Add BytesHandle for working with BytesLocations

Author: ctrueden

src/main/java/org/scijava/io/handle/BytesHandle.java

@@ -0,0 +1,160 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2016 Board of Regents of the University of
+ * Wisconsin-Madison, Broad Institute of MIT and Harvard, and Max Planck
+ * Institute of Molecular Cell Biology and Genetics.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+
+package org.scijava.io.handle;
+
+import java.io.EOFException;
+import java.io.IOException;
+
+import org.scijava.io.ByteBank;
+import org.scijava.io.location.BytesLocation;
+import org.scijava.plugin.Plugin;
+
+/**
+ * {@link DataHandle} for a {@link BytesLocation}.
+ * 
+ * @author Curtis Rueden
+ * @author Melissa Linkert
+ * @author Gabriel Einsdorf
+ */
+@Plugin(type = DataHandle.class)
+public class BytesHandle extends AbstractDataHandle<BytesLocation> {
+
+	private long offset = 0;
+
+	// -- DataHandle methods --
+
+	@Override
+	public long offset() {
+		return offset;
+	}
+
+	@Override
+	public long length() {
+		return bytes().getMaxPos();
+	}
+
+	@Override
+	public void setLength(final long length) throws IOException {
+		// check if new length is legal
+		bytes().basicRangeCheck(0, length);
+		// TODO update the maxLength?
+	}
+
+	@Override
+	public int read(final byte[] b, final int off, int len) throws IOException {
+		if (offset + len > length()) {
+			len = (int) (length() - offset);
+		}
+		bytes().getBytes(offset, b, off, len);
+		offset += len;
+		return len;
+	}
+
+	@Override
+	public void seek(final long pos) throws IOException {
+		if (pos > length()) setLength(pos);
+		offset = pos;
+	}
+
+	// -- DataInput methods --
+
+	@Override
+	public byte readByte() throws IOException {
+		ensureReadable(1);
+		try {
+			// we need to convert the bytes into the range 0-255
+			return bytes().getByte(offset++);
+		}
+		catch (final Exception e) {
+			throw eofException(e);
+		}
+	}
+
+	@Override
+	public void readFully(final byte[] b, final int off, final int len)
+		throws IOException
+	{
+		ensureReadable(len);
+		try {
+			bytes().getBytes(offset, b, off, len);
+			offset += len;
+		}
+		catch (final Exception e) {
+			throw eofException(e);
+		}
+	}
+
+	// -- DataOutput methods --
+
+	@Override
+	public void write(final byte[] b, final int off, final int len)
+		throws IOException
+	{
+		ensureWritable(len);
+		bytes().setBytes(offset, b, off, len);
+		offset += len;
+	}
+
+	@Override
+	public void write(final int b) throws IOException {
+		ensureWritable(1);
+		bytes().setByte(offset, (byte) b);
+		offset++;
+	}
+
+	// -- Closeable methods --
+
+	@Override
+	public void close() {
+		// NB: No action needed.
+	}
+
+	// -- Typed methods --
+
+	@Override
+	public Class<BytesLocation> getType() {
+		return BytesLocation.class;
+	}
+
+	// -- Helper methods --
+
+	private ByteBank bytes() {
+		return get().getByteBank();
+	}
+
+	private EOFException eofException(final Throwable cause) {
+		final EOFException eof = new EOFException();
+		eof.initCause(cause);
+		return eof;
+	}
+
+}