rom/filesys/SFS/FS/objects.h

   1 #ifndef _OBJECTS_H
   2 #define _OBJECTS_H
   3
   4 #include <exec/types.h>
   5 #include <libraries/iffparse.h>
   6 #include <utility/tagitem.h>
   7 #include "blockstructure.h"
   8 #include "nodes.h"
   9
  10 #define OBJECTCONTAINER_ID         AROS_LONG2BE(MAKE_ID('O','B','J','C'))
  11 #define HASHTABLE_ID               AROS_LONG2BE(MAKE_ID('H','T','A','B'))
  12 #define SOFTLINK_ID                AROS_LONG2BE(MAKE_ID('S','L','N','K'))
  13
  14 /* Below is the structure describing an Object.  Objects can be files or
  15    directories.  Multiple Objects can be stored in an ObjectContainer
  16    block.
  17
  18    owneruid & ownergid:  These are not used at the moment.  They have
  19    been reserved for future use.  They must be set to zero for now.
  20
  21    objectnode:  This field contains a number uniquely identifying this
  22    object.  This number can be used to find out the ObjectContainer
  23    where the Object is stored in.  It is used to refer to an Object
  24    without having to use BLCK pointers.
  25
  26    protection:  Contains the Object's protection bits.  By default this
  27    field is set to 0x0000000F, which means bits R, W, E and D are set
  28    (note that this is opposite to what is used by AmigaDOS).
  29
  30    data (files only):  Contains the BLCK number of the first data block of
  31    a file.  To find out where the rest of the data is located this BLCK
  32    number can be looked up in a special B+-Tree structure (see below).
  33
  34    size (files only):  Contains the size of a file in bytes.
  35
  36    hashtable (directories only):  A BLCK pointer.  It points to a
  37    HashTable block.
  38
  39    firstdirblock (directories only):  This BLCK pointer points to the
  40    first ObjectContainer block which belongs to this directory object.
  41    For empty directories this field is zero.
  42
  43    datemodified:  The date of the last modification of this Object.  The
  44    date is stored in seconds from 1-1-1978 (enough for storing 136 years)
  45
  46    bits:  See the defines below.  At the moment this field can be checked
  47    to see if the object is a file or directory.  A bit is reserved for
  48    links, but isn't currently used (and may or may not be used depending
  49    on how and if links are implemented).
  50
  51    name:  Directly following the main structure is the name of the object.
  52    It is zero terminated.
  53
  54    comment:  Directly following the name of the object is the comment
  55    field.  This field is zero terminated as well (even if there is no
  56    comment). */
  57
  58 struct fsObject {
  59   UWORD be_owneruid;
  60   UWORD be_ownergid;
  61   NODE  be_objectnode;
  62   ULONG be_protection;
  63
  64   union {
  65     struct {
  66       BLCK  be_data;
  67       ULONG be_size;
  68     } file;
  69
  70     struct {
  71       BLCK  be_hashtable;   /* for directories & root, 0 means no hashblock */
  72       BLCK  be_firstdirblock;
  73     } dir;
  74   } object;
  75
  76   ULONG be_datemodified;
  77   UBYTE bits;
  78
  79   UBYTE name[0];
  80   UBYTE comment[0];
  81 };
  82
  83 #define OTYPE_HIDDEN      (1)
  84 #define OTYPE_UNDELETABLE (2)
  85 #define OTYPE_QUICKDIR    (4)
  86 #define OTYPE_RINGLIST    (8)     /* Already partially implemented, but
  87                                      doesn't seem to be very useful. */
  88 #define OTYPE_HARDLINK    (32)
  89 #define OTYPE_LINK        (64)
  90 #define OTYPE_DIR         (128)
  91
  92 /* hashtable can be zero as well.  If it is zero then the directory
  93    does not have a hashblock.  This means looking up a file by name
  94    will be slower since the system will fall-back to scanning the
  95    complete directory.  However, file creation speed will be higher
  96    (which includes moving a file to this directory, which happens
  97    often with the Recycled directory for example). */
  98
  99 /* for all types of objects:
 100    -------------------------
 101
 102    HIDDEN: The Object won't be returned by EXAMINE_NEXT or
 103            EXAMINE_ALL.
 104
 105    UNDELETABLE: ACTION_DELETE_OBJECT will return an error for Objects
 106                 protected by this bit.
 107
 108    for directories only:
 109    ---------------------
 110
 111    QUICKDIR: Entries are added at the start of the directory without
 112              checking if there is room anywhere else in the dir. */
 113
 114 /* SFS supports Soft links.  When OTYPE_LINK is set and OTYPE_HARDLINK is
 115    clear then the entry is a soft link.  The path of the soft link isn't
 116    stored with the directory entry, but instead is stored as the file
 117    data. */
 118
 119
 120
 121 /* The fsObjectContainer structure is used to hold various Objects which
 122    have the same parent directory.  Objects always start at 2-byte
 123    boundaries, which means sometimes a padding byte is inserted between
 124    2 fsObject structures.  The next & previous fields link all
 125    ObjectContainers in a doubly linked list.
 126
 127    parent:  The node-number of the parent Object.  The node number can be
 128    used to lookup the BLCK number of the block where the parent Object is
 129    located.
 130
 131    next:  The next ObjectContainer belonging to this directory or zero if
 132    it is the last in the chain.
 133
 134    previous:  The previous ObjectContainer belonging to this directory or
 135    zero if it is the first ObjectContainer.
 136
 137    object:  A variable number of fsObject structures, depending on their
 138    sizes and on the size of the block.  The next object structure can be
 139    found by creating a pointer pointing to the name field of the current
 140    object, then skip 2 strings (name & comment) and if the address is odd,
 141    adding 1. */
 142
 143 struct fsObjectContainer {
 144   struct fsBlockHeader bheader;
 145
 146   NODE be_parent;
 147   BLCK be_next;
 148   BLCK be_previous;   /* 0 for the first block in the directory chain */
 149
 150   struct fsObject object[0];
 151 };
 152
 153
 154
 155 /* fsHashTable is the structure of a HashTable block.  It functions much
 156    like the HashTable found in FFS, except that it is stored in a seperate
 157    block.  This block contains a number of hash-chains (about 120 for a
 158    512 byte block).  Each hash-chain is a chain of Nodes.  Each Node
 159    contains a BLCK pointer to an Object and the node number of the next
 160    entry in the hash-chain.
 161
 162    parent:  The node-number of the parent object.
 163
 164    hashentry:  The node-number of the first entry of a specific
 165    hash-chain. */
 166
 167 struct fsHashTable {
 168   struct fsBlockHeader bheader;
 169
 170   NODE be_parent;
 171
 172   NODE be_hashentry[0];
 173 };
 174
 175
 176
 177 struct fsSoftLink {
 178   struct fsBlockHeader bheader;
 179
 180   NODE be_parent;
 181   BLCK be_next;
 182   BLCK be_previous;
 183
 184   UBYTE string[0];
 185 };
 186
 187
 188
 189 struct fsObjectNode {
 190   struct fsNode node;
 191   NODE  be_next;
 192   UWORD be_hash16;
 193 } __attribute__((packed));
 194
 195
 196
 197 /* Tags used by createobjecttags: */
 198
 199 #define COBASE            (TAG_USER)
 200
 201 #define CO_OBJECTNODE     (COBASE+1)   /* The ObjectNode of the object.  Defaults to creating a
 202                                           new ObjectNode.  If an ObjectNode is passed then its
 203                                           data field will be set to point to the block which
 204                                           contains the new Object. */
 205
 206 #define CO_PROTECTION     (COBASE+2)   /* The protection bits of the object.  Defaults to
 207                                           FIBF_READ|FIBF_WRITE|FIBF_EXECUTE|FIBF_DELETE. */
 208
 209 #define CO_DATEMODIFIED   (COBASE+3)   /* The modification data of the object.  Defaults to
 210                                           current date. */
 211
 212 #define CO_OWNER          (COBASE+4)   /* The owneruid and ownergid of the object.  Default to
 213                                           zero. */
 214
 215 #define CO_COMMENT        (COBASE+5)   /* Comment of the new object (79 chars max).  Defaults to
 216                                           no comment. */
 217
 218 #define CO_BITS           (COBASE+6)   /* See bits in fsObject. */
 219
 220 #define CO_HASHOBJECT     (COBASE+7)   /* If not FALSE, then the new Object will be hashed
 221                                           automatically.  Defaults to FALSE. */
 222
 223 #define CO_UPDATEPARENT   (COBASE+8)   /* If not FALSE, then the new Object's Parent's archive
 224                                           bit will be cleared and its modification date will be
 225                                           updated.  Defaults to FALSE. */
 226
 227 #define CO_ALLOWDUPLICATES (COBASE+9)  /* If not FALSE, then createobjecttags() won't check to
 228                                           see if an object already exists.  Defaults to FALSE. */
 229
 230   /* File specific tags: */
 231
 232 #define CO_SIZE           (COBASE+20)   /* The size of the file.  Defaults to zero.  Ignored if
 233                                           CO_BITS indicates its a directory. */
 234
 235 #define CO_DATA           (COBASE+21)   /* The first block of the file.  Defaults to zero.
 236                                           Ignored if CO_BITS indicates its a directory. */
 237
 238   /* Directory specific tags: */
 239
 240 #define CO_FIRSTDIRBLOCK  (COBASE+30)  /* The first ObjectContainer of the directory.  Defaults
 241                                           to zero.  Ignored if CO_BITS indicates its a file. */
 242
 243 #define CO_HASHBLOCK      (COBASE+31)  /* The Hashblock of the directory.  Defaults to creating
 244                                           a new Hashblock.  Ignored if CO_BITS indicates its a
 245                                           file. */
 246
 247   /* Softlink specific tags: */
 248
 249 #define CO_SOFTLINK       (COBASE+40)  /* The Softlink string.  No default!  Ignored if CO_BITS
 250                                           indicates its not a softlink. */
 251
 252 #endif // _OBJECTS_H