Mercurial > hg > blitz_condensed
diff src/org/prevayler/implementation/NumberFileCreator.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 21 Mar 2009 11:00:06 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/org/prevayler/implementation/NumberFileCreator.java Sat Mar 21 11:00:06 2009 +0000 @@ -0,0 +1,80 @@ +/* + The copyright of all source code included in this Prevayler distribution is + held by Klaus Wuestefeld, except the files that specifically state otherwise. + All rights are reserved. "PREVAYLER" is a trademark of Klaus Wuestefeld. + + + BSD License: + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + - Redistributions of source code must retain the above copyright notice, this + list of conditions and the following disclaimer. + + - Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + + - Neither the name of Prevayler nor the names of its contributors may be used + to endorse or promote products derived from this software without specific + prior written permission. + + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. +*/ + +package org.prevayler.implementation; + +import java.io.*; +import java.text.*; + +/** Creates .log and .snapshot files using a number sequence for the file name. +*/ +class NumberFileCreator { + + public static final String SNAPSHOT_SUFFIX = "snapshot"; + public static final String LOGFILE_SUFFIX = "commandLog"; + public static final DecimalFormat SNAPSHOT_FORMAT = new DecimalFormat("000000000000000000000'.'" + SNAPSHOT_SUFFIX); //21 zeros (enough for a long number). + public static final DecimalFormat LOG_FORMAT = new DecimalFormat("000000000000000000000'.'" + LOGFILE_SUFFIX); //21 zeros (enough for a long number). + + private File directory; + private long nextFileNumber; + + public NumberFileCreator(File directory, long firstFileNumber) { + this.directory = directory; + this.nextFileNumber = firstFileNumber; + } + + File newLog() throws IOException { + File log = new File(directory, LOG_FORMAT.format(nextFileNumber)); + if(!log.createNewFile()) throw new IOException("Attempt to create command log file that already existed: " + log);; + + ++nextFileNumber; + return log; + } + + File newSnapshot() throws IOException { + File snapshot = new File(directory, SNAPSHOT_FORMAT.format(nextFileNumber - 1)); + snapshot.delete(); //If no commands are logged, the same snapshot file will be created over and over. + return snapshot; + } + + File newTempSnapshot() throws IOException { + return File.createTempFile("temp","generatingSnapshot",directory); + } + + NumberFileCleaner newCleaner() { + return new NumberFileCleaner(directory); + } +}