[CFX-22]

- Polishing upload feedback implementation.

SVN: 4123

common/source/java/ch/systemsx/cisd/common/io/SlowInputStream.java

+/*
+ * Copyright 2008 ETH Zuerich, CISD
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.systemsx.cisd.common.io;
+
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.apache.commons.lang.time.DateUtils;
+
+/**
+ * A <code>ProxyInputStream</code> extension which simulates a slow input stream reading.
+ * 
+ * @author Christian Ribeaud
+ */
+public final class SlowInputStream extends FilterInputStream
+{
+    private final long speed;
+
+    /**
+     * @param speed bytes per second to simulate.
+     */
+    public SlowInputStream(final InputStream inputStream, final long speed)
+    {
+        super(inputStream);
+        this.speed = speed;
+    }
+
+    /**
+     * Pause for an appropriate time according to the number of bytes being transferred.
+     * 
+     * @param bytes number of bytes being transferred.
+     */
+    private final void pause(final int bytes)
+    {
+        final long sleepMillis = (bytes * DateUtils.MILLIS_PER_SECOND) / speed;
+        try
+        {
+            Thread.sleep(sleepMillis);
+        } catch (final InterruptedException ignored)
+        {
+        }
+    }
+
+    //
+    // ProxyInputStream
+    //
+
+    @Override
+    public final int read() throws IOException
+    {
+        pause(1);
+        return in.read();
+    }
+
+    // Also handles read(byte[])
+    @Override
+    public final int read(final byte[] b, final int off, final int len) throws IOException
+    {
+        pause(len);
+        return in.read(b, off, len);
+    }
+}