1 files changed, 105 insertions, 0 deletions
diff --git a/src/main/java/de/waldheinz/fs/BlockDevice.java b/src/main/java/de/waldheinz/fs/BlockDevice.java
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+++ b/src/main/java/de/waldheinz/fs/BlockDevice.java
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+/*
+ * 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;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+/**
+ * This is the abstraction used for a device that can hold a {@link FileSystem}.
+ *
+ * @author Ewout Prangsma &lt;epr at jnode.org&gt;
+ * @author Matthias Treydte &lt;waldheinz at gmail.com&gt;
+ */
+public interface BlockDevice {
+
+    /**
+     * Gets the total length of this device in bytes.
+     *
+     * @return the total number of bytes on this device
+     * @throws IOException on error getting the size of this device
+     */
+    public abstract long getSize() throws IOException;
+
+    /**
+     * Read a block of data from this device.
+     *
+     * @param devOffset the byte offset where to read the data from
+     * @param dest the destination buffer where to store the data read
+     * @throws IOException on read error
+     */
+    public abstract void read(long devOffset, ByteBuffer dest)
+            throws IOException;
+
+    /**
+     * Writes a block of data to this device.
+     *
+     * @param devOffset the byte offset where to store the data
+     * @param src the source {@code ByteBuffer} to write to the device
+     * @throws ReadOnlyException if this {@code BlockDevice} is read-only
+     * @throws IOException on write error
+     * @throws IllegalArgumentException if the {@code devOffset} is negative
+     *      or the write would go beyond the end of the device
+     * @see #isReadOnly()
+     */
+    public abstract void write(long devOffset, ByteBuffer src)
+            throws ReadOnlyException, IOException,
+            IllegalArgumentException;
+            
+    /**
+     * Flushes data in caches to the actual storage.
+     *
+     * @throws IOException on write error
+     */
+    public abstract void flush() throws IOException;
+
+    /**
+     * Returns the size of a sector on this device.
+     *
+     * @return the sector size in bytes
+     * @throws IOException on error determining the sector size
+     */
+    public int getSectorSize() throws IOException;
+
+    /**
+     * Closes this {@code BlockDevice}. No methods of this device may be
+     * accesses after this method was called.
+     *
+     * @throws IOException on error closing this device
+     * @see #isClosed() 
+     */
+    public void close() throws IOException;
+
+    /**
+     * Checks if this device was already closed. No methods may be called
+     * on a closed device (except this method).
+     *
+     * @return if this device is closed
+     */
+    public boolean isClosed();
+
+    /**
+     * Checks if this {@code BlockDevice} is read-only.
+     *
+     * @return if this {@code BlockDevice} is read-only
+     */
+    public boolean isReadOnly();
+    
+}