bsd/hfs/hfscommon/Catalog/Catalog.c

   1 /*
   2  * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22
  23 #pragma segment Catalog
  24
  25 #include <sys/param.h>
  26 #include <sys/utfconv.h>
  27
  28 #include        "../../hfs_endian.h"
  29
  30 #include        "../headers/FileMgrInternal.h"
  31 #include        "../headers/BTreesInternal.h"
  32 #include        "../headers/CatalogPrivate.h"
  33 #include        "../headers/HFSUnicodeWrappers.h"
  34
  35
  36 // External routines
  37
  38 extern SInt32 FastRelString( ConstStr255Param str1, ConstStr255Param str2 );
  39
  40
  41 //_________________________________________________________________________________
  42 //      Exported Routines
  43 //
  44 //              CompareCatalogKeys  -  Compares two catalog keys.
  45 //
  46 //_________________________________________________________________________________
  47
  48
  49
  50 UInt32
  51 GetDirEntrySize(BTreeIterator *bip, ExtendedVCB * vol)
  52 {
  53         CatalogKey *    ckp;
  54         CatalogName *   cnp;
  55         ByteCount       utf8chars;
  56         UInt8           name[kdirentMaxNameBytes + 1];
  57         OSErr           result;
  58
  59         ckp = (CatalogKey*) &bip->key;
  60
  61         if (vol->vcbSigWord == kHFSPlusSigWord) {
  62                 cnp = (CatalogName*) &ckp->hfsPlus.nodeName;
  63                 utf8chars = utf8_encodelen(cnp->ustr.unicode,
  64                                     cnp->ustr.length * sizeof(UniChar), ':', 0);
  65                 if (utf8chars > kdirentMaxNameBytes)
  66                         utf8chars = kdirentMaxNameBytes;
  67         } else { /* hfs */
  68                 cnp = (CatalogName*) ckp->hfs.nodeName;
  69                 result = hfs_to_utf8(vol, cnp->pstr, kdirentMaxNameBytes + 1,
  70                                 &utf8chars, name);
  71                 if (result) {
  72                         /*
  73                          * When an HFS name cannot be encoded with the current
  74                          * volume encoding we use MacRoman as a fallback.
  75                          */
  76                         result = mac_roman_to_utf8(cnp->pstr, MAXHFSVNODELEN + 1,
  77                                                                    &utf8chars, name);
  78                 }
  79         }
  80
  81         return DIRENTRY_SIZE(utf8chars);
  82 }
  83 /*
  84  * NOTE  NOTE  NOTE  NOTE  NOTE  NOTE  NOTE  NOTE  NOTE  NOTE  NOTE  NOTE
  85  *
  86  * This is assuming maxinum size of a name is 255 (kdirentMaxNameBytes), which is incorrect.
  87  * Any caller of this has to make sure names > 255 are mangled!!!!!!!!
  88  */
  89
  90 OSErr
  91 PositionIterator(CatalogIterator *cip, UInt32 offset, BTreeIterator *bip, UInt16 *op)
  92 {
  93 #define CAT_START_OFFSET (2 * sizeof(struct hfsdotentry))
  94         ExtendedVCB *   vol;
  95         FCB *           fcb;
  96         OSErr           result = 0;
  97
  98         /* are we past the end of a directory? */
  99         if (cip->folderID != cip->parentID)
 100                 return(cmNotFound);
 101
 102         vol = cip->volume;
 103         fcb = GetFileControlBlock(vol->catalogRefNum);
 104
 105         /* make a btree iterator from catalog iterator */
 106         UpdateBtreeIterator(cip, bip);
 107
 108         if (cip->currentOffset == offset) {
 109                 *op = kBTreeCurrentRecord;
 110
 111         } else if (cip->nextOffset == offset) {
 112                 *op = kBTreeNextRecord;
 113
 114         } else { /* start from beginning */
 115                 *op = kBTreeNextRecord;
 116
 117                 /* Position iterator at the folder's thread record */
 118                 result = BTSearchRecord(fcb, bip, NULL, NULL, bip);
 119                 if (result)
 120                         goto exit;
 121
 122                 /* find offset (note: n^2 / 2) */
 123                 if (offset > CAT_START_OFFSET) {
 124                         HFSCatalogNodeID  pid, *idp;
 125                         UInt32  curOffset, nextOffset;
 126
 127                         /* get first record (ie offset 24) */
 128                         result = BTIterateRecord( fcb, kBTreeNextRecord, bip, NULL, NULL );
 129                         if (result)
 130                                 goto exit;
 131
 132                         if (vol->vcbSigWord == kHFSPlusSigWord)
 133                                 idp = &((CatalogKey*) &bip->key)->hfsPlus.parentID;
 134                         else
 135                                 idp = &((CatalogKey*) &bip->key)->hfs.parentID;
 136
 137                         pid = *idp;
 138
 139                         curOffset = CAT_START_OFFSET;
 140                         nextOffset = CAT_START_OFFSET + GetDirEntrySize(bip, vol);
 141
 142                         while (nextOffset < offset) {
 143                                 result = BTIterateRecord( fcb, kBTreeNextRecord, bip, NULL, NULL );
 144                                 if (result)
 145                                         goto exit;
 146
 147                                 /* check for parent change */
 148                                 if (pid != *idp) {
 149                                         result = cmNotFound;    /* offset past end of directory */
 150                                         goto exit;
 151                                 }
 152
 153                                 curOffset = nextOffset;
 154                                 nextOffset += GetDirEntrySize(bip, vol);
 155                         };
 156
 157                         if (nextOffset != offset) {
 158                                 result = cmNotFound;
 159                                 goto exit;
 160                         }
 161
 162                         UpdateCatalogIterator(bip, cip);
 163                         cip->currentOffset = curOffset;
 164                         cip->nextOffset = nextOffset;
 165                 }
 166         }
 167
 168 exit:
 169         if (result == btNotFound)
 170                 result = cmNotFound;
 171
 172         return result;
 173
 174 } /* end PositionIterator */
 175
 176
 177 //_________________________________________________________________________________
 178 //      Routine:        CompareCatalogKeys
 179 //
 180 //      Function:       Compares two catalog keys (a search key and a trial key).
 181 //
 182 //      Result:         +n  search key > trial key
 183 //                               0  search key = trial key
 184 //                              -n  search key < trial key
 185 //_________________________________________________________________________________
 186
 187 SInt32
 188 CompareCatalogKeys(HFSCatalogKey *searchKey, HFSCatalogKey *trialKey)
 189 {
 190         HFSCatalogNodeID        searchParentID, trialParentID;
 191         SInt32  result;
 192
 193         searchParentID = searchKey->parentID;
 194         trialParentID = trialKey->parentID;
 195
 196         if ( searchParentID > trialParentID )   // parent dirID is unsigned
 197                 result = 1;
 198         else if ( searchParentID < trialParentID )
 199                 result = -1;
 200         else // parent dirID's are equal, compare names
 201                 result = FastRelString(searchKey->nodeName, trialKey->nodeName);
 202
 203         return result;
 204 }
 205
 206
 207 //_________________________________________________________________________________
 208 //      Routine:        CompareExtendedCatalogKeys
 209 //
 210 //      Function:       Compares two large catalog keys (a search key and a trial key).
 211 //
 212 //      Result:         +n  search key > trial key
 213 //                               0  search key = trial key
 214 //                              -n  search key < trial key
 215 //_________________________________________________________________________________
 216
 217 SInt32
 218 CompareExtendedCatalogKeys(HFSPlusCatalogKey *searchKey, HFSPlusCatalogKey *trialKey)
 219 {
 220         SInt32                  result;
 221         HFSCatalogNodeID        searchParentID, trialParentID;
 222
 223         searchParentID = searchKey->parentID;
 224         trialParentID = trialKey->parentID;
 225
 226         if ( searchParentID > trialParentID )   // parent node IDs are unsigned
 227         {
 228                 result = 1;
 229         }
 230         else if ( searchParentID < trialParentID )
 231         {
 232                 result = -1;
 233         }
 234         else // parent node ID's are equal, compare names
 235         {
 236                 if ( searchKey->nodeName.length == 0 || trialKey->nodeName.length == 0 )
 237                         result = searchKey->nodeName.length - trialKey->nodeName.length;
 238                 else
 239                         result = FastUnicodeCompare(&searchKey->nodeName.unicode[0], searchKey->nodeName.length,
 240                                                                                 &trialKey->nodeName.unicode[0], trialKey->nodeName.length);
 241         }
 242
 243         return result;
 244 }
 245