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annotate src/org/dancres/blitz/config/TimeBarrierPersistent.java @ 32:243c74d599bf

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author Dan Creswell <dan.creswell@gmail.com>
date Sat, 12 Jun 2010 10:41:47 +0100
parents 3dc0c5604566
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3dc0c5604566 Initial checkin of blitz 2.0 fcs - no installer yet.
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1 package org.dancres.blitz.config;
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2
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3 /**
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4 <p>Configures Blitz to make operations durable after a certain period of
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5 time such that if an operation was submitted more than that time period ago,
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6 it is guarenteed to be durable.</p>
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7
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8 <p>This kind of persistence provides the developer/administrator with the
3dc0c5604566 Initial checkin of blitz 2.0 fcs - no installer yet.
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9 ability to trade persistence guarentee for speed. Certain applications can
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10 tolerate this sort of behaviour because they incorporate their own
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11 consistency checks which allow them to recover a certain amount of recent
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12 state that the space hadn't yet persisted.</p>
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13 */
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14 public class TimeBarrierPersistent extends PersistentBase {
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16 private long theFlushTime;
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17
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18 /**
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19 @param shouldReset specifies whether to reset the ObjectOutputStream
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20 used for logging. This is a performance vs memory tradeoff
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21
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22 @param shouldClean specifies whether old log files and snapshots should
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23 be cleaned up or left for archiving.
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24
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25 @param aMaxLogsBeforeSync is the maximum number of log entries before
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26 a checkpoint is forced.
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27
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28 @param aLogBufferSize especially useful when doing flushing
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29 All commands are rendered to the buffer before going to disk in one
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30 large block. Without the buffer, each command will trickle to disk as a
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31 small update which isn't good for throughput!
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32
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33 @param aFlushTime the period in millis after which a logged command
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34 should be made durable.
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35 */
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36 public TimeBarrierPersistent(boolean shouldReset, boolean shouldClean,
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37 int aMaxLogsBeforeSync, int aLogBufferSize,
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38 long aFlushTime) {
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39
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40 super(shouldReset, shouldClean, aLogBufferSize, aMaxLogsBeforeSync);
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41 theFlushTime = aFlushTime;
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42 }
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43
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44 public long getFlushTime() {
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45 return theFlushTime;
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46 }
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47 }