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Diffstat (limited to 'src/main/java/de/waldheinz/fs/FsFile.java')
-rw-r--r-- | src/main/java/de/waldheinz/fs/FsFile.java | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/src/main/java/de/waldheinz/fs/FsFile.java b/src/main/java/de/waldheinz/fs/FsFile.java new file mode 100644 index 0000000..dfaa998 --- /dev/null +++ b/src/main/java/de/waldheinz/fs/FsFile.java @@ -0,0 +1,85 @@ +/* + * 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; + +/** + * A FsFile is a representation of a single block of bytes on a filesystem. It + * is comparable to an inode in Unix. + * + * An FsFile does not have any knowledge of who is using this file. It is also + * possible that the system uses a single FsFile instance to create two + * inputstream's for two different principals. + * + * @author Ewout Prangsma <epr at jnode.org> + */ +public interface FsFile extends FsObject { + + /** + * Gets the length (in bytes) of this file. + * + * @return the file size + */ + public long getLength(); + + /** + * Sets the length of this file. + * + * @param length the new length of this file + * @throws IOException on error updating the file size + */ + public void setLength(long length) throws IOException; + + /** + * Reads from this file into the specified {@code ByteBuffer}. The + * first byte read will be put into the buffer at it's + * {@link ByteBuffer#position() position}, and the number of bytes read + * will equal the buffer's {@link ByteBuffer#remaining() remaining} bytes. + * + * @param offset the offset into the file where to start reading + * @param dest the destination buffer where to put the bytes that were read + * @throws IOException on read error + */ + public void read(long offset, ByteBuffer dest) throws IOException; + + /** + * Writes to this file taking the data to write from the specified + * {@code ByteBuffer}. This method will read the buffer's + * {@link ByteBuffer#remaining() remaining} bytes starting at it's + * {@link ByteBuffer#position() position}. + * + * @param offset the offset into the file where the first byte will be + * written + * @param src the source buffer to read the data from + * @throws ReadOnlyException if the file is read-only + * @throws IOException on write error + */ + public void write(long offset, ByteBuffer src) + throws ReadOnlyException, IOException; + + /** + * Flush any possibly cached data to the disk. + * + * @throws IOException on error flushing + */ + public void flush() throws IOException; +} |