Mercurial > hg > digilib-old
annotate servlet/src/digilib/io/DocuDirCache.java @ 99:226624784fe3
Small bug lead to null pointer exception when directory doesn't exist.
| author | robcast |
|---|---|
| date | Mon, 05 May 2003 22:16:21 +0200 |
| parents | a398fc09ba71 |
| children | 55bc0e928ac5 |
| rev | line source |
|---|---|
| 86 | 1 /* DocuDirCache.java |
| 2 | |
| 3 Digital Image Library servlet components | |
| 4 | |
| 5 Copyright (C) 2003 Robert Casties (robcast@mail.berlios.de) | |
| 6 | |
| 7 This program is free software; you can redistribute it and/or modify it | |
| 8 under the terms of the GNU General Public License as published by the | |
| 9 Free Software Foundation; either version 2 of the License, or (at your | |
| 10 option) any later version. | |
| 11 | |
| 12 Please read license.txt for the full details. A copy of the GPL | |
| 13 may be found at http://www.gnu.org/copyleft/lgpl.html | |
| 14 | |
| 15 You should have received a copy of the GNU General Public License | |
| 16 along with this program; if not, write to the Free Software | |
| 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 | |
| 19 * Created on 03.03.2003 | |
| 20 */ | |
| 21 | |
| 22 package digilib.io; | |
| 23 | |
| 24 import java.io.File; | |
| 91 | 25 import java.util.HashMap; |
| 86 | 26 |
| 27 /** | |
| 28 * @author casties | |
| 29 */ | |
| 91 | 30 public class DocuDirCache { |
| 86 | 31 |
| 91 | 32 // HashMap of directories |
| 33 private HashMap map = null; | |
| 86 | 34 // names of base directories |
| 35 private String[] baseDirNames = null; | |
| 91 | 36 // number of files in the whole cache (approximate) |
| 86 | 37 private long numFiles = 0; |
| 38 // number of cache hits | |
| 39 private long hits = 0; | |
| 40 // number of cache misses | |
| 41 private long misses = 0; | |
| 42 | |
| 43 /** Constructor with array of base directory names. | |
| 44 * | |
| 45 * @param bd base directory names | |
| 46 */ | |
| 47 public DocuDirCache(String[] bd) { | |
| 48 baseDirNames = bd; | |
| 91 | 49 map = new HashMap(); |
| 50 } | |
| 51 | |
| 52 /** The number of directories in the cache. | |
| 53 * @return | |
| 54 */ | |
| 55 public int size() { | |
| 56 return (map != null) ? map.size() : 0; | |
| 86 | 57 } |
| 58 | |
| 59 /** Add a DocuDirectory to the cache. | |
| 60 * | |
| 61 * @param newdir | |
| 62 */ | |
| 63 public void put(DocuDirectory newdir) { | |
| 64 String s = newdir.getDirName(); | |
| 91 | 65 if (map.containsKey(s)) { |
| 86 | 66 System.out.println("Baah, duplicate key in DocuDirectory.put!"); |
| 67 } else { | |
| 91 | 68 map.put(s, newdir); |
| 86 | 69 numFiles += newdir.size(); |
| 70 } | |
| 71 } | |
| 72 | |
| 91 | 73 /** Returns the DocuFileset with the pathname <code>fn</code> and the |
| 74 * index <code>in</code>. | |
| 75 * | |
| 76 * If <code>fn</code> is a file then the corresponding Fileset is | |
| 77 * returned and the index is ignored. | |
| 78 * | |
| 79 * @param fn digilib pathname | |
| 80 * @param in file index | |
| 81 * @return | |
| 82 */ | |
| 86 | 83 public DocuFileset getFileset(String fn, int in) { |
| 84 DocuDirectory dd; | |
| 85 // file number is 1-based, vector index is 0-based | |
| 86 int n = in - 1; | |
| 87 // first, assume fn is a directory and look in the cache | |
| 91 | 88 dd = (DocuDirectory) map.get(fn); |
| 89 if (dd == null) { | |
| 90 // cache miss | |
| 91 misses++; | |
| 92 // see if it's a directory | |
| 93 File f = new File(baseDirNames[0] + fn); | |
| 94 if (f.isDirectory()) { | |
| 95 dd = new DocuDirectory(fn, baseDirNames); | |
| 96 if (dd.isValid()) { | |
| 97 // add to the cache | |
| 98 put(dd); | |
| 99 } | |
| 100 } else { | |
| 101 // maybe it's a file | |
| 102 if (f.canRead()) { | |
| 103 // get the parent directory | |
| 104 String d = fn.substring(0, fn.lastIndexOf(File.separator)); | |
| 105 // try it in the cache | |
| 106 dd = (DocuDirectory) map.get(d); | |
| 107 if (dd == null) { | |
| 108 // try to read from disk | |
| 109 dd = new DocuDirectory(d, baseDirNames); | |
| 110 if (dd.isValid()) { | |
| 111 // add to the cache | |
| 112 put(dd); | |
| 113 } else { | |
| 114 // invalid path | |
| 115 return null; | |
| 116 } | |
| 117 } else { | |
|
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118 // then it was not a real cache miss |
| 91 | 119 misses--; |
| 120 } | |
| 121 // get the file's index | |
| 122 n = dd.indexOf(f.getName()); | |
|
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123 } else { |
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124 // it's not even a file :-( |
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125 return null; |
| 91 | 126 } |
| 127 } | |
| 128 } else { | |
| 129 // cache hit | |
| 130 hits++; | |
| 131 } | |
| 132 dd.refresh(); | |
| 133 if (dd.isValid()) { | |
| 134 try { | |
| 135 return dd.get(n); | |
| 136 } catch (ArrayIndexOutOfBoundsException e) { | |
| 137 } | |
| 138 } | |
| 139 return null; | |
| 140 } | |
| 141 | |
| 142 /** Returns the DocuDirectory indicated by the pathname <code>fn</code>. | |
| 143 * | |
| 144 * If <code>fn</code> is a file then its parent directory is returned. | |
| 145 * | |
| 146 * @param fn digilib pathname | |
| 147 * @return | |
| 148 */ | |
| 149 public DocuDirectory getDirectory(String fn) { | |
| 150 DocuDirectory dd; | |
| 151 // first, assume fn is a directory and look in the cache | |
| 152 dd = (DocuDirectory) map.get(fn); | |
| 86 | 153 if (dd == null) { |
| 154 // cache miss | |
| 155 misses++; | |
| 156 // see if it's a directory | |
| 157 File f = new File(baseDirNames[0] + fn); | |
| 158 if (f.isDirectory()) { | |
| 159 dd = new DocuDirectory(fn, baseDirNames); | |
| 160 if (dd.isValid()) { | |
| 161 // add to the cache | |
| 162 put(dd); | |
| 163 } | |
| 164 } else { | |
| 165 // maybe it's a file | |
| 166 if (f.canRead()) { | |
| 167 // try the parent directory in the cache | |
| 91 | 168 dd = (DocuDirectory) map.get(f.getParent()); |
| 86 | 169 if (dd == null) { |
| 170 // try to read from disk | |
| 171 dd = new DocuDirectory(f.getParent(), baseDirNames); | |
| 172 if (dd.isValid()) { | |
| 173 // add to the cache | |
| 174 put(dd); | |
| 175 } else { | |
| 176 // invalid path | |
| 177 return null; | |
| 178 } | |
| 91 | 179 } else { |
| 180 // not a real cache miss then | |
| 181 misses--; | |
| 86 | 182 } |
|
99
226624784fe3
Small bug lead to null pointer exception when directory doesn't exist.
robcast
parents:
91
diff
changeset
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183 } else { |
|
226624784fe3
Small bug lead to null pointer exception when directory doesn't exist.
robcast
parents:
91
diff
changeset
|
184 // it's not even a file :-( |
|
226624784fe3
Small bug lead to null pointer exception when directory doesn't exist.
robcast
parents:
91
diff
changeset
|
185 return null; |
| 86 | 186 } |
| 187 } | |
| 188 } else { | |
| 189 // cache hit | |
| 190 hits++; | |
| 191 } | |
| 192 dd.refresh(); | |
| 193 if (dd.isValid()) { | |
| 194 return dd; | |
| 195 } | |
| 196 return null; | |
| 197 } | |
| 198 | |
| 199 /** | |
| 200 * @return String[] | |
| 201 */ | |
| 202 public String[] getBaseDirNames() { | |
| 203 return baseDirNames; | |
| 204 } | |
| 205 | |
| 206 /** | |
| 207 * @return long | |
| 208 */ | |
| 209 public long getNumFiles() { | |
| 210 return numFiles; | |
| 211 } | |
| 212 | |
| 213 /** | |
| 214 * Sets the baseDirNames. | |
| 215 * @param baseDirNames The baseDirNames to set | |
| 216 */ | |
| 217 public void setBaseDirNames(String[] baseDirNames) { | |
| 218 this.baseDirNames = baseDirNames; | |
| 219 } | |
| 220 | |
| 221 /** | |
| 222 * @return long | |
| 223 */ | |
| 224 public long getHits() { | |
| 225 return hits; | |
| 226 } | |
| 227 | |
| 228 /** | |
| 229 * @return long | |
| 230 */ | |
| 231 public long getMisses() { | |
| 232 return misses; | |
| 233 } | |
| 234 | |
| 235 } |