From 7e58b256186dc6cdb5ff688f4acfa20ba3f2b80b Mon Sep 17 00:00:00 2001
From: akwizgran <akwizgran@users.sourceforge.net>
Date: Wed, 21 Sep 2011 13:47:06 +0100
Subject: [PATCH] Allow the max packet length to be reduced from the default.
---
.../briar/api/protocol/writers/AckWriter.java | 6 ++
.../api/protocol/writers/BatchWriter.java | 6 ++
.../api/protocol/writers/OfferWriter.java | 6 ++
.../briar/protocol/writers/AckWriterImpl.java | 11 ++-
.../protocol/writers/BatchWriterImpl.java | 11 ++-
.../protocol/writers/OfferWriterImpl.java | 11 ++-
.../briar/protocol/writers/ConstantsTest.java | 74 ++++++++++++++++---
7 files changed, 108 insertions(+), 17 deletions(-)
diff --git a/api/net/sf/briar/api/protocol/writers/AckWriter.java b/api/net/sf/briar/api/protocol/writers/AckWriter.java
index 237a487ab9..80fbd88681 100644
--- a/api/net/sf/briar/api/protocol/writers/AckWriter.java
+++ b/api/net/sf/briar/api/protocol/writers/AckWriter.java
@@ -7,6 +7,12 @@ import net.sf.briar.api.protocol.BatchId;
/** An interface for creating an ack packet. */
public interface AckWriter {
+ /**
+ * Sets the maximum length of the serialised ack. If this method is not
+ * called, the default is ProtocolConstants.MAX_PACKET_LENGTH;
+ */
+ void setMaxPacketLength(int length);
+
/**
* Attempts to add the given BatchId to the ack and returns true if it
* was added.
diff --git a/api/net/sf/briar/api/protocol/writers/BatchWriter.java b/api/net/sf/briar/api/protocol/writers/BatchWriter.java
index 60818ac569..e14aa127e7 100644
--- a/api/net/sf/briar/api/protocol/writers/BatchWriter.java
+++ b/api/net/sf/briar/api/protocol/writers/BatchWriter.java
@@ -7,6 +7,12 @@ import net.sf.briar.api.protocol.BatchId;
/** An interface for creating a batch packet. */
public interface BatchWriter {
+ /**
+ * Sets the maximum length of the serialised batch. If this method is not
+ * called, the default is ProtocolConstants.MAX_PACKET_LENGTH;
+ */
+ void setMaxPacketLength(int length);
+
/**
* Attempts to add the given raw message to the batch and returns true if
* it was added.
diff --git a/api/net/sf/briar/api/protocol/writers/OfferWriter.java b/api/net/sf/briar/api/protocol/writers/OfferWriter.java
index 8faee5bed2..35bdafe926 100644
--- a/api/net/sf/briar/api/protocol/writers/OfferWriter.java
+++ b/api/net/sf/briar/api/protocol/writers/OfferWriter.java
@@ -7,6 +7,12 @@ import net.sf.briar.api.protocol.MessageId;
/** An interface for creating an offer packet. */
public interface OfferWriter {
+ /**
+ * Sets the maximum length of the serialised offer. If this method is not
+ * called, the default is ProtocolConstants.MAX_PACKET_LENGTH;
+ */
+ void setMaxPacketLength(int length);
+
/**
* Attempts to add the given message ID to the offer and returns true if it
* was added.
diff --git a/components/net/sf/briar/protocol/writers/AckWriterImpl.java b/components/net/sf/briar/protocol/writers/AckWriterImpl.java
index 2da1a1cece..f1d9722cb4 100644
--- a/components/net/sf/briar/protocol/writers/AckWriterImpl.java
+++ b/components/net/sf/briar/protocol/writers/AckWriterImpl.java
@@ -18,7 +18,7 @@ class AckWriterImpl implements AckWriter {
private final Writer w;
private boolean started = false;
- private int capacity = ProtocolConstants.MAX_PACKET_LENGTH; // FIXME
+ private int capacity = ProtocolConstants.MAX_PACKET_LENGTH;
AckWriterImpl(OutputStream out, SerialComponent serial,
WriterFactory writerFactory) {
@@ -30,6 +30,13 @@ class AckWriterImpl implements AckWriter {
w = writerFactory.createWriter(out);
}
+ public void setMaxPacketLength(int length) {
+ if(started) throw new IllegalStateException();
+ if(length < 0 || length > ProtocolConstants.MAX_PACKET_LENGTH)
+ throw new IllegalArgumentException();
+ capacity = length;
+ }
+
public boolean writeBatchId(BatchId b) throws IOException {
int overhead = started ? footerLength : headerLength + footerLength;
if(capacity < idLength + overhead) return false;
@@ -43,7 +50,7 @@ class AckWriterImpl implements AckWriter {
if(!started) start();
w.writeListEnd();
out.flush();
- capacity = ProtocolConstants.MAX_PACKET_LENGTH; // FIXME
+ capacity = ProtocolConstants.MAX_PACKET_LENGTH;
started = false;
}
diff --git a/components/net/sf/briar/protocol/writers/BatchWriterImpl.java b/components/net/sf/briar/protocol/writers/BatchWriterImpl.java
index 96c982e6a8..bc6bfb0f8e 100644
--- a/components/net/sf/briar/protocol/writers/BatchWriterImpl.java
+++ b/components/net/sf/briar/protocol/writers/BatchWriterImpl.java
@@ -21,7 +21,7 @@ class BatchWriterImpl implements BatchWriter {
private final MessageDigest messageDigest;
private boolean started = false;
- private int capacity = ProtocolConstants.MAX_PACKET_LENGTH; // FIXME
+ private int capacity = ProtocolConstants.MAX_PACKET_LENGTH;
BatchWriterImpl(OutputStream out, SerialComponent serial,
WriterFactory writerFactory, MessageDigest messageDigest) {
@@ -33,6 +33,13 @@ class BatchWriterImpl implements BatchWriter {
this.messageDigest = messageDigest;
}
+ public void setMaxPacketLength(int length) {
+ if(started) throw new IllegalStateException();
+ if(length < 0 || length > ProtocolConstants.MAX_PACKET_LENGTH)
+ throw new IllegalArgumentException();
+ capacity = length;
+ }
+
public boolean writeMessage(byte[] message) throws IOException {
int overhead = started ? footerLength : headerLength + footerLength;
if(capacity < message.length + overhead) return false;
@@ -47,7 +54,7 @@ class BatchWriterImpl implements BatchWriter {
if(!started) start();
w.writeListEnd();
out.flush();
- capacity = ProtocolConstants.MAX_PACKET_LENGTH; // FIXME
+ capacity = ProtocolConstants.MAX_PACKET_LENGTH;
started = false;
return new BatchId(messageDigest.digest());
}
diff --git a/components/net/sf/briar/protocol/writers/OfferWriterImpl.java b/components/net/sf/briar/protocol/writers/OfferWriterImpl.java
index 40a9221afa..04303fbf4d 100644
--- a/components/net/sf/briar/protocol/writers/OfferWriterImpl.java
+++ b/components/net/sf/briar/protocol/writers/OfferWriterImpl.java
@@ -18,7 +18,7 @@ class OfferWriterImpl implements OfferWriter {
private final Writer w;
private boolean started = false;
- private int capacity = ProtocolConstants.MAX_PACKET_LENGTH; // FIXME
+ private int capacity = ProtocolConstants.MAX_PACKET_LENGTH;
OfferWriterImpl(OutputStream out, SerialComponent serial,
WriterFactory writerFactory) {
@@ -30,6 +30,13 @@ class OfferWriterImpl implements OfferWriter {
w = writerFactory.createWriter(out);
}
+ public void setMaxPacketLength(int length) {
+ if(started) throw new IllegalStateException();
+ if(length < 0 || length > ProtocolConstants.MAX_PACKET_LENGTH)
+ throw new IllegalArgumentException();
+ capacity = length;
+ }
+
public boolean writeMessageId(MessageId m) throws IOException {
int overhead = started ? footerLength : headerLength + footerLength;
if(capacity < idLength + overhead) return false;
@@ -43,7 +50,7 @@ class OfferWriterImpl implements OfferWriter {
if(!started) start();
w.writeListEnd();
out.flush();
- capacity = ProtocolConstants.MAX_PACKET_LENGTH; // FIXME
+ capacity = ProtocolConstants.MAX_PACKET_LENGTH;
started = false;
}
diff --git a/test/net/sf/briar/protocol/writers/ConstantsTest.java b/test/net/sf/briar/protocol/writers/ConstantsTest.java
index 6115e08af7..d6a50b20db 100644
--- a/test/net/sf/briar/protocol/writers/ConstantsTest.java
+++ b/test/net/sf/briar/protocol/writers/ConstantsTest.java
@@ -58,15 +58,35 @@ public class ConstantsTest extends TestCase {
}
@Test
- public void testBatchesFitIntoAck() throws Exception {
- // Create an ack with the maximum number of batch IDs
- ByteArrayOutputStream out = new ByteArrayOutputStream(
- ProtocolConstants.MAX_PACKET_LENGTH);
+ public void testBatchesFitIntoLargeAck() throws Exception {
+ testBatchesFitIntoAck(ProtocolConstants.MAX_PACKET_LENGTH);
+ }
+
+ @Test
+ public void testBatchesFitIntoSmallAck() throws Exception {
+ testBatchesFitIntoAck(1000);
+ }
+
+ private void testBatchesFitIntoAck(int length) throws Exception {
+ // Create an ack with as many batch IDs as possible
+ ByteArrayOutputStream out = new ByteArrayOutputStream(length);
AckWriter a = new AckWriterImpl(out, serial, writerFactory);
+ a.setMaxPacketLength(length);
while(a.writeBatchId(new BatchId(TestUtils.getRandomId())));
a.finish();
// Check the size of the serialised ack
- assertTrue(out.size() <= ProtocolConstants.MAX_PACKET_LENGTH);
+ assertTrue(out.size() <= length);
+ }
+
+ @Test
+ public void testEmptyAck() throws Exception {
+ ByteArrayOutputStream out = new ByteArrayOutputStream();
+ AckWriter a = new AckWriterImpl(out, serial, writerFactory);
+ // There's not enough room for a batch ID
+ a.setMaxPacketLength(4);
+ assertFalse(a.writeBatchId(new BatchId(TestUtils.getRandomId())));
+ // Check that nothing was written
+ assertEquals(0, out.size());
}
@Test
@@ -90,7 +110,7 @@ public class ConstantsTest extends TestCase {
ProtocolConstants.MAX_PACKET_LENGTH);
BatchWriter b = new BatchWriterImpl(out, serial, writerFactory,
crypto.getMessageDigest());
- b.writeMessage(message.getBytes());
+ assertTrue(b.writeMessage(message.getBytes()));
b.finish();
// Check the size of the serialised batch
assertTrue(out.size() > UniqueId.LENGTH + Group.MAX_NAME_LENGTH +
@@ -100,15 +120,47 @@ public class ConstantsTest extends TestCase {
}
@Test
- public void testMessagesFitIntoOffer() throws Exception {
- // Create an offer with the maximum number of message IDs
- ByteArrayOutputStream out = new ByteArrayOutputStream(
- ProtocolConstants.MAX_PACKET_LENGTH);
+ public void testEmptyBatch() throws Exception {
+ ByteArrayOutputStream out = new ByteArrayOutputStream();
+ BatchWriter b = new BatchWriterImpl(out, serial, writerFactory,
+ crypto.getMessageDigest());
+ // There's not enough room for a message
+ b.setMaxPacketLength(4);
+ assertFalse(b.writeMessage(new byte[4]));
+ // Check that nothing was written
+ assertEquals(0, out.size());
+ }
+
+ @Test
+ public void testMessagesFitIntoLargeOffer() throws Exception {
+ testMessagesFitIntoOffer(ProtocolConstants.MAX_PACKET_LENGTH);
+ }
+
+ @Test
+ public void testMessagesFitIntoSmallOffer() throws Exception {
+ testMessagesFitIntoOffer(1000);
+ }
+
+ private void testMessagesFitIntoOffer(int length) throws Exception {
+ // Create an offer with as many message IDs as possible
+ ByteArrayOutputStream out = new ByteArrayOutputStream(length);
OfferWriter o = new OfferWriterImpl(out, serial, writerFactory);
+ o.setMaxPacketLength(length);
while(o.writeMessageId(new MessageId(TestUtils.getRandomId())));
o.finish();
// Check the size of the serialised offer
- assertTrue(out.size() <= ProtocolConstants.MAX_PACKET_LENGTH);
+ assertTrue(out.size() <= length);
+ }
+
+ @Test
+ public void testEmptyOffer() throws Exception {
+ ByteArrayOutputStream out = new ByteArrayOutputStream();
+ OfferWriter o = new OfferWriterImpl(out, serial, writerFactory);
+ // There's not enough room for a message ID
+ o.setMaxPacketLength(4);
+ assertFalse(o.writeMessageId(new MessageId(TestUtils.getRandomId())));
+ // Check that nothing was written
+ assertEquals(0, out.size());
}
@Test
--
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