Refactoring + implementation of some methods

doc/protocol.md

@@ -15,11 +15,11 @@ All messages begins with `P2P-JAVA-PROJECT VERSION 1.0\n` (this version of the p
 
 ```Datagram format
 
-[0-7: VERSION(0x11, first quartet is major version, second is minor)]
+1 byte:  [0-7: VERSION(0x11, first quartet is major version, second is minor)]
-[8-15: REQUEST/RESPONSE CODE]
+1 byte:  [8-15: REQUEST/RESPONSE CODE]
-[16-31: RESERVED FOR FUTURE USE]
+2 bytes: [16-31: RESERVED FOR FUTURE USE]
-[32-63: PAYLOAD SIZE IN BYTES]
+4 bytes: [32-63: PAYLOAD SIZE IN BYTES]
-[64-xx: PAYLOAD]
+x bytes: [64-xx: PAYLOAD]
 
 ```
 
@@ -56,10 +56,10 @@ Payload size for Not found is zero.
 Payload contains
 
 ```
-[64-127: OFFSET OF FILE CONTENT IN BYTES]
+8 bytes: [64-127: OFFSET OF FILE CONTENT IN BYTES]
-[128-191: TOTAL FILESIZE]
+8 bytes: [128-191: TOTAL FILESIZE]
-[<FILENAME>\n]
+y bytes: [<FILENAME>\n]
-[FILE CONTENT]
+z bytes: [FILE CONTENT]
 ```
 
 #### Load request

src/protocolP2P/FileList.java

@@ -4,6 +4,7 @@ import protocolP2P.Payload;
 import protocolP2P.RequestResponseCode;
 import exception.ProtocolError;
 import exception.InternalError;
+import exception.SizeError;
 
 /** Representation of payload for list response.
  * @author	Louis Royer
@@ -52,7 +53,7 @@ public class FileList extends Payload {
 	 */
 	protected byte[] toDatagram() {
 		//TODO compute size
-		int size = ;
+		int size = 8 + ;
 		byte[] datagram = new byte[size]; // java initialize all to zero
 		// size is keep blank (ProtocolP2PDatagram will handle it)
 		// set request/response code

src/protocolP2P/FilePart.java

@@ -3,6 +3,8 @@ import protocolP2P.Payload;
 import protocolP2P.RequestResponseCode;
 import exception.ProtocolError;
 import exception.InternalError;
+import exception.SizeError;
+import tools.BytesArrayTools;
 
 /** Representation of payload for load response.
  * @author	Louis Royer
@@ -63,7 +65,7 @@ public class FilePart extends Payload {
 	 */
 	protected byte[] toDatagram() {
 		//TODO : calculate payload size
-		int size = ;
+		int size = 24 + filename.length + 1;
 		byte[] datagram = new byte[size]; // java initialize all to zero
 		// size is keep blank (ProtocolP2PDatagram will handle it)
 		// set request/response code
@@ -76,15 +78,21 @@ public class FilePart extends Payload {
 		//TODO : write partialContent to datagram
 	}
 
+	/** Write from bytes 8 to 15 of datagram into offset.
+	 * @param datagram	received datagram
+	 * @throws	SizeError
+	 */
 	private setOffset(byte[] datagram) throws SizeError {
-		//TODO: copy from 8 to 15 into long and write into offset.
+		offset = BytesArrayTools.readLong(datagram, 8);
-		// throw protocolerror if offset is < 0
 	}
+	/** Write from bytes 16 to 23 of datagram into totalSize.
+	 * @param datagram	received datagram
+	 * @throws	SizeError
+	 */
 	private setTotalFileSize(byte[] datagram) throw SizeError {
-		// TODO: convert from byte 16 to 23 (included)
+		totalSize = BytesArrayTools.readLong(datagram, 16);
-		// into long and write into totalFileSize
-		// throw protocolerror if offset is < 0
 	}
+
 	private int setFilename(byte[] datagram, int payloadSize) throws ProtocolError {
 		// TODO: copy datagram from byte 24 to the first \n (excluded)
 		// into filename unless we excess size

src/protocolP2P/Payload.java

@@ -4,6 +4,8 @@ import protocolP2P.FilePart;
 import protocolP2P.FileList;
 import exception.ProtocolError;
 import exception.InternalError;
+import exception.SizeError;
+import tools.BytesArrayTools;
 /** Representation of payload. If payload has a size, use subclasses instead.
  * @author	Louis Royer
  * @author	Flavien Haas
@@ -78,9 +80,7 @@ public class Payload {
 			// because this is only for reception side
 			throw new InternalError();
 		}
-		for(int i=0;i<4;i++) {
+		BytesArrayTools.write(datagram, PAYLOAD_SIZE_POSITON, size);
-				datagram[Payload.PAYLOAD_SIZE_POSITON + i] = (byte) ((size >> (8 * (3 - i))) & 0xFF);
-		}
 	}
 
 	/** Get payload’s size from a datagram.
@@ -89,15 +89,6 @@ public class Payload {
 	 * @throws	SizeError
 	 */
 	protected static int getPayloadSize(byte[] datagram) throws SizeError {
-		int size = 0;
+		return BytesArrayTools.readInt(datagram, PAYLOAD_SIZE_POSITON];
-		for(int i=0;i<4;i++) {
-			size |= ((int)datagram[PAYLOAD_SIZE_POSITON + i]) << (8* i);
-		}
-		if (size < 0) {
-			// Size in datagram is probably correct
-			// but we cannot store it into a int (or this will be negative)
-			throw new SizeError();
-		}
-		return size;
 	}
 }

src/tools/ByteArrayTools.java

@@ -0,0 +1,66 @@
+package tools;
+import exception.SizeError;
+/** Helper to manipulate byte[].
+ * @author	Louis Royer
+ * @author	Flavien Haas
+ * @author	JS Auge
+ * @version	1.0
+ */
+public class BytesArrayTools {
+	/** Write int in a bytearray
+	 * @param array	the array to write
+	 * @param start	where to begin writting
+	 * @param value	int to write
+	 */
+	public static void write(byte[] array, int start, int value) {
+		for(int i=0;i<4;i++) {
+			array[start + i] = (byte) ((size >> (8 * (3 - i))) & 0xFF);
+		}
+	}
+	/** Write long in a bytearray
+	 * @param array	the array to write
+	 * @param start	where to begin writting
+	 * @param value	long to write
+	 */
+	public static void write(byte[] array, int start, long value) {
+		for(int i=0;i<4;i++) {
+			array[start + i] = (byte) ((size >> (8 * (4 - i))) & 0xFF);
+		}
+	}
+
+	/** Read int from a bytearray
+	 * @param array	the array to read
+	 * @param start	where to begin reading
+	 * @return value read as int
+	 */
+	public static int readInt(byte[] array, int start) throws SizeError {
+		int size = 0;
+		for(int i=0;i<4;i++) {
+			size |= ((int)array[start + i]) << (8* i);
+		}
+		if (size < 0) {
+			// Size in array is probably correct
+			// but we cannot store it into a int (or this will be negative)
+			throw new SizeError();
+		}
+		return size;
+	}
+	/** Read long from a bytearray
+	 * @param array	the array to read
+	 * @param start	where to begin reading
+	 * @return value read as long
+	 */	
+	public static long readLong(byte[] array, int start) throws SizeError {
+		long size = 0;
+		for(int i=0;i<8;i++) {
+			size |= ((int)array[start + i]) << (8* i);
+		}
+		if (size < 0) {
+			// Size in array is probably correct
+			// but we cannot store it into a int (or this will be negative)
+			throw new SizeError();
+		}
+		return size;
+	} 
+
+}