de.ks.flatadocdb.session.dirtycheck.DirtyChecker.java Source code

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Here is the source code for de.ks.flatadocdb.session.dirtycheck.DirtyChecker.java

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/*
 * Copyright [2015] [Christian Loehnert]
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package de.ks.flatadocdb.session.dirtycheck;

import de.ks.flatadocdb.Repository;
import de.ks.flatadocdb.ifc.EntityPersister;
import de.ks.flatadocdb.metamodel.EntityDescriptor;
import de.ks.flatadocdb.metamodel.MetaModel;
import de.ks.flatadocdb.session.SessionEntry;
import org.apache.commons.codec.digest.DigestUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * Very simple dirty checker right now.
 * Need to balloon it up to something hibernate uses, storing the initial state and then comparing all fields
 */
public class DirtyChecker {
    private static final Logger log = LoggerFactory.getLogger(DirtyChecker.class);
    private final Repository repository;
    private final MetaModel metaModel;
    private final Set<Object> insertions = new HashSet<>();
    private final Set<Object> deletions = new HashSet<>();

    public DirtyChecker(Repository repository, MetaModel metaModel) {
        this.repository = repository;
        this.metaModel = metaModel;
    }

    public void trackLoad(SessionEntry sessionEntry) {
        //maybe store initial state und do comparison like hibernate?
    }

    public void trackPersist(SessionEntry sessionEntry) {
        insertions.add(sessionEntry.getObject());
    }

    public void trackDelete(SessionEntry sessionEntry) {
        deletions.add(sessionEntry.getObject());
    }

    public Collection<SessionEntry> findDirty(Collection<SessionEntry> values) {
        return values.stream()//
                .filter(e -> !insertions.contains(e.getObject()))//
                .filter(e -> !deletions.contains(e.getObject()))//
                .filter(e -> {
                    EntityDescriptor entityDescriptor = e.getEntityDescriptor();
                    EntityPersister persister = entityDescriptor.getPersister();
                    byte[] fileContents = persister.createFileContents(repository, entityDescriptor, e.getObject());
                    byte[] md5 = DigestUtils.md5(fileContents);
                    boolean dirty = !Arrays.equals(md5, e.getMd5());
                    if (dirty) {
                        log.debug("Found dirty entity {} {}", e.getObject(), e.getFileName());
                    } else {
                        log.trace("Non-dirty entity {} {}", e.getObject(), e.getFileName());
                    }
                    return dirty;
                }).collect(Collectors.toSet());
    }

    public Set<Object> getDeletions() {
        return deletions;
    }
}