1 files changed, 41 insertions, 0 deletions
diff --git a/logserver/src/main/java/com/yahoo/logserver/handlers/archive/LogWriterLRUCache.java b/logserver/src/main/java/com/yahoo/logserver/handlers/archive/LogWriterLRUCache.java
new file mode 100644
index 00000000000..21ca26efdd2
--- /dev/null
+++ b/logserver/src/main/java/com/yahoo/logserver/handlers/archive/LogWriterLRUCache.java
@@ -0,0 +1,41 @@
+// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.logserver.handlers.archive;
+
+import java.io.IOException;
+import java.util.logging.Logger;
+import java.util.logging.Level;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+/**
+ * @author  <a href="mailto:borud@yahoo-inc.com">Bjorn Borud</a>
+ */
+@SuppressWarnings("serial")
+public class LogWriterLRUCache extends LinkedHashMap<Integer, LogWriter>
+{
+    private static final Logger log
+        = Logger.getLogger(LogWriterLRUCache.class.getName());
+
+    final int maxEntries = 100;
+
+    public LogWriterLRUCache(int initialCapacity,
+                             float loadFactor) {
+        super(initialCapacity, loadFactor, true);
+    }
+
+    // TODO: implement unit test for this
+    protected boolean removeEldestEntry (Map.Entry<Integer, LogWriter> eldest) {
+        if (size() > maxEntries) {
+            LogWriter logWriter = (LogWriter)eldest.getValue();
+            log.fine("Closing oldest LogWriter: " + logWriter);
+            try {
+                logWriter.close();
+            } catch (IOException e) {
+                log.log(Level.WARNING, "closing LogWriter failed", e);
+            }
+            return true;
+        }
+
+        return false;
+    }
+}