Cleaned up serial and protocol packages in preparation for user-defined types.

components/net/sf/briar/protocol/DigestingConsumer.java

@@ -0,0 +1,28 @@
+package net.sf.briar.protocol;
+
+import java.io.IOException;
+import java.security.MessageDigest;
+
+import net.sf.briar.api.serial.Consumer;
+
+/** A consumer that passes its input through a message digest. */
+class DigestingConsumer implements Consumer {
+
+	private final MessageDigest messageDigest;
+
+	DigestingConsumer(MessageDigest messageDigest) {
+		this.messageDigest = messageDigest;
+	}
+
+	public void write(byte b) throws IOException {
+		messageDigest.update(b);
+	}
+
+	public void write(byte[] b) throws IOException {
+		messageDigest.update(b);
+	}
+
+	public void write(byte[] b, int off, int len) throws IOException {
+		messageDigest.update(b, off, len);
+	}
+}