internalversionhistoryimpl.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.jackrabbit.core.version;

import org.apache.jackrabbit.core.NodeImpl;
import org.apache.jackrabbit.core.NodeId;
import org.apache.jackrabbit.core.state.ItemStateException;
import org.apache.jackrabbit.core.state.NodeState;
import org.apache.jackrabbit.core.state.PropertyState;
import org.apache.jackrabbit.core.value.InternalValue;
import org.apache.jackrabbit.name.QName;
import org.apache.jackrabbit.uuid.UUID;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.jcr.PropertyType;
import javax.jcr.ReferentialIntegrityException;
import javax.jcr.RepositoryException;
import javax.jcr.Value;
import javax.jcr.version.VersionException;
import java.util.Calendar;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

/**
 * Implements a <code>InternalVersionHistory</code>
 */
class InternalVersionHistoryImpl extends InternalVersionItemImpl
        implements InternalVersionHistory {

    /**
     * default logger
     */
    private static Logger log = LoggerFactory.getLogger(InternalVersionHistory.class);

    /**
     * the cache of the version labels
     * key = version label (String)
     * value = version
     */
    private HashMap labelCache = new HashMap();

    /**
     * the root version of this history
     */
    private InternalVersion rootVersion;

    /**
     * the hashmap of all versions
     * key = versionId (NodeId)
     * value = version
     */
    private HashMap versionCache = new HashMap();

    /**
     * Temporary version cache, used on a refresh.
     */
    private HashMap tempVersionCache = new HashMap();

    /**
     * the node that holds the label nodes
     */
    private NodeStateEx labelNode;

    /**
     * the id of this history
     */
    private NodeId historyId;

    /**
     * the id of the versionable node
     */
    private NodeId versionableId;

    /**
     * Creates a new VersionHistory object for the given node state.
     */
    public InternalVersionHistoryImpl(AbstractVersionManager vMgr, NodeStateEx node)
            throws RepositoryException {
        super(vMgr, node);
        init();
    }

    /**
     * Initialies the history and loads all internal caches
     *
     * @throws RepositoryException
     */
    private void init() throws RepositoryException {
        versionCache.clear();
        labelCache.clear();

        // get id
        historyId = node.getNodeId();

        // get versionable id
        versionableId = NodeId.valueOf(node.getPropertyValue(QName.JCR_VERSIONABLEUUID).toString());

        // get entries
        NodeStateEx[] children = node.getChildNodes();
        for (int i = 0; i < children.length; i++) {
            NodeStateEx child = children[i];
            if (child.getName().equals(QName.JCR_VERSIONLABELS)) {
                labelNode = child;
                continue;
            }
            InternalVersionImpl v = createVersionInstance(child);
            versionCache.put(v.getId(), v);
            if (v.isRootVersion()) {
                rootVersion = v;
            }
            vMgr.versionCreated(v);
        }

        // check for legacy version nodes that had 'virtual' jcr:successor property
        if (rootVersion.getSuccessors().length==0 && versionCache.size()>1) {
            // resolve successors and predecessors
            Iterator iter = versionCache.values().iterator();
            while (iter.hasNext()) {
                InternalVersionImpl v = (InternalVersionImpl) iter.next();
                v.legacyResolveSuccessors();
            }
        }

        try {
            // init label cache
            PropertyState[] labels = labelNode.getProperties();
            for (int i = 0; i < labels.length; i++) {
                PropertyState pState = labels[i];
                if (pState.getType() == PropertyType.REFERENCE) {
                    QName name = pState.getName();
                    UUID ref = (UUID) pState.getValues()[0].internalValue();
                    InternalVersionImpl v = (InternalVersionImpl) getVersion(new NodeId(ref));
                    if (v != null) {
                        labelCache.put(name, v);
                        v.internalAddLabel(name);
                    } else {
                        log.warn("Error while resolving label reference. Version missing: " + ref);
                    }
                }
            }
        } catch (ItemStateException e) {
            throw new RepositoryException(e);
        }
    }

    /**
     * Reload this object and all its dependent version objects.
     */
    void reload() throws RepositoryException {
        tempVersionCache.putAll(versionCache);

        init();

        // invalidate all versions that are not referenced any more
        Iterator iter = tempVersionCache.values().iterator();
        while (iter.hasNext()) {
            InternalVersionImpl v = (InternalVersionImpl) iter.next();
            v.invalidate();
        }
        tempVersionCache.clear();
    }

    /**
     * Create a version instance. May resurrect versions temporarily swapped
     * out when refreshing this history.
     */
    InternalVersionImpl createVersionInstance(NodeStateEx child) {
        InternalVersionImpl v = (InternalVersionImpl) tempVersionCache.remove(child.getNodeId());
        if (v != null) {
            v.clear();
        } else {
            v = new InternalVersionImpl(this, child, child.getName());
        }
        return v;
    }

    /**
     * {@inheritDoc}
     */
    public NodeId getId() {
        return historyId;
    }

    /**
     * {@inheritDoc}
     */
    public InternalVersionItem getParent() {
        return null;
    }

    /**
     * {@inheritDoc}
     */
    public InternalVersion getRootVersion() {
        return rootVersion;
    }

    /**
     * {@inheritDoc}
     */
    public InternalVersion getVersion(QName versionName) throws VersionException {
        // maybe add cache by name?
        Iterator iter = versionCache.values().iterator();
        while (iter.hasNext()) {
            InternalVersion v = (InternalVersion) iter.next();
            if (v.getName().equals(versionName)) {
                return v;
            }
        }
        throw new VersionException("Version " + versionName + " does not exist.");
    }

    /**
     * {@inheritDoc}
     */
    public boolean hasVersion(QName versionName) {
        // maybe add cache?
        Iterator iter = versionCache.values().iterator();
        while (iter.hasNext()) {
            InternalVersion v = (InternalVersion) iter.next();
            if (v.getName().equals(versionName)) {
                return true;
            }
        }
        return false;
    }

    /**
     * {@inheritDoc}
     */
    public boolean hasVersion(NodeId id) {
        return versionCache.containsKey(id);
    }

    /**
     * {@inheritDoc}
     */
    public InternalVersion getVersion(NodeId id) {
        return (InternalVersion) versionCache.get(id);
    }