[lifx] Improve selector logic (#8941)

* Properly handle datagrams that are not immediately available so no NPEs are logged on debug
* Properly handle sockets channels that are not connected so no NPEs are logged on debug
* Prevent load/garbage by reusing ByteBuffer and not allocating trace logging strings

Fixes #8932

Signed-off-by: Wouter Born <github@maindrain.net>

diff --git a/bundles/org.openhab.binding.lifx/src/main/java/org/openhab/binding/lifx/internal/util/LifxSelectorUtil.java b/bundles/org.openhab.binding.lifx/src/main/java/org/openhab/binding/lifx/internal/util/LifxSelectorUtil.java
index ca0ebeca261b44757991360d6a9407d580be49e3..18735cffc912107b73f5ded45c3398d4c8ab1a2e 100644 (file)
--- a/bundles/org.openhab.binding.lifx/src/main/java/org/openhab/binding/lifx/internal/util/LifxSelectorUtil.java
+++ b/bundles/org.openhab.binding.lifx/src/main/java/org/openhab/binding/lifx/internal/util/LifxSelectorUtil.java
@@ -135,6 +135,7 @@ public class LifxSelectorUtil {
                     e.getMessage());
         }
 
+        ByteBuffer readBuffer = ByteBuffer.allocate(LifxNetworkUtil.getBufferSize());
         Iterator<SelectionKey> keyIterator = selector.selectedKeys().iterator();
 
         while (keyIterator.hasNext()) {
@@ -151,22 +152,34 @@ public class LifxSelectorUtil {
             }
 
             if (key.isValid() && key.isReadable()) {
-                LOGGER.trace("{} : Channel is ready for reading", logId);
+                if (LOGGER.isTraceEnabled()) {
+                    LOGGER.trace("{} : Channel is ready for reading", logId);
+                }
+
                 SelectableChannel channel = key.channel();
-                ByteBuffer readBuffer = ByteBuffer.allocate(LifxNetworkUtil.getBufferSize());
+                readBuffer.rewind();
 
                 try {
                     if (channel instanceof DatagramChannel) {
                         InetSocketAddress address = (InetSocketAddress) ((DatagramChannel) channel).receive(readBuffer);
-                        if (isRemoteAddress(address.getAddress())) {
+                        if (address == null) {
+                            if (LOGGER.isTraceEnabled()) {
+                                LOGGER.trace("{} : No datagram is available", logId);
+                            }
+                        } else if (isRemoteAddress(address.getAddress())) {
                             supplyParsedPacketToConsumer(readBuffer, address, packetConsumer, logId);
                         }
                     } else if (channel instanceof SocketChannel) {
-                        InetSocketAddress address = (InetSocketAddress) ((SocketChannel) channel).getRemoteAddress();
                         ((SocketChannel) channel).read(readBuffer);
-                        if (isRemoteAddress(address.getAddress())) {
+                        InetSocketAddress address = (InetSocketAddress) ((SocketChannel) channel).getRemoteAddress();
+                        if (address == null) {
+                            if (LOGGER.isTraceEnabled()) {
+                                LOGGER.trace("{} : Channel socket is not connected", logId);
+                            }
+                        } else if (isRemoteAddress(address.getAddress())) {
                             supplyParsedPacketToConsumer(readBuffer, address, packetConsumer, logId);
                         }
+
                     }
                 } catch (Exception e) {
                     LOGGER.debug("{} while reading data for the light ({}) : {}", e.getClass().getSimpleName(), logId,