/* Glazed Lists (c) 2003-2006 */
/* http://publicobject.com/glazedlists/ publicobject.com,*/
/* O'Dell Engineering Ltd.*/
package ca.odell.glazedlists.impl.rbp;
// NIO is used for BRP
import ca.odell.glazedlists.impl.io.Bufferlo;
import java.text.ParseException;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;
/**
* A binary message between peers.
*
* @author <a href="mailto:jesse@swank.ca">Jesse Wilson</a>
*/
class PeerBlock {
/** constants used in the protocol */
private static final String RESOURCE_URI = "Resource-Uri";
private static final String SESSION_ID = "Session-Id";
private static final String UPDATE_ID = "Update-Id";
private static final String ACTION = "Action";
private static final String ACTION_SUBSCRIBE = "Subscribe";
private static final String ACTION_SUBSCRIBE_CONFIRM = "Subscribe-Confirm";
private static final String ACTION_UPDATE = "Update";
private static final String ACTION_UNSUBSCRIBE = "Unsubscribe";
private static final String ACTION_UNPUBLISH = "Unpublish";
/** the resource this block is concerned with */
private ResourceUri resourceUri = null;
/** a check id */
private int sessionId = -1;
/** the action of this block */
private String action = null;
/** the sequence ID of this block */
private int updateId = -1;
/** the binary data of this block */
private Bufferlo payload = null;
/**
* Create a new PeerBlock.
*/
private PeerBlock(ResourceUri resourceUri, int sessionId, String action, int updateId, Bufferlo payload) {
this.resourceUri = resourceUri;
this.sessionId = sessionId;
this.action = action;
this.updateId = updateId;
this.payload = payload;
}
/**
* Create a new subscribe block.
*/
public static PeerBlock subscribeConfirm(ResourceUri resourceUri, int sessionId, int updateId, Bufferlo snapshot) {
return new PeerBlock(resourceUri, sessionId, PeerBlock.ACTION_SUBSCRIBE_CONFIRM, updateId, snapshot);
}
/**
* Create a new subscribe block.
*/
public static PeerBlock update(ResourceUri resourceUri, int sessionId, int updateId, Bufferlo delta) {
return new PeerBlock(resourceUri, sessionId, PeerBlock.ACTION_UPDATE, updateId, delta);
}
/**
* Create a new subscribe block.
*/
public static PeerBlock subscribe(ResourceUri resourceUri) {
return new PeerBlock(resourceUri, -1, PeerBlock.ACTION_SUBSCRIBE, -1, null);
}
/**
* Create a new subscribe block.
*/
public static PeerBlock unsubscribe(ResourceUri resourceUri) {
return new PeerBlock(resourceUri, -1, PeerBlock.ACTION_UNSUBSCRIBE, -1, null);
}
/**
* Create a new subscribe block.
*/
public static PeerBlock unpublish(ResourceUri resourceUri) {
return new PeerBlock(resourceUri, -1, PeerBlock.ACTION_UNPUBLISH, -1, null);
}
/**
* Whether this is a subscribe-confirm block.
*/
public boolean isSubscribeConfirm() {
return ACTION_SUBSCRIBE_CONFIRM.equals(action);
}
/**
* Whether this is an update block.
*/
public boolean isUpdate() {
return ACTION_UPDATE.equals(action);
}
/**
* Whether this is a subscribe block.
*/
public boolean isSubscribe() {
return ACTION_SUBSCRIBE.equals(action);
}
/**
* Whether this is an unsubscribe block.
*/
public boolean isUnsubscribe() {
return ACTION_UNSUBSCRIBE.equals(action);
}
/**
* Whether this is an unpublish block.
*/
public boolean isUnpublish() {
return ACTION_UNPUBLISH.equals(action);
}
/**
* Get the PeerBlock from the specified bytes.
*
* @return the first PeerBlock from the specified bytes, it it exists. The
* result may be null indicating an incomplete PeerBlock. There may be
* multiple PeerBlocks available in the specified list of bytes.
*/
public static PeerBlock fromBytes(Bufferlo bytes, String localHost, int localPort) throws ParseException {
// if a full block is not loaded
int blockEndIndex = bytes.indexOf("\\r\\n");
if(blockEndIndex == -1) return null;
// read the bytes of the first block
String blockSizeInDecimal = bytes.readUntil("\\r\\n", false);
int blockSizeWithHeaders = Integer.parseInt(blockSizeInDecimal);
// if the full block is not loaded, give up
int bytesRequired = blockEndIndex + 2 + blockSizeWithHeaders + 2;
if(bytes.length() < bytesRequired) {
return null;
}
// consume the size
bytes.consume("[0-9]*\\r\\n");
// load the headers
int lengthBeforeHeaders = bytes.length();
Map headers = new TreeMap();
while(true) {
if(bytes.indexOf("\\r\\n") == 0) break;
String key = bytes.readUntil("\\:( )*");
String value = bytes.readUntil("\\r\\n");
headers.put(key, value);
}
bytes.consume("\\r\\n");
int lengthAfterHeaders = bytes.length();
int headersLength = lengthBeforeHeaders - lengthAfterHeaders;
// load the data
int payloadLength = blockSizeWithHeaders - headersLength;
Bufferlo payload = bytes.consume(payloadLength);
bytes.consume("\\r\\n");
// parse the headers
String resourceUriString = (String)headers.get(RESOURCE_URI);
ResourceUri resourceUri = ResourceUri.localOrRemote(resourceUriString, localHost, localPort);
String sessionIdString = (String)headers.get(SESSION_ID);
String action = (String)headers.get(ACTION);
String updateIdString = (String)headers.get(UPDATE_ID);
int sessionId = (sessionIdString != null) ? Integer.parseInt(sessionIdString) : -1;
int updateId = (updateIdString != null) ? Integer.parseInt(updateIdString) : -1;
// return the result
return new PeerBlock(resourceUri, sessionId, action, updateId, payload);
}
/**
* Get the bytes for this block.
*/
public Bufferlo toBytes(String localHost, int localPort) {
// the writer with no size info
Bufferlo writer = new Bufferlo();
// populate the map of headers
Map headers = new TreeMap();
if(resourceUri != null) headers.put(RESOURCE_URI, resourceUri.toString(localHost, localPort));
if(sessionId != -1) headers.put(SESSION_ID, new Integer(sessionId));
if(action != null) headers.put(ACTION, action);
if(updateId != -1) headers.put(UPDATE_ID, new Integer(updateId));
// write the header values
for(Iterator i = headers.entrySet().iterator(); i.hasNext(); ) {
Map.Entry mapEntry = (Map.Entry)i.next();
writer.write(mapEntry.getKey().toString());
writer.write(": ");
writer.write(mapEntry.getValue().toString());
writer.write("\r\n");
}
writer.write("\r\n");
// write the payload
if(payload != null) {
writer.append(payload.duplicate());
}
// wrap the size
Bufferlo writerWithSize = new Bufferlo();
writerWithSize.write("" + writer.length());
writerWithSize.write("\r\n");
writerWithSize.append(writer);
writerWithSize.write("\r\n");
// all done
return writerWithSize;
}
/**
* Gets the action of this block.
*/
public String getAction() {
return action;
}
/**
* Gets the binary data of this block.
*/
public Bufferlo getPayload() {
return payload;
}
/**
* Gets the update ID of this block.
*/
public int getUpdateId() {
return updateId;
}
/**
* Gets the session ID of this block.
*/
public int getSessionId() {
return sessionId;
}
/**
* Gets the resource that this block is for.
*/
public ResourceUri getResourceUri() {
return resourceUri;
}
}