| /* |
| * Copyright (C) 2003-2009 JNode.org |
| * 2009,2010 Matthias Treydte <mt@waldheinz.de> |
| * |
| * This library is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU Lesser General Public License as published |
| * by the Free Software Foundation; either version 2.1 of the License, or |
| * (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public |
| * License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public License |
| * along with this library; If not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| */ |
| |
| package de.waldheinz.fs.fat; |
| |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| |
| /** |
| * This is the abstract base class for all directory implementations. |
| * |
| * @author Ewout Prangsma <epr at jnode.org> |
| * @author Matthias Treydte <waldheinz at gmail.com> |
| */ |
| abstract class AbstractDirectory { |
| |
| /** |
| * The maximum length of the volume label. |
| * |
| * @see #setLabel(java.lang.String) |
| */ |
| public static final int MAX_LABEL_LENGTH = 11; |
| |
| private final List<FatDirectoryEntry> entries; |
| private final boolean readOnly; |
| private final boolean isRoot; |
| |
| private boolean dirty; |
| private int capacity; |
| private String volumeLabel; |
| |
| /** |
| * Creates a new instance of {@code AbstractDirectory}. |
| * |
| * @param capacity the initial capacity of the new instance |
| * @param readOnly if the instance should be read-only |
| * @param isRoot if the new {@code AbstractDirectory} represents a root |
| * directory |
| */ |
| protected AbstractDirectory( |
| int capacity, boolean readOnly, boolean isRoot) { |
| |
| this.entries = new ArrayList<FatDirectoryEntry>(); |
| this.capacity = capacity; |
| this.readOnly = readOnly; |
| this.isRoot = isRoot; |
| } |
| |
| /** |
| * Gets called when the {@code AbstractDirectory} must read it's content |
| * off the backing storage. This method must always fill the buffer's |
| * remaining space with the bytes making up this directory, beginning with |
| * the first byte. |
| * |
| * @param data the {@code ByteBuffer} to fill |
| * @throws IOException on read error |
| */ |
| protected abstract void read(ByteBuffer data) throws IOException; |
| |
| /** |
| * Gets called when the {@code AbstractDirectory} wants to write it's |
| * contents to the backing storage. This method is expected to write the |
| * buffer's remaining data to the storage, beginning with the first byte. |
| * |
| * @param data the {@code ByteBuffer} to write |
| * @throws IOException on write error |
| */ |
| protected abstract void write(ByteBuffer data) throws IOException; |
| |
| /** |
| * Returns the number of the cluster where this directory is stored. This |
| * is important when creating the ".." entry in a sub-directory, as this |
| * entry must poing to the storage cluster of it's parent. |
| * |
| * @return this directory's storage cluster |
| */ |
| protected abstract long getStorageCluster(); |
| |
| /** |
| * Gets called by the {@code AbstractDirectory} when it has determined that |
| * it should resize because the number of entries has changed. |
| * |
| * @param entryCount the new number of entries this directory needs to store |
| * @throws IOException on write error |
| * @throws DirectoryFullException if the FAT12/16 root directory is full |
| * @see #sizeChanged(long) |
| * @see #checkEntryCount(int) |
| */ |
| protected abstract void changeSize(int entryCount) |
| throws DirectoryFullException, IOException; |
| |
| /** |
| * Replaces all entries in this directory. |
| * |
| * @param newEntries the new directory entries |
| */ |
| public void setEntries(List<FatDirectoryEntry> newEntries) { |
| if (newEntries.size() > capacity) |
| throw new IllegalArgumentException("too many entries"); |
| |
| this.entries.clear(); |
| this.entries.addAll(newEntries); |
| } |
| |
| /** |
| * |
| * |
| * @param newSize the new storage space for the directory in bytes |
| * @see #changeSize(int) |
| */ |
| protected final void sizeChanged(long newSize) throws IOException { |
| final long newCount = newSize / FatDirectoryEntry.SIZE; |
| if (newCount > Integer.MAX_VALUE) |
| throw new IOException("directory too large"); |
| |
| this.capacity = (int) newCount; |
| } |
| |
| public final FatDirectoryEntry getEntry(int idx) { |
| return this.entries.get(idx); |
| } |
| |
| /** |
| * Returns the current capacity of this {@code AbstractDirectory}. |
| * |
| * @return the number of entries this directory can hold in its current |
| * storage space |
| * @see #changeSize(int) |
| */ |
| public final int getCapacity() { |
| return this.capacity; |
| } |
| |
| /** |
| * The number of entries that are currently stored in this |
| * {@code AbstractDirectory}. |
| * |
| * @return the current number of directory entries |
| */ |
| public final int getEntryCount() { |
| return this.entries.size(); |
| } |
| |
| public boolean isReadOnly() { |
| return readOnly; |
| } |
| |
| public final boolean isRoot() { |
| return this.isRoot; |
| } |
| |
| /** |
| * Gets the number of directory entries in this directory. This is the |
| * number of "real" entries in this directory, possibly plus one if a |
| * volume label is set. |
| * |
| * @return the number of entries in this directory |
| */ |
| public int getSize() { |
| return entries.size() + ((this.volumeLabel != null) ? 1 : 0); |
| } |
| |
| /** |
| * Mark this directory as dirty. |
| */ |
| protected final void setDirty() { |
| this.dirty = true; |
| } |
| |
| /** |
| * Checks if this {@code AbstractDirectory} is a root directory. |
| * |
| * @throws UnsupportedOperationException if this is not a root directory |
| * @see #isRoot() |
| */ |
| private void checkRoot() throws UnsupportedOperationException { |
| if (!isRoot()) { |
| throw new UnsupportedOperationException( |
| "only supported on root directories"); |
| } |
| } |
| |
| /** |
| * Mark this directory as not dirty. |
| */ |
| private void resetDirty() { |
| this.dirty = false; |
| } |
| |
| /** |
| * Flush the contents of this directory to the persistent storage |
| */ |
| public void flush() throws IOException { |
| |
| final ByteBuffer data = ByteBuffer.allocate( |
| getCapacity() * FatDirectoryEntry.SIZE); |
| |
| for (int i=0; i < entries.size(); i++) { |
| final FatDirectoryEntry entry = entries.get(i); |
| |
| if (entry != null) { |
| entry.write(data); |
| } |
| } |
| |
| /* TODO: the label could be placed directly the dot entries */ |
| |
| if (this.volumeLabel != null) { |
| final FatDirectoryEntry labelEntry = |
| FatDirectoryEntry.createVolumeLabel(volumeLabel); |
| |
| labelEntry.write(data); |
| } |
| |
| if (data.hasRemaining()) { |
| FatDirectoryEntry.writeNullEntry(data); |
| } |
| |
| data.flip(); |
| |
| write(data); |
| resetDirty(); |
| } |
| |
| protected final void read() throws IOException { |
| final ByteBuffer data = ByteBuffer.allocate( |
| getCapacity() * FatDirectoryEntry.SIZE); |
| |
| read(data); |
| data.flip(); |
| |
| for (int i=0; i < getCapacity(); i++) { |
| final FatDirectoryEntry e = |
| FatDirectoryEntry.read(data, isReadOnly()); |
| |
| if (e == null) break; |
| |
| if (e.isVolumeLabel()) { |
| if (!this.isRoot) throw new IOException( |
| "volume label in non-root directory"); |
| |
| this.volumeLabel = e.getVolumeLabel(); |
| } else { |
| entries.add(e); |
| } |
| } |
| } |
| |
| public void addEntry(FatDirectoryEntry e) throws IOException { |
| assert (e != null); |
| |
| if (getSize() == getCapacity()) { |
| changeSize(getCapacity() + 1); |
| } |
| |
| entries.add(e); |
| } |
| |
| public void addEntries(FatDirectoryEntry[] entries) |
| throws IOException { |
| |
| if (getSize() + entries.length > getCapacity()) { |
| changeSize(getSize() + entries.length); |
| } |
| |
| this.entries.addAll(Arrays.asList(entries)); |
| } |
| |
| public void removeEntry(FatDirectoryEntry entry) throws IOException { |
| assert (entry != null); |
| |
| this.entries.remove(entry); |
| changeSize(getSize()); |
| } |
| |
| /** |
| * Returns the volume label that is stored in this directory. Reading the |
| * volume label is only supported for the root directory. |
| * |
| * @return the volume label stored in this directory, or {@code null} |
| * @throws UnsupportedOperationException if this is not a root directory |
| * @see #isRoot() |
| */ |
| public String getLabel() throws UnsupportedOperationException { |
| checkRoot(); |
| |
| return volumeLabel; |
| } |
| |
| public FatDirectoryEntry createSub(Fat fat) throws IOException { |
| final ClusterChain chain = new ClusterChain(fat, false); |
| chain.setChainLength(1); |
| |
| final FatDirectoryEntry entry = FatDirectoryEntry.create(true); |
| entry.setStartCluster(chain.getStartCluster()); |
| |
| final ClusterChainDirectory dir = |
| new ClusterChainDirectory(chain, false); |
| |
| /* add "." entry */ |
| |
| final FatDirectoryEntry dot = FatDirectoryEntry.create(true); |
| dot.setShortName(ShortName.DOT); |
| dot.setStartCluster(dir.getStorageCluster()); |
| copyDateTimeFields(entry, dot); |
| dir.addEntry(dot); |
| |
| /* add ".." entry */ |
| |
| final FatDirectoryEntry dotDot = FatDirectoryEntry.create(true); |
| dotDot.setShortName(ShortName.DOT_DOT); |
| dotDot.setStartCluster(getStorageCluster()); |
| copyDateTimeFields(entry, dotDot); |
| dir.addEntry(dotDot); |
| |
| dir.flush(); |
| |
| return entry; |
| } |
| |
| private static void copyDateTimeFields( |
| FatDirectoryEntry src, FatDirectoryEntry dst) { |
| |
| dst.setCreated(src.getCreated()); |
| dst.setLastAccessed(src.getLastAccessed()); |
| dst.setLastModified(src.getLastModified()); |
| } |
| |
| /** |
| * Sets the volume label that is stored in this directory. Setting the |
| * volume label is supported on the root directory only. |
| * |
| * @param label the new volume label |
| * @throws IllegalArgumentException if the label is too long |
| * @throws UnsupportedOperationException if this is not a root directory |
| * @see #isRoot() |
| */ |
| public void setLabel(String label) throws IllegalArgumentException, |
| UnsupportedOperationException, IOException { |
| |
| checkRoot(); |
| |
| if (label.length() > MAX_LABEL_LENGTH) throw new |
| IllegalArgumentException("label too long"); |
| |
| if (this.volumeLabel != null) { |
| if (label == null) { |
| changeSize(getSize() - 1); |
| this.volumeLabel = null; |
| } else { |
| ShortName.checkValidChars(label.toCharArray()); |
| this.volumeLabel = label; |
| } |
| } else { |
| if (label != null) { |
| changeSize(getSize() + 1); |
| ShortName.checkValidChars(label.toCharArray()); |
| this.volumeLabel = label; |
| } |
| } |
| |
| this.dirty = true; |
| } |
| |
| } |