--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/dancres/blitz/config/Persistent.java	Sat Mar 21 11:00:06 2009 +0000
@@ -0,0 +1,57 @@
+package org.dancres.blitz.config;
+
+/**
+   Configures Blitz to be maximally durable with all operations being recorded
+   on disk immediately they are commited.
+
+   @todo Add MAX_LOGS_BEFORE_SYNC disable
+ */
+public class Persistent extends PersistentBase {
+
+    private boolean useConcurrentBatcher;
+    private int theBatchWriteWindowSize;
+
+    /**
+       @param shouldReset specifies whether to reset the ObjectOutputStream
+       used for logging. This is a performance vs memory tradeoff
+
+       @param shouldClean specifies whether old log files and snapshots should
+       be cleaned up or left for archiving.
+
+       @param aBatchWriteWindowSize specifies a batch-write window for logging.
+       Set this to zero to disable batching. Batch-writing can reduce the
+       number of forced flushes to disk whilst increasing the amount of data
+       written with each flush.  This has a positive effect on throughput
+       under concurrent load. Time is specified in ms, first thread into
+       barrier waits this amount of time for other writers.  Other writers
+       entering the barrier are now blocked until the first entrant commits all
+       writes to log.
+
+       @param useConcurrent should increase log throughput by allowing the
+       next batch to form whilst the current batch is being written to log.
+
+       @param aMaxLogsBeforeSync is the maximum number of log entries before
+       a checkpoint is forced.
+
+       @param aLogBufferSize especially useful when doing batching.
+       All commands are rendered to the buffer before going to disk in one
+       large block. Without the buffer, each command will trickle to disk as a
+       small update which isn't good for throughput!
+     */
+    public Persistent(boolean shouldReset, boolean shouldClean,
+                      int aBatchWriteWindowSize, boolean useConcurrent,
+                      int aMaxLogsBeforeSync, int aLogBufferSize) {
+
+        super(shouldReset, shouldClean, aLogBufferSize, aMaxLogsBeforeSync);
+        useConcurrentBatcher = useConcurrent;
+        theBatchWriteWindowSize = aBatchWriteWindowSize;
+    }
+
+    public boolean useConcurrentWriteBatcher() {
+        return useConcurrentBatcher;
+    }
+
+    public int getBatchWriteWindowSize() {
+        return theBatchWriteWindowSize;
+    }
+}