Fix tests.

bramble-api/src/main/java/org/briarproject/bramble/api/io/BlockSink.java

@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api.io;
+
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.sync.tree.TreeHash;
+
+import java.util.List;
+
+public interface BlockSink {
+
+	/**
+	 * Stores a block of the message with the given temporary ID.
+	 */
+	void putBlock(HashingId h, int blockNumber, byte[] data) throws DbException;
+
+	/**
+	 * Sets the hash tree path of a previously stored block.
+	 */
+	void setPath(HashingId h, int blockNumber, List<TreeHash> path)
+			throws DbException;
+}

bramble-api/src/main/java/org/briarproject/bramble/api/io/HashingId.java

@@ -0,0 +1,27 @@
+package org.briarproject.bramble.api.io;
+
+import org.briarproject.bramble.api.UniqueId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.Message;
+import org.briarproject.bramble.api.sync.MessageId;
+
+import javax.annotation.concurrent.ThreadSafe;
+
+/**
+ * Type-safe wrapper for a byte array that uniquely identifies a
+ * {@link Message} while it's being hashed and the {@link MessageId} is not
+ * yet known.
+ */
+@ThreadSafe
+@NotNullByDefault
+public class HashingId extends UniqueId {
+
+	public HashingId(byte[] id) {
+		super(id);
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof HashingId && super.equals(o);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/sync/MessageFactory.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.api.sync;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.tree.TreeHash;
 
 @NotNullByDefault
 public interface MessageFactory {
@@ -10,4 +11,6 @@ public interface MessageFactory {
 	Message createMessage(byte[] raw);
 
 	byte[] getRawMessage(Message m);
+
+	MessageId getMessageId(GroupId g, long timestamp, TreeHash rootHash);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/MessageId.java

@@ -24,6 +24,12 @@ public class MessageId extends UniqueId {
 	public static final String BLOCK_LABEL =
 			"org.briarproject.bramble/MESSAGE_BLOCK";
 
+	/**
+	 * Label for hashing two tree hashes to produce a parent.
+	 */
+	public static final String TREE_LABEL =
+			"org.briarproject.bramble/MESSAGE_TREE";
+
 	public MessageId(byte[] id) {
 		super(id);
 	}

bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncConstants.java

@@ -35,4 +35,9 @@ public interface SyncConstants {
 	 * The maximum number of message IDs in an ack, offer or request record.
 	 */
 	int MAX_MESSAGE_IDS = MAX_RECORD_PAYLOAD_BYTES / UniqueId.LENGTH;
+
+	/**
+	 * The maximum length of a message block in bytes.
+	 */
+	int MAX_BLOCK_LENGTH = 32 * 2014; // 32 KiB
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/tree/LeafNode.java

@@ -0,0 +1,21 @@
+package org.briarproject.bramble.api.sync.tree;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public class LeafNode extends TreeNode {
+
+	public LeafNode(TreeHash hash, int blockNumber) {
+		super(hash, 0, blockNumber, blockNumber);
+	}
+
+	@Override
+	public TreeNode getLeftChild() {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	public TreeNode getRightChild() {
+		throw new UnsupportedOperationException();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/sync/tree/ParentNode.java

@@ -0,0 +1,26 @@
+package org.briarproject.bramble.api.sync.tree;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public class ParentNode extends TreeNode {
+
+	private final TreeNode left, right;
+
+	public ParentNode(TreeHash hash, TreeNode left, TreeNode right) {
+		super(hash, Math.max(left.getHeight(), right.getHeight()) + 1,
+				left.getFirstBlockNumber(), right.getLastBlockNumber());
+		this.left = left;
+		this.right = right;
+	}
+
+	@Override
+	public TreeNode getLeftChild() {
+		return left;
+	}
+
+	@Override
+	public TreeNode getRightChild() {
+		return right;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/sync/tree/StreamHasher.java

@@ -0,0 +1,21 @@
+package org.briarproject.bramble.api.sync.tree;
+
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.io.BlockSink;
+import org.briarproject.bramble.api.io.HashingId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+@NotNullByDefault
+public interface StreamHasher {
+
+	/**
+	 * Reads the given input stream, divides the data into blocks, stores
+	 * the blocks and the resulting hash tree using the given block sink and
+	 * temporary ID, and returns the hash tree.
+	 */
+	TreeNode hash(InputStream in, BlockSink sink, HashingId h)
+			throws IOException, DbException;
+}

bramble-api/src/main/java/org/briarproject/bramble/api/sync/tree/TreeHash.java

@@ -0,0 +1,24 @@
+package org.briarproject.bramble.api.sync.tree;
+
+import org.briarproject.bramble.api.UniqueId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.ThreadSafe;
+
+/**
+ * Type-safe wrapper for a byte array that uniquely identifies a sequence of
+ * one or more message blocks.
+ */
+@ThreadSafe
+@NotNullByDefault
+public class TreeHash extends UniqueId {
+
+	public TreeHash(byte[] id) {
+		super(id);
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof TreeHash && super.equals(o);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/sync/tree/TreeHasher.java

@@ -0,0 +1,11 @@
+package org.briarproject.bramble.api.sync.tree;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public interface TreeHasher {
+
+	LeafNode hashBlock(int blockNumber, byte[] data);
+
+	ParentNode mergeTrees(TreeNode left, TreeNode right);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/sync/tree/TreeNode.java

@@ -0,0 +1,38 @@
+package org.briarproject.bramble.api.sync.tree;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public abstract class TreeNode {
+
+	private final TreeHash hash;
+	private final int height, firstBlockNumber, lastBlockNumber;
+
+	TreeNode(TreeHash hash, int height, int firstBlockNumber,
+			int lastBlockNumber) {
+		this.hash = hash;
+		this.height = height;
+		this.firstBlockNumber = firstBlockNumber;
+		this.lastBlockNumber = lastBlockNumber;
+	}
+
+	public TreeHash getHash() {
+		return hash;
+	}
+
+	public int getHeight() {
+		return height;
+	}
+
+	public int getFirstBlockNumber() {
+		return firstBlockNumber;
+	}
+
+	public int getLastBlockNumber() {
+		return lastBlockNumber;
+	}
+
+	public abstract TreeNode getLeftChild();
+
+	public abstract TreeNode getRightChild();
+}

bramble-api/src/main/java/org/briarproject/bramble/util/ByteUtils.java

@@ -1,7 +1,5 @@
 package org.briarproject.bramble.util;
 
-import org.briarproject.bramble.api.FormatException;
-
 public class ByteUtils {
 
 	/**
@@ -14,26 +12,15 @@ public class ByteUtils {
 	 */
 	public static final long MAX_32_BIT_UNSIGNED = 4294967295L; // 2^32 - 1
 
-	/**
+	/** The number of bytes needed to encode a 16-bit integer. */
-	 * The number of bytes needed to encode a 16-bit integer.
-	 */
 	public static final int INT_16_BYTES = 2;
 
-	/**
+	/** The number of bytes needed to encode a 32-bit integer. */
-	 * The number of bytes needed to encode a 32-bit integer.
-	 */
 	public static final int INT_32_BYTES = 4;
 
-	/**
+	/** The number of bytes needed to encode a 64-bit integer. */
-	 * The number of bytes needed to encode a 64-bit integer.
-	 */
 	public static final int INT_64_BYTES = 8;
 
-	/**
-	 * The maximum number of bytes needed to encode a variable-length integer.
-	 */
-	public static final int MAX_VARINT_BYTES = 9;
-
 	public static void writeUint16(int src, byte[] dest, int offset) {
 		if (src < 0) throw new IllegalArgumentException();
 		if (src > MAX_16_BIT_UNSIGNED) throw new IllegalArgumentException();
@@ -68,42 +55,6 @@ public class ByteUtils {
 		dest[offset + 7] = (byte) (src & 0xFF);
 	}
 
-	/**
-	 * Returns the number of bytes needed to represent 'src' as a
-	 * variable-length integer.
-	 * <p>
-	 * 'src' must not be negative.
-	 */
-	public static int getVarIntBytes(long src) {
-		if (src < 0) throw new IllegalArgumentException();
-		int len = 1;
-		while ((src >>= 7) > 0) len++;
-		return len;
-	}
-
-	/**
-	 * Writes 'src' to 'dest' as a variable-length integer, starting at
-	 * 'offset', and returns the number of bytes written.
-	 * <p>
-	 * `src` must not be negative.
-	 */
-	public static int writeVarInt(long src, byte[] dest, int offset) {
-		if (src < 0) throw new IllegalArgumentException();
-		int len = getVarIntBytes(src);
-		if (dest.length < offset + len) throw new IllegalArgumentException();
-		// Work backwards from the end
-		int end = offset + len - 1;
-		for (int i = end; i >= offset; i--) {
-			// Encode 7 bits
-			dest[i] = (byte) (src & 0x7F);
-			// Raise the continuation flag, except for the last byte
-			if (i < end) dest[i] |= (byte) 0x80;
-			// Shift out the bits that were encoded
-			src >>= 7;
-		}
-		return len;
-	}
-
 	public static int readUint16(byte[] src, int offset) {
 		if (src.length < offset + INT_16_BYTES)
 			throw new IllegalArgumentException();
@@ -132,46 +83,14 @@ public class ByteUtils {
 				| (src[offset + 7] & 0xFFL);
 	}
 
-	/**
+	public static int readUint(byte[] src, int bits) {
-	 * Returns the length in bytes of a variable-length integer encoded in
+		if (src.length << 3 < bits) throw new IllegalArgumentException();
-	 * 'src' starting at 'offset'.
+		int dest = 0;
-	 *
+		for (int i = 0; i < bits; i++) {
-	 * @throws FormatException if there is not a valid variable-length integer
+			if ((src[i >> 3] & 128 >> (i & 7)) != 0) dest |= 1 << bits - i - 1;
-	 * at the specified position.
-	 */
-	public static int getVarIntBytes(byte[] src, int offset)
-			throws FormatException {
-		if (src.length < offset) throw new IllegalArgumentException();
-		for (int i = 0; i < MAX_VARINT_BYTES && offset + i < src.length; i++) {
-			// If the continuation flag is lowered, this is the last byte
-			if ((src[offset + i] & 0x80) == 0) return i + 1;
 		}
-		// We've read 9 bytes or reached the end of the input without finding
+		if (dest < 0) throw new AssertionError();
-		// the last byte
+		if (dest >= 1 << bits) throw new AssertionError();
-		throw new FormatException();
+		return dest;
-	}
-
-	/**
-	 * Reads a variable-length integer from 'src' starting at 'offset' and
-	 * returns it.
-	 *
-	 * @throws FormatException if there is not a valid variable-length integer
-	 * at the specified position.
-	 */
-	public static long readVarInt(byte[] src, int offset)
-			throws FormatException {
-		if (src.length < offset) throw new IllegalArgumentException();
-		long dest = 0;
-		for (int i = 0; i < MAX_VARINT_BYTES && offset + i < src.length; i++) {
-			// Decode 7 bits
-			dest |= src[offset + i] & 0x7F;
-			// If the continuation flag is lowered, this is the last byte
-			if ((src[offset + i] & 0x80) == 0) return dest;
-			// Make room for the next 7 bits
-			dest <<= 7;
-		}
-		// We've read 9 bytes or reached the end of the input without finding
-		// the last byte
-		throw new FormatException();
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/sync/MessageFactoryImpl.java

@@ -7,6 +7,7 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.bramble.api.sync.tree.TreeHash;
 import org.briarproject.bramble.util.ByteUtils;
 
 import javax.annotation.concurrent.Immutable;
@@ -39,13 +40,19 @@ class MessageFactoryImpl implements MessageFactory {
 		if (body.length == 0) throw new IllegalArgumentException();
 		if (body.length > MAX_MESSAGE_BODY_LENGTH)
 			throw new IllegalArgumentException();
-		MessageId id = getMessageId(g, timestamp, body);
+		MessageId id = getMessageIdFromBody(g, timestamp, body);
 		return new Message(id, g, timestamp, body);
 	}
 
-	private MessageId getMessageId(GroupId g, long timestamp, byte[] body) {
+	private MessageId getMessageIdFromBody(GroupId g, long timestamp,
+			byte[] body) {
 		// There's only one block, so the root hash is the hash of the block
 		byte[] rootHash = crypto.hash(BLOCK_LABEL, FORMAT_VERSION_BYTES, body);
+		return getMessageIdFromRootHash(g, timestamp, rootHash);
+	}
+
+	private MessageId getMessageIdFromRootHash(GroupId g, long timestamp,
+			byte[] rootHash) {
 		byte[] timeBytes = new byte[INT_64_BYTES];
 		ByteUtils.writeUint64(timestamp, timeBytes, 0);
 		byte[] idHash = crypto.hash(ID_LABEL, FORMAT_VERSION_BYTES,
@@ -65,7 +72,7 @@ class MessageFactoryImpl implements MessageFactory {
 		long timestamp = ByteUtils.readUint64(raw, UniqueId.LENGTH);
 		byte[] body = new byte[raw.length - MESSAGE_HEADER_LENGTH];
 		System.arraycopy(raw, MESSAGE_HEADER_LENGTH, body, 0, body.length);
-		MessageId id = getMessageId(g, timestamp, body);
+		MessageId id = getMessageIdFromBody(g, timestamp, body);
 		return new Message(id, g, timestamp, body);
 	}
 
@@ -78,4 +85,10 @@ class MessageFactoryImpl implements MessageFactory {
 		System.arraycopy(body, 0, raw, MESSAGE_HEADER_LENGTH, body.length);
 		return raw;
 	}
+
+	@Override
+	public MessageId getMessageId(GroupId g, long timestamp,
+			TreeHash rootHash) {
+		return getMessageIdFromRootHash(g, timestamp, rootHash.getBytes());
+	}
 }

bramble-core/src/main/java/org/briarproject/bramble/sync/tree/HashTree.java

@@ -0,0 +1,16 @@
+package org.briarproject.bramble.sync.tree;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.tree.LeafNode;
+import org.briarproject.bramble.api.sync.tree.TreeNode;
+
+import javax.annotation.concurrent.NotThreadSafe;
+
+@NotThreadSafe
+@NotNullByDefault
+interface HashTree {
+
+	void addLeaf(LeafNode leaf);
+
+	TreeNode getRoot();
+}

bramble-core/src/main/java/org/briarproject/bramble/sync/tree/HashTreeImpl.java

@@ -0,0 +1,46 @@
+package org.briarproject.bramble.sync.tree;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.tree.LeafNode;
+import org.briarproject.bramble.api.sync.tree.TreeHasher;
+import org.briarproject.bramble.api.sync.tree.TreeNode;
+
+import java.util.Deque;
+import java.util.LinkedList;
+
+import javax.inject.Inject;
+
+@NotNullByDefault
+class HashTreeImpl implements HashTree {
+
+	private final TreeHasher treeHasher;
+	private final Deque<TreeNode> nodes = new LinkedList<>();
+
+	@Inject
+	HashTreeImpl(TreeHasher treeHasher) {
+		this.treeHasher = treeHasher;
+	}
+
+	@Override
+	public void addLeaf(LeafNode leaf) {
+		TreeNode add = leaf;
+		int height = leaf.getHeight();
+		TreeNode last = nodes.peekLast();
+		while (last != null && last.getHeight() == height) {
+			add = treeHasher.mergeTrees(last, add);
+			height = add.getHeight();
+			nodes.removeLast();
+			last = nodes.peekLast();
+		}
+		nodes.addLast(add);
+	}
+
+	@Override
+	public TreeNode getRoot() {
+		TreeNode root = nodes.removeLast();
+		while (!nodes.isEmpty()) {
+			root = treeHasher.mergeTrees(nodes.removeLast(), root);
+		}
+		return root;
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/sync/tree/StreamHasherImpl.java

@@ -0,0 +1,85 @@
+package org.briarproject.bramble.sync.tree;
+
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.io.BlockSink;
+import org.briarproject.bramble.api.io.HashingId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.tree.StreamHasher;
+import org.briarproject.bramble.api.sync.tree.TreeHash;
+import org.briarproject.bramble.api.sync.tree.TreeHasher;
+import org.briarproject.bramble.api.sync.tree.TreeNode;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.LinkedList;
+
+import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
+import javax.inject.Provider;
+
+import static java.util.Arrays.copyOfRange;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_BLOCK_LENGTH;
+
+@Immutable
+@NotNullByDefault
+class StreamHasherImpl implements StreamHasher {
+
+	private final TreeHasher treeHasher;
+	private final Provider<HashTree> hashTreeProvider;
+
+	@Inject
+	StreamHasherImpl(TreeHasher treeHasher,
+			Provider<HashTree> hashTreeProvider) {
+		this.treeHasher = treeHasher;
+		this.hashTreeProvider = hashTreeProvider;
+	}
+
+	@Override
+	public TreeNode hash(InputStream in, BlockSink sink, HashingId h)
+			throws IOException, DbException {
+		HashTree tree = hashTreeProvider.get();
+		byte[] block = new byte[MAX_BLOCK_LENGTH];
+		int read;
+		for (int blockNumber = 0; (read = read(in, block)) > 0; blockNumber++) {
+			byte[] data;
+			if (read == block.length) data = block;
+			else data = copyOfRange(block, 0, read);
+			sink.putBlock(h, blockNumber, data);
+			tree.addLeaf(treeHasher.hashBlock(blockNumber, data));
+		}
+		TreeNode root = tree.getRoot();
+		setPaths(sink, h, root, new LinkedList<>());
+		return root;
+	}
+
+	/**
+	 * Reads a block from the given input stream and returns the number of
+	 * bytes read, or 0 if no bytes were read before reaching the end of the
+	 * stream.
+	 */
+	private int read(InputStream in, byte[] block) throws IOException {
+		int offset = 0;
+		while (offset < block.length) {
+			int read = in.read(block, offset, block.length - offset);
+			if (read == -1) return offset;
+			offset += read;
+		}
+		return offset;
+	}
+
+	private void setPaths(BlockSink sink, HashingId h, TreeNode node,
+			LinkedList<TreeHash> path) throws DbException {
+		if (node.getHeight() == 0) {
+			// We've reached a leaf - store the path
+			sink.setPath(h, node.getFirstBlockNumber(), path);
+		} else {
+			// Add the right child's hash to the path and traverse the left
+			path.addFirst(node.getRightChild().getHash());
+			setPaths(sink, h, node.getLeftChild(), path);
+			// Add the left child's hash to the path and traverse the right
+			path.removeFirst();
+			path.addFirst(node.getLeftChild().getHash());
+			setPaths(sink, h, node.getRightChild(), path);
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/sync/tree/TreeHasherImpl.java

@@ -0,0 +1,44 @@
+package org.briarproject.bramble.sync.tree;
+
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.tree.LeafNode;
+import org.briarproject.bramble.api.sync.tree.ParentNode;
+import org.briarproject.bramble.api.sync.tree.TreeHash;
+import org.briarproject.bramble.api.sync.tree.TreeHasher;
+import org.briarproject.bramble.api.sync.tree.TreeNode;
+
+import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
+
+import static org.briarproject.bramble.api.sync.Message.FORMAT_VERSION;
+import static org.briarproject.bramble.api.sync.MessageId.BLOCK_LABEL;
+import static org.briarproject.bramble.api.sync.MessageId.TREE_LABEL;
+
+@Immutable
+@NotNullByDefault
+class TreeHasherImpl implements TreeHasher {
+
+	private static final byte[] FORMAT_VERSION_BYTES =
+			new byte[] {FORMAT_VERSION};
+
+	private final CryptoComponent crypto;
+
+	@Inject
+	TreeHasherImpl(CryptoComponent crypto) {
+		this.crypto = crypto;
+	}
+
+	@Override
+	public LeafNode hashBlock(int blockNumber, byte[] data) {
+		byte[] hash = crypto.hash(BLOCK_LABEL, FORMAT_VERSION_BYTES, data);
+		return new LeafNode(new TreeHash(hash), blockNumber);
+	}
+
+	@Override
+	public ParentNode mergeTrees(TreeNode left, TreeNode right) {
+		byte[] hash = crypto.hash(TREE_LABEL, FORMAT_VERSION_BYTES,
+				left.getHash().getBytes(), right.getHash().getBytes());
+		return new ParentNode(new TreeHash(hash), left, right);
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/test/TestMessageFactory.java

@@ -4,6 +4,8 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
+import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.bramble.api.sync.tree.TreeHash;
 
 import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
 
@@ -27,4 +29,10 @@ public class TestMessageFactory implements MessageFactory {
 		System.arraycopy(body, 0, raw, MESSAGE_HEADER_LENGTH, body.length);
 		return raw;
 	}
+
+	@Override
+	public MessageId getMessageId(GroupId g, long timestamp,
+			TreeHash rootHash) {
+		throw new UnsupportedOperationException();
+	}
 }

bramble-core/src/test/java/org/briarproject/bramble/util/ByteUtilsTest.java

@@ -1,135 +1,118 @@
 package org.briarproject.bramble.util;
 
-import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.junit.Test;
 
-import java.util.Random;
-
-import static java.util.Arrays.fill;
 import static org.briarproject.bramble.util.ByteUtils.MAX_16_BIT_UNSIGNED;
 import static org.briarproject.bramble.util.ByteUtils.MAX_32_BIT_UNSIGNED;
-import static org.briarproject.bramble.util.ByteUtils.MAX_VARINT_BYTES;
-import static org.briarproject.bramble.util.ByteUtils.getVarIntBytes;
-import static org.briarproject.bramble.util.ByteUtils.readUint16;
-import static org.briarproject.bramble.util.ByteUtils.readUint32;
-import static org.briarproject.bramble.util.ByteUtils.readUint64;
-import static org.briarproject.bramble.util.ByteUtils.readVarInt;
-import static org.briarproject.bramble.util.ByteUtils.writeUint16;
-import static org.briarproject.bramble.util.ByteUtils.writeUint32;
-import static org.briarproject.bramble.util.ByteUtils.writeUint64;
-import static org.briarproject.bramble.util.ByteUtils.writeVarInt;
-import static org.briarproject.bramble.util.StringUtils.fromHexString;
-import static org.briarproject.bramble.util.StringUtils.toHexString;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
 
-@SuppressWarnings("ResultOfMethodCallIgnored")
 public class ByteUtilsTest extends BrambleTestCase {
 
 	@Test
 	public void testReadUint16() {
-		byte[] b = fromHexString("00000000");
+		byte[] b = StringUtils.fromHexString("00000000");
-		assertEquals(0, readUint16(b, 1));
+		assertEquals(0, ByteUtils.readUint16(b, 1));
-		b = fromHexString("00000100");
+		b = StringUtils.fromHexString("00000100");
-		assertEquals(1, readUint16(b, 1));
+		assertEquals(1, ByteUtils.readUint16(b, 1));
-		b = fromHexString("007FFF00");
+		b = StringUtils.fromHexString("007FFF00");
-		assertEquals(Short.MAX_VALUE, readUint16(b, 1));
+		assertEquals(Short.MAX_VALUE, ByteUtils.readUint16(b, 1));
-		b = fromHexString("00FFFF00");
+		b = StringUtils.fromHexString("00FFFF00");
-		assertEquals(65535, readUint16(b, 1));
+		assertEquals(65535, ByteUtils.readUint16(b, 1));
 	}
 
 	@Test(expected = IllegalArgumentException.class)
 	public void testReadUint16ValidatesArguments1() {
-		readUint16(new byte[1], 0);
+		ByteUtils.readUint16(new byte[1], 0);
 	}
 
 	@Test(expected = IllegalArgumentException.class)
 	public void testReadUint16ValidatesArguments2() {
-		readUint16(new byte[2], 1);
+		ByteUtils.readUint16(new byte[2], 1);
 	}
 
 	@Test
 	public void testReadUint32() {
-		byte[] b = fromHexString("000000000000");
+		byte[] b = StringUtils.fromHexString("000000000000");
-		assertEquals(0, readUint32(b, 1));
+		assertEquals(0, ByteUtils.readUint32(b, 1));
-		b = fromHexString("000000000100");
+		b = StringUtils.fromHexString("000000000100");
-		assertEquals(1, readUint32(b, 1));
+		assertEquals(1, ByteUtils.readUint32(b, 1));
-		b = fromHexString("007FFFFFFF00");
+		b = StringUtils.fromHexString("007FFFFFFF00");
-		assertEquals(Integer.MAX_VALUE, readUint32(b, 1));
+		assertEquals(Integer.MAX_VALUE, ByteUtils.readUint32(b, 1));
-		b = fromHexString("00FFFFFFFF00");
+		b = StringUtils.fromHexString("00FFFFFFFF00");
-		assertEquals(4294967295L, readUint32(b, 1));
+		assertEquals(4294967295L, ByteUtils.readUint32(b, 1));
 	}
 
 	@Test(expected = IllegalArgumentException.class)
 	public void testReadUint32ValidatesArguments1() {
-		readUint32(new byte[3], 0);
+		ByteUtils.readUint32(new byte[3], 0);
 	}
 
 	@Test(expected = IllegalArgumentException.class)
 	public void testReadUint32ValidatesArguments2() {
-		readUint32(new byte[4], 1);
+		ByteUtils.readUint32(new byte[4], 1);
 	}
 
 	@Test
 	public void testReadUint64() {
-		byte[] b = fromHexString("00000000000000000000");
+		byte[] b = StringUtils.fromHexString("00000000000000000000");
-		assertEquals(0L, readUint64(b, 1));
+		assertEquals(0L, ByteUtils.readUint64(b, 1));
-		b = fromHexString("00000000000000000100");
+		b = StringUtils.fromHexString("00000000000000000100");
-		assertEquals(1L, readUint64(b, 1));
+		assertEquals(1L, ByteUtils.readUint64(b, 1));
-		b = fromHexString("007FFFFFFFFFFFFFFF00");
+		b = StringUtils.fromHexString("007FFFFFFFFFFFFFFF00");
-		assertEquals(Long.MAX_VALUE, readUint64(b, 1));
+		assertEquals(Long.MAX_VALUE, ByteUtils.readUint64(b, 1));
-		b = fromHexString("00800000000000000000");
+		b = StringUtils.fromHexString("00800000000000000000");
-		assertEquals(Long.MIN_VALUE, readUint64(b, 1));
+		assertEquals(Long.MIN_VALUE, ByteUtils.readUint64(b, 1));
-		b = fromHexString("00FFFFFFFFFFFFFFFF00");
+		b = StringUtils.fromHexString("00FFFFFFFFFFFFFFFF00");
-		assertEquals(-1L, readUint64(b, 1));
+		assertEquals(-1L, ByteUtils.readUint64(b, 1));
 	}
 
 	@Test(expected = IllegalArgumentException.class)
 	public void testReadUint64ValidatesArguments1() {
-		readUint64(new byte[7], 0);
+		ByteUtils.readUint64(new byte[7], 0);
 	}
 
 	@Test(expected = IllegalArgumentException.class)
 	public void testReadUint64ValidatesArguments2() {
-		readUint64(new byte[8], 1);
+		ByteUtils.readUint64(new byte[8], 1);
 	}
 
 	@Test
 	public void testWriteUint16() {
 		byte[] b = new byte[4];
-		writeUint16(0, b, 1);
+		ByteUtils.writeUint16(0, b, 1);
-		assertEquals("00000000", toHexString(b));
+		assertEquals("00000000", StringUtils.toHexString(b));
-		writeUint16(1, b, 1);
+		ByteUtils.writeUint16(1, b, 1);
-		assertEquals("00000100", toHexString(b));
+		assertEquals("00000100", StringUtils.toHexString(b));
-		writeUint16(Short.MAX_VALUE, b, 1);
+		ByteUtils.writeUint16(Short.MAX_VALUE, b, 1);
-		assertEquals("007FFF00", toHexString(b));
+		assertEquals("007FFF00", StringUtils.toHexString(b));
-		writeUint16(MAX_16_BIT_UNSIGNED, b, 1);
+		ByteUtils.writeUint16(MAX_16_BIT_UNSIGNED, b, 1);
-		assertEquals("00FFFF00", toHexString(b));
+		assertEquals("00FFFF00", StringUtils.toHexString(b));
 	}
 
 	@Test
 	public void testWriteUint16ValidatesArguments() {
 		try {
-			writeUint16(0, new byte[1], 0);
+			ByteUtils.writeUint16(0, new byte[1], 0);
 			fail();
 		} catch (IllegalArgumentException expected) {
 			// Expected
 		}
 		try {
-			writeUint16(0, new byte[2], 1);
+			ByteUtils.writeUint16(0, new byte[2], 1);
 			fail();
 		} catch (IllegalArgumentException expected) {
 			// Expected
 		}
 		try {
-			writeUint16(-1, new byte[2], 0);
+			ByteUtils.writeUint16(-1, new byte[2], 0);
 			fail();
 		} catch (IllegalArgumentException expected) {
 			// Expected
 		}
 		try {
-			writeUint16(MAX_16_BIT_UNSIGNED + 1, new byte[2], 0);
+			ByteUtils.writeUint16(MAX_16_BIT_UNSIGNED + 1, new byte[2], 0);
 			fail();
 		} catch (IllegalArgumentException expected) {
 			// Expected
@@ -139,38 +122,38 @@ public class ByteUtilsTest extends BrambleTestCase {
 	@Test
 	public void testWriteUint32() {
 		byte[] b = new byte[6];
-		writeUint32(0, b, 1);
+		ByteUtils.writeUint32(0, b, 1);
-		assertEquals("000000000000", toHexString(b));
+		assertEquals("000000000000", StringUtils.toHexString(b));
-		writeUint32(1, b, 1);
+		ByteUtils.writeUint32(1, b, 1);
-		assertEquals("000000000100", toHexString(b));
+		assertEquals("000000000100", StringUtils.toHexString(b));
-		writeUint32(Integer.MAX_VALUE, b, 1);
+		ByteUtils.writeUint32(Integer.MAX_VALUE, b, 1);
-		assertEquals("007FFFFFFF00", toHexString(b));
+		assertEquals("007FFFFFFF00", StringUtils.toHexString(b));
-		writeUint32(MAX_32_BIT_UNSIGNED, b, 1);
+		ByteUtils.writeUint32(MAX_32_BIT_UNSIGNED, b, 1);
-		assertEquals("00FFFFFFFF00", toHexString(b));
+		assertEquals("00FFFFFFFF00", StringUtils.toHexString(b));
 	}
 
 	@Test
 	public void testWriteUint32ValidatesArguments() {
 		try {
-			writeUint32(0, new byte[3], 0);
+			ByteUtils.writeUint32(0, new byte[3], 0);
 			fail();
 		} catch (IllegalArgumentException expected) {
 			// Expected
 		}
 		try {
-			writeUint32(0, new byte[4], 1);
+			ByteUtils.writeUint32(0, new byte[4], 1);
 			fail();
 		} catch (IllegalArgumentException expected) {
 			// Expected
 		}
 		try {
-			writeUint32(-1, new byte[4], 0);
+			ByteUtils.writeUint32(-1, new byte[4], 0);
 			fail();
 		} catch (IllegalArgumentException expected) {
 			// Expected
 		}
 		try {
-			writeUint32(MAX_32_BIT_UNSIGNED + 1, new byte[4], 0);
+			ByteUtils.writeUint32(MAX_32_BIT_UNSIGNED + 1, new byte[4], 0);
 			fail();
 		} catch (IllegalArgumentException expected) {
 			// Expected
@@ -180,30 +163,30 @@ public class ByteUtilsTest extends BrambleTestCase {
 	@Test
 	public void testWriteUint64() {
 		byte[] b = new byte[10];
-		writeUint64(0, b, 1);
+		ByteUtils.writeUint64(0, b, 1);
-		assertEquals("00000000000000000000", toHexString(b));
+		assertEquals("00000000000000000000", StringUtils.toHexString(b));
-		writeUint64(1, b, 1);
+		ByteUtils.writeUint64(1, b, 1);
-		assertEquals("00000000000000000100", toHexString(b));
+		assertEquals("00000000000000000100", StringUtils.toHexString(b));
-		writeUint64(Long.MAX_VALUE, b, 1);
+		ByteUtils.writeUint64(Long.MAX_VALUE, b, 1);
-		assertEquals("007FFFFFFFFFFFFFFF00", toHexString(b));
+		assertEquals("007FFFFFFFFFFFFFFF00", StringUtils.toHexString(b));
 	}
 
 	@Test
 	public void testWriteUint64ValidatesArguments() {
 		try {
-			writeUint64(0, new byte[7], 0);
+			ByteUtils.writeUint64(0, new byte[7], 0);
 			fail();
 		} catch (IllegalArgumentException expected) {
 			// Expected
 		}
 		try {
-			writeUint64(0, new byte[8], 1);
+			ByteUtils.writeUint64(0, new byte[8], 1);
 			fail();
 		} catch (IllegalArgumentException expected) {
 			// Expected
 		}
 		try {
-			writeUint64(-1, new byte[8], 0);
+			ByteUtils.writeUint64(-1, new byte[8], 0);
 			fail();
 		} catch (IllegalArgumentException expected) {
 			// Expected
@@ -211,170 +194,17 @@ public class ByteUtilsTest extends BrambleTestCase {
 	}
 
 	@Test
-	public void testGetVarIntBytesToWrite() {
+	public void testReadUint() {
-		assertEquals(1, getVarIntBytes(0));
+		byte[] b = new byte[1];
-		assertEquals(1, getVarIntBytes(0x7F)); // Max 7-bit int
+		b[0] = (byte) 128;
-		assertEquals(2, getVarIntBytes(0x7F + 1));
+		for (int i = 0; i < 8; i++) {
-		assertEquals(2, getVarIntBytes(0x3FFF)); // Max 14-bit int
+			assertEquals(1 << i, ByteUtils.readUint(b, i + 1));
-		assertEquals(3, getVarIntBytes(0x3FFF + 1));
+		}
-		assertEquals(3, getVarIntBytes(0x1FFFFF)); // Max 21-bit int
+		b = new byte[2];
-		assertEquals(4, getVarIntBytes(0x1FFFFF + 1));
+		for (int i = 0; i < 65535; i++) {
-		assertEquals(4, getVarIntBytes(0xFFFFFFF)); // Max 28-bit int
+			ByteUtils.writeUint16(i, b, 0);
-		assertEquals(5, getVarIntBytes(0xFFFFFFF + 1));
+			assertEquals(i, ByteUtils.readUint(b, 16));
-		assertEquals(5, getVarIntBytes(0x7FFFFFFFFL)); // Max 35-bit int
+			assertEquals(i >> 1, ByteUtils.readUint(b, 15));
-		assertEquals(6, getVarIntBytes(0x7FFFFFFFFL + 1));
-		assertEquals(6, getVarIntBytes(0x3FFFFFFFFFFL)); // Max 42-bit int
-		assertEquals(7, getVarIntBytes(0x3FFFFFFFFFFL + 1));
-		assertEquals(7, getVarIntBytes(0x1FFFFFFFFFFFFL)); // Max 49-bit int
-		assertEquals(8, getVarIntBytes(0x1FFFFFFFFFFFFL + 1));
-		assertEquals(8, getVarIntBytes(0xFFFFFFFFFFFFFFL)); // Max 56-bit int
-		assertEquals(9, getVarIntBytes(0xFFFFFFFFFFFFFFL + 1));
-		assertEquals(9, getVarIntBytes(0x7FFFFFFFFFFFFFFFL)); // Max 63-bit int
-		assertEquals(MAX_VARINT_BYTES, getVarIntBytes(Long.MAX_VALUE)); // Same
-	}
-
-	@Test
-	public void testWriteVarInt() {
-		testWriteVarInt(0, 1, "00");
-		testWriteVarInt(1, 1, "01");
-		testWriteVarInt(0x7F, 1, "7F"); // Max 7-bit int
-		testWriteVarInt(0x7F + 1, 2, "8100");
-		testWriteVarInt(0x3FFF, 2, "FF7F"); // Max 14-bit int
-		testWriteVarInt(0x3FFF + 1, 3, "818000");
-		testWriteVarInt(0x1FFFFF, 3, "FFFF7F"); // Max 21-bit int
-		testWriteVarInt(0x1FFFFF + 1, 4, "81808000");
-		testWriteVarInt(0xFFFFFFF, 4, "FFFFFF7F"); // Max 28-bit int
-		testWriteVarInt(0xFFFFFFF + 1, 5, "8180808000");
-		testWriteVarInt(0x7FFFFFFFFL, 5, "FFFFFFFF7F"); // Max 35-bit int
-		testWriteVarInt(0x7FFFFFFFFL + 1, 6, "818080808000");
-		testWriteVarInt(0x3FFFFFFFFFFL, 6, "FFFFFFFFFF7F"); // Max 42-bit int
-		testWriteVarInt(0x3FFFFFFFFFFL + 1, 7, "81808080808000");
-		testWriteVarInt(0x1FFFFFFFFFFFFL, 7, "FFFFFFFFFFFF7F"); // Max 49
-		testWriteVarInt(0x1FFFFFFFFFFFFL + 1, 8, "8180808080808000");
-		testWriteVarInt(0xFFFFFFFFFFFFFFL, 8, "FFFFFFFFFFFFFF7F"); // Max 56
-		testWriteVarInt(0xFFFFFFFFFFFFFFL + 1, 9, "818080808080808000");
-		testWriteVarInt(0x7FFFFFFFFFFFFFFFL, 9, "FFFFFFFFFFFFFFFF7F"); // Max 63
-		testWriteVarInt(Long.MAX_VALUE, MAX_VARINT_BYTES, "FFFFFFFFFFFFFFFF7F");
-	}
-
-	private void testWriteVarInt(long src, int len, String destHex) {
-		byte[] dest = new byte[9];
-		assertEquals(len, writeVarInt(src, dest, 0));
-		assertEquals(destHex, toHexString(dest).substring(0, len * 2));
-	}
-
-	@Test
-	public void testGetVarIntBytesToRead() throws FormatException {
-		testGetVarIntBytesToRead(1, "00", 0);
-		testGetVarIntBytesToRead(1, "01", 0);
-		testGetVarIntBytesToRead(1, "7F", 0); // Max 7-bit int
-		testGetVarIntBytesToRead(2, "8100", 0);
-		testGetVarIntBytesToRead(2, "FF7F", 0); // Max 14-bit int
-		testGetVarIntBytesToRead(3, "818000", 0);
-		testGetVarIntBytesToRead(3, "FFFF7F", 0); // Max 21-bit int
-		testGetVarIntBytesToRead(4, "81808000", 0);
-		testGetVarIntBytesToRead(4, "FFFFFF7F", 0); // Max 28-bit int
-		testGetVarIntBytesToRead(5, "8180808000", 0);
-		testGetVarIntBytesToRead(5, "FFFFFFFF7F", 0); // Max 35-bit int
-		testGetVarIntBytesToRead(6, "818080808000", 0);
-		testGetVarIntBytesToRead(6, "FFFFFFFFFF7F", 0); // Max 42-bit int
-		testGetVarIntBytesToRead(7, "81808080808000", 0);
-		testGetVarIntBytesToRead(7, "FFFFFFFFFFFF7F", 0); // Max 49-bit int
-		testGetVarIntBytesToRead(8, "8180808080808000", 0);
-		testGetVarIntBytesToRead(8, "FFFFFFFFFFFFFF7F", 0); // Max 56-bit int
-		testGetVarIntBytesToRead(9, "818080808080808000", 0);
-		testGetVarIntBytesToRead(9, "FFFFFFFFFFFFFFFF7F", 0); // Max 63-bit int
-		// Start at offset, ignore trailing data
-		testGetVarIntBytesToRead(1, "FF0000", 1);
-		testGetVarIntBytesToRead(9, "00FFFFFFFFFFFFFFFF7F00", 1);
-	}
-
-	private void testGetVarIntBytesToRead(int len, String srcHex, int offset)
-			throws FormatException {
-		assertEquals(len, getVarIntBytes(fromHexString(srcHex), offset));
-	}
-
-	@Test(expected = FormatException.class)
-	public void testGetVarIntBytesToReadThrowsExceptionAtEndOfInput()
-			throws FormatException {
-		byte[] src = new byte[MAX_VARINT_BYTES - 1];
-		fill(src, (byte) 0xFF);
-		// Reaches end of input without finding lowered continuation flag
-		getVarIntBytes(src, 0);
-	}
-
-	@Test(expected = FormatException.class)
-	public void testGetVarIntBytesToReadThrowsExceptionAfterNineBytes()
-			throws FormatException {
-		byte[] src = new byte[MAX_VARINT_BYTES];
-		fill(src, (byte) 0xFF);
-		// Reaches max length without finding lowered continuation flag
-		getVarIntBytes(src, 0);
-	}
-
-	@Test
-	public void testReadVarInt() throws FormatException {
-		testReadVarInt(0, "00", 0);
-		testReadVarInt(1, "01", 0);
-		testReadVarInt(0x7F, "7F", 0); // Max 7-bit int
-		testReadVarInt(0x7F + 1, "8100", 0);
-		testReadVarInt(0x3FFF, "FF7F", 0); // Max 14-bit int
-		testReadVarInt(0x3FFF + 1, "818000", 0);
-		testReadVarInt(0x1FFFFF, "FFFF7F", 0); // Max 21-bit int
-		testReadVarInt(0x1FFFFF + 1, "81808000", 0);
-		testReadVarInt(0xFFFFFFF, "FFFFFF7F", 0); // Max 28-bit int
-		testReadVarInt(0xFFFFFFF + 1, "8180808000", 0);
-		testReadVarInt(0x7FFFFFFFFL, "FFFFFFFF7F", 0); // Max 35-bit int
-		testReadVarInt(0x7FFFFFFFFL + 1, "818080808000", 0);
-		testReadVarInt(0x3FFFFFFFFFFL, "FFFFFFFFFF7F", 0); // Max 42-bit int
-		testReadVarInt(0x3FFFFFFFFFFL + 1, "81808080808000", 0);
-		testReadVarInt(0x1FFFFFFFFFFFFL, "FFFFFFFFFFFF7F", 0); // Max 49-bit int
-		testReadVarInt(0x1FFFFFFFFFFFFL + 1, "8180808080808000", 0);
-		testReadVarInt(0xFFFFFFFFFFFFFFL, "FFFFFFFFFFFFFF7F", 0); // Max 56
-		testReadVarInt(0xFFFFFFFFFFFFFFL + 1, "818080808080808000", 0);
-		testReadVarInt(0x7FFFFFFFFFFFFFFFL, "FFFFFFFFFFFFFFFF7F", 0); // Max 63
-		testReadVarInt(Long.MAX_VALUE, "FFFFFFFFFFFFFFFF7F", 0);
-		// Start at offset, ignore trailing data
-		testReadVarInt(0, "FF0000", 1);
-		testReadVarInt(Long.MAX_VALUE, "00FFFFFFFFFFFFFFFF7F00", 1);
-	}
-
-	private void testReadVarInt(long dest, String srcHex, int offset)
-			throws FormatException {
-		assertEquals(dest, readVarInt(fromHexString(srcHex), offset));
-	}
-
-	@Test(expected = FormatException.class)
-	public void testReadVarIntThrowsExceptionAtEndOfInput()
-			throws FormatException {
-		byte[] src = new byte[MAX_VARINT_BYTES - 1];
-		fill(src, (byte) 0xFF);
-		// Reaches end of input without finding lowered continuation flag
-		readVarInt(src, 0);
-	}
-
-	@Test(expected = FormatException.class)
-	public void testReadVarIntThrowsExceptionAfterNineBytes()
-			throws FormatException {
-		byte[] src = new byte[MAX_VARINT_BYTES];
-		fill(src, (byte) 0xFF);
-		// Reaches max length without finding lowered continuation flag
-		readVarInt(src, 0);
-	}
-
-	@Test
-	public void testWriteAndReadVarInt() throws FormatException {
-		Random random = new Random();
-		int padding = 10;
-		byte[] buf = new byte[MAX_VARINT_BYTES + padding];
-		for (int i = 0; i < 1000; i++) {
-			long src = random.nextLong() & 0x7FFFFFFFFFFFFFFFL; // Non-negative
-			int offset = random.nextInt(padding);
-			int len = getVarIntBytes(src);
-			assertEquals(len, writeVarInt(src, buf, offset));
-			assertEquals(len, getVarIntBytes(buf, offset));
-			assertEquals(src, readVarInt(buf, offset));
-			fill(buf, (byte) 0);
 		}
 	}
 }