| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.io.InputStreamFile |
| 4 | |
| 5 | Copyright 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.impl.io; |
| 22 | |
| 23 | import org.apache.derby.io.StorageFactory; |
| 24 | import org.apache.derby.io.StorageFile; |
| 25 | import org.apache.derby.io.StorageRandomAccessFile; |
| 26 | |
| 27 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 28 | |
| 29 | import java.io.File; |
| 30 | import java.io.InputStream; |
| 31 | import java.io.OutputStream; |
| 32 | import java.io.IOException; |
| 33 | import java.io.FileNotFoundException; |
| 34 | import java.net.MalformedURLException; |
| 35 | import java.net.URL; |
| 36 | |
| 37 | /** |
| 38 | * This class provides the base for read-only stream implementations of the StorageFile interface. It is used with the |
| 39 | * classpath, jar, http, and https subsubprotocols |
| 40 | */ |
| 41 | abstract class InputStreamFile implements StorageFile |
| 42 | { |
| 43 | |
| 44 | final String path; |
| 45 | final int nameStart; // getName() = path.substring( nameStart) |
| 46 | final BaseStorageFactory storageFactory; |
| 47 | |
| 48 | InputStreamFile( BaseStorageFactory storageFactory, String path) |
| 49 | { |
| 50 | this.storageFactory = storageFactory; |
| 51 | if( path == null || path.length() == 0) |
| 52 | { |
| 53 | this.path = storageFactory.dataDirectory; |
| 54 | nameStart = -1; |
| 55 | } |
| 56 | else |
| 57 | { |
| 58 | StringBuffer sb = new StringBuffer( storageFactory.separatedDataDirectory); |
| 59 | if( File.separatorChar != '/') |
| 60 | sb.append( path.replace( File.separatorChar, '/')); |
| 61 | else |
| 62 | sb.append( path); |
| 63 | this.path = sb.toString(); |
| 64 | nameStart = this.path.lastIndexOf( '/') + 1; |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | InputStreamFile( BaseStorageFactory storageFactory, String parent, String name) |
| 69 | { |
| 70 | this.storageFactory = storageFactory; |
| 71 | StringBuffer sb = new StringBuffer( storageFactory.separatedDataDirectory); |
| 72 | if( File.separatorChar != '/') |
| 73 | { |
| 74 | sb.append( parent.replace( File.separatorChar, '/')); |
| 75 | sb.append( '/'); |
| 76 | sb.append( name.replace( File.separatorChar, '/')); |
| 77 | } |
| 78 | else |
| 79 | { |
| 80 | sb.append( parent); |
| 81 | sb.append( '/'); |
| 82 | sb.append( name); |
| 83 | } |
| 84 | path = sb.toString(); |
| 85 | nameStart = this.path.lastIndexOf( '/') + 1; |
| 86 | } |
| 87 | |
| 88 | InputStreamFile( InputStreamFile dir, String name) |
| 89 | { |
| 90 | this.storageFactory = dir.storageFactory; |
| 91 | StringBuffer sb = new StringBuffer( dir.path); |
| 92 | sb.append( '/'); |
| 93 | if( File.separatorChar != '/') |
| 94 | sb.append( name.replace( File.separatorChar, '/')); |
| 95 | else |
| 96 | sb.append( name); |
| 97 | path = sb.toString(); |
| 98 | nameStart = this.path.lastIndexOf( '/') + 1; |
| 99 | } |
| 100 | |
| 101 | InputStreamFile( BaseStorageFactory storageFactory, String child, int pathLen) |
| 102 | { |
| 103 | this.storageFactory = storageFactory; |
| 104 | path = child.substring( 0, pathLen); |
| 105 | nameStart = this.path.lastIndexOf( '/') + 1; |
| 106 | } |
| 107 | |
| 108 | public boolean equals( Object other) |
| 109 | { |
| 110 | if( other == null || ! getClass().equals( other.getClass())) |
| 111 | return false; |
| 112 | InputStreamFile otherFile = (InputStreamFile) other; |
| 113 | return path.equals( otherFile.path); |
| 114 | } |
| 115 | |
| 116 | public int hashCode() |
| 117 | { |
| 118 | return path.hashCode(); |
| 119 | } |
| 120 | |
| 121 | /** |
| 122 | * Get the names of all files and sub-directories in the directory named by this path name. |
| 123 | * |
| 124 | * @return An array of the names of the files and directories in this |
| 125 | * directory denoted by this abstract pathname. The returned array will have length 0 |
| 126 | * if this directory is empty. Returns null if this StorageFile is not a directory, or |
| 127 | * if an I/O error occurs. |
| 128 | */ |
| 129 | public String[] list() |
| 130 | { |
| 131 | return null; |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * Determine whether the named file is writable. |
| 136 | * |
| 137 | * @return <b>true</b> if the file exists and is writable, <b>false</b> if not. |
| 138 | */ |
| 139 | public boolean canWrite() |
| 140 | { |
| 141 | return false; |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * Tests whether the named file exists. |
| 146 | * |
| 147 | * @return <b>true</b> if the named file exists, <b>false</b> if not. |
| 148 | */ |
| 149 | public abstract boolean exists(); |
| 150 | |
| 151 | /** |
| 152 | * Tests whether the named file is a directory, or not. This is only called in writable storage factories. |
| 153 | * |
| 154 | * @return <b>true</b> if named file exists and is a directory, <b>false</b> if not. |
| 155 | * The return value is undefined if the storage is read-only. |
| 156 | */ |
| 157 | public boolean isDirectory() |
| 158 | { |
| 159 | return false; |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * Deletes the named file or empty directory. This method does not delete non-empty directories. |
| 164 | * |
| 165 | * @return <b>true</b> if the named file or directory is successfully deleted, <b>false</b> if not |
| 166 | */ |
| 167 | public boolean delete() |
| 168 | { |
| 169 | return false; |
| 170 | } |
| 171 | |
| 172 | /** |
| 173 | * Deletes the named file and, if it is a directory, all the files and directories it contains. |
| 174 | * |
| 175 | * @return <b>true</b> if the named file or directory is successfully deleted, <b>false</b> if not |
| 176 | */ |
| 177 | public boolean deleteAll() |
| 178 | { |
| 179 | return false; |
| 180 | } |
| 181 | |
| 182 | /** |
| 183 | * Converts this StorageFile into a pathname string. The character returned by StorageFactory.getSeparator() |
| 184 | * is used to separate the directory and file names in the sequence. |
| 185 | * |
| 186 | *<p> |
| 187 | *<b>The returned path may include the database directory. Therefore it cannot be directly used to make an StorageFile |
| 188 | * equivalent to this one.</b> |
| 189 | * |
| 190 | * @return The pathname as a string. |
| 191 | * |
| 192 | * @see StorageFactory#getSeparator |
| 193 | */ |
| 194 | public String getPath() |
| 195 | { |
| 196 | if( File.separatorChar != '/') |
| 197 | return path.replace( '/', File.separatorChar); |
| 198 | return path; |
| 199 | } // end of getPath |
| 200 | |
| 201 | public String getCanonicalPath() throws IOException |
| 202 | { |
| 203 | return storageFactory.getCanonicalName() + "/" + path; |
| 204 | } |
| 205 | |
| 206 | /** |
| 207 | * @return The last segment in the path name, "" if the path name sequence is empty. |
| 208 | */ |
| 209 | public String getName() |
| 210 | { |
| 211 | return (nameStart < 0) ? "" : path.substring( nameStart); |
| 212 | } |
| 213 | |
| 214 | /** |
| 215 | * If the named file does not already exist then create it as an empty normal file. |
| 216 | * |
| 217 | * The implementation |
| 218 | * must synchronize with other threads accessing the same file (in the same or a different process). |
| 219 | * If two threads both attempt to create a file with the same name |
| 220 | * at the same time then at most one should succeed. |
| 221 | * |
| 222 | * @return <b>true</b> if this thread's invocation of createNewFile successfully created the named file; |
| 223 | * <b>false</b> if not, i.e. <b>false</b> if the named file already exists or if another concurrent thread created it. |
| 224 | * |
| 225 | * @exception IOException - If the directory does not exist or some other I/O error occurred |
| 226 | */ |
| 227 | public boolean createNewFile() throws IOException |
| 228 | { |
| 229 | throw new IOException( "createNewFile called in a read-only file system."); |
| 230 | } |
| 231 | |
| 232 | /** |
| 233 | * Rename the file denoted by this name. Note that StorageFile objects are immutable. This method |
| 234 | * renames the underlying file, it does not change this StorageFile object. The StorageFile object denotes the |
| 235 | * same name as before, however the exists() method will return false after the renameTo method |
| 236 | * executes successfully. |
| 237 | * |
| 238 | *<p>It is not specified whether this method will succeed if a file already exists under the new name. |
| 239 | * |
| 240 | * @param newName the new name. |
| 241 | * |
| 242 | * @return <b>true</b> if the rename succeeded, <b>false</b> if not. |
| 243 | */ |
| 244 | public boolean renameTo( StorageFile newName) |
| 245 | { |
| 246 | return false; |
| 247 | } |
| 248 | |
| 249 | /** |
| 250 | * Creates the named directory. |
| 251 | * |
| 252 | * @return <b>true</b> if the directory was created; <b>false</b> if not. |
| 253 | */ |
| 254 | public boolean mkdir() |
| 255 | { |
| 256 | return false; |
| 257 | } |
| 258 | |
| 259 | /** |
| 260 | * Creates the named directory, and all nonexistent parent directories. |
| 261 | * |
| 262 | * @return <b>true</b> if the directory was created, <b>false</b> if not |
| 263 | */ |
| 264 | public boolean mkdirs() |
| 265 | { |
| 266 | return false; |
| 267 | } |
| 268 | |
| 269 | /** |
| 270 | * Returns the length of the named file if it is not a directory. The return value is not specified |
| 271 | * if the file is a directory. |
| 272 | * |
| 273 | * @return The length, in bytes, of the named file if it exists and is not a directory, |
| 274 | * 0 if the file does not exist, or any value if the named file is a directory. |
| 275 | */ |
| 276 | public long length() |
| 277 | { |
| 278 | try |
| 279 | { |
| 280 | InputStream is = getInputStream(); |
| 281 | if( is == null) |
| 282 | return 0; |
| 283 | long len = is.available(); |
| 284 | is.close(); |
| 285 | return len; |
| 286 | } |
| 287 | catch( IOException e){ return 0;} |
| 288 | } // end of length |
| 289 | |
| 290 | /** |
| 291 | * Get the name of the parent directory if this name includes a parent. |
| 292 | * |
| 293 | * @return An StorageFile denoting the parent directory of this StorageFile, if it has a parent, null if |
| 294 | * it does not have a parent. |
| 295 | */ |
| 296 | public StorageFile getParentDir() |
| 297 | { |
| 298 | if( path.length() <= storageFactory.separatedDataDirectory.length()) |
| 299 | return null; |
| 300 | return getParentDir( path.lastIndexOf( '/')); |
| 301 | } |
| 302 | |
| 303 | /** |
| 304 | * Get the parent of this file. |
| 305 | * |
| 306 | * @param pathLen the length of the parent's path name. |
| 307 | */ |
| 308 | abstract StorageFile getParentDir( int pathLen); |
| 309 | |
| 310 | /** |
| 311 | * Make the named file or directory read-only. This interface does not specify whether this |
| 312 | * also makes the file undeletable. |
| 313 | * |
| 314 | * @return <b>true</b> if the named file or directory was made read-only, or it already was read-only; |
| 315 | * <b>false</b> if not. |
| 316 | */ |
| 317 | public boolean setReadOnly() |
| 318 | { |
| 319 | return true; |
| 320 | } |
| 321 | |
| 322 | /** |
| 323 | * Creates an output stream from a file name. If a normal file already exists with this name it |
| 324 | * will first be truncated to zero length. |
| 325 | * |
| 326 | * @return an output stream suitable for writing to the file. |
| 327 | * |
| 328 | * @exception FileNotFoundException if the file exists but is a directory |
| 329 | * rather than a regular file, does not exist but cannot be created, or |
| 330 | * cannot be opened for any other reason. |
| 331 | */ |
| 332 | public OutputStream getOutputStream( ) throws FileNotFoundException |
| 333 | { |
| 334 | throw new FileNotFoundException( "Attempt to write into a read only file system."); |
| 335 | } |
| 336 | |
| 337 | |
| 338 | /** |
| 339 | * Creates an output stream from a file name. If a normal file already exists with this name it |
| 340 | * will first be truncated to zero length. |
| 341 | * |
| 342 | * @return an output stream suitable for writing to the file. |
| 343 | * |
| 344 | * @exception FileNotFoundException if the file exists but is a directory |
| 345 | * rather than a regular file, does not exist but cannot be created, or |
| 346 | * cannot be opened for any other reason. |
| 347 | */ |
| 348 | public OutputStream getOutputStream( boolean append) throws FileNotFoundException |
| 349 | { |
| 350 | throw new FileNotFoundException( "Attempt to write into a read only file system."); |
| 351 | } |
| 352 | |
| 353 | |
| 354 | /** |
| 355 | * Creates an input stream from a file name. |
| 356 | * |
| 357 | * @return an input stream suitable for reading from the file. |
| 358 | * |
| 359 | * @exception FileNotFoundException if the file is not found. |
| 360 | */ |
| 361 | abstract public InputStream getInputStream( ) throws FileNotFoundException; |
| 362 | |
| 363 | /** |
| 364 | * Get an exclusive lock with this name. This is used to ensure that two or more JVMs do not open the same database |
| 365 | * at the same time. |
| 366 | * |
| 367 | * @return EXCLUSIVE_FILE_LOCK_NOT_AVAILABLE if the lock cannot be acquired because it is already held.<br> |
| 368 | * EXCLUSIVE_FILE_LOCK if the lock was successfully acquired.<br> |
| 369 | * NO_FILE_LOCK_SUPPORT if the system does not support exclusive locks.<br> |
| 370 | */ |
| 371 | public int getExclusiveFileLock() |
| 372 | { |
| 373 | return NO_FILE_LOCK_SUPPORT; |
| 374 | } |
| 375 | |
| 376 | /** |
| 377 | * Release the resource associated with an earlier acquired exclusive lock |
| 378 | * |
| 379 | * @see #getExclusiveFileLock |
| 380 | */ |
| 381 | public void releaseExclusiveFileLock() |
| 382 | {} |
| 383 | |
| 384 | /** |
| 385 | * Get a random access file. |
| 386 | * |
| 387 | * @param mode "r", "rw", "rws", or "rwd". The "rws" and "rwd" modes specify |
| 388 | * that the data is to be written to persistent store, consistent with the |
| 389 | * java.io.RandomAccessFile class ("synchronized" with the persistent |
| 390 | * storage, in the file system meaning of the word "synchronized"). However |
| 391 | * the implementation is not required to implement the "rws" or "rwd" |
| 392 | * modes. The implementation may treat "rws" and "rwd" as "rw". It is up to |
| 393 | * the user of this interface to call the StorageRandomAccessFile.sync |
| 394 | * method. However, if the "rws" or "rwd" modes are supported and the |
| 395 | * RandomAccessFile was opened in "rws" or "rwd" mode then the |
| 396 | * implementation of StorageRandomAccessFile.sync need not do anything. |
| 397 | * |
| 398 | * @return an object that can be used for random access to the file. |
| 399 | * |
| 400 | * @exception IllegalArgumentException if the mode argument is not equal to one of "r", "rw", "rws", or "rwd". |
| 401 | * @exception FileNotFoundException if the file exists but is a directory rather than a regular |
| 402 | * file, or cannot be opened or created for any other reason . |
| 403 | * |
| 404 | * @see <a href="http://java.sun.com/j2se/1.4.2/docs/api/java/io/RandomAccessFile.html">java.io.RandomAccessFile</a> |
| 405 | */ |
| 406 | public StorageRandomAccessFile getRandomAccessFile( String mode) throws FileNotFoundException |
| 407 | { |
| 408 | if( SanityManager.DEBUG) |
| 409 | SanityManager.NOTREACHED(); |
| 410 | return null; |
| 411 | } |
| 412 | |
| 413 | /** |
| 414 | * Get the file name for diagnostic purposes. Usually the same as getPath(). |
| 415 | * |
| 416 | * @return the file name |
| 417 | */ |
| 418 | public String toString() |
| 419 | { |
| 420 | return path; |
| 421 | } |
| 422 | |
| 423 | /** |
| 424 | * @see org.apache.derby.io.StorageFile#getURL() |
| 425 | */ |
| 426 | public URL getURL() throws MalformedURLException { |
| 427 | throw new MalformedURLException(toString()); |
| 428 | } |
| 429 | } |