| // Licensed under Apache License version 2.0 |
| package javax.jmdns.impl.tasks.state; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.logging.Level; |
| import java.util.logging.Logger; |
| |
| import javax.jmdns.ServiceInfo; |
| import javax.jmdns.impl.DNSOutgoing; |
| import javax.jmdns.impl.DNSStatefulObject; |
| import javax.jmdns.impl.JmDNSImpl; |
| import javax.jmdns.impl.ServiceInfoImpl; |
| import javax.jmdns.impl.constants.DNSConstants; |
| import javax.jmdns.impl.constants.DNSState; |
| import javax.jmdns.impl.tasks.DNSTask; |
| |
| /** |
| * This is the root class for all state tasks. These tasks work with objects that implements the {@link javax.jmdns.impl.DNSStatefulObject} interface and therefore participate in the state machine. |
| * |
| * @author Pierre Frisch |
| */ |
| public abstract class DNSStateTask extends DNSTask { |
| static Logger logger1 = Logger.getLogger(DNSStateTask.class.getName()); |
| |
| /** |
| * By setting a 0 ttl we effectively expire the record. |
| */ |
| private final int _ttl; |
| |
| private static int _defaultTTL = DNSConstants.DNS_TTL; |
| |
| /** |
| * The state of the task. |
| */ |
| private DNSState _taskState = null; |
| |
| public abstract String getTaskDescription(); |
| |
| public static int defaultTTL() { |
| return _defaultTTL; |
| } |
| |
| /** |
| * For testing only do not use in production. |
| * |
| * @param value |
| */ |
| public static void setDefaultTTL(int value) { |
| _defaultTTL = value; |
| } |
| |
| /** |
| * @param jmDNSImpl |
| * @param ttl |
| */ |
| public DNSStateTask(JmDNSImpl jmDNSImpl, int ttl) { |
| super(jmDNSImpl); |
| _ttl = ttl; |
| } |
| |
| /** |
| * @return the ttl |
| */ |
| public int getTTL() { |
| return _ttl; |
| } |
| |
| /** |
| * Associate the DNS host and the service infos with this task if not already associated and in the same state. |
| * |
| * @param state |
| * target state |
| */ |
| protected void associate(DNSState state) { |
| synchronized (this.getDns()) { |
| this.getDns().associateWithTask(this, state); |
| } |
| for (ServiceInfo serviceInfo : this.getDns().getServices().values()) { |
| ((ServiceInfoImpl) serviceInfo).associateWithTask(this, state); |
| } |
| } |
| |
| /** |
| * Remove the DNS host and service info association with this task. |
| */ |
| protected void removeAssociation() { |
| // Remove association from host to this |
| synchronized (this.getDns()) { |
| this.getDns().removeAssociationWithTask(this); |
| } |
| |
| // Remove associations from services to this |
| for (ServiceInfo serviceInfo : this.getDns().getServices().values()) { |
| ((ServiceInfoImpl) serviceInfo).removeAssociationWithTask(this); |
| } |
| } |
| |
| @Override |
| public void run() { |
| DNSOutgoing out = this.createOugoing(); |
| try { |
| if (!this.checkRunCondition()) { |
| this.cancel(); |
| return; |
| } |
| List<DNSStatefulObject> stateObjects = new ArrayList<DNSStatefulObject>(); |
| // send probes for JmDNS itself |
| synchronized (this.getDns()) { |
| if (this.getDns().isAssociatedWithTask(this, this.getTaskState())) { |
| logger1.finer(this.getName() + ".run() JmDNS " + this.getTaskDescription() + " " + this.getDns().getName()); |
| stateObjects.add(this.getDns()); |
| out = this.buildOutgoingForDNS(out); |
| } |
| } |
| // send probes for services |
| for (ServiceInfo serviceInfo : this.getDns().getServices().values()) { |
| ServiceInfoImpl info = (ServiceInfoImpl) serviceInfo; |
| |
| synchronized (info) { |
| if (info.isAssociatedWithTask(this, this.getTaskState())) { |
| logger1.fine(this.getName() + ".run() JmDNS " + this.getTaskDescription() + " " + info.getQualifiedName()); |
| stateObjects.add(info); |
| out = this.buildOutgoingForInfo(info, out); |
| } |
| } |
| } |
| if (!out.isEmpty()) { |
| logger1.finer(this.getName() + ".run() JmDNS " + this.getTaskDescription() + " #" + this.getTaskState()); |
| this.getDns().send(out); |
| |
| // Advance the state of objects. |
| this.advanceObjectsState(stateObjects); |
| } else { |
| // Advance the state of objects. |
| this.advanceObjectsState(stateObjects); |
| |
| // If we have nothing to send, another timer taskState ahead of us has done the job for us. We can cancel. |
| cancel(); |
| return; |
| } |
| } catch (Throwable e) { |
| logger1.log(Level.WARNING, this.getName() + ".run() exception ", e); |
| this.recoverTask(e); |
| } |
| |
| this.advanceTask(); |
| } |
| |
| protected abstract boolean checkRunCondition(); |
| |
| protected abstract DNSOutgoing buildOutgoingForDNS(DNSOutgoing out) throws IOException; |
| |
| protected abstract DNSOutgoing buildOutgoingForInfo(ServiceInfoImpl info, DNSOutgoing out) throws IOException; |
| |
| protected abstract DNSOutgoing createOugoing(); |
| |
| protected void advanceObjectsState(List<DNSStatefulObject> list) { |
| if (list != null) { |
| for (DNSStatefulObject object : list) { |
| synchronized (object) { |
| object.advanceState(this); |
| } |
| } |
| } |
| } |
| |
| protected abstract void recoverTask(Throwable e); |
| |
| protected abstract void advanceTask(); |
| |
| /** |
| * @return the taskState |
| */ |
| protected DNSState getTaskState() { |
| return this._taskState; |
| } |
| |
| /** |
| * @param taskState |
| * the taskState to set |
| */ |
| protected void setTaskState(DNSState taskState) { |
| this._taskState = taskState; |
| } |
| |
| } |