--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/dancres/blitz/entry/ci/FifoIndexer.java	Sat Mar 21 11:00:06 2009 +0000
@@ -0,0 +1,57 @@
+package org.dancres.blitz.entry.ci;
+
+import java.util.*;
+
+import java.util.logging.*;
+
+import org.dancres.blitz.entry.EntrySleeve;
+import org.dancres.blitz.entry.TupleLocator;
+
+import org.dancres.blitz.mangler.MangledField;
+import org.dancres.blitz.mangler.MangledEntry;
+
+import org.dancres.blitz.cache.Cache;
+import org.dancres.blitz.cache.CacheListener;
+import org.dancres.blitz.cache.Identifiable;
+
+import org.dancres.blitz.oid.OID;
+
+import org.dancres.blitz.Logging;
+
+/**
+   <p>This CacheIndexer enforces ordering of its UIDs such that searches
+   favour the smallest UID's first.  There is a corresponding policy in
+   UID allocation which must be adopted for Fifo guarentees which is to ensure
+   that we allocate UID's serially from smallest to largets.</p>
+
+   <p>Finally, we have to ensure that all searches favour disk then dirty
+   cache then Entry cache because the oldest Entry's are more likely to be
+   on disk than in the cache.</p>
+
+   @see org.dancres.blitz.oid.AllocatorFactory
+   @see org.dancres.blitz.entry.SleeveCache
+*/
+public class FifoIndexer extends CacheIndexerImpl {
+
+    FifoIndexer(String aType) {
+        super(aType);
+    }
+
+    Set newIds() {
+        /*
+        In order to ensure FIFO ordering of searches we must use some
+        form of SortedSet thus we use TreeSet which guarentees us that
+        iteration and toArray etc give us the ordering we require so long as
+        the OIDs are allocated appropriately.
+        */
+        return new TreeSet();
+    }
+
+    CacheLines[] newLinesArray(int aSize) {
+        return new FifoCacheLines[aSize];
+    }
+
+    CacheLines newLines(int anIndex, String aFieldName) {
+        return new FifoCacheLines(anIndex, aFieldName);
+    }
+}