include/ntfs-3g/runlist.h

   1 /*
   2  * runlist.h - Exports for runlist handling. Originated from the Linux-NTFS project.
   3  *
   4  * Copyright (c) 2002 Anton Altaparmakov
   5  * Copyright (c) 2002 Richard Russon
   6  *
   7  * This program/include file is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as published
   9  * by the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program/include file is distributed in the hope that it will be
  13  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program (in the main directory of the NTFS-3G
  19  * distribution in the file COPYING); if not, write to the Free Software
  20  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #ifndef _NTFS_RUNLIST_H
  24 #define _NTFS_RUNLIST_H
  25
  26 #include "types.h"
  27
  28 /* Forward declarations */
  29 typedef struct _runlist_element runlist_element;
  30 typedef runlist_element runlist;
  31
  32 #include "attrib.h"
  33 #include "volume.h"
  34
  35 /**
  36  * struct _runlist_element - in memory vcn to lcn mapping array element.
  37  * @vcn:        starting vcn of the current array element
  38  * @lcn:        starting lcn of the current array element
  39  * @length:     length in clusters of the current array element
  40  *
  41  * The last vcn (in fact the last vcn + 1) is reached when length == 0.
  42  *
  43  * When lcn == -1 this means that the count vcns starting at vcn are not
  44  * physically allocated (i.e. this is a hole / data is sparse).
  45  */
  46 struct _runlist_element {/* In memory vcn to lcn mapping structure element. */
  47         VCN vcn;        /* vcn = Starting virtual cluster number. */
  48         LCN lcn;        /* lcn = Starting logical cluster number. */
  49         s64 length;     /* Run length in clusters. */
  50 };
  51
  52 extern runlist_element *ntfs_rl_extend(ntfs_attr *na, runlist_element *rl,
  53                         int more_entries);
  54
  55 extern LCN ntfs_rl_vcn_to_lcn(const runlist_element *rl, const VCN vcn);
  56
  57 extern s64 ntfs_rl_pread(const ntfs_volume *vol, const runlist_element *rl,
  58                 const s64 pos, s64 count, void *b);
  59 extern s64 ntfs_rl_pwrite(const ntfs_volume *vol, const runlist_element *rl,
  60                 s64 ofs, const s64 pos, s64 count, void *b);
  61
  62 extern runlist_element *ntfs_runlists_merge(runlist_element *drl,
  63                 runlist_element *srl);
  64
  65 extern runlist_element *ntfs_mapping_pairs_decompress(const ntfs_volume *vol,
  66                 const ATTR_RECORD *attr, runlist_element *old_rl);
  67
  68 extern int ntfs_get_nr_significant_bytes(const s64 n);
  69
  70 extern int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol,
  71                 const runlist_element *rl, const VCN start_vcn, int max_size);
  72
  73 extern int ntfs_write_significant_bytes(u8 *dst, const u8 *dst_max,
  74                 const s64 n);
  75
  76 extern int ntfs_mapping_pairs_build(const ntfs_volume *vol, u8 *dst,
  77                 const int dst_len, const runlist_element *rl,
  78                 const VCN start_vcn, runlist_element const **stop_rl);
  79
  80 extern int ntfs_rl_truncate(runlist **arl, const VCN start_vcn);
  81
  82 extern int ntfs_rl_sparse(runlist *rl);
  83 extern s64 ntfs_rl_get_compressed_size(ntfs_volume *vol, runlist *rl);
  84
  85 #ifdef NTFS_TEST
  86 int test_rl_main(int argc, char *argv[]);
  87 #endif
  88
  89 #endif /* defined _NTFS_RUNLIST_H */
  90