rom/filesys/AmberRAM/filesystem.c

   1 /*
   2
   3 File: filesystem.c
   4 Author: Neil Cafferkey
   5 Copyright (C) 2001-2008 Neil Cafferkey
   6
   7 This file is free software; you can redistribute it and/or modify it
   8 under the terms of the GNU Lesser General Public License as
   9 published by the Free Software Foundation; either version 2.1 of the
  10 License, or (at your option) any later version.
  11
  12 This file is distributed in the hope that it will be useful, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15 Lesser General Public License for more details.
  16
  17 You should have received a copy of the GNU Lesser General Public
  18 License along with this file; if not, write to the Free Software
  19 Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  20 MA 02111-1307, USA.
  21
  22 */
  23
  24
  25 #include "handler_protos.h"
  26
  27
  28 static struct Block *AddDataBlock(struct Handler *handler,
  29    struct Object *file, UPINT length);
  30 static VOID FreeDataBlock(struct Handler *handler, struct Object *file,
  31    struct Block *block);
  32 static struct Block *GetLastBlock(struct Object *file);
  33
  34
  35
  36 /****i* ram.handler/DeleteHandler ******************************************
  37 *
  38 *   NAME
  39 *       DeleteHandler --
  40 *
  41 *   SYNOPSIS
  42 *       DeleteHandler(handler)
  43 *
  44 *       VOID DeleteHandler(struct Handler *);
  45 *
  46 *   FUNCTION
  47 *
  48 *   INPUTS
  49 *
  50 *   RESULT
  51 *
  52 *   EXAMPLE
  53 *
  54 *   NOTES
  55 *
  56 *   BUGS
  57 *
  58 *   SEE ALSO
  59 *
  60 ****************************************************************************
  61 *
  62 */
  63
  64 VOID DeleteHandler(struct Handler *handler)
  65 {
  66    struct DosList *volume;
  67    struct Object *root_dir;
  68    struct Lock *root_lock;
  69    APTR base;
  70
  71    if(handler != NULL)
  72    {
  73       root_dir = handler->root_dir;
  74
  75       if(root_dir != NULL)
  76       {
  77          root_lock = root_dir->lock;
  78          if(root_lock != NULL)
  79             CmdFreeLock(handler, root_lock);
  80          DeleteObject(handler, root_dir);
  81       }
  82
  83       volume = handler->volume;
  84       if(volume != NULL)
  85       {
  86          RemDosEntry(volume);
  87          MyFreeDosEntry(handler, volume);
  88       }
  89
  90       DeletePool(handler->public_pool);
  91       DeletePool(handler->muddy_pool);
  92       DeletePool(handler->clear_pool);
  93
  94       DeleteMsgPort(handler->notify_port);
  95
  96       /* Close libraries */
  97
  98       base = LocaleBase;
  99       if(base != NULL) {
 100         if (handler->locale)
 101              CloseLocale(handler->locale);
 102          CloseLibrary(base);
 103       }
 104
 105       base = UtilityBase;
 106       if(base != NULL)
 107          CloseLibrary(base);
 108
 109       FreeMem(handler, sizeof(struct Handler));
 110    }
 111
 112    return;
 113 }
 114
 115
 116
 117 /****i* ram.handler/CreateObject *******************************************
 118 *
 119 *   NAME
 120 *       CreateObject --
 121 *
 122 *   SYNOPSIS
 123 *       object = CreateObject(handler, name, type,
 124 *           parent)
 125 *
 126 *       struct Object *CreateObject(struct Handler *, TEXT *, BYTE,
 127 *           struct Object *);
 128 *
 129 *   FUNCTION
 130 *       Creates a new filesystem object. The existence of a duplicate object
 131 *       must be checked for beforehand.
 132 *
 133 *   INPUTS
 134 *       name - The name of the new object, without a path prefixed.
 135 *       type - The type of object to create.
 136 *       parent - The new object's parent directory, or NULL for none.
 137 *
 138 *   RESULT
 139 *       object - The newly created object, or NULL for failure.
 140 *
 141 *   EXAMPLE
 142 *
 143 *   NOTES
 144 *
 145 *   BUGS
 146 *
 147 *   SEE ALSO
 148 *
 149 ****************************************************************************
 150 *
 151 */
 152
 153 struct Object *CreateObject(struct Handler *handler, const TEXT *name,
 154    BYTE type, struct Object *parent)
 155 {
 156    struct Object *object = NULL;
 157    LONG error = 0;
 158
 159    /* Get the real parent in case it's a hard link */
 160
 161    if(parent != NULL)
 162       parent = GetRealObject(parent);
 163
 164    /* Create a new object structure */
 165
 166    object = AllocPooled(handler->clear_pool, sizeof(struct Object));
 167    if(object == NULL)
 168       error = ERROR_DISK_FULL;
 169
 170    if(error == 0)
 171    {
 172       object->block_count = MEMBLOCKS(sizeof(struct Object));
 173       handler->block_count += MEMBLOCKS(sizeof(struct Object));
 174
 175       NewList((struct List *)&object->elements);
 176       ((struct Node *)object)->ln_Pri = type;
 177       object->parent = parent;
 178       DateStamp(&object->date);
 179       NewList((struct List *)&object->notifications);
 180
 181       if(type == ST_FILE)
 182          AddTail((APTR)&object->elements, (APTR)&object->start_block);
 183
 184       if(name != NULL)
 185       {
 186          if(!SetName(handler, object, name))
 187             error = IoErr();
 188       }
 189
 190       if(parent != NULL)
 191       {
 192          AddTail((struct List *)&parent->elements, (struct Node *)object);
 193          CopyMem(&object->date, &parent->date, sizeof(struct DateStamp));
 194       }
 195    }
 196
 197    if(error == 0)
 198       MatchNotifyRequests(handler);
 199
 200    if(error != 0)
 201    {
 202       DeleteObject(handler, object);
 203       object = NULL;
 204    }
 205
 206    /* Return the new object */
 207
 208    SetIoErr(error);
 209    return object;
 210 }
 211
 212
 213
 214 /****i* ram.handler/AttemptDeleteObject ************************************
 215 *
 216 *   NAME
 217 *       AttemptDeleteObject -- Attempt to delete an object.
 218 *
 219 *   SYNOPSIS
 220 *       success = AttemptDeleteObject(handler, object)
 221 *
 222 *       BOOL AttemptDeleteObject(struct Handler *, struct Object *);
 223 *
 224 *   FUNCTION
 225 *       Attempts to delete the specified object. Note that this function
 226 *       does not check permissions.
 227 *
 228 *   INPUTS
 229 *       object - the object to be deleted, or NULL for no action.
 230 *
 231 *   RESULT
 232 *       success - success indicator.
 233 *
 234 *   EXAMPLE
 235 *
 236 *   NOTES
 237 *
 238 *   BUGS
 239 *
 240 *   SEE ALSO
 241 *
 242 ****************************************************************************
 243 *
 244 */
 245
 246 BOOL AttemptDeleteObject(struct Handler *handler, struct Object *object,
 247    BOOL notify)
 248 {
 249    LONG error = 0;
 250    BYTE object_type;
 251
 252    if(object != NULL)
 253    {
 254       /* Check for a non-empty, unlinked directory */
 255
 256       object_type = ((struct Node *)object)->ln_Pri;
 257       if(object_type == ST_USERDIR && object->hard_link.mln_Succ == NULL
 258          && !IsListEmpty((struct List *)&object->elements))
 259          error = ERROR_DIRECTORY_NOT_EMPTY;
 260
 261       /* Ensure the object either isn't in use or is only a link */
 262
 263       if(object->lock != NULL)
 264          error = ERROR_OBJECT_IN_USE;
 265
 266       /* Delete object and notify anyone who's interested */
 267
 268       if(error == 0)
 269       {
 270          if(notify)
 271             NotifyAll(handler, object, FALSE);
 272          UnmatchNotifyRequests(handler, object);
 273          AdjustExaminations(handler, object);
 274          DeleteObject(handler, object);
 275       }
 276    }
 277
 278    /* Return result */
 279
 280    SetIoErr(error);
 281    return error == 0;
 282 }
 283
 284
 285
 286 /****i* ram.handler/DeleteObject *******************************************
 287 *
 288 *   NAME
 289 *       DeleteObject --
 290 *
 291 *   SYNOPSIS
 292 *       success = DeleteObject(handler, object)
 293 *
 294 *       BOOL DeleteObject(struct Handler *, struct Object *);
 295 *
 296 *   FUNCTION
 297 *
 298 *   INPUTS
 299 *       object - the object to be deleted, or NULL for no action.
 300 *
 301 *   RESULT
 302 *       None.
 303 *
 304 *   EXAMPLE
 305 *
 306 *   NOTES
 307 *
 308 *   BUGS
 309 *
 310 *   SEE ALSO
 311 *
 312 ****************************************************************************
 313 *
 314 */
 315
 316 VOID DeleteObject(struct Handler *handler, struct Object *object)
 317 {
 318    BYTE object_type;
 319    struct Block *block;
 320    struct MinNode *node;
 321    struct Object *real_object, *master_link, *heir;
 322    PINT block_diff;
 323
 324    if(object != NULL)
 325    {
 326       object_type = ((struct Node *)object)->ln_Pri;
 327       real_object = GetRealObject(object);
 328
 329       /* Remove the object from its directory */
 330
 331       if(object->parent != NULL)
 332          Remove((struct Node *)object);
 333
 334       /* Delete a hard link */
 335
 336       if(object_type == ST_LINKFILE || object_type == ST_LINKDIR)
 337       {
 338          node = real_object->hard_link.mln_Succ;
 339          master_link = HARDLINK(node);
 340          node = node->mln_Succ;
 341          Remove((APTR)&object->hard_link);
 342          if(object == master_link)
 343          {
 344             if(node->mln_Succ != NULL)
 345             {
 346                master_link = HARDLINK(node);
 347                while((node = (APTR)RemHead((APTR)&object->elements))
 348                   != NULL)
 349                   AddTail((APTR)&master_link->elements, (APTR)node);
 350             }
 351             else
 352             {
 353                real_object->hard_link.mln_Succ = NULL;
 354                real_object->hard_link.mln_Pred = NULL;
 355             }
 356          }
 357       }
 358
 359       /* Delete a linked object */
 360
 361       else if((node = object->hard_link.mln_Succ) != NULL)
 362       {
 363          master_link = HARDLINK(node);
 364          heir = HARDLINK(RemTail((APTR)&master_link->elements));
 365
 366          /* Swap names and comments */
 367
 368          block_diff = SwapStrings((TEXT **)&((struct Node *)heir)->ln_Name,
 369             (TEXT **)&((struct Node *)object)->ln_Name);
 370          block_diff += SwapStrings(&heir->comment, &object->comment);
 371          object->block_count += block_diff;
 372          heir->block_count -= block_diff;
 373
 374          /* Put object in its new directory */
 375
 376          object->parent = heir->parent;
 377          AddTail((APTR)&object->parent->elements, (APTR)object);
 378
 379          if(heir == master_link)
 380          {
 381             real_object->hard_link.mln_Succ = NULL;
 382             real_object->hard_link.mln_Pred = NULL;
 383          }
 384
 385          /* Prepare to destroy "heir" link */
 386
 387          Remove((APTR)heir);
 388          object = heir;
 389       }
 390
 391       /* Delete an unlinked object */
 392
 393       else
 394       {
 395          /* Remove all blocks if the object is a file */
 396
 397          while((block = (APTR)RemTail((struct List *)&object->elements))
 398             != NULL)
 399          {
 400             if(block->length != 0)
 401                FreePooled(handler->muddy_pool, block,
 402                   sizeof(struct Block) + block->length);
 403          }
 404       }
 405
 406       /* Free object's memory */
 407
 408       SetString(handler, (TEXT **)&((struct Node *)object)->ln_Name, NULL);
 409       SetString(handler, &object->comment, NULL);
 410       handler->block_count -= object->block_count;
 411       FreePooled(handler->clear_pool, object, sizeof(struct Object));
 412    }
 413
 414    return;
 415 }
 416
 417
 418
 419 /****i* ram.handler/GetHardObject ******************************************
 420 *
 421 *   NAME
 422 *       GetHardObject -- Find a non-soft-link object given a lock and path.
 423 *
 424 *   SYNOPSIS
 425 *       object = GetHardObject(handler, lock, name,
 426 *           parent)
 427 *
 428 *       struct Object *GetHardObject(struct Handler *, struct Lock *, TEXT *,
 429 *           struct Object **);
 430 *
 431 *   FUNCTION
 432 *       Looks for the object corresponding to the specified lock and path
 433 *       combination. If any part of the path is a soft link, NULL is returned
 434 *       and the appropriate error code is set.
 435 *
 436 *   INPUTS
 437 *       lock - .
 438 *       name - .
 439 *       parent - parent directory will be returned here (will be NULL if
 440 *           path is invalid or contains a soft link).
 441 *
 442 *   RESULT
 443 *       object - The located object, or NULL if not found.
 444 *
 445 *   EXAMPLE
 446 *
 447 *   NOTES
 448 *
 449 *   BUGS
 450 *
 451 *   SEE ALSO
 452 *
 453 ****************************************************************************
 454 *
 455 */
 456
 457 struct Object *GetHardObject(struct Handler *handler, struct Lock *lock,
 458    const TEXT *name, struct Object **parent)
 459 {
 460    struct Object *object;
 461
 462    object = GetObject(handler, lock, name, parent, NULL);
 463    if(IoErr() == ERROR_IS_SOFT_LINK)
 464       object = NULL;
 465
 466    return object;
 467 }
 468
 469
 470 /****i* ram.handler/GetObject **********************************************
 471 *
 472 *   NAME
 473 *       GetObject -- Find an object given a lock and path.
 474 *
 475 *   SYNOPSIS
 476 *       object = GetObject(handler, lock, name,
 477 *           parent, remainder_pos)
 478 *
 479 *       struct Object *GetObject(struct Handler *, struct Lock *, TEXT *,
 480 *           struct Object **, LONG *);
 481 *
 482 *   FUNCTION
 483 *       Looks for the object corresponding to the specified lock and path
 484 *       combination. If any part of the path is a soft link, the link object
 485 *       is returned and ERROR_IS_SOFT_LINK is set. IoErr() will be zero if a
 486 *       hard object is returned.
 487 *
 488 *   INPUTS
 489 *       lock - .
 490 *       name - .
 491 *       parent - parent directory will be returned here (will be NULL if
 492 *           path is invalid or contains a soft link).
 493 *
 494 *   RESULT
 495 *       object - The located object, or NULL if not found.
 496 *
 497 *   EXAMPLE
 498 *
 499 *   NOTES
 500 *
 501 *   BUGS
 502 *
 503 *   SEE ALSO
 504 *
 505 ****************************************************************************
 506 *
 507 */
 508
 509 struct Object *GetObject(struct Handler *handler, struct Lock *lock,
 510    const TEXT *name, struct Object **parent, LONG *remainder_pos)
 511 {
 512    const TEXT *p;
 513    TEXT ch, buffer[MAX_NAME_SIZE + 1];
 514    LONG error = 0, pos = 0;
 515    struct Object *object, *old_object;
 516
 517    /* Skip device name */
 518
 519    for(ch = *(p = name); ch != ':' && ch != '\0'; ch = *(++p));
 520    if(ch == ':')
 521       pos = p - name + 1;
 522
 523    /* Get object referenced by lock */
 524
 525    lock = FIXLOCK(handler, lock);
 526    object = (APTR)((struct FileLock *)lock)->fl_Key;
 527    old_object = object->parent;
 528
 529    /* Traverse textual portion of path */
 530
 531    while(pos != -1 && error == 0)
 532    {
 533       pos = SplitName(name, '/', buffer, pos, MAX_NAME_SIZE);
 534       if(*buffer != '\0')
 535       {
 536          if(((struct Node *)object)->ln_Pri > 0)
 537          {
 538             old_object = object;
 539             object = GetRealObject(object);
 540             object = (struct Object *)
 541                FindNameNoCase(handler, (struct List *)&object->elements, buffer);
 542             if(object != NULL)
 543             {
 544                /* Check for and handle a soft link */
 545
 546                if(((struct Node *)object)->ln_Pri == ST_SOFTLINK)
 547                {
 548                   if(remainder_pos != NULL)
 549                      *remainder_pos = pos;
 550                   error = ERROR_IS_SOFT_LINK;
 551                }
 552             }
 553             else
 554                error = ERROR_OBJECT_NOT_FOUND;
 555          }
 556          else
 557          {
 558             error = ERROR_OBJECT_NOT_FOUND;
 559             object = NULL;
 560             old_object = NULL;
 561          }
 562       }
 563       else if(pos != -1)
 564       {
 565          object = object->parent;
 566          if(object == NULL)
 567             error = ERROR_OBJECT_NOT_FOUND;
 568       }
 569    }
 570
 571    /* Record the parent directory of the supplied path, if it exists */
 572
 573    if(parent != NULL)
 574    {
 575       if(pos == -1 && error != ERROR_IS_SOFT_LINK)
 576          *parent = old_object;
 577       else
 578          *parent = NULL;
 579    }
 580
 581    /* Return the located object */
 582
 583    SetIoErr(error);
 584    return object;
 585 }
 586
 587
 588
 589 /****i* ram.handler/ChangeFileSize *****************************************
 590 *
 591 *   NAME
 592 *       ChangeFileSize --
 593 *
 594 *   SYNOPSIS
 595 *       new_size = ChangeFileSize(handler, opening, offset,
 596 *          mode)
 597 *
 598 *       PINT ChangeFileSize(struct Handler *, struct Opening *, PINT,
 599 *          LONG);
 600 *
 601 *   FUNCTION
 602 *       If there is not enough space for the requested size, the file size
 603 *       will remain at its initial value and -1 will be returned.
 604 *
 605 *   INPUTS
 606 *
 607 *   RESULT
 608 *
 609 *   EXAMPLE
 610 *
 611 *   NOTES
 612 *
 613 *   BUGS
 614 *
 615 *   SEE ALSO
 616 *
 617 ****************************************************************************
 618 *
 619 */
 620
 621 PINT ChangeFileSize(struct Handler *handler, struct Opening *opening,
 622    PINT offset, LONG mode)
 623 {
 624    PINT length, new_length, remainder, end_length, full_length;
 625    UPINT diff, old_pos, block_count;
 626    struct Block *block, *end_block;
 627    struct Object *file;
 628    LONG error = 0;
 629    struct MinList *openings;
 630    struct Opening *tail;
 631
 632    /* Get origin */
 633
 634    file = opening->file;
 635
 636    if(mode == OFFSET_BEGINNING)
 637       new_length = 0;
 638    else if(mode == OFFSET_CURRENT)
 639       new_length = opening->pos;
 640    else
 641       new_length = file->length;
 642
 643    /* Check new size won't be negative */
 644
 645    if(-offset > new_length)
 646    {
 647       SetIoErr(ERROR_SEEK_ERROR);
 648       return -1;
 649    }
 650
 651    /* Get new length */
 652
 653    new_length += offset;
 654    length = file->length;
 655    block_count = file->block_count;
 656
 657    /* Get full length (including any unused area in last block) */
 658
 659    old_pos = opening->pos;
 660    full_length = length;
 661    end_length = file->end_length;
 662
 663    block = GetLastBlock(file);
 664    full_length += block->length - end_length;
 665
 666    /* Change size */
 667
 668    if(new_length > length)
 669    {
 670       /* Add the required number of data bytes */
 671
 672       remainder = new_length - full_length;
 673       end_length -= remainder;
 674
 675       while(remainder > 0)
 676       {
 677          block = AddDataBlock(handler, file, remainder);
 678          if(block != NULL)
 679          {
 680             end_length = remainder;
 681             remainder -= block->length;
 682          }
 683          else
 684             remainder = 0;
 685       }
 686
 687       /* Remove new blocks upon failure */
 688
 689       if(block == NULL)
 690       {
 691          new_length = -1;
 692          error = IoErr();
 693          ChangeFileSize(handler, opening, length, OFFSET_BEGINNING);
 694       }
 695       else
 696          file->end_length = end_length;
 697    }
 698    else if(length != new_length)
 699    {
 700       /* Remove surplus blocks from the file */
 701
 702       block = NULL;
 703       while(full_length > new_length)
 704       {
 705          FreeDataBlock(handler, file, block);
 706          block = (APTR)RemTail((APTR)&file->elements);
 707          full_length -= block->length;
 708       }
 709       end_block = (APTR)file->elements.mlh_TailPred;
 710       file->end_length = end_length = end_block->length;
 711
 712       /* Allocate a suitably sized end block and copy old data to it */
 713
 714       diff = new_length - full_length;
 715       file->length = full_length;
 716       CmdSeek(handler, opening, 0, OFFSET_END);
 717
 718       if(ChangeFileSize(handler, opening, diff, OFFSET_END) != -1)
 719       {
 720          WriteData(handler, opening,
 721             ((UBYTE *)block) + sizeof(struct Block), diff);
 722          FreeDataBlock(handler, file, block);
 723       }
 724       else
 725          AddTail((struct List *)&file->elements, (APTR)block);
 726    }
 727
 728    /* Store new file size */
 729
 730    if(new_length != -1)
 731       file->length = new_length;
 732    handler->block_count += file->block_count - block_count;
 733
 734    /* Re-establish old seek position */
 735
 736    opening->pos = old_pos;
 737
 738    /* Adjust all openings for this file to ensure that their position isn't
 739       past the new EOF and that their block and block position are valid */
 740
 741    openings = &file->lock->openings;
 742    opening = (APTR)openings->mlh_Head;
 743    tail = (APTR)&openings->mlh_Tail;
 744
 745    while(opening != tail)
 746    {
 747       if(opening->pos > file->length)
 748       {
 749          opening->pos = file->length;
 750       }
 751       CmdSeek(handler, opening, opening->pos, OFFSET_BEGINNING);
 752       opening = (APTR)((struct MinNode *)opening)->mln_Succ;
 753    }
 754
 755    SetIoErr(error);
 756    return new_length;
 757 }
 758
 759
 760
 761 /****i* ram.handler/ReadData ***********************************************
 762 *
 763 *   NAME
 764 *       ReadData --
 765 *
 766 *   SYNOPSIS
 767 *       read_length = ReadData(opening, buffer, length)
 768 *
 769 *       UPINT ReadData(struct Opening *, UBYTE *, UPINT);
 770 *
 771 *   FUNCTION
 772 *
 773 *   INPUTS
 774 *
 775 *   RESULT
 776 *
 777 *   EXAMPLE
 778 *
 779 *   NOTES
 780 *
 781 *   BUGS
 782 *
 783 *   SEE ALSO
 784 *
 785 ****************************************************************************
 786 *
 787 */
 788
 789 UPINT ReadData(struct Opening *opening, UBYTE *buffer, UPINT length)
 790 {
 791    struct Block *block;
 792    UPINT block_pos, block_length, read_length = 0, remainder;
 793    struct Object *file;
 794
 795    /* Fill buffer until request has been fulfilled or EOF is reached */
 796
 797    block = opening->block;
 798    block_pos = opening->block_pos;
 799    file = opening->file;
 800
 801    remainder = file->length - opening->pos;
 802    if(length > remainder)
 803       length = remainder;
 804    remainder = length;
 805
 806    while(remainder > 0)
 807    {
 808       /* Get number of remaining valid bytes in this block */
 809
 810       block_length = block->length - block_pos;
 811
 812       /* Get next block if end of current one has been reached */
 813
 814       if(block_length == 0)
 815       {
 816          block = (struct Block *)((struct MinNode *)block)->mln_Succ;
 817          block_pos = 0;
 818          /*read_length = 0;*/
 819          block_length = block->length;
 820       }
 821
 822       /* Copy block contents into the caller's buffer */
 823
 824       read_length = MIN(remainder, block_length);
 825       CopyMem(((UBYTE *)block) + sizeof(struct Block) + block_pos, buffer,
 826          read_length);
 827       remainder -= read_length;
 828       buffer += read_length;
 829       block_pos += read_length;
 830    }
 831
 832    /* Record new position for next access */
 833
 834    opening->block = block;
 835    opening->block_pos = block_pos;
 836    opening->pos += length;
 837
 838    /* Return number of bytes read */
 839
 840    return length;
 841 }
 842
 843
 844
 845 /****i* ram.handler/WriteData **********************************************
 846 *
 847 *   NAME
 848 *       WriteData --
 849 *
 850 *   SYNOPSIS
 851 *       write_length = WriteData(handler, opening, buffer, length)
 852 *
 853 *       UPINT WriteData(struct Handler *, struct Opening *, UBYTE *, UPINT);
 854 *
 855 *   FUNCTION
 856 *
 857 *   INPUTS
 858 *
 859 *   RESULT
 860 *
 861 *   EXAMPLE
 862 *
 863 *   NOTES
 864 *
 865 *   BUGS
 866 *
 867 *   SEE ALSO
 868 *
 869 ****************************************************************************
 870 *
 871 */
 872
 873 UPINT WriteData(struct Handler *handler, struct Opening *opening,
 874    UBYTE *buffer, UPINT length)
 875 {
 876    struct Block *block, *new_block, *end_block;
 877    struct Object *file;
 878    UPINT block_pos, block_length, write_length, remainder = length,
 879       old_block_count, file_length, pos;
 880    LONG error = 0;
 881
 882    file = opening->file;
 883    file_length = file->length;
 884    old_block_count = file->block_count;
 885    pos = opening->pos;
 886    block = opening->block;
 887    block_pos = opening->block_pos;
 888
 889    while(remainder > 0 && error == 0)
 890    {
 891       block_length = block->length - block_pos;
 892
 893       /* Move on to next block if end of current block reached */
 894
 895       if(block_length == 0)
 896       {
 897          block = (struct Block *)((struct MinNode *)block)->mln_Succ;
 898          block_pos = 0;
 899
 900          /* Add another block to the file if required */
 901
 902          if(((struct MinNode *)block)->mln_Succ == NULL)
 903          {
 904             new_block = AddDataBlock(handler, opening->file, remainder);
 905             if(new_block != NULL)
 906             {
 907                block = new_block;
 908                file->end_length = 0;
 909             }
 910             else
 911                error = IoErr();
 912          }
 913
 914          block_length = block->length;
 915       }
 916
 917       /* Write as much as possible to the current block */
 918
 919       if(error == 0)
 920       {
 921          write_length = MIN(remainder, block_length);
 922          CopyMem(buffer,
 923             ((UBYTE *)block) + sizeof(struct Block) + block_pos,
 924             write_length);
 925          remainder -= write_length;
 926          buffer += write_length;
 927          block_pos += write_length;
 928       }
 929    }
 930
 931    /* Recalculate length of used portion of last block */
 932
 933    end_block = GetLastBlock(file);
 934    if(block == end_block && block_pos >= file->end_length)
 935       file->end_length = block_pos;
 936
 937    /* Update file size, volume size and current position */
 938
 939    length -= remainder;
 940    pos += length;
 941    if(pos > file_length)
 942       file->length = pos;
 943    opening->pos = pos;
 944    opening->block = block;
 945    opening->block_pos = block_pos;
 946    handler->block_count += file->block_count - old_block_count;
 947
 948    /* Return number of bytes written */
 949
 950    SetIoErr(error);
 951    return length;
 952 }
 953
 954
 955
 956 /****i* ram.handler/LockObject *********************************************
 957 *
 958 *   NAME
 959 *       LockObject --
 960 *
 961 *   SYNOPSIS
 962 *       lock = LockObject(handler, object,
 963 *           access)
 964 *
 965 *       struct Lock *LockObject(struct Handler *handler, struct Object *,
 966 *           LONG);
 967 *
 968 *   FUNCTION
 969 *
 970 *   INPUTS
 971 *
 972 *   RESULT
 973 *
 974 *   EXAMPLE
 975 *
 976 *   NOTES
 977 *
 978 *   BUGS
 979 *
 980 *   SEE ALSO
 981 *
 982 ****************************************************************************
 983 *
 984 */
 985
 986 struct Lock *LockObject(struct Handler *handler, struct Object *object,
 987    LONG access)
 988 {
 989    struct Lock *lock;
 990    LONG error = 0, lock_access;
 991
 992    object = GetRealObject(object);
 993    lock = object->lock;
 994
 995    if(lock == NULL)
 996    {
 997       lock = AllocPooled(handler->public_pool, sizeof(struct Lock));
 998
 999       if(lock != NULL)
1000       {
1001          object->lock = lock;
1002
1003          ((struct FileLock *)lock)->fl_Key = (PINT)object;
1004          ((struct FileLock *)lock)->fl_Access = access;
1005          ((struct FileLock *)lock)->fl_Task = handler->proc_port;
1006          ((struct FileLock *)lock)->fl_Volume = MKBADDR(handler->volume);
1007
1008          NewList((struct List *)&lock->openings);
1009       }
1010       else
1011          error = IoErr();
1012    }
1013    else
1014    {
1015       lock_access = ((struct FileLock *)lock)->fl_Access;
1016       if(access == ACCESS_WRITE || lock_access == ACCESS_WRITE)
1017       {
1018          lock = NULL;
1019          error = ERROR_OBJECT_IN_USE;
1020       }
1021    }
1022
1023    if(lock != NULL)
1024    {
1025       lock->lock_count++;
1026       handler->lock_count++;
1027    }
1028
1029    SetIoErr(error);
1030
1031    return lock;
1032 }
1033
1034
1035
1036 /****i* ram.handler/ExamineObject ******************************************
1037 *
1038 *   NAME
1039 *       ExamineObject --
1040 *
1041 *   SYNOPSIS
1042 *       success = ExamineObject(handler, object,
1043 *           info)
1044 *
1045 *       BOOL ExamineObject(struct Handler *, struct Object *,
1046 *           struct FileInfoBlock *);
1047 *
1048 *   FUNCTION
1049 *
1050 *   INPUTS
1051 *
1052 *   RESULT
1053 *
1054 *   EXAMPLE
1055 *
1056 *   NOTES
1057 *
1058 *   BUGS
1059 *
1060 *   SEE ALSO
1061 *
1062 ****************************************************************************
1063 *
1064 */
1065
1066 BOOL ExamineObject(struct Handler *handler, struct Object *object,
1067    struct FileInfoBlock *info)
1068 {
1069    BOOL success;
1070    struct Object *next_object;
1071    TEXT *s;
1072    LONG entry_type;
1073
1074    if(object == NULL)
1075    {
1076       object = (struct Object *)info->fib_DiskKey;
1077       next_object = (APTR)((struct Node *)object)->ln_Succ;
1078    }
1079    else
1080       next_object = (APTR)object->elements.mlh_Head;
1081
1082    if(next_object != NULL)
1083    {
1084       /* Fill in information from object */
1085
1086       entry_type = ((struct Node *)object)->ln_Pri;
1087       info->fib_DirEntryType = entry_type;
1088       info->fib_EntryType = entry_type;
1089       s = ((struct Node *)object)->ln_Name;
1090       info->fib_FileName[0] = StrSize(s) - 1;
1091       CopyMem(s, &info->fib_FileName[1], info->fib_FileName[0]);
1092       s = object->comment;
1093       if(s != NULL && ((struct Node *)object)->ln_Pri != ST_SOFTLINK) {
1094          info->fib_Comment[0] = StrSize(s) - 1;
1095          CopyMem(s, &info->fib_Comment[1], info->fib_Comment[0]);
1096       } else
1097          info->fib_Comment[0] = '\0';
1098       info->fib_NumBlocks = object->block_count;
1099
1100       /* Fill in information from real object */
1101
1102       object = GetRealObject(object);
1103
1104       info->fib_Protection = object->protection;
1105       info->fib_Size = object->length;
1106       CopyMem(&object->date, &info->fib_Date, sizeof(struct DateStamp));
1107
1108       /* Prepare for next examination */
1109
1110       success = TRUE;
1111       info->fib_DiskKey = (PINT)next_object;
1112    }
1113    else
1114    {
1115       success = FALSE;
1116       SetIoErr(ERROR_NO_MORE_ENTRIES);
1117    }
1118
1119    return success;
1120 }
1121
1122
1123
1124 /****i* ram.handler/AdjustExaminations *************************************
1125 *
1126 *   NAME
1127 *       AdjustExaminations -- Prevent ExAll() getting confused or crashing
1128 *
1129 *   SYNOPSIS
1130 *       AdjustExaminations(handler, object)
1131 *
1132 *       VOID AdjustExaminations(struct Handler *, struct Object *);
1133 *
1134 *   FUNCTION
1135 *
1136 *   INPUTS
1137 *
1138 *   RESULT
1139 *
1140 *   EXAMPLE
1141 *
1142 *   NOTES
1143 *
1144 *   BUGS
1145 *
1146 *   SEE ALSO
1147 *
1148 ****************************************************************************
1149 *
1150 */
1151
1152 VOID AdjustExaminations(struct Handler *handler, struct Object *object)
1153 {
1154    struct Examination *examination, *tail;
1155
1156    /* Adjust any ExAll()s that were due to examine the object */
1157
1158    examination = (APTR)handler->examinations.mlh_Head;
1159    tail = (APTR)&handler->examinations.mlh_Tail;
1160
1161    while(examination != tail)
1162    {
1163       if(examination->next_object == object)
1164          examination->next_object = (APTR)((struct Node *)object)->ln_Succ;
1165       examination = (APTR)((struct MinNode *)examination)->mln_Succ;
1166    }
1167
1168    return;
1169 }
1170
1171
1172 /****i* ram.handler/SetName ************************************************
1173 *
1174 *   NAME
1175 *       SetName --
1176 *
1177 *   SYNOPSIS
1178 *       success = SetName(handler, object, name)
1179 *
1180 *       BOOL SetName(struct Handler *, struct Object *, TEXT *);
1181 *
1182 *   FUNCTION
1183 *
1184 *   INPUTS
1185 *
1186 *   RESULT
1187 *
1188 *   EXAMPLE
1189 *
1190 *   NOTES
1191 *
1192 *   BUGS
1193 *
1194 *   SEE ALSO
1195 *
1196 ****************************************************************************
1197 *
1198 */
1199
1200 BOOL SetName(struct Handler *handler, struct Object *object,
1201    const TEXT *name)
1202 {
1203    LONG error = 0;
1204    const TEXT *p;
1205    TEXT ch;
1206    struct Locale *locale;
1207    PINT block_diff;
1208
1209    /* Check name isn't too long */
1210
1211    if(StrSize(name) > MAX_NAME_SIZE)
1212       error = ERROR_INVALID_COMPONENT_NAME;
1213
1214    /* Check name doesn't have any strange characters in it */
1215
1216    if ((locale = handler->locale)) {
1217        for(p = name; (ch = *p) != '\0'; p++)
1218            if((ch & 0x80) == 0
1219                && (!IsPrint(locale, ch) || IsCntrl(locale, ch) || ch == ':'))
1220                error = ERROR_INVALID_COMPONENT_NAME;
1221    }
1222
1223    /* Store new name */
1224
1225    if(error == 0)
1226    {
1227       block_diff = SetString(handler,
1228          (TEXT **)&((struct Node *)object)->ln_Name, name);
1229       error = IoErr();
1230    }
1231
1232    if(error == 0)
1233    {
1234       object->block_count += block_diff;
1235       handler->block_count += block_diff;
1236    }
1237
1238    /* Return success indicator */
1239
1240    SetIoErr(error);
1241    return error == 0;
1242 }
1243
1244
1245
1246 /****i* ram.handler/AddDataBlock *******************************************
1247 *
1248 *   NAME
1249 *       AddDataBlock --
1250 *
1251 *   SYNOPSIS
1252 *       block = AddDataBlock(file, length)
1253 *
1254 *       struct Block *AddDataBlock(struct Object *, UPINT);
1255 *
1256 *   FUNCTION
1257 *
1258 *   INPUTS
1259 *
1260 *   RESULT
1261 *
1262 *   EXAMPLE
1263 *
1264 *   NOTES
1265 *       Attempts to allocate a smaller block if the requested size cannot be
1266 *       obtained.
1267 *
1268 *   BUGS
1269 *
1270 *   SEE ALSO
1271 *
1272 ****************************************************************************
1273 *
1274 */
1275
1276 static struct Block *AddDataBlock(struct Handler *handler,
1277    struct Object *file, UPINT length)
1278 {
1279    struct Block *block;
1280    UPINT alloc_size;
1281    ULONG limit;
1282
1283    /* Ensure block size is within limits */
1284
1285    alloc_size = sizeof(struct Block) + length;
1286
1287    limit = handler->max_block_size;
1288    if(alloc_size > limit)
1289       alloc_size = limit;
1290
1291    limit = handler->min_block_size;
1292    if(alloc_size < limit)
1293       alloc_size = limit;
1294
1295    /* Allocate a multiple of the memory block size */
1296
1297    block = NULL;
1298    while(block == NULL && alloc_size >= limit)
1299    {
1300       alloc_size = ((alloc_size - 1) & (~MEM_BLOCKMASK)) + MEM_BLOCKSIZE;
1301       block = AllocPooled(handler->muddy_pool, alloc_size);
1302       if(block == NULL)
1303          alloc_size >>= 1;
1304    }
1305
1306    /* Add the block to the end of the file */
1307
1308    if(block != NULL)
1309    {
1310       AddTail((struct List *)&file->elements, (struct Node *)block);
1311       block->length = alloc_size - sizeof(struct Block);
1312       file->block_count += alloc_size >> MEM_BLOCKSHIFT;
1313    }
1314    else
1315       SetIoErr(ERROR_DISK_FULL);
1316
1317    /* Return the new block */
1318
1319    return block;
1320 }
1321
1322
1323
1324 /****i* ram.handler/FreeDataBlock ******************************************
1325 *
1326 *   NAME
1327 *       FreeDataBlock --
1328 *
1329 *   SYNOPSIS
1330 *       FreeDataBlock(file, block)
1331 *
1332 *       VOID FreeDataBlock(struct Object *, struct Block *);
1333 *
1334 *   FUNCTION
1335 *
1336 *   INPUTS
1337 *
1338 *   RESULT
1339 *
1340 *   EXAMPLE
1341 *
1342 *   NOTES
1343 *
1344 *   BUGS
1345 *
1346 *   SEE ALSO
1347 *
1348 ****************************************************************************
1349 *
1350 */
1351
1352 static VOID FreeDataBlock(struct Handler *handler, struct Object *file,
1353    struct Block *block)
1354 {
1355    UPINT alloc_size;
1356
1357    if(block != NULL)
1358    {
1359       alloc_size = sizeof(struct Block) + block->length;
1360       file->block_count -= alloc_size >> MEM_BLOCKSHIFT;
1361       FreePooled(handler->muddy_pool, block, alloc_size);
1362    }
1363
1364    return;
1365 }
1366
1367
1368
1369 /****i* ram.handler/GetRealObject ******************************************
1370 *
1371 *   NAME
1372 *       GetRealObject -- Dereference a hard link if necessary.
1373 *
1374 *   SYNOPSIS
1375 *       real_object = GetRealObject(object)
1376 *
1377 *       struct Object *GetRealObject(struct Object *);
1378 *
1379 *   FUNCTION
1380 *       If the specified object is a file, directory or soft link, the same
1381 *       object is returned. If the object is a hard link, the link target is
1382 *       returned instead.
1383 *
1384 *   INPUTS
1385 *
1386 *   RESULT
1387 *
1388 *   EXAMPLE
1389 *
1390 *   NOTES
1391 *
1392 *   BUGS
1393 *
1394 *   SEE ALSO
1395 *
1396 ****************************************************************************
1397 *
1398 */
1399
1400 struct Object *GetRealObject(struct Object *object)
1401 {
1402    struct MinNode *node, *pred;
1403
1404    /* Get first node in list */
1405
1406    node = &object->hard_link;
1407    if(node->mln_Pred != NULL)
1408    {
1409       while((pred = node->mln_Pred) != NULL)
1410          node = pred;
1411       node = node->mln_Succ;
1412    }
1413
1414    /* Get object from node address */
1415
1416    object = HARDLINK(node);
1417    return object;
1418 }
1419
1420
1421
1422 /****i* ram.handler/GetBlockLength *****************************************
1423 *
1424 *   NAME
1425 *       GetBlockLength -- Get the number of utilised bytes in a block.
1426 *
1427 *   SYNOPSIS
1428 *       length = GetBlockLength(file, block)
1429 *
1430 *       UPINT GetBlockLength(struct Object *, struct Block *);
1431 *
1432 *   FUNCTION
1433 *
1434 *   INPUTS
1435 *
1436 *   RESULT
1437 *
1438 *   EXAMPLE
1439 *
1440 *   NOTES
1441 *
1442 *   BUGS
1443 *
1444 *   SEE ALSO
1445 *
1446 ****************************************************************************
1447 *
1448 */
1449
1450 UPINT GetBlockLength(struct Object *file, struct Block *block)
1451 {
1452    UPINT length;
1453
1454    if(block == (APTR)file->elements.mlh_TailPred)
1455       length = file->end_length;
1456    else
1457       length = block->length;
1458
1459    return length;
1460 }
1461
1462
1463
1464 /****i* ram.handler/GetLastBlock *******************************************
1465 *
1466 *   NAME
1467 *       GetLastBlock --
1468 *
1469 *   SYNOPSIS
1470 *       block = GetLastBlock(file)
1471 *
1472 *       struct Block *GetLastBlock(struct Object *);
1473 *
1474 *   FUNCTION
1475 *
1476 *   INPUTS
1477 *
1478 *   RESULT
1479 *
1480 *   EXAMPLE
1481 *
1482 *   NOTES
1483 *
1484 *   BUGS
1485 *
1486 *   SEE ALSO
1487 *
1488 ****************************************************************************
1489 *
1490 */
1491
1492 static struct Block *GetLastBlock(struct Object *file)
1493 {
1494    struct Block *block;
1495
1496    block = (APTR)file->elements.mlh_TailPred;
1497
1498    return block;
1499 }
1500
1501
1502