DataHandle: add a mutator for the length

In SCIFIO and Bio-Formats, this was a feature of the AbstractNIOHandle.
But there is no reason to limit it to NIO-flavored handles only.

Author: ctrueden

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

@@ -66,6 +66,14 @@ public interface DataHandle<L extends Location> extends WrapperPlugin<L>,
 	/** Returns the length of the stream. */
 	long length() throws IOException;
 
+	/**
+	 * Sets the new length of the handle.
+	 * 
+	 * @param length New length.
+	 * @throws IOException If there is an error changing the handle's length.
+	 */
+	void setLength(long length) throws IOException;
+
 	/**
 	 * Returns the current order of the stream.
 	 * 

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

@@ -83,6 +83,11 @@ public long length() throws IOException {
 		return raf().length();
 	}
 
+	@Override
+	public void setLength(final long length) throws IOException {
+		raf().setLength(length);
+	}
+
 	@Override
 	public int read() throws IOException {
 		return raf().read();