Author: fhanik
Date: Mon May 22 20:41:04 2006
New Revision: 408823
URL: http://svn.apache.org/viewvc?rev=408823&view=rev
Log:
Defined the algorithm for leadership election, need to create a state diagram
so that the implementation doesn't become a clutter
Modified:
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/group/AbsoluteOrder.java
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/group/interceptors/NonBlockingCoordinator.java
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/membership/Membership.java
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/util/Arrays.java
Modified:
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/group/AbsoluteOrder.java
URL:
http://svn.apache.org/viewvc/tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/group/AbsoluteOrder.java?rev=408823&r1=408822&r2=408823&view=diff
==============================================================================
---
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/group/AbsoluteOrder.java
(original)
+++
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/group/AbsoluteOrder.java
Mon May 22 20:41:04 2006
@@ -27,7 +27,7 @@
* @see org.apache.catalina.tribes.Member
*/
public class AbsoluteOrder {
- protected static AbsoluteComparator comp = new AbsoluteComparator();
+ public static final AbsoluteComparator comp = new AbsoluteComparator();
protected AbsoluteOrder() {
super();
Modified:
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/group/interceptors/NonBlockingCoordinator.java
URL:
http://svn.apache.org/viewvc/tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/group/interceptors/NonBlockingCoordinator.java?rev=408823&r1=408822&r2=408823&view=diff
==============================================================================
---
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/group/interceptors/NonBlockingCoordinator.java
(original)
+++
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/group/interceptors/NonBlockingCoordinator.java
Mon May 22 20:41:04 2006
@@ -26,6 +26,8 @@
import org.apache.catalina.tribes.util.UUIDGenerator;
import org.apache.catalina.tribes.group.AbsoluteOrder;
import org.apache.catalina.tribes.util.Arrays;
+import org.apache.catalina.tribes.io.ChannelData;
+import org.apache.catalina.tribes.Channel;
/**
* <p>Title: NonBlockingCoordinator</p>
@@ -33,39 +35,215 @@
* <p>Description: Implementation of a simple coordinator algorithm.</p>
* <p>This algorithm is non blocking meaning it allows for transactions while
the coordination phase is going on
* </p>
- * <p>Implementation based on ideas fetched from <a
href="http://www.cs.chalmers.se/~hanssv/";>Hans Svensson</a></p>
+ * <p>This implementation is based on a home brewed algorithm that uses the
AbsoluteOrder of a membership
+ * to pass a token ring of the current membership.<br>
+ * This is not the same as just using AbsoluteOrder! Consider the following
scenario:<br>
+ * Nodes, A,B,C,D,E on a network, in that priority. AbsoluteOrder will only
work if all
+ * nodes are receiving pings from all the other nodes.
+ * meaning, that node{i} receives pings from node{all}-node{i}<br>
+ * but the following could happen if a multicast problem occurs.
+ * A has members {B,C,D}<br>
+ * B has members {A,C}<br>
+ * C has members {D,E}<br>
+ * D has members {A,B,C,E}<br>
+ * E has members {A,C,D}<br>
+ * Because the default Tribes membership implementation, relies on the
multicast packets to
+ * arrive at all nodes correctly, there is nothing guaranteeing that it
will.<br>
+ * <br>
+ * To best explain how this algorithm works, lets take the above example:
+ * For simplicity we assume that a send operation is O(1) for all nodes,
although this algorithm will work
+ * where messages overlap, as they all depend on absolute order<br>
+ * Scenario 1: A,B,C,D,E all come online at the same time
+ * Eval phase, A thinks of itself as leader, B thinks of A as leader,
+ * C thinks of itself as leader, D,E think of A as leader<br>
+ * Token phase:<br>
+ * (1) A sends out a message X{A-ldr, A-src, mbrs-A,B,C,D} to B where X is the
id for the message(and the view)<br>
+ * (1) C sends out a message Y{C-ldr, C-src, mbrs-C,D,E} to D where Y is the
id for the message(and the view)<br>
+ * (2) B receives X{A-ldr, A-src, mbrs-A,B,C,D}, sends X{A-ldr, A-src,
mbrs-A,B,C,D} to C <br>
+ * (2) D receives Y{C-ldr, C-src, mbrs-C,D,E} D is aware of A,B, sends
Y{A-ldr, C-src, mbrs-A,B,C,D,E} to E<br>
+ * (3) C receives X{A-ldr, A-src, mbrs-A,B,C,D}, sends X{A-ldr, A-src,
mbrs-A,B,C,D,E} to D<br>
+ * (3) E receives Y{A-ldr, C-src, mbrs-A,B,C,D,E} sends Y{A-ldr, C-src,
mbrs-A,B,C,D,E} to A<br>
+ * (4) D receives X{A-ldr, A-src, mbrs-A,B,C,D,E} sends sends X{A-ldr, A-src,
mbrs-A,B,C,D,E} to A<br>
+ * (4) A receives Y{A-ldr, C-src, mbrs-A,B,C,D,E}, holds the message, add E to
its list of members<br>
+ * (5) A receives X{A-ldr, A-src, mbrs-A,B,C,D,E} <br>
+ * At this point, the state looks like<br>
+ * A - {A-ldr, mbrs-A,B,C,D,E, id=X}<br>
+ * B - {A-ldr, mbrs-A,B,C,D, id=X}<br>
+ * C - {A-ldr, mbrs-A,B,C,D,E, id=X}<br>
+ * D - {A-ldr, mbrs-A,B,C,D,E, id=X}<br>
+ * E - {A-ldr, mbrs-A,B,C,D,E, id=Y}<br>
+ * <br>
+ * A message doesn't stop until it reaches its original sender, unless its
dropped by a higher leader.
+ * As you can see, E still thinks the viewId=Y, which is not correct. But at
this point we have
+ * arrived at the same membership and all nodes are informed of each other.<br>
+ * To synchronize the rest we simply perform the following check at A when A
receives X:<br>
+ * Original X{A-ldr, A-src, mbrs-A,B,C,D} == Arrived X{A-ldr, A-src,
mbrs-A,B,C,D,E}<br>
+ * Since the condition is false, A, will resend the token, and A sends
X{A-ldr, A-src, mbrs-A,B,C,D,E} to B
+ * When A receives X again, the token is complete.
+ * </p>
+ * <p>
+ * Lets assume that C1 arrives, C1 has lower priority than C, but higher
priority than D.<br>
+ * Lets also assume that C1 sees the following view {B,D,E}<br>
+ * C1 sends Z{B-ldr, C-src, mbrs-B,C1,D,E} to D<br>
+ * D receives Z{B-ldr, C-src, mbrs-B,C1,D,E} sends Z{A-ldr, D-src,
mbrs-A,B,C,C1,D,E} to E<br>
+ * Once the message reaches A, A will issue a new view and send a new
message<br>
+ * A view is not accepted by a member unless ldr==src in the token.<br>
+ * </p>
+ * <p>
+ * Lets assume that A0 arrives A0 being higher than A.<br>
+ * Lets also assume that A0 sees view {B,D,E}<br>
+ * A0 will issue a similar view statement and the same scenario as above will
happen.<br>
+ * If A0 sees {A,B,C,D} it simply sends the message to A rather than B.
+ * </p>
+ * <p>If we wanted to ensure that the view gets implemented at all nodes at
the same time,
+ * ie, implementing a blocking coordinator, we would simply require that
each view, before it gets installed
+ * has to receive a VIEW_CONF message.
+ *
* <p>Ideally, the interceptor below this one would be the TcpFailureDetector
to ensure correct memberships</p>
*
+ * <p>The example above, of course can be simplified with a finite
statemachine:<br>
+ * But I suck at writing state machines, my head gets all confused. One day I
will document this algorithm though.<br>
+ * Maybe I'll do a state diagram :)
+ * </p>
+ *
* @author Filip Hanik
* @version 1.0
- * @todo
- * when sending a HALT message, btw, only the highest in the membership
group will do that
- * allow for some time to pass, incase there is a higher member around
- * preferrably, place a mcast interceptor below, so that we can mcast this
sucker
+ *
+ *
+ *
*/
public class NonBlockingCoordinator extends ChannelInterceptorBase {
- protected Membership membership = null;
-
- protected static byte[] NBC_HEADER = new byte[] {-86, 38, -34, -29, -98,
90, 65, 63, -81, -122, -6, -110, 99, -54, 13, 63};
- protected static byte[] NBC_REQUEST = new byte[] {-55, -37, 18, -52, -105,
107, 72, 40, -122, 29, 70, -19, -74, 123, 61, 110};
- protected static byte[] NBC_REPLY = new byte[] {6, -15, 14, 23, -96, 106,
78, 124, -94, -122, -85, 31, 88, 21, 126, 20};
-
- protected static byte[] NBC_HALT = new byte[] {12, -28, 85, -97, -102,
-35, 74, 9, -65, -78, -83, -84, -29, -70, -23, -15};
- protected static byte[] NBC_ACK = new byte[] {12, -49, 117, -70, 77, 52,
65, -91, -93, -110, 37, 34, -28, -127, 26, 18};
- protected static byte[] NBC_NORM = new byte[] {34, -110, 83, 118, -109,
-55, 67, -27, -97, -94, -84, -72, -82, -114, 65, 81};
- protected static byte[] NBC_NOTNORM = new byte[] {125, -70, -102, -125,
-78, -39, 73, -80, -89, 84, 120, 83, 25, 42, 88, -76};
- protected static byte[] NBC_LDR = new byte[] {97, 31, -23, 30, -42, -72,
72, 116, -97, 7, 112, 25, 82, -96, -87, -48};
- protected static byte[] NBC_HASLDR = new byte[] {93, -80, -88, -58, -127,
21, 76, -90, -89, 77, 58, 25, -55, 65, -1, -83};
- protected static byte[] NBC_ISLDR = new byte[] {104, -95, -92, -42, 114,
-36, 71, -19, -79, 20, 122, 101, -1, -48, -49, 30};
+ /**
+ * header for a coordination message
+ */
+ protected static final byte[] COORD_HEADER = new byte[] {-86, 38, -34,
-29, -98, 90, 65, 63, -81, -122, -6, -110, 99, -54, 13, 63};
+ /**
+ * Coordination request
+ */
+ protected static final byte[] COORD_REQUEST = new byte[] {104, -95, -92,
-42, 114, -36, 71, -19, -79, 20, 122, 101, -1, -48, -49, 30};
+ /**
+ * Coordination confirmation, for blocking installations
+ */
+ protected static final byte[] COORD_CONF = new byte[] {67, 88, 107, -86,
69, 23, 76, -70, -91, -23, -87, -25, -125, 86, 75, 20};
protected Member coordinator = null;
+
+ protected Membership view = null;
+ protected Membership suggestedview = null;
+ protected UniqueId viewId;
+ protected UniqueId suggestedviewId;
+
+ protected boolean started = false;
+ protected final int startsvc = 0xFFFF;
+
+ protected Object electionMutex = new Object();
+ protected boolean runningElection = false;
public NonBlockingCoordinator() {
super();
}
+ public void start(int svc) throws ChannelException {
+ try {
+ halt();
+ if ( started ) return;
+ super.start(startsvc);
+ started = true;
+
+ }finally {
+ release();
+ }
+ //coordination can happen before this line of code executes
+ Member local = getLocalMember(false);
+ if (local != null && coordinator == null) coordinator = local;
+ }
+
+ public void stop(int svc) throws ChannelException {
+ try {
+ halt();
+ if ( !started ) return;
+ super.stop(startsvc);
+ started = false;
+ }finally {
+ release();
+ }
+ this.coordinator = null;
+ }
+
+ public void elect() {
+ synchronized (electionMutex) {
+ try {
+ Member[] mbrs = super.getMembers();
+ //no members, exit
+ if ( mbrs.length == 0 ) return;
+ AbsoluteOrder.absoluteOrder(mbrs);
+ MemberImpl local = (MemberImpl)getLocalMember(false);
+ //I'm not the higest, exit
+ if ( !local.equals(mbrs[0]) ) return;
+ //I'm already running an election
+ if ( suggestedview.hasMembers() ) return;
+ //create a suggestedview
+ suggestedview.addMember((MemberImpl)local);
+ Arrays.fill(suggestedview,mbrs);
+ suggestedviewId = new UniqueId(UUIDGenerator.randomUUID(true));
+ CoordinationMessage msg = new
CoordinationMessage(local,local,suggestedview.getMembers(),suggestedviewId);
+ for (int i=0; i<mbrs.length; i++ ) {
+ try {
+ sendMessage(msg,mbrs[i]);
+ break;
+ } catch ( ChannelException x ) {
+ log.error("Unable to send election message, trying
next node.",x);
+ }
+ }
+ halt();
+ } finally {
+ //dont release, election running
+ //release will happen on processCoordMessage
+ }
+ }
+ }
+
+ protected void viewChange(UniqueId viewId, Member[] view) {
+ //invoke any listeners
+ }
+
+ protected void processCoordMessage(CoordinationMessage msg, Member sender)
{
+ synchronized (electionMutex) {
+ MemberImpl local = (MemberImpl) getLocalMember(false);
+ if (suggestedviewId != null) {
+ //we are running our own election
+ if (suggestedviewId.equals(msg.getId())) {
+ //we received our own token
+ Member[] suggested = suggestedview.getMembers();
+ Member[] received = msg.getMembers();
+ if (Arrays.sameMembers(suggested,received) ) {
+ //did the view change
+ suggestedviewId = null;
+ suggestedview.reset();
+ viewChange(msg.getId(),received);
+ } else {
+ //view or leadership changed
+
+ }
+ }
+ } else {
+
+ }
+ }
+ }
+
+
+ protected void sendMessage(CoordinationMessage msg, Member dest) throws
ChannelException {
+ ChannelData data = new
ChannelData(UUIDGenerator.randomUUID(false),msg.getBuffer(),System.currentTimeMillis());
+ data.setOptions(Channel.SEND_OPTIONS_USE_ACK);
+ Member[] destination = new Member[] {dest};
+ sendMessage(destination,data,null);
+ }
+
+
+
public Member getCoordinator() {
return coordinator;
}
@@ -76,8 +254,8 @@
}
public void messageReceived(ChannelMessage msg) {
- if (
Arrays.contains(msg.getMessage().getBytesDirect(),0,NBC_HEADER,0,NBC_HEADER.length)
) {
- receiveNBC(msg.getMessage());
+ if (
Arrays.contains(msg.getMessage().getBytesDirect(),0,COORD_HEADER,0,COORD_HEADER.length)
) {
+ processCoordMessage(new
CoordinationMessage(msg.getMessage()),msg.getAddress());
} else {
super.messageReceived(msg);
}
@@ -90,8 +268,6 @@
public void memberAdded(Member member) {
try {
halt();
- if (membership == null) setupMembership();
- membership.addMember( (MemberImpl) member);
}finally {
release();
}
@@ -101,8 +277,7 @@
public void memberDisappeared(Member member) {
try {
halt();
- if (membership == null) setupMembership();
- membership.removeMember( (MemberImpl) member);
+ if ( started ) elect();
}finally {
release();
}
@@ -117,8 +292,8 @@
* has members
*/
public boolean hasMembers() {
- if ( membership == null ) setupMembership();
- return membership.hasMembers();
+ if ( view == null ) setupMembership();
+ return view.hasMembers();
}
/**
@@ -126,9 +301,8 @@
* @return all members or empty array
*/
public Member[] getMembers() {
- if ( membership == null ) setupMembership();
- Member[] members = membership.getMembers();
- AbsoluteOrder.absoluteOrder(members);
+ if ( view == null ) setupMembership();
+ Member[] members = view.getMembers();
return members;
}
@@ -138,8 +312,8 @@
* @return Member
*/
public Member getMember(Member mbr) {
- if ( membership == null ) setupMembership();
- return membership.getMember(mbr);
+ if ( view == null ) setupMembership();
+ return view.getMember(mbr);
}
/**
@@ -149,13 +323,14 @@
*/
public Member getLocalMember(boolean incAlive) {
Member local = super.getLocalMember(incAlive);
- if ( membership == null && (local != null)) setupMembership();
+ if ( view == null && (local != null)) setupMembership();
return local;
}
protected synchronized void setupMembership() {
- if ( membership == null ) {
- membership = new
Membership((MemberImpl)super.getLocalMember(true));
+ if ( view == null || suggestedview == null ) {
+ view = new Membership((MemberImpl)super.getLocalMember(true));
+ suggestedview = new
Membership((MemberImpl)super.getLocalMember(true));
}
}
@@ -180,38 +355,123 @@
}
- /**
- * A message is:<br>
- * HEADER, REQUEST|REPLY, ID, MSG, SOURCE_LEN, SOURCE, PAYLOAD_LEN, PAYLOAD
- * @param type byte[] - either NBC_REQUEST or NBC_REPLY
- * @param msg byte[] - NBC_HALT, NBC_ACK, NBC_NORM, NBC_NOTNORM, NBC_LDR
- */
- protected UniqueId createNBCMessage(XByteBuffer buf, byte[] type, byte[]
msg, byte[] payload) {
- UniqueId id = new UniqueId(UUIDGenerator.randomUUID(true));
- Member local = getLocalMember(false);
- byte[] ldata = ((MemberImpl)local).getData(false,false);
- buf.reset();
- buf.append(NBC_HEADER,0,NBC_HEADER.length);
- buf.append(type,0,type.length);
- buf.append(id.getBytes(),0,id.getBytes().length);
- buf.append(msg,0,msg.length);
- buf.append(ldata.length);
- buf.append(ldata,0,ldata.length);
- buf.append(payload.length);
- buf.append(payload,0,payload.length);
- return id;
- }
-
- protected void receiveNBC(XByteBuffer buf) {
+ public static class CoordinationMessage {
+ //X{A-ldr, A-src, mbrs-A,B,C,D}
+ protected XByteBuffer buf;
+ protected MemberImpl leader;
+ protected MemberImpl source;
+ protected MemberImpl[] view;
+ protected UniqueId id;
+
+ public CoordinationMessage(XByteBuffer buf) {
+ this.buf = buf;
+ }
+
+ public CoordinationMessage(MemberImpl leader,
+ MemberImpl source,
+ MemberImpl[] view,
+ UniqueId id) {
+ this.buf = new XByteBuffer(4096,false);
+ this.leader = leader;
+ this.source = source;
+ this.view = view;
+ this.id = id;
+ this.write();
+ }
+
+
+ public byte[] getHeader() {
+ return NonBlockingCoordinator.COORD_HEADER;
+ }
+
+ public MemberImpl getLeader() {
+ if ( leader == null ) parse();
+ return leader;
+ }
+
+ public MemberImpl getSource() {
+ if ( source == null ) parse();
+ return source;
+ }
+
+ public UniqueId getId() {
+ if ( id == null ) parse();
+ return id;
+ }
+
+ public MemberImpl[] getMembers() {
+ if ( view == null ) parse();
+ return view;
+ }
+
+ public XByteBuffer getBuffer() {
+ return this.buf;
+ }
+
+ public void parse() {
+ //header
+ int offset = 16;
+ //leader
+ int ldrLen = buf.toInt(buf.getBytesDirect(),offset);
+ offset += 4;
+ byte[] ldr = new byte[ldrLen];
+ System.arraycopy(buf.getBytesDirect(),offset,ldr,0,ldrLen);
+ leader = MemberImpl.getMember(ldr);
+ offset += ldrLen;
+ //source
+ int srcLen = buf.toInt(buf.getBytesDirect(),offset);
+ offset += 4;
+ byte[] src = new byte[srcLen];
+ System.arraycopy(buf.getBytesDirect(),offset,src,0,srcLen);
+ source = MemberImpl.getMember(src);
+ offset += srcLen;
+ //view
+ int mbrCount = buf.toInt(buf.getBytesDirect(),offset);
+ offset += 4;
+ view = new MemberImpl[mbrCount];
+ for (int i=0; i<view.length; i++ ) {
+ int mbrLen = buf.toInt(buf.getBytesDirect(),offset);
+ offset += 4;
+ byte[] mbr = new byte[mbrLen];
+ System.arraycopy(buf.getBytesDirect(), offset, mbr, 0, mbrLen);
+ view[i] = MemberImpl.getMember(mbr);
+ offset += mbrLen;
+ }
+ //id
+ this.id = new UniqueId(buf.getBytesDirect(),offset,16);
+ offset += 16;
+ }
+
+ public void write() {
+ buf.reset();
+ //header
+ buf.append(COORD_HEADER,0,COORD_HEADER.length);
+ //leader
+ byte[] ldr = leader.getData(false,false);
+ buf.append(ldr.length);
+ buf.append(ldr,0,ldr.length);
+ ldr = null;
+ //source
+ byte[] src = source.getData(false,false);
+ buf.append(src.length);
+ buf.append(src,0,src.length);
+ src = null;
+ //view
+ buf.append(view.length);
+ for (int i=0; i<view.length; i++ ) {
+ byte[] mbr = view[i].getData(false,false);
+ buf.append(mbr.length);
+ buf.append(mbr,0,mbr.length);
+ }
+ //id
+ buf.append(id.getBytes(),0,id.getBytes().length);
+ }
+
+
+
}
- public void start(int svc) throws ChannelException {
- super.start(svc);
- //coordination can happen before this line of code executes
- Member local = getLocalMember(false);
- if (local != null && coordinator == null) coordinator = local;
- }
Modified:
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/membership/Membership.java
URL:
http://svn.apache.org/viewvc/tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/membership/Membership.java?rev=408823&r1=408822&r2=408823&view=diff
==============================================================================
---
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/membership/Membership.java
(original)
+++
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/membership/Membership.java
Mon May 22 20:41:04 2006
@@ -114,12 +114,14 @@
public synchronized MbrEntry addMember(MemberImpl member) {
synchronized (members) {
MbrEntry entry = new MbrEntry(member);
- map.put(member,entry);
- MemberImpl results[] = new MemberImpl[members.length + 1];
- for (int i = 0; i < members.length; i++) results[i] = members[i];
- results[members.length] = member;
- members = results;
- Arrays.sort(members, memberComparator);
+ if (!map.containsKey(member) ) {
+ map.put(member, entry);
+ MemberImpl results[] = new MemberImpl[members.length + 1];
+ for (int i = 0; i < members.length; i++) results[i] = members[i];
+ results[members.length] = member;
+ members = results;
+ Arrays.sort(members, memberComparator);
+ }
return entry;
}
}
@@ -139,10 +141,8 @@
break;
}
}
- if (n < 0)
- return;
- MemberImpl results[] =
- new MemberImpl[members.length - 1];
+ if (n < 0) return;
+ MemberImpl results[] = new MemberImpl[members.length - 1];
int j = 0;
for (int i = 0; i < members.length; i++) {
if (i != n)
@@ -151,7 +151,7 @@
members = results;
}
}
-
+
/**
* Runs a refresh cycle and returns a list of members that has expired.
* This also removes the members from the membership, in such a way that
Modified:
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/util/Arrays.java
URL:
http://svn.apache.org/viewvc/tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/util/Arrays.java?rev=408823&r1=408822&r2=408823&view=diff
==============================================================================
---
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/util/Arrays.java
(original)
+++
tomcat/container/tc5.5.x/modules/groupcom/src/share/org/apache/catalina/tribes/util/Arrays.java
Mon May 22 20:41:04 2006
@@ -17,6 +17,13 @@
import org.apache.catalina.tribes.UniqueId;
import org.apache.catalina.tribes.ChannelMessage;
+import org.apache.catalina.tribes.Member;
+import org.apache.catalina.tribes.group.AbsoluteOrder;
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.Comparator;
+import org.apache.catalina.tribes.membership.Membership;
+import org.apache.catalina.tribes.membership.MemberImpl;
/**
* @author Filip Hanik
@@ -53,12 +60,45 @@
return buf.toString();
}
+ public static int add(int[] data) {
+ int result = 0;
+ for (int i=0;i<data.length; i++ ) result += data[i];
+ return result;
+ }
+
public static UniqueId getUniqudId(ChannelMessage msg) {
return new UniqueId(msg.getUniqueId());
}
public static UniqueId getUniqudId(byte[] data) {
return new UniqueId(data);
+ }
+
+ public static boolean equals(Object[] o1, Object[] o2) {
+ boolean result = o1.length == o2.length;
+ if ( result ) for (int i=0; i<o1.length && result; i++ ) result =
o1[i].equals(o2[i]);
+ return result;
+ }
+
+ public static boolean sameMembers(Member[] m1, Member[] m2) {
+ AbsoluteOrder.absoluteOrder(m1);
+ AbsoluteOrder.absoluteOrder(m2);
+ return equals(m1,m2);
+ }
+
+ public static Member[] merge(Member[] m1, Member[] m2) {
+ AbsoluteOrder.absoluteOrder(m1);
+ AbsoluteOrder.absoluteOrder(m2);
+ ArrayList list = new ArrayList(java.util.Arrays.asList(m1));
+ for (int i=0; i<m2.length; i++) if ( !list.contains(m2[i]) )
list.add(m2[i]);
+ Member[] result = new Member[list.size()];
+ list.toArray(result);
+ AbsoluteOrder.absoluteOrder(result);
+ return result;
+ }
+
+ public static void fill(Membership mbrship, Member[] m) {
+ for (int i=0; i<m.length; i++ ) mbrship.addMember((MemberImpl)m[i]);
}
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