@Test
/** Test entire encoding */
public void testEncoding() throws UnknownHostException {
String expectedHeader = " 172.17.152.12253200 172.17.152.17 2016D 1";
String payload = "Hi Mom!";
String padding = " ";
String checksumStr = " 3352";
assertEquals("Header length", ReliableTransportMessage.HEADER_LEN, expectedHeader.length());
assertEquals("padding length", 23, padding.length());
InetAddress srcIP = InetAddress.getByName("172.17.152.122");
InetAddress destIP = InetAddress.getByName("172.17.152.17");
ReliableTransportMessage msg =
new ReliableTransportMessage(
srcIP, destIP, 53200, 2016, ReliableTransportMessage.DATA, 1, payload);
assertEquals("source IP", "/172.17.152.122", msg.getSourceIP().toString());
assertEquals("dest IP", "/172.17.152.17", msg.getDestIP().toString());
msg.encode();
String expectedEncoding = expectedHeader + payload + padding + checksumStr;
assertEquals("Expected Encoding length", 78, expectedEncoding.length());
assertEquals(
"Checksum input length",
73,
ReliableTransportMessage.HEADER_LEN + ReliableTransportMessage.PAYLOAD_LEN);
for (int i = 0; i < 73; i++)
// check i-th term of checksum
assertEquals("Checksum term " + i, (int) expectedEncoding.charAt(i), msg.getChecksumTerm(i));
String encodingStr = new String(msg.getBuffer());
assertEquals("encoded length", 78, encodingStr.length());
assertEquals("computed checksum", 3352, msg.getComputedChecksum());
assertEquals("encoding", expectedEncoding, encodingStr);
}
/** Test reconstituting a message */
public void testReconstituteMessage() {
String encoding1 =
" 172.17.152.12253200 172.17.152.17 2017D 1TCP, the Queen of Protocols! 4587";
char[] encodingChars = encoding1.toCharArray();
byte[] encodingBytes = new byte[encodingChars.length];
for (int i = 0; i < encodingChars.length; i++)
// convert i-th char to byte
encodingBytes[i] = (byte) encodingChars[i];
assertEquals("encoding1 length", ReliableTransportMessage.BUFFER_LEN, encoding1.length());
ReliableTransportMessage msg1 = ReliableTransportMessage.reconstitute(encodingBytes);
assertNotNull("reconstituted message 1 is NULL", msg1);
assertEquals("Source IP", "/172.17.152.122", msg1.getSourceIP().toString());
assertEquals("Dest IP", "/172.17.152.17", msg1.getDestIP().toString());
assertEquals("Source port", 53200, msg1.getSrcPort());
assertEquals("Dest port", 2017, msg1.getDestPort());
assertEquals("Op code", ReliableTransportMessage.DATA, msg1.getOpCode());
assertEquals("seq no", 1, msg1.getSequenceNo());
assertEquals(
"Payload length", ReliableTransportMessage.PAYLOAD_LEN, msg1.getPayload().length());
assertEquals("Payload", "TCP, the Queen of Protocols! ", msg1.getPayload());
assertEquals("Computed checksum", 4587, msg1.getComputedChecksum());
assertEquals("Stored checksum", 4587, msg1.getStoredChecksum());
// encoding with garbled contents
String encoding2 =
" 172.17.152.12253200 172.17.152.17 2017D 1Drink Coca-cola! 4568";
assertEquals("encoding2 length", ReliableTransportMessage.BUFFER_LEN, encoding2.length());
encodingChars = encoding2.toCharArray();
byte[] encodingBytes2 = new byte[encodingChars.length];
for (int i = 0; i < encodingChars.length; i++)
// convert i-th char to byte
encodingBytes2[i] = (byte) encodingChars[i];
ReliableTransportMessage msg2 = ReliableTransportMessage.reconstitute(encodingBytes2);
assertNull("reconstituted message 2 is not NULL", msg2);
}