--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/internal/WorkingCopyContent.java	Thu May 16 19:46:13 2013 +0200
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2013 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@hg4j.com
+ */
+package org.tmatesoft.hg.internal;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+import org.tmatesoft.hg.core.HgCommitCommand;
+import org.tmatesoft.hg.core.HgIOException;
+import org.tmatesoft.hg.repo.HgDataFile;
+import org.tmatesoft.hg.repo.HgInvalidFileException;
+import org.tmatesoft.hg.repo.HgInvalidStateException;
+import org.tmatesoft.hg.repo.HgRepository;
+import org.tmatesoft.hg.util.ByteChannel;
+import org.tmatesoft.hg.util.CancelledException;
+
+/**
+ * Access content of the working copy. The difference with {@link FileContentSupplier} is that this one doesn't need {@link File}
+ * in the working directory. However, provided this class is used from {@link HgCommitCommand} when "modified" file was detected,
+ * it's odd to expect no file in the working dir.
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public class WorkingCopyContent implements DataSerializer.DataSource {
+	private final HgDataFile file;
+
+	public WorkingCopyContent(HgDataFile dataFile) {
+		file = dataFile;
+		if (!dataFile.exists()) {
+			throw new IllegalArgumentException();
+		}
+	}
+
+	public void serialize(final DataSerializer out) throws HgIOException {
+		final HgIOException failure[] = new HgIOException[1];
+		try {
+			// TODO #workingCopy API is very limiting, CancelledException is inconvenient, 
+			// and absence of HgIOException is very uncomfortable
+			file.workingCopy(new ByteChannel() {
+				
+				public int write(ByteBuffer buffer) throws IOException {
+					try {
+						if (buffer.hasArray()) {
+							out.write(buffer.array(), buffer.position(), buffer.remaining());
+						}
+						int rv = buffer.remaining();
+						buffer.position(buffer.limit()); // pretend we've consumed the data
+						return rv;
+					} catch (HgIOException ex) {
+						failure[0] = ex;
+						throw new IOException(ex);
+					}
+				}
+			});
+		} catch (HgInvalidFileException ex) {
+			if (failure[0] != null) {
+				throw failure[0];
+			}
+			throw new HgIOException("Write failure", ex, new File(file.getRepo().getWorkingDir(), file.getPath().toString()));
+		} catch (CancelledException ex) {
+			throw new HgInvalidStateException("Our channel doesn't cancel here");
+		}
+	}
+
+	public int serializeLength() {
+		return file.getLength(HgRepository.WORKING_COPY);
+	}
+}
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