org.jgroups.protocols.FORK Maven / Gradle / Ivy
package org.jgroups.protocols;
import org.jgroups.Event;
import org.jgroups.Header;
import org.jgroups.Message;
import org.jgroups.annotations.*;
import org.jgroups.conf.ClassConfigurator;
import org.jgroups.conf.ConfiguratorFactory;
import org.jgroups.conf.ProtocolConfiguration;
import org.jgroups.fork.ForkConfig;
import org.jgroups.fork.ForkProtocol;
import org.jgroups.fork.ForkProtocolStack;
import org.jgroups.stack.Configurator;
import org.jgroups.stack.Protocol;
import org.jgroups.stack.ProtocolStack;
import org.jgroups.util.Bits;
import org.jgroups.util.MessageBatch;
import org.jgroups.util.Util;
import org.w3c.dom.Node;
import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.AccessControlException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
/**
* The FORK protocol; multiplexes messages to different forks in a stack (https://issues.jboss.org/browse/JGRP-1613).
* See doc/design/FORK.txt for details
* @author Bela Ban
* @since 3.4
*/
@XmlInclude(schema="fork-stacks.xsd",type=XmlInclude.Type.IMPORT,namespace="fork",alias="fork")
@XmlElement(name="fork-stacks",type="fork:ForkStacksType")
@MBean(description="Implementation of FORK protocol")
public class FORK extends Protocol {
public static short ID=ClassConfigurator.getProtocolId(FORK.class);
@Property(description="Points to an XML file defining the fork-stacks, which will be created at initialization. " +
"Ignored if null")
protected String config;
// mappings between fork-stack-ids and fork-stacks (bottom-most protocol)
protected final ConcurrentMap fork_stacks=new ConcurrentHashMap();
public Protocol get(String fork_stack_id) {return fork_stacks.get(fork_stack_id);}
public Protocol putIfAbsent(String fork_stack_id, Protocol prot) {return fork_stacks.put(fork_stack_id, prot);}
@ManagedAttribute(description="Number of fork-stacks")
public int getForkStacks() {return fork_stacks.size();}
public void init() throws Exception {
super.init();
if(config != null)
createForkStacks(config, false);
}
public Object up(Event evt) {
switch(evt.getType()) {
case Event.MSG:
Message msg=(Message)evt.getArg();
ForkHeader hdr=(ForkHeader)msg.getHeader(id);
if(hdr == null)
break;
if(hdr.fork_stack_id == null)
throw new IllegalArgumentException("header has a null fork_stack_id");
Protocol bottom_prot=get(hdr.fork_stack_id);
return bottom_prot != null? bottom_prot.up(evt) : null;
case Event.VIEW_CHANGE:
for(Protocol bottom: fork_stacks.values())
bottom.up(evt);
break;
}
return up_prot.up(evt);
}
public void up(MessageBatch batch) {
// Sort fork messages by fork-stack-id
Map> map=new HashMap>();
for(Message msg: batch) {
ForkHeader hdr=(ForkHeader)msg.getHeader(id);
if(hdr != null) {
batch.remove(msg);
List list=map.get(hdr.fork_stack_id);
if(list == null) {
list=new ArrayList();
map.put(hdr.fork_stack_id, list);
}
list.add(msg);
}
}
// Now pass fork messages up, batched by fork-stack-id
for(Map.Entry> entry: map.entrySet()) {
String fork_stack_id=entry.getKey();
List list=entry.getValue();
Protocol bottom_prot=get(fork_stack_id);
if(bottom_prot == null)
continue;
MessageBatch mb=new MessageBatch(batch.dest(), batch.sender(), batch.clusterName(), batch.multicast(), list);
try {
bottom_prot.up(mb);
}
catch(Throwable t) {
log.error("failed passing up batch", t);
}
}
if(!batch.isEmpty())
up_prot.up(batch);
}
protected void createForkStacks(String config, boolean replace_existing) throws Exception {
InputStream in=getForkStream(config);
if(in == null)
throw new FileNotFoundException("fork stacks config " + config + " not found");
Map> protocols=ForkConfig.parse(in);
createForkStacks(protocols, replace_existing);
}
protected void createForkStacks(Map> protocols, boolean replace_existing) throws Exception {
for(Map.Entry> entry: protocols.entrySet()) {
String fork_stack_id=entry.getKey();
if(get(fork_stack_id) != null && !replace_existing)
continue;
ProtocolStack fork_prot_stack=new ForkProtocolStack();
List prots=createProtocols(fork_prot_stack,entry.getValue());
createForkStack(fork_stack_id, fork_prot_stack, replace_existing, prots);
}
}
public void parse(Node node) throws Exception {
Map> protocols=ForkConfig.parse(node);
createForkStacks(protocols, false);
}
/**
* Creates a new fork-stack from protocols and adds it into the hashmap of fork-stack (key is fork_stack_id).
* Method init() will be called on each protocol, from bottom to top.
* @param fork_stack_id The key under which the new fork-stack should be added to the fork-stacks hashmap
* @param stack The protocol stack under which to create the protocols
* @param replace_existing If true, and existing fork-stack is simply replaced (de-initializing it first).
* Otherwise, if the stack already exists, the new fork-stack will not be created.
* @param protocols A list of protocols from bottom to top to be inserted. They will be sandwiched
* between ForkProtocolStack (top) and ForkProtocol (bottom). The list can be empty (or null) in
* which case we won't create any protocols, but still have a separate fork-stack inserted.
* @return The bottom-most protocol of the new stack, or the existing stack (if present)
*/
public Protocol createForkStack(String fork_stack_id, final ProtocolStack stack, boolean replace_existing,
List protocols) throws Exception {
Protocol bottom;
if((bottom=get(fork_stack_id)) != null && !replace_existing) {
log.warn("fork-stack %s is already present, won't replace it", fork_stack_id);
return bottom;
}
Protocol current=stack; // top
if(protocols != null && !protocols.isEmpty()) {
for(int i=protocols.size()-1; i >= 0; i--) {
Protocol prot=protocols.get(i);
current.setDownProtocol(prot);
prot.setUpProtocol(current);
current=prot;
}
}
bottom=new ForkProtocol(fork_stack_id); // bottom
current.setDownProtocol(bottom);
bottom.setUpProtocol(current);
bottom.setDownProtocol(this);
stack.topProtocol(stack.getDownProtocol()).bottomProtocol(bottom);
fork_stacks.put(fork_stack_id, bottom);
// call init() on the created protocols, from bottom to top
//current=bottom;
while(current != null && !(current instanceof ProtocolStack)) {
current.init();
current=current.getUpProtocol();
}
return bottom;
}
/** Creates a fork-stack from the configuration, initializes all protocols (setting values),
* sets the protocol stack as top protocol, connects the protocols and calls init() on them. Returns
* the protocols in a list, from bottom to top */
protected static List createProtocols(ProtocolStack stack, List protocol_configs) throws Exception {
return Configurator.createProtocols(protocol_configs,stack);
}
public static InputStream getForkStream(String config) throws IOException {
InputStream configStream = null;
try {
configStream=new FileInputStream(config);
}
catch(FileNotFoundException fnfe) {
}
catch(AccessControlException access_ex) { // fixes http://jira.jboss.com/jira/browse/JGRP-94
}
// Check to see if the properties string is a URL.
if(configStream == null) {
try {
configStream=new URL(config).openStream();
}
catch (MalformedURLException mre) {
}
}
// Check to see if the properties string is the name of a resource, e.g. udp.xml.
if(configStream == null)
configStream=Util.getResourceAsStream(config, ConfiguratorFactory.class);
return configStream;
}
public static class ForkHeader extends Header {
protected String fork_stack_id, fork_channel_id;
public ForkHeader() {
}
public ForkHeader(String fork_stack_id, String fork_channel_id) {
this.fork_stack_id=fork_stack_id;
this.fork_channel_id=fork_channel_id;
}
public String getForkStackId() {
return fork_stack_id;
}
public void setForkStackId(String fork_stack_id) {
this.fork_stack_id=fork_stack_id;
}
public String getForkChannelId() {
return fork_channel_id;
}
public void setForkChannelId(String fork_channel_id) {
this.fork_channel_id=fork_channel_id;
}
public int size() {return Util.size(fork_stack_id) + Util.size(fork_channel_id);}
public void writeTo(DataOutput out) throws Exception {
Bits.writeString(fork_stack_id,out);
Bits.writeString(fork_channel_id,out);
}
public void readFrom(DataInput in) throws Exception {
fork_stack_id=Bits.readString(in);
fork_channel_id=Bits.readString(in);
}
public String toString() {return fork_stack_id + ":" + fork_channel_id;}
}
}
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