org/jpc/diskimages/TreeFile.java

   1 /*
   2     JPC-RR: A x86 PC Hardware Emulator
   3     Release 1
   4
   5     Copyright (C) 2007-2009 Isis Innovation Limited
   6     Copyright (C) 2009 H. Ilari Liusvaara
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License version 2 as published by
  10     the Free Software Foundation.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     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 along
  18     with this program; if not, write to the Free Software Foundation, Inc.,
  19     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20
  21     Based on JPC x86 PC Hardware emulator,
  22     A project from the Physics Dept, The University of Oxford
  23
  24     Details about original JPC can be found at:
  25
  26     www-jpc.physics.ox.ac.uk
  27
  28 */
  29
  30 package org.jpc.diskimages;
  31
  32 import java.io.*;
  33 import java.util.*;
  34
  35 public abstract class TreeFile
  36 {
  37     protected int clusterSize;           //In sectors.
  38     protected int startCluster;          //Root directory can have this negative!!!
  39     protected int clusterZeroOffset;     //Quite purely abstract concept. Two cluster sizes before data area start.
  40     protected String selfName;
  41     protected TreeFile parent;
  42
  43     protected TreeFile(String self)
  44     {
  45         clusterSize = 1;
  46         startCluster = 0;
  47         clusterZeroOffset = 0;
  48         selfName = self;
  49         parent = null;
  50     }
  51
  52     protected String getSelfName()
  53     {
  54         return selfName;
  55     }
  56
  57     protected void parentTo(TreeFile newParent)
  58     {
  59         parent = newParent;
  60     }
  61
  62     protected void doSetClusterSize(int cluster)
  63     {
  64         clusterSize = cluster;
  65     }
  66
  67     public int getClusterSize()
  68     {
  69         return clusterSize;
  70     }
  71
  72     protected void setStartCluster(int cluster)
  73     {
  74         startCluster = cluster;
  75     }
  76
  77     public int getStartCluster()
  78     {
  79         return startCluster;
  80     }
  81
  82     public int getEndCluster()
  83     {
  84         return startCluster + getSizeInClusters() - 1;
  85     }
  86
  87     protected void doSetClusterZeroOffset(int offset)
  88     {
  89         clusterZeroOffset = offset;
  90     }
  91
  92     public int getSizeInClusters()
  93     {
  94         int sectors = getSizeInSectors();
  95         return (sectors + clusterSize - 1) / clusterSize;
  96     }
  97
  98     public int getSizeInSectors()
  99     {
 100         int bytes = getSize();
 101         return (bytes + 511) / 512;
 102     }
 103
 104     //Recurse and call doSetClusterZeroOffset().
 105     public abstract void setClusterZeroOffset(int offset);
 106     //Recurse and call doSetClusterSize().
 107     public abstract void setClusterSize(int size);
 108     //Return all-zeroes after file has ended.
 109     public abstract void readSector(int sector, byte[] data) throws IOException;
 110     //Hint that readSectors have ended.
 111     public abstract void readSectorEnd();
 112     //Recursively assign clusters to files. Call setStartCluster(base) and return next cluster number.
 113     public abstract int assignCluster(int base);
 114     //Return next entry in tree, or null if none exists.
 115     public abstract TreeFile nextFile();
 116     //Return next entry from given one.
 117     protected abstract TreeFile nextFile(String key);
 118     //Add file.
 119     public abstract void addFile(TreeFile newFile) throws Exception;
 120     //Get true size of file.
 121     public abstract int getSize();
 122     //Get comments.
 123     public abstract List<String> getComments(String prefix, String timestamp);
 124 };