| 1 | /* |
| 2 | * jDTAUS Core Utilities |
| 3 | * Copyright (C) 2005 Christian Schulte |
| 4 | * <cs@schulte.it> |
| 5 | * |
| 6 | * This library is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or any later version. |
| 10 | * |
| 11 | * This library is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with this library; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | * |
| 20 | */ |
| 21 | package org.jdtaus.core.io.util; |
| 22 | |
| 23 | import java.io.IOException; |
| 24 | import java.io.InputStream; |
| 25 | import java.io.OutputStream; |
| 26 | import java.util.Iterator; |
| 27 | import java.util.Locale; |
| 28 | import java.util.Map; |
| 29 | import java.util.TreeMap; |
| 30 | import org.jdtaus.core.container.ContainerFactory; |
| 31 | import org.jdtaus.core.io.FileOperations; |
| 32 | import org.jdtaus.core.lang.spi.MemoryManager; |
| 33 | import org.jdtaus.core.logging.spi.Logger; |
| 34 | |
| 35 | /** |
| 36 | * Coalescing {@code FileOperations} cache. |
| 37 | * <p>This implementation implements a coalescing cache for |
| 38 | * {@code FileOperations} implementations. The cache is controlled by |
| 39 | * configuration property {@code blockSize}. By default property |
| 40 | * {@code blockSize} is initialized to {@code 2097152} leading to a cache |
| 41 | * size of 10 MB (multiplied by property {@code cacheSize} which defaults to |
| 42 | * {@code 5}). All memory is allocated during instantiation so that an |
| 43 | * {@code OutOfMemoryError} may be thrown when constructing the cache but not |
| 44 | * when working with the instance.</p> |
| 45 | * |
| 46 | * <p><b>Note:</b><br> |
| 47 | * This implementation is not thread-safe and concurrent changes to the |
| 48 | * underlying {@code FileOperations} implementation are not supported.</p> |
| 49 | * |
| 50 | * @author <a href="mailto:cs@schulte.it">Christian Schulte</a> |
| 51 | * @version $JDTAUS: CoalescingFileOperations.java 8743 2012-10-07 03:06:20Z schulte $ |
| 52 | */ |
| 53 | public final class CoalescingFileOperations implements FlushableFileOperations |
| 54 | { |
| 55 | //--Dependencies------------------------------------------------------------ |
| 56 | |
| 57 | // <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:jdtausDependencies |
| 58 | // This section is managed by jdtaus-container-mojo. |
| 59 | |
| 60 | /** |
| 61 | * Gets the configured <code>MemoryManager</code> implementation. |
| 62 | * |
| 63 | * @return The configured <code>MemoryManager</code> implementation. |
| 64 | */ |
| 65 | private MemoryManager getMemoryManager() |
| 66 | { |
| 67 | return (MemoryManager) ContainerFactory.getContainer(). |
| 68 | getDependency( this, "MemoryManager" ); |
| 69 | |
| 70 | } |
| 71 | |
| 72 | /** |
| 73 | * Gets the configured <code>Locale</code> implementation. |
| 74 | * |
| 75 | * @return The configured <code>Locale</code> implementation. |
| 76 | */ |
| 77 | private Locale getLocale() |
| 78 | { |
| 79 | return (Locale) ContainerFactory.getContainer(). |
| 80 | getDependency( this, "Locale" ); |
| 81 | |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Gets the configured <code>Logger</code> implementation. |
| 86 | * |
| 87 | * @return The configured <code>Logger</code> implementation. |
| 88 | */ |
| 89 | private Logger getLogger() |
| 90 | { |
| 91 | return (Logger) ContainerFactory.getContainer(). |
| 92 | getDependency( this, "Logger" ); |
| 93 | |
| 94 | } |
| 95 | |
| 96 | // </editor-fold>//GEN-END:jdtausDependencies |
| 97 | |
| 98 | //------------------------------------------------------------Dependencies-- |
| 99 | //--Properties-------------------------------------------------------------- |
| 100 | |
| 101 | // <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:jdtausProperties |
| 102 | // This section is managed by jdtaus-container-mojo. |
| 103 | |
| 104 | /** |
| 105 | * Gets the value of property <code>defaultCacheBlocks</code>. |
| 106 | * |
| 107 | * @return Default number of cache blocks. |
| 108 | */ |
| 109 | private java.lang.Integer getDefaultCacheBlocks() |
| 110 | { |
| 111 | return (java.lang.Integer) ContainerFactory.getContainer(). |
| 112 | getProperty( this, "defaultCacheBlocks" ); |
| 113 | |
| 114 | } |
| 115 | |
| 116 | /** |
| 117 | * Gets the value of property <code>defaultBlockSize</code>. |
| 118 | * |
| 119 | * @return Default size of one cache block in byte. |
| 120 | */ |
| 121 | private java.lang.Integer getDefaultBlockSize() |
| 122 | { |
| 123 | return (java.lang.Integer) ContainerFactory.getContainer(). |
| 124 | getProperty( this, "defaultBlockSize" ); |
| 125 | |
| 126 | } |
| 127 | |
| 128 | // </editor-fold>//GEN-END:jdtausProperties |
| 129 | |
| 130 | //--------------------------------------------------------------Properties-- |
| 131 | //--FileOperations---------------------------------------------------------- |
| 132 | |
| 133 | public long getLength() throws IOException |
| 134 | { |
| 135 | this.assertNotClosed(); |
| 136 | |
| 137 | return this.getFileOperations().getLength(); |
| 138 | } |
| 139 | |
| 140 | public void setLength( final long newLength ) throws IOException |
| 141 | { |
| 142 | this.assertNotClosed(); |
| 143 | |
| 144 | // Update the length of any cache nodes involved in the operation. |
| 145 | final long oldLength = this.getLength(); |
| 146 | if ( newLength > oldLength ) |
| 147 | { |
| 148 | final long delta = newLength - oldLength; |
| 149 | |
| 150 | assert delta <= Integer.MAX_VALUE : |
| 151 | "Unexpected implementation limit reached."; |
| 152 | |
| 153 | final Node[] nodes = |
| 154 | this.getCacheNodesForLength( oldLength, (int) delta ); |
| 155 | |
| 156 | for ( int i = 0; i < nodes.length; i++ ) |
| 157 | { |
| 158 | final long startPos = nodes[i].block * this.getBlockSize(); |
| 159 | final long blockDelta = newLength - startPos; |
| 160 | |
| 161 | assert blockDelta <= Integer.MAX_VALUE : |
| 162 | "Unexpected implementation limit reached."; |
| 163 | |
| 164 | nodes[i].length = blockDelta >= this.getBlockSize() |
| 165 | ? this.getBlockSize() |
| 166 | : (int) blockDelta; |
| 167 | |
| 168 | } |
| 169 | } |
| 170 | else if ( newLength < oldLength ) |
| 171 | { |
| 172 | final long delta = oldLength - newLength; |
| 173 | |
| 174 | assert delta <= Integer.MAX_VALUE : |
| 175 | "Unexpected implementation limit reached."; |
| 176 | |
| 177 | final Node[] nodes = |
| 178 | this.getCacheNodesForLength( newLength, (int) delta ); |
| 179 | |
| 180 | for ( int i = 0; i < nodes.length; i++ ) |
| 181 | { |
| 182 | final long startPos = nodes[i].block * this.getBlockSize(); |
| 183 | if ( startPos > newLength ) |
| 184 | { // Discard the block. |
| 185 | this.root.remove( new Long( nodes[i].block ) ); |
| 186 | } |
| 187 | else |
| 188 | { // Update the blocks length. |
| 189 | final long blockDelta = newLength - startPos; |
| 190 | |
| 191 | assert blockDelta <= Integer.MAX_VALUE : |
| 192 | "Unexpected implementation limit reached."; |
| 193 | |
| 194 | nodes[i].length = blockDelta >= this.getBlockSize() |
| 195 | ? this.getBlockSize() |
| 196 | : (int) blockDelta; |
| 197 | |
| 198 | } |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | this.getFileOperations().setLength( newLength ); |
| 203 | |
| 204 | if ( this.filePointer > newLength ) |
| 205 | { |
| 206 | this.filePointer = newLength; |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | public long getFilePointer() throws IOException |
| 211 | { |
| 212 | this.assertNotClosed(); |
| 213 | |
| 214 | return this.filePointer; |
| 215 | } |
| 216 | |
| 217 | public void setFilePointer( final long pos ) throws IOException |
| 218 | { |
| 219 | this.assertNotClosed(); |
| 220 | |
| 221 | this.filePointer = pos; |
| 222 | } |
| 223 | |
| 224 | public int read( final byte[] buf, int off, int len ) throws IOException |
| 225 | { |
| 226 | if ( buf == null ) |
| 227 | { |
| 228 | throw new NullPointerException( "buf" ); |
| 229 | } |
| 230 | if ( off < 0 ) |
| 231 | { |
| 232 | throw new IndexOutOfBoundsException( Integer.toString( off ) ); |
| 233 | } |
| 234 | if ( len < 0 ) |
| 235 | { |
| 236 | throw new IndexOutOfBoundsException( Integer.toString( len ) ); |
| 237 | } |
| 238 | if ( off + len > buf.length ) |
| 239 | { |
| 240 | throw new IndexOutOfBoundsException( Integer.toString( off + len ) ); |
| 241 | } |
| 242 | |
| 243 | this.assertNotClosed(); |
| 244 | |
| 245 | int read = FileOperations.EOF; |
| 246 | |
| 247 | if ( len == 0 ) |
| 248 | { |
| 249 | read = 0; |
| 250 | } |
| 251 | else if ( this.filePointer < this.getLength() ) |
| 252 | { // End of file not reached. |
| 253 | final Node[] nodes = |
| 254 | this.getCacheNodesForLength( this.filePointer, len ); |
| 255 | |
| 256 | // Ensure cache holds the data of the involved blocks. |
| 257 | this.fillCache( nodes ); |
| 258 | |
| 259 | int copied = 0; |
| 260 | for ( int i = 0; i < nodes.length; i++ ) |
| 261 | { |
| 262 | if ( nodes[i].length == FileOperations.EOF ) |
| 263 | { // Skip any end of file nodes. |
| 264 | continue; |
| 265 | } |
| 266 | |
| 267 | if ( nodes[i].cacheIndex != Node.NO_CACHEINDEX ) |
| 268 | { // Node is associated with cache memory; cache is used. |
| 269 | |
| 270 | // Use the current file pointer as the starting index. |
| 271 | final long delta = |
| 272 | nodes[i].cacheIndex + |
| 273 | ( this.filePointer - nodes[i].block * |
| 274 | this.getBlockSize() ); |
| 275 | |
| 276 | assert delta <= Integer.MAX_VALUE : |
| 277 | "Unexpected implementation limit reached."; |
| 278 | |
| 279 | final int blockOffset = (int) delta; |
| 280 | final int blockDelta = nodes[i].length - |
| 281 | ( blockOffset - nodes[i].cacheIndex ); |
| 282 | |
| 283 | final int copyLength = len > blockDelta |
| 284 | ? blockDelta |
| 285 | : len; |
| 286 | |
| 287 | System.arraycopy( this.getCache(), blockOffset, buf, off, |
| 288 | copyLength ); |
| 289 | |
| 290 | off += copyLength; |
| 291 | len -= copyLength; |
| 292 | copied += copyLength; |
| 293 | this.filePointer += copyLength; |
| 294 | } |
| 295 | else |
| 296 | { // Node is not associated with cache memory; read directly. |
| 297 | this.getFileOperations().setFilePointer( this.filePointer ); |
| 298 | copied += this.getFileOperations().read( buf, off, len ); |
| 299 | this.filePointer += len; |
| 300 | |
| 301 | this.getLogger().debug( |
| 302 | this.getReadBypassesCacheMessage( |
| 303 | this.getLocale(), |
| 304 | new Integer( this.getBlockSize() ), |
| 305 | new Integer( this.getCacheBlocks() ), |
| 306 | new Integer( len ) ) ); |
| 307 | |
| 308 | |
| 309 | break; |
| 310 | } |
| 311 | } |
| 312 | |
| 313 | read = copied; |
| 314 | } |
| 315 | |
| 316 | return read; |
| 317 | } |
| 318 | |
| 319 | public void write( final byte[] buf, int off, int len ) throws IOException |
| 320 | { |
| 321 | if ( buf == null ) |
| 322 | { |
| 323 | throw new NullPointerException( "buf" ); |
| 324 | } |
| 325 | if ( off < 0 ) |
| 326 | { |
| 327 | throw new IndexOutOfBoundsException( Integer.toString( off ) ); |
| 328 | } |
| 329 | if ( len < 0 ) |
| 330 | { |
| 331 | throw new IndexOutOfBoundsException( Integer.toString( len ) ); |
| 332 | } |
| 333 | if ( off + len > buf.length ) |
| 334 | { |
| 335 | throw new IndexOutOfBoundsException( Integer.toString( off + len ) ); |
| 336 | } |
| 337 | |
| 338 | this.assertNotClosed(); |
| 339 | |
| 340 | if ( this.filePointer + len > this.getLength() ) |
| 341 | { // Expand the file of the backing instance. |
| 342 | this.setLength( this.filePointer + len ); |
| 343 | } |
| 344 | |
| 345 | final Node[] nodes = |
| 346 | this.getCacheNodesForLength( this.filePointer, len ); |
| 347 | |
| 348 | // Ensure cache holds the data of the involved blocks. |
| 349 | this.fillCache( nodes ); |
| 350 | |
| 351 | for ( int i = 0; i < nodes.length; i++ ) |
| 352 | { |
| 353 | // Check for correct file length update. |
| 354 | assert nodes[i].length != FileOperations.EOF : |
| 355 | "Unexpected cache state."; |
| 356 | |
| 357 | if ( nodes[i].cacheIndex != Node.NO_CACHEINDEX ) |
| 358 | { // Node is associated with cache memory; cache is used. |
| 359 | |
| 360 | // Use the current file pointer as the starting index. |
| 361 | final long delta = nodes[i].cacheIndex + |
| 362 | ( this.filePointer - nodes[i].block * |
| 363 | this.getBlockSize() ); |
| 364 | |
| 365 | assert delta <= Integer.MAX_VALUE : |
| 366 | "Unexpected implementation limit reached."; |
| 367 | |
| 368 | final int blockOffset = (int) delta; |
| 369 | final int blockDelta = nodes[i].length - |
| 370 | ( blockOffset - nodes[i].cacheIndex ); |
| 371 | |
| 372 | final int copyLength = len > blockDelta |
| 373 | ? blockDelta |
| 374 | : len; |
| 375 | |
| 376 | System.arraycopy( buf, off, this.getCache(), blockOffset, |
| 377 | copyLength ); |
| 378 | |
| 379 | off += copyLength; |
| 380 | len -= copyLength; |
| 381 | this.filePointer += copyLength; |
| 382 | nodes[i].dirty = true; |
| 383 | } |
| 384 | else |
| 385 | { // Node is not associated with cache memory; write out directly. |
| 386 | this.getFileOperations().setFilePointer( this.filePointer ); |
| 387 | this.getFileOperations().write( buf, off, len ); |
| 388 | this.filePointer += len; |
| 389 | |
| 390 | this.getLogger().debug( |
| 391 | this.getWriteBypassesCacheMessage( |
| 392 | this.getLocale(), |
| 393 | new Integer( this.getBlockSize() ), |
| 394 | new Integer( this.getCacheBlocks() ), |
| 395 | new Integer( len ) ) ); |
| 396 | |
| 397 | |
| 398 | break; |
| 399 | } |
| 400 | } |
| 401 | } |
| 402 | |
| 403 | public void read( final OutputStream out ) throws IOException |
| 404 | { |
| 405 | this.assertNotClosed(); |
| 406 | |
| 407 | this.getFileOperations().read( out ); |
| 408 | this.filePointer = this.getFileOperations().getFilePointer(); |
| 409 | } |
| 410 | |
| 411 | public void write( final InputStream in ) throws IOException |
| 412 | { |
| 413 | this.assertNotClosed(); |
| 414 | |
| 415 | this.getFileOperations().write( in ); |
| 416 | this.filePointer = this.getFileOperations().getFilePointer(); |
| 417 | } |
| 418 | |
| 419 | /** |
| 420 | * {@inheritDoc} |
| 421 | * Flushes the cache and closes the {@code FileOperations} implementation |
| 422 | * backing the instance. |
| 423 | * |
| 424 | * @throws IOException if flushing or closing the {@code FileOperations} |
| 425 | * implementation backing the instance fails, or if the instance already |
| 426 | * is closed. |
| 427 | */ |
| 428 | public void close() throws IOException |
| 429 | { |
| 430 | this.assertNotClosed(); |
| 431 | |
| 432 | this.flush(); |
| 433 | this.getFileOperations().close(); |
| 434 | this.closed = true; |
| 435 | } |
| 436 | |
| 437 | //----------------------------------------------------------FileOperations-- |
| 438 | //--FlushableFileOperations------------------------------------------------- |
| 439 | |
| 440 | /** |
| 441 | * {@inheritDoc} |
| 442 | * This method calls the {@code flush()} method of an underlying |
| 443 | * {@code FlushableFileOperations} implementation, if any. |
| 444 | * |
| 445 | * @throws IOException if writing any pending changes fails or if the |
| 446 | * instance is closed. |
| 447 | */ |
| 448 | public void flush() throws IOException |
| 449 | { |
| 450 | this.assertNotClosed(); |
| 451 | |
| 452 | this.defragmentCache(); |
| 453 | |
| 454 | long startPos = FileOperations.EOF; |
| 455 | int startIndex = FileOperations.EOF; |
| 456 | int length = FileOperations.EOF; |
| 457 | Node previous = null; |
| 458 | boolean dirty = false; |
| 459 | |
| 460 | for ( final Iterator it = this.root.entrySet().iterator(); |
| 461 | it.hasNext(); ) |
| 462 | { |
| 463 | final Map.Entry entry = (Map.Entry) it.next(); |
| 464 | final long block = ( (Long) entry.getKey() ).longValue(); |
| 465 | final Node current = (Node) entry.getValue(); |
| 466 | |
| 467 | // Skip any end of file nodes and nodes not associated with memory. |
| 468 | if ( current.length == FileOperations.EOF || |
| 469 | current.cacheIndex == Node.NO_CACHEINDEX ) |
| 470 | { |
| 471 | continue; |
| 472 | } |
| 473 | |
| 474 | assert current.block == block : "Unexpected cache state."; |
| 475 | |
| 476 | if ( previous == null ) |
| 477 | { // Start the first chunk. |
| 478 | previous = current; |
| 479 | startPos = current.block * this.getBlockSize(); |
| 480 | startIndex = current.cacheIndex; |
| 481 | length = current.length; |
| 482 | dirty = current.dirty; |
| 483 | } |
| 484 | else if ( current.block == previous.block + 1L ) |
| 485 | { // Expand the current chunk. |
| 486 | |
| 487 | assert current.cacheIndex == previous.cacheIndex + |
| 488 | this.getBlockSize() : |
| 489 | "Unexpected cache state."; |
| 490 | |
| 491 | previous = current; |
| 492 | length += current.length; |
| 493 | if ( !dirty ) |
| 494 | { |
| 495 | dirty = current.dirty; |
| 496 | } |
| 497 | } |
| 498 | else |
| 499 | { // Write out the current chunk and start a new one. |
| 500 | if ( dirty ) |
| 501 | { |
| 502 | this.getFileOperations().setFilePointer( startPos ); |
| 503 | this.getFileOperations().write( |
| 504 | this.getCache(), startIndex, length ); |
| 505 | |
| 506 | } |
| 507 | |
| 508 | previous = current; |
| 509 | startPos = current.block * this.getBlockSize(); |
| 510 | startIndex = current.cacheIndex; |
| 511 | length = current.length; |
| 512 | dirty = current.dirty; |
| 513 | } |
| 514 | } |
| 515 | |
| 516 | if ( dirty ) |
| 517 | { // Write the remaining chunk. |
| 518 | this.getFileOperations().setFilePointer( startPos ); |
| 519 | this.getFileOperations().write( |
| 520 | this.getCache(), startIndex, length ); |
| 521 | |
| 522 | } |
| 523 | |
| 524 | // Reset cache state. |
| 525 | for ( final Iterator it = this.root.entrySet().iterator(); |
| 526 | it.hasNext(); ) |
| 527 | { |
| 528 | final Map.Entry entry = (Map.Entry) it.next(); |
| 529 | final Node current = (Node) entry.getValue(); |
| 530 | |
| 531 | current.cacheIndex = Node.NO_CACHEINDEX; |
| 532 | current.dirty = false; |
| 533 | } |
| 534 | |
| 535 | this.nextCacheIndex = 0; |
| 536 | |
| 537 | if ( this.getFileOperations() instanceof FlushableFileOperations ) |
| 538 | { // Cache of the backing instance also needs to get flushed. |
| 539 | ( (FlushableFileOperations) this.getFileOperations() ).flush(); |
| 540 | } |
| 541 | } |
| 542 | |
| 543 | //-------------------------------------------------FlushableFileOperations-- |
| 544 | //--CoalescingFileOperations------------------------------------------------ |
| 545 | |
| 546 | /** Node describing a cache block. */ |
| 547 | private static final class Node |
| 548 | { |
| 549 | |
| 550 | private static final int NO_CACHEINDEX = Integer.MIN_VALUE; |
| 551 | |
| 552 | private Node() |
| 553 | { |
| 554 | super(); |
| 555 | } |
| 556 | |
| 557 | private long block; |
| 558 | |
| 559 | private int cacheIndex = NO_CACHEINDEX; |
| 560 | |
| 561 | private int length; |
| 562 | |
| 563 | private boolean dirty; |
| 564 | |
| 565 | } |
| 566 | |
| 567 | /** The {@code FileOperations} backing the instance. */ |
| 568 | private final FileOperations fileOperations; |
| 569 | |
| 570 | /** Cached blocks. */ |
| 571 | private byte[] cache; |
| 572 | |
| 573 | /** Second cache memory used during defragmentation. */ |
| 574 | private byte[] defragCache; |
| 575 | |
| 576 | /** Index of the next free cached block. */ |
| 577 | private int nextCacheIndex; |
| 578 | |
| 579 | /** Maps blocks to corresponding {@code Node}s. */ |
| 580 | private final Map root = new TreeMap(); |
| 581 | |
| 582 | /** File pointer. */ |
| 583 | private long filePointer; |
| 584 | |
| 585 | /** Caches the value returned by method {@code getFilePointerBlock}. */ |
| 586 | private long cachedFilePointerBlock = NO_FILEPOINTERBLOCK; |
| 587 | |
| 588 | private long cachedFilePointerBlockStart = FileOperations.EOF; |
| 589 | |
| 590 | private static final long NO_FILEPOINTERBLOCK = Long.MIN_VALUE; |
| 591 | |
| 592 | /** Flags the instance as beeing closed. */ |
| 593 | private boolean closed; |
| 594 | |
| 595 | /** The number of bytes occupied by one cache block. */ |
| 596 | private Integer blockSize; |
| 597 | |
| 598 | /** The number of cache blocks. */ |
| 599 | private Integer cacheBlocks; |
| 600 | |
| 601 | /** |
| 602 | * Creates a new {@code CoalescingFileOperations} instance taking the |
| 603 | * {@code FileOperations} backing the instance. |
| 604 | * |
| 605 | * @param fileOperations the {@code FileOperations} backing the instance. |
| 606 | * |
| 607 | * @throws NullPointerException if {@code fileOperations} is {@code null}. |
| 608 | * @throws IOException if reading fails. |
| 609 | */ |
| 610 | public CoalescingFileOperations( final FileOperations fileOperations ) |
| 611 | throws IOException |
| 612 | { |
| 613 | super(); |
| 614 | |
| 615 | if ( fileOperations == null ) |
| 616 | { |
| 617 | throw new NullPointerException( "fileOperations" ); |
| 618 | } |
| 619 | |
| 620 | this.fileOperations = fileOperations; |
| 621 | this.filePointer = fileOperations.getFilePointer(); |
| 622 | } |
| 623 | |
| 624 | /** |
| 625 | * Creates a new {@code CoalescingFileOperations} instance taking the |
| 626 | * {@code FileOperations} backing the instance and the number of bytes |
| 627 | * occupied by one cache block. |
| 628 | * |
| 629 | * @param fileOperations the {@code FileOperations} backing the instance. |
| 630 | * @param blockSize the number of bytes occupied by one cache block. |
| 631 | * |
| 632 | * @throws NullPointerException if {@code fileOperations} is {@code null}. |
| 633 | * @throws IOException if reading fails. |
| 634 | */ |
| 635 | public CoalescingFileOperations( final FileOperations fileOperations, |
| 636 | final int blockSize ) throws IOException |
| 637 | { |
| 638 | this( fileOperations ); |
| 639 | if ( blockSize > 0 ) |
| 640 | { |
| 641 | this.blockSize = new Integer( blockSize ); |
| 642 | } |
| 643 | } |
| 644 | |
| 645 | /** |
| 646 | * Creates a new {@code CoalescingFileOperations} instance taking the |
| 647 | * {@code FileOperations} backing the instance, the number of bytes |
| 648 | * occupied by one cache block and the number of cache blocks. |
| 649 | * |
| 650 | * @param fileOperations the {@code FileOperations} backing the instance. |
| 651 | * @param blockSize the number of bytes occupied by one cache block. |
| 652 | * @param cacheBlocks number of cache blocks. |
| 653 | * |
| 654 | * @throws NullPointerException if {@code fileOperations} is {@code null}. |
| 655 | * @throws IOException if reading fails. |
| 656 | */ |
| 657 | public CoalescingFileOperations( final FileOperations fileOperations, |
| 658 | final int blockSize, |
| 659 | final int cacheBlocks ) |
| 660 | throws IOException |
| 661 | { |
| 662 | this( fileOperations, blockSize ); |
| 663 | if ( cacheBlocks > 0 ) |
| 664 | { |
| 665 | this.cacheBlocks = new Integer( cacheBlocks ); |
| 666 | } |
| 667 | } |
| 668 | |
| 669 | /** |
| 670 | * Gets the {@code FileOperations} implementation operations are performed |
| 671 | * with. |
| 672 | * |
| 673 | * @return the {@code FileOperations} implementation operations are |
| 674 | * performed with. |
| 675 | */ |
| 676 | public FileOperations getFileOperations() |
| 677 | { |
| 678 | return this.fileOperations; |
| 679 | } |
| 680 | |
| 681 | /** |
| 682 | * Gets the number of bytes occupied by one cache block. |
| 683 | * |
| 684 | * @return the number of bytes occupied by one cache block. |
| 685 | */ |
| 686 | public int getBlockSize() |
| 687 | { |
| 688 | if ( this.blockSize == null ) |
| 689 | { |
| 690 | this.blockSize = this.getDefaultBlockSize(); |
| 691 | } |
| 692 | |
| 693 | return this.blockSize.intValue(); |
| 694 | } |
| 695 | |
| 696 | /** |
| 697 | * Gets the number of blocks in the cache. |
| 698 | * |
| 699 | * @return the number of blocks in the cache. |
| 700 | */ |
| 701 | public int getCacheBlocks() |
| 702 | { |
| 703 | if ( this.cacheBlocks == null ) |
| 704 | { |
| 705 | this.cacheBlocks = this.getDefaultCacheBlocks(); |
| 706 | } |
| 707 | |
| 708 | return this.cacheBlocks.intValue(); |
| 709 | } |
| 710 | |
| 711 | /** |
| 712 | * Gets the cache buffer. |
| 713 | * |
| 714 | * @return the cache buffer. |
| 715 | */ |
| 716 | private byte[] getCache() |
| 717 | { |
| 718 | if ( this.cache == null ) |
| 719 | { |
| 720 | this.cache = this.getMemoryManager().allocateBytes( |
| 721 | this.getBlockSize() * this.getCacheBlocks() ); |
| 722 | |
| 723 | } |
| 724 | |
| 725 | return this.cache; |
| 726 | } |
| 727 | |
| 728 | /** |
| 729 | * Gets the buffer used during defragmentation of the cache. |
| 730 | * |
| 731 | * @return the buffer used during defragmentation of the cache. |
| 732 | */ |
| 733 | private byte[] getDefragCache() |
| 734 | { |
| 735 | if ( this.defragCache == null ) |
| 736 | { |
| 737 | this.defragCache = this.getMemoryManager().allocateBytes( |
| 738 | this.getBlockSize() * this.getCacheBlocks() ); |
| 739 | |
| 740 | } |
| 741 | |
| 742 | return this.defragCache; |
| 743 | } |
| 744 | |
| 745 | /** |
| 746 | * Gets the block pointed to by a given file pointer value. |
| 747 | * |
| 748 | * @param filePointer the file pointer value for which to return the |
| 749 | * corresponding block. |
| 750 | * |
| 751 | * @return the block pointed to by {@code filePointer}. |
| 752 | */ |
| 753 | private long getFilePointerBlock( final long filePointer ) |
| 754 | { |
| 755 | if ( this.cachedFilePointerBlock == NO_FILEPOINTERBLOCK ) |
| 756 | { |
| 757 | this.cachedFilePointerBlock = |
| 758 | ( filePointer / this.getBlockSize() ) - |
| 759 | ( ( filePointer % this.getBlockSize() ) / this.getBlockSize() ); |
| 760 | |
| 761 | this.cachedFilePointerBlockStart = |
| 762 | this.cachedFilePointerBlock * this.getBlockSize(); |
| 763 | |
| 764 | } |
| 765 | else |
| 766 | { |
| 767 | if ( !( filePointer >= this.cachedFilePointerBlockStart && |
| 768 | filePointer <= this.cachedFilePointerBlockStart + |
| 769 | this.getBlockSize() ) ) |
| 770 | { |
| 771 | this.cachedFilePointerBlock = |
| 772 | ( filePointer / this.getBlockSize() ) - |
| 773 | ( ( filePointer % this.getBlockSize() ) / |
| 774 | this.getBlockSize() ); |
| 775 | |
| 776 | this.cachedFilePointerBlockStart = |
| 777 | this.cachedFilePointerBlock * this.getBlockSize(); |
| 778 | |
| 779 | } |
| 780 | } |
| 781 | |
| 782 | return this.cachedFilePointerBlock; |
| 783 | } |
| 784 | |
| 785 | /** |
| 786 | * Gets the cache nodes for all blocks involved in a read or write operation |
| 787 | * of a given length for a given file pointer value. |
| 788 | * |
| 789 | * @param filePointer the file pointer value to use for computing the |
| 790 | * number of involved blocks for a read or write operation of |
| 791 | * {@code length}. |
| 792 | * @param length the length of the operation to perform. |
| 793 | * |
| 794 | * @return an array of cache nodes for all blocks involved in the |
| 795 | * operation in the order corresponding to the operation's needs. |
| 796 | */ |
| 797 | private Node[] getCacheNodesForLength( final long filePointer, |
| 798 | final int length ) |
| 799 | { |
| 800 | final long startingBlock = this.getFilePointerBlock( filePointer ); |
| 801 | final long endingBlock = |
| 802 | this.getFilePointerBlock( filePointer + length ); |
| 803 | |
| 804 | assert endingBlock - startingBlock <= Integer.MAX_VALUE : |
| 805 | "Unexpected implementation limit reached."; |
| 806 | |
| 807 | final Node[] nodes = |
| 808 | new Node[ (int) ( endingBlock - startingBlock + 1L ) ]; |
| 809 | |
| 810 | if ( startingBlock == endingBlock ) |
| 811 | { |
| 812 | nodes[0] = this.getCacheNode( startingBlock ); |
| 813 | } |
| 814 | else |
| 815 | { |
| 816 | int i; |
| 817 | long block; |
| 818 | |
| 819 | for ( block = startingBlock, i = 0; block <= endingBlock; |
| 820 | block++, i++ ) |
| 821 | { |
| 822 | nodes[i] = this.getCacheNode( block ); |
| 823 | } |
| 824 | } |
| 825 | |
| 826 | return nodes; |
| 827 | } |
| 828 | |
| 829 | /** |
| 830 | * Fills the cache for a given set of cache nodes. |
| 831 | * <p>This method ensures that each given node gets associated with |
| 832 | * corresponding cache memory possibly flushing the cache before |
| 833 | * reading.</p> |
| 834 | * |
| 835 | * @param nodes the nodes to fill the cache for. |
| 836 | * |
| 837 | * @throws NullPointerException if {@code nodes} is {@code null}. |
| 838 | * @throws IOException if reading fails. |
| 839 | */ |
| 840 | private void fillCache( final Node[] nodes ) throws IOException |
| 841 | { |
| 842 | if ( nodes == null ) |
| 843 | { |
| 844 | throw new NullPointerException( "nodes" ); |
| 845 | } |
| 846 | |
| 847 | // Calculate the amount of bytes needed to be available in the cache |
| 848 | // and flush the cache if nodes would not fit. |
| 849 | long neededBytes = 0L; |
| 850 | for ( int i = nodes.length - 1; i >= 0; i-- ) |
| 851 | { |
| 852 | if ( nodes[i].cacheIndex == Node.NO_CACHEINDEX ) |
| 853 | { // Node's block needs to be read. |
| 854 | neededBytes += this.getBlockSize(); |
| 855 | } |
| 856 | } |
| 857 | |
| 858 | if ( this.nextCacheIndex + neededBytes > this.getCache().length ) |
| 859 | { // Cache cannot hold the needed blocks so needs flushing. |
| 860 | this.flush(); |
| 861 | } |
| 862 | |
| 863 | // Associate each node with cache memory for nodes not already |
| 864 | // associated with cache memory and fill these nodes' cache memory. |
| 865 | for ( int i = nodes.length - 1; i >= 0; i-- ) |
| 866 | { |
| 867 | if ( nodes[i].cacheIndex == Node.NO_CACHEINDEX && |
| 868 | this.nextCacheIndex < this.getCache().length ) |
| 869 | { // Node is not associated with any cache memory and can be read. |
| 870 | |
| 871 | // Update the length field of the node for the block checking |
| 872 | // for a possible end of file condition. |
| 873 | final long pos = nodes[i].block * this.getBlockSize(); |
| 874 | if ( pos > this.getLength() ) |
| 875 | { // Node is behind the end of the file. |
| 876 | nodes[i].length = FileOperations.EOF; |
| 877 | continue; |
| 878 | } |
| 879 | else if ( pos + this.getBlockSize() > this.getLength() ) |
| 880 | { |
| 881 | final long delta = this.getLength() - pos; |
| 882 | |
| 883 | assert delta <= Integer.MAX_VALUE : |
| 884 | "Unexpected implementation limit reached."; |
| 885 | |
| 886 | nodes[i].length = (int) delta; |
| 887 | } |
| 888 | else |
| 889 | { |
| 890 | nodes[i].length = this.getBlockSize(); |
| 891 | } |
| 892 | |
| 893 | // Associated the node with cache memory. |
| 894 | nodes[i].cacheIndex = this.nextCacheIndex; |
| 895 | this.nextCacheIndex += this.getBlockSize(); |
| 896 | |
| 897 | // Read the node's block into cache. |
| 898 | int read = FileOperations.EOF; |
| 899 | int totalRead = 0; |
| 900 | int toRead = nodes[i].length; |
| 901 | this.getFileOperations().setFilePointer( pos ); |
| 902 | |
| 903 | do |
| 904 | { |
| 905 | read = this.getFileOperations().read( |
| 906 | this.getCache(), nodes[i].cacheIndex + totalRead, |
| 907 | toRead ); |
| 908 | |
| 909 | assert read != FileOperations.EOF : |
| 910 | "Unexpected end of file."; |
| 911 | |
| 912 | totalRead += read; |
| 913 | toRead -= read; |
| 914 | |
| 915 | } |
| 916 | while ( totalRead < nodes[i].length ); |
| 917 | } |
| 918 | } |
| 919 | } |
| 920 | |
| 921 | /** Defragments the cache. */ |
| 922 | private void defragmentCache() |
| 923 | { |
| 924 | int defragIndex = 0; |
| 925 | |
| 926 | // Step through the cached blocks and defragment the cache. |
| 927 | for ( final Iterator it = this.root.entrySet().iterator(); |
| 928 | it.hasNext(); ) |
| 929 | { |
| 930 | final Map.Entry entry = (Map.Entry) it.next(); |
| 931 | final long block = ( (Long) entry.getKey() ).longValue(); |
| 932 | final Node current = (Node) entry.getValue(); |
| 933 | |
| 934 | // Skip any end of file nodes and nodes not associated with memory. |
| 935 | if ( current.length == FileOperations.EOF || |
| 936 | current.cacheIndex == Node.NO_CACHEINDEX ) |
| 937 | { |
| 938 | continue; |
| 939 | } |
| 940 | |
| 941 | assert current.block == block : "Unexpected cache state."; |
| 942 | |
| 943 | System.arraycopy( this.getCache(), current.cacheIndex, |
| 944 | this.getDefragCache(), defragIndex, |
| 945 | this.getBlockSize() ); |
| 946 | |
| 947 | current.cacheIndex = defragIndex; |
| 948 | defragIndex += this.getBlockSize(); |
| 949 | } |
| 950 | |
| 951 | System.arraycopy( this.getDefragCache(), 0, this.getCache(), 0, |
| 952 | this.getCache().length ); |
| 953 | |
| 954 | } |
| 955 | |
| 956 | /** |
| 957 | * Gets the cache node for a given block. |
| 958 | * |
| 959 | * @param block the block to return the corresponding cache node for. |
| 960 | * |
| 961 | * @return the cache node for {@code block}. |
| 962 | */ |
| 963 | private Node getCacheNode( final long block ) |
| 964 | { |
| 965 | final Long key = new Long( block ); |
| 966 | Node node = (Node) this.root.get( key ); |
| 967 | if ( node == null ) |
| 968 | { |
| 969 | node = new Node(); |
| 970 | node.block = block; |
| 971 | this.root.put( key, node ); |
| 972 | } |
| 973 | |
| 974 | return node; |
| 975 | } |
| 976 | |
| 977 | /** |
| 978 | * Checks that the instance is not closed. |
| 979 | * |
| 980 | * @throws IOException if the instance is closed. |
| 981 | */ |
| 982 | private void assertNotClosed() throws IOException |
| 983 | { |
| 984 | if ( this.closed ) |
| 985 | { |
| 986 | throw new IOException( this.getAlreadyClosedMessage( |
| 987 | this.getLocale() ) ); |
| 988 | |
| 989 | } |
| 990 | } |
| 991 | |
| 992 | //------------------------------------------------CoalescingFileOperations-- |
| 993 | //--Messages---------------------------------------------------------------- |
| 994 | |
| 995 | // <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:jdtausMessages |
| 996 | // This section is managed by jdtaus-container-mojo. |
| 997 | |
| 998 | /** |
| 999 | * Gets the text of message <code>readBypassesCache</code>. |
| 1000 | * <blockquote><pre>Eine Lese-Operation umging den Cache. Cache zu klein dimensioniert. Aktuelle Blockgröße ist {0,number} und Cache umfaßt {1,number} Blöcke. {2,number} Bytes konnten nicht zwischengespeichert werden.</pre></blockquote> |
| 1001 | * <blockquote><pre>A read operation bypassed the cache. Consider increasing the cache. Current block size is {0,number} and current number of cache blocks is {1,number}. {2,number} bytes could not be cached.</pre></blockquote> |
| 1002 | * |
| 1003 | * @param locale The locale of the message instance to return. |
| 1004 | * @param blockSize The current block size in use. |
| 1005 | * @param cacheBlocks The current number of blocks in use. |
| 1006 | * @param uncachedBytes The number of bytes bypassing caching. |
| 1007 | * |
| 1008 | * @return Information about a misconfigured cache. |
| 1009 | */ |
| 1010 | private String getReadBypassesCacheMessage( final Locale locale, |
| 1011 | final java.lang.Number blockSize, |
| 1012 | final java.lang.Number cacheBlocks, |
| 1013 | final java.lang.Number uncachedBytes ) |
| 1014 | { |
| 1015 | return ContainerFactory.getContainer(). |
| 1016 | getMessage( this, "readBypassesCache", locale, |
| 1017 | new Object[] |
| 1018 | { |
| 1019 | blockSize, |
| 1020 | cacheBlocks, |
| 1021 | uncachedBytes |
| 1022 | }); |
| 1023 | |
| 1024 | } |
| 1025 | |
| 1026 | /** |
| 1027 | * Gets the text of message <code>writeBypassesCache</code>. |
| 1028 | * <blockquote><pre>Eine Schreib-Operation umging den Cache. Cache zu klein dimensioniert. Aktuelle Blockgröße ist {0,number} und Cache umfaßt {1,number} Blöcke. {2,number} Bytes konnten nicht zwischengespeichert werden.</pre></blockquote> |
| 1029 | * <blockquote><pre>A write operation bypassed the cache. Consider increasing the cache. Current block size is {0,number} and current number of cache blocks is {1,number}. {2,number} bytes could not be cached.</pre></blockquote> |
| 1030 | * |
| 1031 | * @param locale The locale of the message instance to return. |
| 1032 | * @param blockSize The current block size in use. |
| 1033 | * @param cacheBlocks The current number of blocks in use. |
| 1034 | * @param uncachedBytes The number of bytes bypassing caching. |
| 1035 | * |
| 1036 | * @return Information about a misconfigured cache. |
| 1037 | */ |
| 1038 | private String getWriteBypassesCacheMessage( final Locale locale, |
| 1039 | final java.lang.Number blockSize, |
| 1040 | final java.lang.Number cacheBlocks, |
| 1041 | final java.lang.Number uncachedBytes ) |
| 1042 | { |
| 1043 | return ContainerFactory.getContainer(). |
| 1044 | getMessage( this, "writeBypassesCache", locale, |
| 1045 | new Object[] |
| 1046 | { |
| 1047 | blockSize, |
| 1048 | cacheBlocks, |
| 1049 | uncachedBytes |
| 1050 | }); |
| 1051 | |
| 1052 | } |
| 1053 | |
| 1054 | /** |
| 1055 | * Gets the text of message <code>alreadyClosed</code>. |
| 1056 | * <blockquote><pre>Instanz geschlossen - keine E/A-Operationen möglich.</pre></blockquote> |
| 1057 | * <blockquote><pre>Instance closed - cannot perform I/O.</pre></blockquote> |
| 1058 | * |
| 1059 | * @param locale The locale of the message instance to return. |
| 1060 | * |
| 1061 | * @return Message stating that an instance is already closed. |
| 1062 | */ |
| 1063 | private String getAlreadyClosedMessage( final Locale locale ) |
| 1064 | { |
| 1065 | return ContainerFactory.getContainer(). |
| 1066 | getMessage( this, "alreadyClosed", locale, null ); |
| 1067 | |
| 1068 | } |
| 1069 | |
| 1070 | // </editor-fold>//GEN-END:jdtausMessages |
| 1071 | |
| 1072 | //----------------------------------------------------------------Messages-- |
| 1073 | } |