diff src/org/tmatesoft/hg/internal/ByteArrayChannel.java @ 115:c0cc2535462c

Introduced channels to pipeline (and easily filter) data streams
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Thu, 03 Feb 2011 23:32:08 +0100
parents
children 7567f4a42fe5
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/internal/ByteArrayChannel.java	Thu Feb 03 23:32:08 2011 +0100
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2011 TMate Software Ltd
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * For information on how to redistribute this software under
+ * the terms of a license other than GNU General Public License
+ * contact TMate Software at support@svnkit.com
+ */
+package org.tmatesoft.hg.internal;
+
+import java.nio.ByteBuffer;
+import java.util.LinkedList;
+import java.util.List;
+
+import org.tmatesoft.hg.util.ByteChannel;
+
+/**
+ *
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public class ByteArrayChannel implements ByteChannel {
+	private final List<ByteBuffer> buffers;
+	private ByteBuffer target;
+	private byte[] result;
+	
+	public ByteArrayChannel() {
+		this(-1);
+	}
+	
+	public ByteArrayChannel(int size) {
+		if (size == -1) {
+			buffers = new LinkedList<ByteBuffer>();
+		} else {
+			if (size < 0) {
+				throw new IllegalArgumentException(String.valueOf(size));
+			}
+			buffers = null;
+			target = ByteBuffer.allocate(size);
+		}
+	}
+
+	// TODO document what happens on write after toArray() in each case
+	public int write(ByteBuffer buffer) throws Exception {
+		int rv = buffer.remaining();
+		if (buffers == null) {
+			target.put(buffer);
+		} else {
+			ByteBuffer copy = ByteBuffer.allocate(rv);
+			copy.put(buffer);
+			buffers.add(copy);
+		}
+		return rv;
+	}
+
+	public byte[] toArray() {
+		if (result != null) {
+			return result;
+		}
+		if (buffers == null) {
+			assert target.hasArray();
+			// int total = target.position();
+			// System.arraycopy(target.array(), new byte[total]);
+			// I don't want to duplicate byte[] for now
+			// although correct way of doing things is to make a copy and discard target
+			return target.array();
+		} else {
+			int total = 0;
+			for (ByteBuffer bb : buffers) {
+				bb.flip();
+				total += bb.limit();
+			}
+			result = new byte[total];
+			int off = 0;
+			for (ByteBuffer bb : buffers) {
+				bb.get(result, off, bb.limit());
+				off += bb.limit();
+			}
+			buffers.clear();
+			return result;
+		}
+	}
+}