--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/internal/FileUtils.java	Wed May 15 20:10:09 2013 +0200
@@ -0,0 +1,98 @@
+/*
+ * 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 static org.tmatesoft.hg.util.LogFacility.Severity.Debug;
+
+import java.io.Closeable;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.channels.FileChannel;
+
+import org.tmatesoft.hg.core.HgIOException;
+import org.tmatesoft.hg.util.LogFacility;
+import org.tmatesoft.hg.util.LogFacility.Severity;
+
+/**
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+final class FileUtils {
+	
+	private final LogFacility log;
+	
+	public static void copyFile(File from, File to) throws HgIOException {
+		new FileUtils(new StreamLogFacility(Debug, true, System.err)).copy(from, to);
+	}
+
+	public FileUtils(LogFacility logFacility) {
+		log = logFacility;
+	}
+
+	public void copy(File from, File to) throws HgIOException {
+		FileInputStream fis = null;
+		FileOutputStream fos = null;
+		try {
+			fis = new FileInputStream(from);
+			fos = new FileOutputStream(to);
+			FileChannel input = fis.getChannel();
+			FileChannel output = fos.getChannel();
+			long count = input.size();
+			long pos = 0;
+			int zeroCopied = 0; // flag to prevent hang-up
+			do {
+				long c = input.transferTo(pos, count, output);
+				pos += c;
+				count -= c;
+				if (c == 0) {
+					if (++zeroCopied == 3) {
+						String m = String.format("Can't copy %s to %s, transferTo copies 0 bytes. Position: %d, bytes left:%d", from.getName(), to.getName(), pos, count);
+						throw new IOException(m);
+					}
+				} else {
+					// reset
+					zeroCopied = 0;
+				}
+			} while (count > 0);
+			fos.close();
+			fos = null;
+			fis.close();
+			fis = null;
+		} catch (IOException ex) {
+			// not in finally because I don't want to loose exception from fos.close()
+			closeQuietly(fis);
+			closeQuietly(fos);
+			String m = String.format("Failed to copy %s to %s", from.getName(), to.getName());
+			throw new HgIOException(m, ex, from);
+		}
+	}
+	
+	public void closeQuietly(Closeable stream) {
+		if (stream != null) {
+			try {
+				stream.close();
+			} catch (IOException ex) {
+				// ignore
+				log.dump(getClass(), Severity.Warn, ex, "Exception while closing stream quietly");
+			}
+		}
+	}
+
+}