From cb9434d637a4316caf088c5ea49d0463c5a53d2b Mon Sep 17 00:00:00 2001
From: David Gillingham <David.Gillingham@raytheon.com>
Date: Wed, 19 Sep 2012 10:35:13 -0500
Subject: [PATCH] Issue #1190: Cache hostnames for WsId to speed up logging.

Change-Id: I3e8e5ad046853d8543eba861c4a7dff36dd0281d

Former-commit-id: 1b9000ca72e73590cd008e366aa0f00cfc56d544 [formerly c0641faefe6432aed0a35214f0511cb3180b49bf] [formerly 3ada98ba44cffca898c055b025af88496f7d91b0 [formerly e036304b9ba7f93c6e836529f60a63c9b4c1c353]]
Former-commit-id: 3ada98ba44cffca898c055b025af88496f7d91b0
Former-commit-id: 6a0eac44b273f11f38770566928bebd2ad419342
---
 .../com/raytheon/uf/common/message/WsId.java  | 52 +++++++++++++++++--
 1 file changed, 47 insertions(+), 5 deletions(-)

diff --git a/edexOsgi/com.raytheon.uf.common.message/src/com/raytheon/uf/common/message/WsId.java b/edexOsgi/com.raytheon.uf.common.message/src/com/raytheon/uf/common/message/WsId.java
index 94087dd4bb..e0893706ed 100644
--- a/edexOsgi/com.raytheon.uf.common.message/src/com/raytheon/uf/common/message/WsId.java
+++ b/edexOsgi/com.raytheon.uf.common.message/src/com/raytheon/uf/common/message/WsId.java
@@ -23,6 +23,10 @@ import java.io.Serializable;
 import java.lang.management.ManagementFactory;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Map.Entry;
 
 import com.raytheon.uf.common.message.adapter.WsIdAdapter;
 import com.raytheon.uf.common.serialization.ISerializableObject;
@@ -39,6 +43,8 @@ import com.raytheon.uf.common.serialization.annotations.DynamicSerializeTypeAdap
  * ------------ ---------- ----------- --------------------------
  * Jun 10, 2009            randerso     Initial creation
  * Apr 25, 2012       545  randerso     Repurposed the lockKey field as threadId
+ * Sep 19, 2012     #1190  dgilling     Cache host names so toPrettyString() doesn't
+ *                                      get delayed behind DNS requests.
  * 
  * </pre>
  * 
@@ -49,8 +55,33 @@ import com.raytheon.uf.common.serialization.annotations.DynamicSerializeTypeAdap
 @DynamicSerialize
 @DynamicSerializeTypeAdapter(factory = WsIdAdapter.class)
 public class WsId implements Serializable, ISerializableObject {
+
+    private static class BoundedMap<K, V> extends LinkedHashMap<K, V> {
+        private static final long serialVersionUID = 1L;
+
+        private final int maxSize;
+
+        public BoundedMap(int maxSize) {
+            super(16, 0.75f, true);
+            this.maxSize = maxSize;
+        }
+
+        /*
+         * (non-Javadoc)
+         * 
+         * @see java.util.LinkedHashMap#removeEldestEntry(java.util.Map.Entry)
+         */
+        @Override
+        protected boolean removeEldestEntry(Entry<K, V> eldest) {
+            return size() > maxSize;
+        }
+    }
+
     private static final long serialVersionUID = 1L;
 
+    private static final Map<InetAddress, String> hostNameCache = Collections
+            .synchronizedMap(new BoundedMap<InetAddress, String>(100));
+
     private final InetAddress networkId;
 
     private final String userName;
@@ -61,7 +92,7 @@ public class WsId implements Serializable, ISerializableObject {
 
     // replaced A1 lockKey with threadId for A2.
     // lockKey was not used in A2. This allows A2 to retain
-    // compatibility with A1 for ISC purposes by not chaning
+    // compatibility with A1 for ISC purposes by not changing
     // the format of the WsId
     private final long threadId;
 
@@ -157,7 +188,6 @@ public class WsId implements Serializable, ISerializableObject {
             }
             this.networkId = addr;
         }
-
     }
 
     /*
@@ -188,14 +218,26 @@ public class WsId implements Serializable, ISerializableObject {
      * @return WsId as pretty string
      */
     public String toPrettyString() {
+        String hostname = retrieveFromHostCache(networkId);
+
         StringBuilder o = new StringBuilder();
-        o.append(userName).append('@').append(networkId.getHostName())
-                .append(':').append(progName).append(':').append(pid)
-                .append(':').append(threadId);
+        o.append(userName).append('@').append(hostname).append(':')
+                .append(progName).append(':').append(pid).append(':')
+                .append(threadId);
 
         return o.toString();
     }
 
+    private String retrieveFromHostCache(InetAddress address) {
+        String hostName = hostNameCache.get(address);
+        if (hostName == null) {
+            hostName = address.getHostName();
+            hostNameCache.put(address, hostName);
+        }
+
+        return hostName;
+    }
+
     /**
      * @return the _networkId
      */