Merge branch 'more-handles-buffering'

Author: gab1one

pom.xml

@@ -184,6 +184,11 @@ Konstanz, and KNIME GmbH.</license.copyrightOwners>
 			<artifactId>junit</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<scope>test</scope>
+			</dependency>
 	</dependencies>
 
 	<build>

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

@@ -0,0 +1,115 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2017 Board of Regents of the University of
+ * Wisconsin-Madison, Broad Institute of MIT and Harvard, Max Planck
+ * Institute of Molecular Cell Biology and Genetics, University of
+ * Konstanz, and KNIME GmbH.
+ * %%
+ * 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.IOException;
+
+import org.scijava.io.location.Location;
+
+/**
+ * Abstract superclass for {@link DataHandle}s that operate over other
+ * {@link DataHandle}s.
+ *
+ * @author Gabriel Einsdorf
+ */
+public abstract class AbstractHigherOrderHandle<L extends Location> extends
+	AbstractDataHandle<L>
+{
+
+	private DataHandle<L> handle;
+	private boolean closed;
+
+	public AbstractHigherOrderHandle(final DataHandle<L> handle) {
+		this.handle = handle;
+		set(handle.get()); // provides access to underlying location
+	}
+
+	@Override
+	public boolean isReadable() {
+		return !closed && handle.isReadable();
+	}
+
+	@Override
+	public boolean isWritable() {
+		return !closed && handle.isWritable();
+	}
+
+	@Override
+	public long length() throws IOException {
+		ensureOpen();
+		return handle.length();
+	}
+
+	@Override
+	public Class<L> getType() {
+		return handle.getType();
+	}
+
+	@Override
+	public boolean exists() throws IOException {
+		return handle.exists();
+	}
+
+	@Override
+	public void close() throws IOException {
+		if (!closed) {
+			cleanup();
+			closed = true;
+			handle.close();
+			handle = null;
+		}
+	}
+
+	protected void ensureOpen() throws IOException {
+		if (closed) {
+			throw new IOException("This handle is closed!");
+		}
+	}
+
+	/**
+	 * Clean up data structures after a handle has been closed in the
+	 * {@link #close()} method.
+	 *
+	 * @throws IOException
+	 */
+	protected abstract void cleanup() throws IOException;
+
+	/**
+	 * @return the {@link DataHandle} wrapped by this
+	 *         {@link AbstractHigherOrderHandle}
+	 */
+	protected DataHandle<L> handle() {
+		return handle;
+	}
+
+}

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

@@ -33,6 +33,7 @@
 package org.scijava.io.handle;
 
 import java.io.IOException;
+import java.util.Objects;
 
 import org.scijava.io.IOService;
 import org.scijava.io.location.Location;
@@ -79,4 +80,40 @@ default boolean exists(final Location location) throws IOException {
 			return handle.exists();
 		}
 	}
+
+	/**
+	 * Wraps the provided {@link DataHandle} in a read-only buffer for accelerated
+	 * reading.
+	 *
+	 * @param handle the handle to wrap
+	 * @see ReadBufferDataHandle#ReadBufferDataHandle(DataHandle)
+	 */
+	default DataHandle<Location> readBuffer(final DataHandle<Location> handle) {
+		Objects.nonNull(handle);
+		return new ReadBufferDataHandle(handle);
+	}
+
+	/**
+	 * Creates a {@link DataHandle} on the provided {@link Location} wrapped in a
+	 * read-only buffer for accelerated reading.
+	 *
+	 * @param location the handle to wrap
+	 * @see ReadBufferDataHandle#ReadBufferDataHandle(DataHandle)
+	 */
+	default DataHandle<Location> readBuffer(final Location location) {
+		final DataHandle<Location> handle = create(location);
+		return handle == null ? null : new ReadBufferDataHandle(handle);
+	}
+
+	/**
+	 * Wraps the provided {@link DataHandle} in a write-only buffer for
+	 * accelerated writing.
+	 *
+	 * @param handle the handle to wrap
+	 * @see WriteBufferDataHandle#WriteBufferDataHandle(DataHandle)
+	 */
+	default DataHandle<Location> writeBuffer(final DataHandle<Location> handle) {
+		Objects.nonNull(handle);
+		return new WriteBufferDataHandle(handle);
+	}
 }

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

@@ -112,6 +112,15 @@ private static synchronized void initUTFMethod() {
 				"No usable DataOutputStream.writeUTF(String, DataOutput)", exc);
 		}
 	}
+	
+	protected static IOException readOnlyException() {
+		return new IOException("This handle is read-only!");
+	}
+
+	protected static IOException writeOnlyException() {
+		return new IOException("This handle is write-only!");
+	}
+
 
 	/**
 	 * Copies all bytes from the input to the output handle. Reading and writing