小程序 JActor的文件持久化组件 JFile（源码）.zip

/* * Copyright 2012 Bill La Forge * * This file is part of AgileWiki and is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License (LGPL) as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This code is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * or navigate to the following url http://www.gnu.org/licenses/lgpl-2.1.txt * * Note however that only Scala, Java and JavaScript files are being covered by LGPL. * All other files are covered by the Common Public License (CPL). * A copy of this license is also included and can be * found as well at http://www.opensource.org/licenses/cpl1.0.txt */ package org.agilewiki.jfile.transactions.db.inMemory; import org.agilewiki.jactor.Actor; import org.agilewiki.jactor.ExceptionHandler; import org.agilewiki.jactor.MailboxFactory; import org.agilewiki.jactor.RP; import org.agilewiki.jactor.factory.JAFactory; import org.agilewiki.jfile.ForceBeforeWriteRootJid; import org.agilewiki.jfile.JFile; import org.agilewiki.jfile.block.Block; import org.agilewiki.jfile.block.LTA32Block; import org.agilewiki.jfile.transactions.db.DB; import org.agilewiki.jid.JidFactories; import org.agilewiki.jid._Jid; import org.agilewiki.jid.collection.vlenc.map.StringMapJid; import org.agilewiki.jid.scalar.flens.bool.BooleanJid; import org.agilewiki.jid.scalar.flens.dbl.DoubleJid; import org.agilewiki.jid.scalar.flens.flt.FloatJid; import org.agilewiki.jid.scalar.flens.integer.IntegerJid; import org.agilewiki.jid.scalar.flens.lng.LongJid; import org.agilewiki.jid.scalar.vlens.actor.ActorJid; import org.agilewiki.jid.scalar.vlens.actor.RootJid; import org.agilewiki.jid.scalar.vlens.bytes.BytesJid; import org.agilewiki.jid.scalar.vlens.string.StringJid; import java.nio.file.Path; import java.nio.file.StandardOpenOption; /** * In-memory database. */ public class IMDB extends DB { public static final String LOG_POSITION = "$$LOG_POSITION"; public static final String LOG_FILE_NAME = "$$LOG_FILE_NAME"; private JFile dbFile; private RootJid rootJid; private StringMapJid stringMapJid; private boolean pendingWrite; private boolean isFirstRootJid; public int maxSize; private boolean closed; private boolean online; public IMDB() {} public IMDB(MailboxFactory mailboxFactory, Actor parent, Path directoryPath, int maxSize) throws Exception { super(mailboxFactory, parent, directoryPath); this.maxSize = maxSize; } @Override protected boolean generateCheckpoints() { return online; } @Override public void openDbFile(int logReaderMaxSize, RP rp) throws Exception { if (dbFile == null) { dbFile = new JFile(); dbFile.initialize(getMailboxFactory().createAsyncMailbox()); } Path dbPath = directoryPath.resolve("imdb.jadb"); dbFile.open( dbPath, StandardOpenOption.READ, StandardOpenOption.WRITE, StandardOpenOption.CREATE); initializeDb(logReaderMaxSize); Block block0 = newDbBlock(); block0.setCurrentPosition(0L); block0.setFileName(dbPath.toString()); dbFile.readRootJid(block0, maxSize); RootJid rootJid0 = block0.getRootJid(getMailboxFactory().createMailbox(), getParent()); long timestamp0 = block0.getTimestamp(); Block block1 = newDbBlock(); block1.setCurrentPosition(maxSize); block1.setFileName(dbPath.toString()); dbFile.readRootJid(block1, maxSize); RootJid rootJid1 = block1.getRootJid(getMailboxFactory().createMailbox(), getParent()); long timestamp1 = block0.getTimestamp(); if (rootJid0 == null) { rootJid = rootJid1; isFirstRootJid = false; } else if (rootJid1 == null) { rootJid = rootJid0; isFirstRootJid = true; } else if (timestamp0 < timestamp1) { rootJid = rootJid1; isFirstRootJid = false; } else { rootJid = rootJid0; isFirstRootJid = true; } Long position = getLong(LOG_POSITION); if (position == null) { processLogFile(0L, 0, rp); return; } String logFileName = getString(LOG_FILE_NAME); int fileIndex = 0; while (fileIndex < logFileNames.length && !logFileNames[fileIndex].equals(logFileName)) fileIndex += 1; if (fileIndex == logFileNames.length) throw new IllegalStateException("Missing log file: " + logFileName); processLogFile(position, fileIndex, rp); online = true; } @Override public void closeDbFile() { super.closeDbFile(); closed = true; dbFile.close(); } protected Block newDbBlock() { return new LTA32Block(); } protected RootJid makeRootJid() throws Exception { if (rootJid == null) { JAFactory factory = (JAFactory) getAncestor(JAFactory.class); rootJid = (RootJid) factory.newActor( JidFactories.ROOT_JID_TYPE, getMailboxFactory().createMailbox(), getParent()); } return rootJid; } public StringMapJid getStringMapJid() throws Exception { if (rootJid == null) return null; if (stringMapJid == null) { stringMapJid = (StringMapJid) rootJid.getValue(); } return stringMapJid; } public StringMapJid makeStringMapJid() throws Exception { if (stringMapJid == null) { RootJid rj = makeRootJid(); stringMapJid = (StringMapJid) rj.getValue(); if (stringMapJid == null) { rj.setValue(JidFactories.STRING_ACTOR_MAP_JID_TYPE); stringMapJid = (StringMapJid) rj.getValue(); } } return stringMapJid; } public ActorJid getActorJid(String key) throws Exception { StringMapJid smj = getStringMapJid(); if (smj == null) return null; return (ActorJid) smj.kGet(key); } public ActorJid makeActorJid(String key) throws Exception { StringMapJid smj = makeStringMapJid(); ActorJid actorJid = (ActorJid) smj.kGet(key); if (actorJid == null) { smj.kMake(key); actorJid = (ActorJid) smj.kGet(key); } return actorJid; } public _Jid getJid(String key) throws Exception { ActorJid aj = getActorJid(key); if (aj == null) return null; _Jid jid = aj.getValue(); return jid; } public _Jid makeJid(String key, String factoryName) throws Exception { ActorJid aj = makeActorJid(key); _Jid jid = aj.getValue(); if (jid == null) { aj.setValue(factoryName); jid = aj.getValue(); } return jid; } public BooleanJid getBooleanJid(String key) throws Exception { return (BooleanJid) getJid(key); } public Boolean getBoolean(String key) throws Exception { BooleanJid ij = getBooleanJid(key); if (ij == null) return null; return ij.getValue(); } public BooleanJid makeBooleanJid(String key) throws Exception { return