--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/dancres/blitz/arc/Lru.java	Sat Mar 21 11:00:06 2009 +0000
@@ -0,0 +1,94 @@
+package org.dancres.blitz.arc;
+
+import java.io.IOException;
+
+import java.util.logging.*;
+
+import org.dancres.struct.LinkedInstances;
+
+class Lru {
+    static final int T1 = 0;
+    static final int T2 = 1;
+    static final int B1 = 2;
+    static final int B2 = 3;
+
+    private static final String[] NAMES = {"T1", "T2", "B1", "B2"};
+
+    private LinkedInstances theEntries = new LinkedInstances();
+
+    private int theId;
+
+    Lru(int anId) {
+        theId = anId;
+    }
+
+    synchronized void remove(CacheBlockDescriptor aDesc) {
+        if (aDesc.getWhere() != theId)
+            throw new RuntimeException("I don't own this descriptor");
+
+        theEntries.remove(aDesc);
+    }
+
+    synchronized void mruInsert(CacheBlockDescriptor aDesc) {
+        theEntries.insert(aDesc);
+        aDesc.setWhere(theId);
+    }
+
+    synchronized void lruInsert(CacheBlockDescriptor aDesc) {
+        theEntries.add(aDesc);
+        aDesc.setWhere(theId);
+    }
+
+    synchronized CacheBlockDescriptor lruRemove() {
+        return (CacheBlockDescriptor) theEntries.removeLast();
+    }
+
+    synchronized int length() {
+        return theEntries.getSize();
+    }
+
+    synchronized void dump() {
+        Logger myLogger = ArcCache.theLogger;
+
+        myLogger.log(Level.FINE, "AC: " + NAMES[theId]);
+
+        CacheBlockDescriptor myCBD = 
+            (CacheBlockDescriptor) theEntries.getHead();
+
+        while (myCBD != null) {
+
+            try {
+                myCBD.acquire();
+
+                myLogger.log(Level.FINE, myCBD.getId() + ", " +
+                             myCBD.getId().hashCode() + ", ");
+
+                myCBD.release();
+            } catch (InterruptedException anIE) {
+                myLogger.log(Level.FINE, "Interrupted locking CBD");
+            }
+
+            myCBD = (CacheBlockDescriptor) myCBD.getNext();
+        }
+    }
+
+    synchronized void sync(BackingStore aStore) throws IOException {
+        CacheBlockDescriptor myCBD = 
+            (CacheBlockDescriptor) theEntries.getHead();
+
+        while (myCBD != null) {
+
+            try {
+                myCBD.acquire();
+
+                aStore.save(myCBD.getContent());
+
+                myCBD.release();
+            } catch (InterruptedException anIE) {
+                throw new IOException();
+            }
+
+            myCBD = (CacheBlockDescriptor) myCBD.getNext();
+        }
+    }
+}