node of a B*-tree |
| 231 |
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*/ |
| 232 |
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int bt_writehdr(btree *bt) |
| 233 |
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{ |
| 234 |
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byte *ptr, *map; |
| 235 |
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unsigned long mapsz, nnum; |
| 236 |
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int i; |
| 237 |
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|
| 238 |
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ASSERT(bt->hdrnd.bt == bt && |
| 239 |
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bt->hdrnd.nnum == 0 && |
| 240 |
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bt->hdrnd.nd.ndType == ndHdrNode && |
| 241 |
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bt->hdrnd.nd.ndNRecs == 3); |
| 242 |
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| 243 |
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ptr = HFS_NODEREC(bt->hdrnd, 0); |
| 244 |
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| 245 |
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d_storeuw(&ptr, bt->hdr.bthDepth); |
| 246 |
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d_storeul(&ptr, bt->hdr.bthRoot); |
| 247 |
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d_storeul(&ptr, bt->hdr.bthNRecs); |
| 248 |
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d_storeul(&ptr, bt->hdr.bthFNode); |
| 249 |
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d_storeul(&ptr, bt->hdr.bthLNode); |
| 250 |
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d_storeuw(&ptr, bt->hdr.bthNodeSize); |
| 251 |
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d_storeuw(&ptr, bt->hdr.bthKeyLen); |
| 252 |
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d_storeul(&ptr, bt->hdr.bthNNodes); |
| 253 |
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d_storeul(&ptr, bt->hdr.bthFree); |
| 254 |
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|
| 255 |
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for (i = 0; i < 76; ++i) |
| 256 |
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d_storesb(&ptr, bt->hdr.bthResv[i]); |
| 257 |
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|
| 258 |
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memcpy(HFS_NODEREC(bt->hdrnd, 2), bt->map, HFS_MAP1SZ); |
| 259 |
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|
| 260 |
|
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if (bt_putnode(&bt->hdrnd) == -1) |
| 261 |
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goto fail; |
| 262 |
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| 263 |
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map = bt->map + HFS_MAP1SZ; |
| 264 |
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mapsz = bt->mapsz - HFS_MAP1SZ; |
| 265 |
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| 266 |
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nnum = bt->hdrnd.nd.ndFLink; |
| 267 |
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|
| 268 |
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while (mapsz) |
| 269 |
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{ |
| 270 |
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node n; |
| 271 |
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|
| 272 |
|
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if (nnum == 0) |
| 273 |
|
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ERROR(EIO, "truncated b*-tree map"); |
| 274 |
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|
| 275 |
|
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if (bt_getnode(&n, bt, nnum) == -1) |
| 276 |
|
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goto fail; |
| 277 |
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|
| 278 |
|
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if (n.nd.ndType != ndMapNode || |
| 279 |
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n.nd.ndNRecs != 1 || |
| 280 |
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n.roff[0] != 0x00e || |
| 281 |
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n.roff[1] != 0x1fa) |
| 282 |
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ERROR(EIO, "malformed b*-tree map node"); |
| 283 |
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|
| 284 |
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memcpy(HFS_NODEREC(n, 0), map, HFS_MAPXSZ); |
| 285 |
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|
| 286 |
|
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if (bt_putnode(&n) == -1) |
| 287 |
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goto fail; |
| 288 |
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|
| 289 |
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map += HFS_MAPXSZ; |
| 290 |
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mapsz -= HFS_MAPXSZ; |
| 291 |
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|
| 292 |
|
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nnum = n.nd.ndFLink; |
| 293 |
|
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} |
| 294 |
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|
| 295 |
|
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bt->flags &= ~HFS_BT_UPDATE_HDR; |
| 296 |
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|
| 297 |
|
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return 0; |
| 298 |
|
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|
| 299 |
|
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fail: |
| 300 |
|
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return -1; |
| 301 |
|
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} |
| 302 |
|
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|
| 303 |
|
|
/* High-Level B*-Tree Routines ============================================= */ |
| 304 |
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|
| 305 |
|
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/* |
| 306 |
|
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* NAME: btree->space() |
| 307 |
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* DESCRIPTION: assert space for new records, or extend the file |
| 308 |
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*/ |
| 309 |
|
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int bt_space(btree *bt, unsigned int nrecs) |
| 310 |
|
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{ |
| 311 |
|
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unsigned int nnodes; |
| 312 |
|
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long space; |
| 313 |
|
|
|
| 314 |
|
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nnodes = nrecs * (bt->hdr.bthDepth + 1); |
| 315 |
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|
| 316 |
|
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if (nnodes <= bt->hdr.bthFree) |
| 317 |
|
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goto done; |
| 318 |
|
|
|
| 319 |
|
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/* make sure the extents tree has room too */ |
| 320 |
|
|
|
| 321 |
|
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if (bt != &bt->f.vol->ext) |
| 322 |
|
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{ |
| 323 |
|
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if (bt_space(&bt->f.vol->ext, 1) == -1) |
| 324 |
|
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goto fail; |
| 325 |
|
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} |
| 326 |
|
|
|
| 327 |
|
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space = f_alloc(&bt->f); |
| 328 |
|
|
if (space == -1) |
| 329 |
|
|
goto fail; |
| 330 |
|
|
|
| 331 |
|
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nnodes = space * (bt->f.vol->mdb.drAlBlkSiz / bt->hdr.bthNodeSize); |
| 332 |
|
|
|
| 333 |
|
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bt->hdr.bthNNodes += nnodes; |
| 334 |
|
|
bt->hdr.bthFree += nnodes; |
| 335 |
|
|
|
| 336 |
|
|
bt->flags |= HFS_BT_UPDATE_HDR; |
| 337 |
|
|
|
| 338 |
|
|
bt->f.vol->flags |= HFS_VOL_UPDATE_ALTMDB; |
| 339 |
|
|
|
| 340 |
|
|
while (bt->hdr.bthNNodes > bt->mapsz * 8) |
| 341 |
|
|
{ |
| 342 |
|
|
byte *newmap; |
| 343 |
|
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node mapnd; |
| 344 |
|
|
|
| 345 |
|
|
/* extend tree map */ |
| 346 |
|
|
|
| 347 |
|
|
newmap = REALLOC(bt->map, byte, bt->mapsz + HFS_MAPXSZ); |
| 348 |
|
|
if (newmap == 0) |
| 349 |
|
|
ERROR(ENOMEM, 0); |
| 350 |
|
|
|
| 351 |
|
|
memset(newmap + bt->mapsz, 0, HFS_MAPXSZ); |
| 352 |
|
|
|
| 353 |
|
|
bt->map = newmap; |
| 354 |
|
|
bt->mapsz += HFS_MAPXSZ; |
| 355 |
|
|
|
| 356 |
|
|
n_init(&mapnd, bt, ndMapNode, 0); |
| 357 |
|
|
if (n_new(&mapnd) == -1) |
| 358 |
|
|
goto fail; |
| 359 |
|
|
|
| 360 |
|
|
mapnd.nd.ndNRecs = 1; |
| 361 |
|
|
mapnd.roff[1] = 0x1fa; |
| 362 |
|
|
|
| 363 |
|
|
/* link the new map node */ |
| 364 |
|
|
|
| 365 |
|
|
if (bt->hdrnd.nd.ndFLink == 0) |
| 366 |
|
|
{ |
| 367 |
|
|
bt->hdrnd.nd.ndFLink = mapnd.nnum; |
| 368 |
|
|
mapnd.nd.ndBLink = 0; |
| 369 |
|
|
} |
| 370 |
|
|
else |
| 371 |
|
|
{ |
| 372 |
|
|
node n; |
| 373 |
|
|
unsigned long nnum; |
| 374 |
|
|
|
| 375 |
|
|
nnum = bt->hdrnd.nd.ndFLink; |
| 376 |
|
|
|
| 377 |
|
|
while (1) |
| 378 |
|
|
{ |
| 379 |
|
|
if (bt_getnode(&n, bt, nnum) == -1) |
| 380 |
|
|
goto fail; |
| 381 |
|
|
|
| 382 |
|
|
if (n.nd.ndFLink == 0) |
| 383 |
|
|
break; |
| 384 |
|
|
|
| 385 |
|
|
nnum = n.nd.ndFLink; |
| 386 |
|
|
} |
| 387 |
|
|
|
| 388 |
|
|
n.nd.ndFLink = mapnd.nnum; |
| 389 |
|
|
mapnd.nd.ndBLink = n.nnum; |
| 390 |
|
|
|
| 391 |
|
|
if (bt_putnode(&n) == -1) |
| 392 |
|
|
goto fail; |
| 393 |
|
|
} |
| 394 |
|
|
|
| 395 |
|
|
if (bt_putnode(&mapnd) == -1) |
| 396 |
|
|
goto fail; |
| 397 |
|
|
} |
| 398 |
|
|
|
| 399 |
|
|
done: |
| 400 |
|
|
return 0; |
| 401 |
|
|
|
| 402 |
|
|
fail: |
| 403 |
|
|
return -1; |
| 404 |
|
|
} |
| 405 |
|
|
|
| 406 |
|
|
/* |
| 407 |
|
|
* NAME: insertx() |
| 408 |
|
|
* DESCRIPTION: recursively locate a node and insert a record |
| 409 |
|
|
*/ |
| 410 |
|
|
static |
| 411 |
|
|
int insertx(node *np, byte *record, unsigned int *reclen) |
| 412 |
|
|
{ |
| 413 |
|
|
node child; |
| 414 |
|
|
byte *rec; |
| 415 |
|
|
int result = 0; |
| 416 |
|
|
|
| 417 |
|
|
if (n_search(np, record)) |
| 418 |
|
|
ERROR(EIO, "b*-tree record already exists"); |
| 419 |
|
|
|
| 420 |
|
|
switch (np->nd.ndType) |
| 421 |
|
|
{ |
| 422 |
|
|
case ndIndxNode: |
| 423 |
|
|
if (np->rnum == -1) |
| 424 |
|
|
rec = HFS_NODEREC(*np, 0); |
| 425 |
|
|
else |
| 426 |
|
|
rec = HFS_NODEREC(*np, np->rnum); |
| 427 |
|
|
|
| 428 |
|
|
if (bt_getnode(&child, np->bt, d_getul(HFS_RECDATA(rec))) == -1 || |
| 429 |
|
|
insertx(&child, record, reclen) == -1) |
| 430 |
|
|
goto fail; |
| 431 |
|
|
|
| 432 |
|
|
if (np->rnum == -1) |
| 433 |
|
|
{ |
| 434 |
|
|
n_index(&child, rec, 0); |
| 435 |
|
|
if (*reclen == 0) |
| 436 |
|
|
{ |
| 437 |
|
|
result = bt_putnode(np); |
| 438 |
|
|
goto done; |
| 439 |
|
|
} |
| 440 |
|
|
} |
| 441 |
|
|
|
| 442 |
|
|
if (*reclen) |
| 443 |
|
|
result = n_insert(np, record, reclen); |
| 444 |
|
|
|
| 445 |
|
|
break; |
| 446 |
|
|
|
| 447 |
|
|
case ndLeafNode: |
| 448 |
|
|
result = n_insert(np, record, reclen); |
| 449 |
|
|
break; |
| 450 |
|
|
|
| 451 |
|
|
default: |
| 452 |
|
|
ERROR(EIO, "unexpected b*-tree node"); |
| 453 |
|
|
} |
| 454 |
|
|
|
| 455 |
|
|
done: |
| 456 |
|
|
return result; |
| 457 |
|
|
|
| 458 |
|
|
fail: |
| 459 |
|
|
return -1; |
| 460 |
|
|
} |
| 461 |
|
|
|
| 462 |
|
|
/* |
| 463 |
|
|
* NAME: btree->insert() |
| 464 |
|
|
* DESCRIPTION: insert a new node record into a tree |
| 465 |
|
|
*/ |
| 466 |
|
|
int bt_insert(btree *bt, const byte *record, unsigned int reclen) |
| 467 |
|
|
{ |
| 468 |
|
|
node root; |
| 469 |
|
|
byte newrec[HFS_MAX_RECLEN]; |
| 470 |
|
|
|
| 471 |
|
|
if (bt->hdr.bthRoot == 0) |
| 472 |
|
|
{ |
| 473 |
|
|
/* create root node */ |
| 474 |
|
|
|
| 475 |
|
|
n_init(&root, bt, ndLeafNode, 1); |
| 476 |
|
|
if (n_new(&root) == -1 || |
| 477 |
|
|
bt_putnode(&root) == -1) |
| 478 |
|
|
goto fail; |
| 479 |
|
|
|
| 480 |
|
|
bt->hdr.bthDepth = 1; |
| 481 |
|
|
bt->hdr.bthRoot = root.nnum; |
| 482 |
|
|
bt->hdr.bthFNode = root.nnum; |
| 483 |
|
|
bt->hdr.bthLNode = root.nnum; |
| 484 |
|
|
|
| 485 |
|
|
bt->flags |= HFS_BT_UPDATE_HDR; |
| 486 |
|
|
} |
| 487 |
|
|
else if (bt_getnode(&root, bt, bt->hdr.bthRoot) == -1) |
| 488 |
|
|
goto fail; |
| 489 |
|
|
|
| 490 |
|
|
memcpy(newrec, record, reclen); |
| 491 |
|
|
|
| 492 |
|
|
if (insertx(&root, newrec, &reclen) == -1) |
| 493 |
|
|
goto fail; |
| 494 |
|
|
|
| 495 |
|
|
if (reclen) |
| 496 |
|
|
{ |
| 497 |
|
|
byte oroot[HFS_MAX_RECLEN]; |
| 498 |
|
|
unsigned int orootlen; |
| 499 |
|
|
|
| 500 |
|
|
/* root node was split; create a new root */ |
| 501 |
|
|
|
| 502 |
|
|
n_index(&root, oroot, &orootlen); |
| 503 |
|
|
|
| 504 |
|
|
n_init(&root, bt, ndIndxNode, root.nd.ndNHeight + 1); |
| 505 |
|
|
if (n_new(&root) == -1) |
| 506 |
|
|
goto fail; |
| 507 |
|
|
|
| 508 |
|
|
++bt->hdr.bthDepth; |
| 509 |
|
|
bt->hdr.bthRoot = root.nnum; |
| 510 |
|
|
|
| 511 |
|
|
bt->flags |= HFS_BT_UPDATE_HDR; |
| 512 |
|
|
|
| 513 |
|
|
/* insert index records for new root */ |
| 514 |
|
|
|
| 515 |
|
|
n_search(&root, oroot); |
| 516 |
|
|
n_insertx(&root, oroot, orootlen); |
| 517 |
|
|
|
| 518 |
|
|
n_search(&root, newrec); |
| 519 |
|
|
n_insertx(&root, newrec, reclen); |
| 520 |
|
|
|
| 521 |
|
|
if (bt_putnode(&root) == -1) |
| 522 |
|
|
goto fail; |
| 523 |
|
|
} |
| 524 |
|
|
|
| 525 |
|
|
++bt->hdr.bthNRecs; |
| 526 |
|
|
bt->flags |= HFS_BT_UPDATE_HDR; |
| 527 |
|
|
|
| 528 |
|
|
return 0; |
| 529 |
|
|
|
| 530 |
|
|
fail: |
| 531 |
|
|
return -1; |
| 532 |
|
|
} |
| 533 |
|
|
|
| 534 |
|
|
/* |
| 535 |
|
|
* NAME: deletex() |
| 536 |
|
|
* DESCRIPTION: recursively locate a node and delete a record |
| 537 |
|
|
*/ |
| 538 |
|
|
static |
| 539 |
|
|
int deletex(node *np, const byte *key, byte *record, int *flag) |
| 540 |
|
|
{ |
| 541 |
|
|
node child; |
| 542 |
|
|
byte *rec; |
| 543 |
|
|
int found, result = 0; |
| 544 |
|
|
|
| 545 |
|
|
found = n_search(np, key); |
| 546 |
|
|
|
| 547 |
|
|
switch (np->nd.ndType) |
| 548 |
|
|
{ |
| 549 |
|
|
case ndIndxNode: |
| 550 |
|
|
if (np->rnum == -1) |
| 551 |
|
|
ERROR(EIO, "b*-tree record not found"); |
| 552 |
|
|
|
| 553 |
|
|
rec = HFS_NODEREC(*np, np->rnum); |
| 554 |
|
|
|
| 555 |
|
|
if (bt_getnode(&child, np->bt, d_getul(HFS_RECDATA(rec))) == -1 || |
| 556 |
|
|
deletex(&child, key, rec, flag) == -1) |
| 557 |
|
|
goto fail; |
| 558 |
|
|
|
| 559 |
|
|
if (*flag) |
| 560 |
|
|
{ |
| 561 |
|
|
*flag = 0; |
| 562 |
|
|
|
| 563 |
|
|
if (HFS_RECKEYLEN(rec) == 0) |
| 564 |
|
|
{ |
| 565 |
|
|
result = n_delete(np, record, flag); |
| 566 |
|
|
break; |
| 567 |
|
|
} |
| 568 |
|
|
|
| 569 |
|
|
if (np->rnum == 0) |
| 570 |
|
|
{ |
| 571 |
|
|
/* propagate index record change into parent */ |
| 572 |
|
|
|
| 573 |
|
|
n_index(np, record, 0); |
| 574 |
|
|
*flag = 1; |
| 575 |
|
|
} |
| 576 |
|
|
|
| 577 |
|
|
result = bt_putnode(np); |
| 578 |
|
|
} |
| 579 |
|
|
|
| 580 |
|
|
break; |
| 581 |
|
|
|
| 582 |
|
|
case ndLeafNode: |
| 583 |
|
|
if (found == 0) |
| 584 |
|
|
ERROR(EIO, "b*-tree record not found"); |
| 585 |
|
|
|
| 586 |
|
|
result = n_delete(np, record, flag); |
| 587 |
|
|
break; |
| 588 |
|
|
|
| 589 |
|
|
default: |
| 590 |
|
|
ERROR(EIO, "unexpected b*-tree node"); |
| 591 |
|
|
} |
| 592 |
|
|
|
| 593 |
|
|
return result; |
| 594 |
|
|
|
| 595 |
|
|
fail: |
| 596 |
|
|
return -1; |
| 597 |
|
|
} |
| 598 |
|
|
|
| 599 |
|
|
/* |
| 600 |
|
|
* NAME: btree->delete() |
| 601 |
|
|
* DESCRIPTION: remove a node record from a tree |
| 602 |
|
|
*/ |
| 603 |
|
|
int bt_delete(btree *bt, const byte *key) |
| 604 |
|
|
{ |
| 605 |
|
|
node root; |
| 606 |
|
|
byte record[HFS_MAX_RECLEN]; |
| 607 |
|
|
int flag = 0; |
| 608 |
|
|
|
| 609 |
|
|
if (bt->hdr.bthRoot == 0) |
| 610 |
|
|
ERROR(EIO, "empty b*-tree"); |
| 611 |
|
|
|
| 612 |
|
|
if (bt_getnode(&root, bt, bt->hdr.bthRoot) == -1 || |
| 613 |
|
|
deletex(&root, key, record, &flag) == -1) |
| 614 |
|
|
goto fail; |
| 615 |
|
|
|
| 616 |
|
|
if (bt->hdr.bthDepth > 1 && root.nd.ndNRecs == 1) |
| 617 |
|
|
{ |
| 618 |
|
|
const byte *rec; |
| 619 |
|
|
|
| 620 |
|
|
/* root only has one record; eliminate it and decrease the tree depth */ |
| 621 |
|
|
|
| 622 |
|
|
rec = HFS_NODEREC(root, 0); |
| 623 |
|
|
|
| 624 |
|
|
--bt->hdr.bthDepth; |
| 625 |
|
|
bt->hdr.bthRoot = d_getul(HFS_RECDATA(rec)); |
| 626 |
|
|
|
| 627 |
|
|
if (n_free(&root) == -1) |
| 628 |
|
|
goto fail; |
| 629 |
|
|
} |
| 630 |
|
|
else if (bt->hdr.bthDepth == 1 && root.nd.ndNRecs == 0) |
| 631 |
|
|
{ |
| 632 |
|
|
/* root node was deleted */ |
| 633 |
|
|
|
| 634 |
|
|
bt->hdr.bthDepth = 0; |
| 635 |
|
|
bt->hdr.bthRoot = 0; |
| 636 |
|
|
} |
| 637 |
|
|
|
| 638 |
|
|
--bt->hdr.bthNRecs; |
| 639 |
|
|
bt->flags |= HFS_BT_UPDATE_HDR; |
| 640 |
|
|
|
| 641 |
|
|
return 0; |
| 642 |
|
|
|
| 643 |
|
|
fail: |
| 644 |
|
|
return -1; |
| 645 |
|
|
} |
| 646 |
|
|
|
| 647 |
|
|
/* |
| 648 |
|
|
* NAME: btree->search() |
| 649 |
|
|
* DESCRIPTION: locate a data record given a search key |
| 650 |
|
|
*/ |
| 651 |
|
|
int bt_search(btree *bt, const byte *key, node *np) |
| 652 |
|
|
{ |
| 653 |
|
|
int found = 0; |
| 654 |
|
|
unsigned long nnum; |
| 655 |
|
|
|
| 656 |
|
|
nnum = bt->hdr.bthRoot; |
| 657 |
|
|
|
| 658 |
|
|
if (nnum == 0) |
| 659 |
|
|
ERROR(ENOENT, 0); |
| 660 |
|
|
|
| 661 |
|
|
while (1) |
| 662 |
|
|
{ |
| 663 |
|
|
const byte *rec; |
| 664 |
|
|
|
| 665 |
|
|
if (bt_getnode(np, bt, nnum) == -1) |
| 666 |
|
|
{ |
| 667 |
|
|
found = -1; |
| 668 |
|
|
goto fail; |
| 669 |
|
|
} |
| 670 |
|
|
|
| 671 |
|
|
found = n_search(np, key); |
| 672 |
|
|
|
| 673 |
|
|
switch (np->nd.ndType) |
| 674 |
|
|
{ |
| 675 |
|
|
case ndIndxNode: |
| 676 |
|
|
if (np->rnum == -1) |
| 677 |
|
|
ERROR(ENOENT, 0); |
| 678 |
|
|
|
| 679 |
|
|
rec = HFS_NODEREC(*np, np->rnum); |
| 680 |
|
|
nnum = d_getul(HFS_RECDATA(rec)); |
| 681 |
|
|
|
| 682 |
|
|
break; |
| 683 |
|
|
|
| 684 |
|
|
case ndLeafNode: |
| 685 |
|
|
if (! found) |
| 686 |
|
|
ERROR(ENOENT, 0); |
| 687 |
|
|
|
| 688 |
|
|
goto done; |
| 689 |
|
|
|
| 690 |
|
|
default: |
| 691 |
|
|
found = -1; |
| 692 |
|
|
ERROR(EIO, "unexpected b*-tree node"); |
| 693 |
|
|
} |
| 694 |
|
|
} |
| 695 |
|
|
|
| 696 |
|
|
done: |
| 697 |
|
|
fail: |
| 698 |
|
|
return found; |
| 699 |
|
|
} |
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