Merge pull request #6522 from rocknitive/feature/coap-piggyback-response

[3.4] Piggybacked CoAP responses

application/src/main/resources/thingsboard.yml

@@ -706,6 +706,7 @@ transport:
     bind_address: "${COAP_BIND_ADDRESS:0.0.0.0}"
     bind_port: "${COAP_BIND_PORT:5683}"
     timeout: "${COAP_TIMEOUT:10000}"
+    piggyback_timeout: "${COAP_PIGGYBACK_TIMEOUT:500}"
     psm_activity_timer: "${COAP_PSM_ACTIVITY_TIMER:10000}"
     paging_transmission_window: "${COAP_PAGING_TRANSMISSION_WINDOW:10000}"
     dtls:

common/coap-server/src/main/java/org/thingsboard/server/coapserver/CoapServerContext.java

@@ -38,6 +38,10 @@ public class CoapServerContext {
     @Value("${transport.coap.timeout}")
     private Long timeout;
 
+    @Getter
+    @Value("${transport.coap.piggyback_timeout}")
+    private Long piggybackTimeout;
+
     @Getter
     @Value("${transport.coap.psm_activity_timer:10000}")
     private long psmActivityTimer;

common/coap-server/src/main/java/org/thingsboard/server/coapserver/CoapServerService.java

@@ -29,4 +29,6 @@ public interface CoapServerService {
 
     long getTimeout();
 
+    long getPiggybackTimeout();
+
 }

common/coap-server/src/main/java/org/thingsboard/server/coapserver/DefaultCoapServerService.java

@@ -88,6 +88,11 @@ public class DefaultCoapServerService implements CoapServerService {
         return coapServerContext.getTimeout();
     }
 
+    @Override
+    public long getPiggybackTimeout() {
+        return coapServerContext.getPiggybackTimeout();
+    }
+
     private CoapServer createCoapServer() throws UnknownHostException {
         Configuration networkConfig = new Configuration();
         networkConfig.set(CoapConfig.BLOCKWISE_STRICT_BLOCK2_OPTION, true);

common/transport/coap/src/main/java/org/thingsboard/server/transport/coap/CoapTransportResource.java

@@ -69,6 +69,7 @@ public class CoapTransportResource extends AbstractCoapTransportResource {
 
     private final ConcurrentMap<InetSocketAddress, TbCoapDtlsSessionInfo> dtlsSessionsMap;
     private final long timeout;
+    private final long piggybackTimeout;
     private final CoapClientContext clients;
 
     public CoapTransportResource(CoapTransportContext ctx, CoapServerService coapServerService, String name) {
@@ -77,6 +78,7 @@ public class CoapTransportResource extends AbstractCoapTransportResource {
         this.addObserver(new CoapResourceObserver());
         this.dtlsSessionsMap = coapServerService.getDtlsSessionsMap();
         this.timeout = coapServerService.getTimeout();
+        this.piggybackTimeout = coapServerService.getPiggybackTimeout();
         this.clients = ctx.getClientContext();
         long sessionReportTimeout = ctx.getSessionReportTimeout();
         ctx.getScheduler().scheduleAtFixedRate(clients::reportActivity, new Random().nextInt((int) sessionReportTimeout), sessionReportTimeout, TimeUnit.MILLISECONDS);
@@ -169,7 +171,7 @@ public class CoapTransportResource extends AbstractCoapTransportResource {
     }
 
     private void processProvision(CoapExchange exchange) {
-        exchange.accept();
+        deferAccept(exchange);
         try {
             UUID sessionId = UUID.randomUUID();
             log.trace("[{}] Processing provision publish msg [{}]!", sessionId, exchange.advanced().getRequest());
@@ -195,7 +197,7 @@ public class CoapTransportResource extends AbstractCoapTransportResource {
 
     private void processRequest(CoapExchange exchange, SessionMsgType type) {
         log.trace("Processing {}", exchange.advanced().getRequest());
-        exchange.accept();
+        deferAccept(exchange);
         Exchange advanced = exchange.advanced();
         Request request = advanced.getRequest();
 
@@ -346,6 +348,20 @@ public class CoapTransportResource extends AbstractCoapTransportResource {
                 new CoapNoOpCallback(exchange));
     }
 
+    /**
+     * Send an empty ACK if we are unable to send the full response within the timeout.
+     * If the full response is transmitted before the timeout this will not do anything.
+     * If this is triggered the full response will be sent in a separate CON/NON message.
+     * Essentially this allows the use of piggybacked responses.
+     */
+    private void deferAccept(CoapExchange exchange) {
+        if (piggybackTimeout > 0) {
+            transportContext.getScheduler().schedule(exchange::accept, piggybackTimeout, TimeUnit.MILLISECONDS);
+        } else {
+            exchange.accept();
+        }
+    }
+
     private UUID toSessionId(TransportProtos.SessionInfoProto sessionInfoProto) {
         return new UUID(sessionInfoProto.getSessionIdMSB(), sessionInfoProto.getSessionIdLSB());
     }

transport/coap/src/main/resources/tb-coap-transport.yml

@@ -89,6 +89,7 @@ transport:
     bind_address: "${COAP_BIND_ADDRESS:0.0.0.0}"
     bind_port: "${COAP_BIND_PORT:5683}"
     timeout: "${COAP_TIMEOUT:10000}"
+    piggyback_timeout: "${COAP_PIGGYBACK_TIMEOUT:500}"
     psm_activity_timer: "${COAP_PSM_ACTIVITY_TIMER:10000}"
     paging_transmission_window: "${COAP_PAGING_TRANSMISSION_WINDOW:10000}"
     dtls: