Moved writers into their own package, replaced public static fields in

CryptoModule with provider methods.

components/net/sf/briar/protocol/writers/AckWriterImpl.java

@@ -0,0 +1,49 @@
+package net.sf.briar.protocol.writers;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+import net.sf.briar.api.protocol.Ack;
+import net.sf.briar.api.protocol.BatchId;
+import net.sf.briar.api.protocol.Tags;
+import net.sf.briar.api.protocol.writers.AckWriter;
+import net.sf.briar.api.serial.Writer;
+import net.sf.briar.api.serial.WriterFactory;
+
+class AckWriterImpl implements AckWriter {
+
+	private final OutputStream out;
+	private final Writer w;
+
+	private boolean started = false, finished = false;
+
+	AckWriterImpl(OutputStream out, WriterFactory writerFactory) {
+		this.out = out;
+		this.w = writerFactory.createWriter(out);
+	}
+
+	public boolean addBatchId(BatchId b) throws IOException {
+		if(finished) throw new IllegalStateException();
+		if(!started) {
+			w.writeUserDefinedTag(Tags.ACK);
+			w.writeListStart();
+			started = true;
+		}
+		int capacity = Ack.MAX_SIZE - (int) w.getBytesWritten() - 1;
+		if(capacity < BatchId.SERIALISED_LENGTH) return false;
+		b.writeTo(w);
+		return true;
+	}
+
+	public void finish() throws IOException {
+		if(finished) throw new IllegalStateException();
+		if(!started) {
+			w.writeUserDefinedTag(Tags.ACK);
+			w.writeListStart();
+			started = true;
+		}
+		w.writeListEnd();
+		out.flush();
+		finished = true;
+	}
+}

components/net/sf/briar/protocol/writers/BatchWriterImpl.java

@@ -0,0 +1,62 @@
+package net.sf.briar.protocol.writers;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.security.DigestOutputStream;
+import java.security.MessageDigest;
+
+import net.sf.briar.api.protocol.Batch;
+import net.sf.briar.api.protocol.BatchId;
+import net.sf.briar.api.protocol.Tags;
+import net.sf.briar.api.protocol.writers.BatchWriter;
+import net.sf.briar.api.serial.Writer;
+import net.sf.briar.api.serial.WriterFactory;
+
+class BatchWriterImpl implements BatchWriter {
+
+	private final DigestOutputStream out;
+	private final Writer w;
+	private final MessageDigest messageDigest;
+
+	private boolean started = false, finished = false;
+
+	BatchWriterImpl(OutputStream out, WriterFactory writerFactory,
+			MessageDigest messageDigest) {
+		this.out = new DigestOutputStream(out, messageDigest);
+		w = writerFactory.createWriter(this.out);
+		this.messageDigest = messageDigest;
+	}
+
+	public int getCapacity() {
+		return Batch.MAX_SIZE - 3;
+	}
+
+	public boolean addMessage(byte[] message) throws IOException {
+		if(finished) throw new IllegalStateException();
+		if(!started) {
+			messageDigest.reset();
+			w.writeUserDefinedTag(Tags.BATCH);
+			w.writeListStart();
+			started = true;
+		}
+		int capacity = Batch.MAX_SIZE - (int) w.getBytesWritten() - 1;
+		if(capacity < message.length) return false;
+		// Bypass the writer and write each raw message directly
+		out.write(message);
+		return true;
+	}
+
+	public BatchId finish() throws IOException {
+		if(finished) throw new IllegalStateException();
+		if(!started) {
+			messageDigest.reset();
+			w.writeUserDefinedTag(Tags.BATCH);
+			w.writeListStart();
+			started = true;
+		}
+		w.writeListEnd();
+		out.flush();
+		finished = true;
+		return new BatchId(messageDigest.digest());
+	}
+}

components/net/sf/briar/protocol/writers/PacketWriterFactoryImpl.java

@@ -0,0 +1,44 @@
+package net.sf.briar.protocol.writers;
+
+import java.io.OutputStream;
+import java.security.MessageDigest;
+
+import net.sf.briar.api.protocol.writers.AckWriter;
+import net.sf.briar.api.protocol.writers.BatchWriter;
+import net.sf.briar.api.protocol.writers.PacketWriterFactory;
+import net.sf.briar.api.protocol.writers.SubscriptionWriter;
+import net.sf.briar.api.protocol.writers.TransportWriter;
+import net.sf.briar.api.serial.WriterFactory;
+
+import com.google.inject.Inject;
+
+class PacketWriterFactoryImpl implements PacketWriterFactory {
+
+	private final MessageDigest messageDigest;
+	private final WriterFactory writerFactory;
+
+	@Inject
+	PacketWriterFactoryImpl(MessageDigest messageDigest,
+			WriterFactory writerFactory) {
+		this.messageDigest = messageDigest;
+		this.writerFactory = writerFactory;
+	}
+
+	public AckWriter createAckWriter(OutputStream out) {
+		return new AckWriterImpl(out, writerFactory);
+	}
+
+	public BatchWriter createBatchWriter(OutputStream out) {
+		return new BatchWriterImpl(out, writerFactory, messageDigest);
+	}
+
+	public SubscriptionWriter createSubscriptionWriter(OutputStream out) {
+		// TODO Auto-generated method stub
+		return null;
+	}
+
+	public TransportWriter createTransportWriter(OutputStream out) {
+		// TODO Auto-generated method stub
+		return null;
+	}
+}

components/net/sf/briar/protocol/writers/WritersModule.java

@@ -0,0 +1,14 @@
+package net.sf.briar.protocol.writers;
+
+
+import net.sf.briar.api.protocol.writers.PacketWriterFactory;
+
+import com.google.inject.AbstractModule;
+
+public class WritersModule extends AbstractModule {
+
+	@Override
+	protected void configure() {
+		bind(PacketWriterFactory.class).to(PacketWriterFactoryImpl.class);
+	}
+}