/*
* 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.oak.plugins.version;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import javax.annotation.CheckForNull;
import javax.annotation.Nonnull;
import javax.jcr.RepositoryException;
import javax.jcr.UnsupportedRepositoryOperationException;
import org.apache.jackrabbit.oak.api.PropertyState;
import org.apache.jackrabbit.oak.api.Root;
import org.apache.jackrabbit.oak.api.Tree;
import org.apache.jackrabbit.oak.api.Type;
import org.apache.jackrabbit.oak.commons.PathUtils;
import org.apache.jackrabbit.oak.core.IdentifierManager;
import org.apache.jackrabbit.oak.plugins.nodetype.ReadOnlyNodeTypeManager;
import org.apache.jackrabbit.oak.util.TreeUtil;
/**
* {@code ReadOnlyVersionManager} provides implementations for read-only
* version operations modeled after the ones available in {@link javax.jcr.version.VersionManager}.
*/
public abstract class ReadOnlyVersionManager {
/**
* @return the read-only {@link Tree} for the jcr:versionStorage node. The
* returned {@code Tree} instance must be up-to-date with the
* {@code Root} returned by {@link #getWorkspaceRoot()}.
*/
@Nonnull
protected abstract Tree getVersionStorage();
/**
/**
* @return the {@code Root} of the workspace.
*/
@Nonnull
protected abstract Root getWorkspaceRoot();
/**
* @return the node type manager of this repository.
*/
@Nonnull
protected abstract ReadOnlyNodeTypeManager getNodeTypeManager();
/**
* Returns {@code true} if the tree is checked out; otherwise
* {@code false}.
*
* @param tree the tree to check.
* @return whether the tree is checked out or not.
*/
public boolean isCheckedOut(@Nonnull Tree tree) {
if (checkNotNull(tree).exists()) {
PropertyState p = tree.getProperty(VersionConstants.JCR_ISCHECKEDOUT);
if (p != null) {
return p.getValue(Type.BOOLEAN);
} else if (tree.isRoot()) {
return true;
}
} else {
// FIXME: this actually means access to the tree is restricted
// and may result in wrong isCheckedOut value. This should never
// be the case in a commit hook because it operates on non-access-
// controlled NodeStates. This means consistency is not at risk
// but it may mean oak-jcr sees a node as checked out even though
// it is in fact read-only because of a checked-in ancestor.
}
// otherwise return checkedOut status of parent
return isCheckedOut(tree.getParent());
}
/**
* Returns {@code true} if the tree at the given absolute Oak path is
* checked out; otherwise {@code false}.
*
* @param absOakPath an absolute path.
* @return whether the tree at the given path is checked out or not.
*/
public boolean isCheckedOut(@Nonnull String absOakPath) {
return isCheckedOut(getWorkspaceRoot().getTree(checkNotNull(absOakPath)));
}
/**
* Returns the tree representing the version history of the given
* versionable tree or {@code null} if none exists yet.
*
* @param versionable the versionable tree.
* @return the version history or {@code null} if none exists yet.
* @throws UnsupportedRepositoryOperationException
* if the versionable tree is not actually
* versionable.
* @throws RepositoryException if an error occurs while checking the node
* type of the tree.
*/
@CheckForNull
public Tree getVersionHistory(@Nonnull Tree versionable)
throws UnsupportedRepositoryOperationException,
RepositoryException {
checkVersionable(versionable);
String uuid = versionable.getProperty(VersionConstants.JCR_UUID).getValue(Type.STRING);
return TreeUtil.getTree(getVersionStorage(), getVersionHistoryPath(uuid));
}
/**
* Returns the path of the version history for the given {@code uuid}.
* The returned path is relative to the version storage tree as returned
* by {@link #getVersionStorage()}.
*
* @param uuid the uuid of the versionable node
* @return the relative path of the version history for the given uuid.
*/
@Nonnull
public String getVersionHistoryPath(@Nonnull String uuid) {
String relPath = "";
for (int i = 0; i < 3; i++) {
String name = uuid.substring(i * 2, i * 2 + 2);
relPath = PathUtils.concat(relPath, name);
}
return PathUtils.concat(relPath, uuid);
}
/**
* Returns the tree representing the base version of the given versionable
* tree or {@code null} if none exists yet. This is the case when a
* versionable node is created, but is not yet saved.
*
* @param versionable the versionable tree.
* @return the tree representing the base version or {@code null}.
* @throws UnsupportedRepositoryOperationException
* if the versionable tree is not actually
* versionable.
* @throws RepositoryException if an error occurs while checking the node
* type of the tree.
*/
@CheckForNull
public Tree getBaseVersion(@Nonnull Tree versionable)
throws UnsupportedRepositoryOperationException,
RepositoryException {
checkVersionable(versionable);
PropertyState p = versionable.getProperty(VersionConstants.JCR_BASEVERSION);
if (p == null) {
// version history does not yet exist
return null;
}
return getIdentifierManager().getTree(p.getValue(Type.STRING));
}
//----------------------------< internal >----------------------------------
@Nonnull
private static String getRelativePath(@Nonnull String absJcrPath) {
checkArgument(checkNotNull(absJcrPath).startsWith("/"),
"Path is not absolute: " + absJcrPath);
String relPath = absJcrPath.substring(1);
checkArgument(!relPath.startsWith("/"), "Invalid path: " + absJcrPath);
return relPath;
}
/**
* @return an identifier manager that is able to resolve identifiers of
* nodes in the version storage.
*/
protected IdentifierManager getIdentifierManager() {
// FIXME: may need to revise this, because getVersionStorageTree()
// is not the same Root as getWorkspaceRoot()
return new IdentifierManager(getWorkspaceRoot());
}
/**
* Checks if the given {@code tree} is versionable and throws a {@link
* UnsupportedRepositoryOperationException} if it is not.
*
* @param tree the tree to check.
* @return the passed tree.
* @throws UnsupportedRepositoryOperationException
* if the tree is not versionable.
* @throws RepositoryException if an error occurs while checking the node
* type of the tree.
*/
@Nonnull
protected Tree checkVersionable(@Nonnull Tree tree)
throws UnsupportedRepositoryOperationException,
RepositoryException {
if (!isVersionable(checkNotNull(tree))) {
throw new UnsupportedRepositoryOperationException("Node at " +
tree.getPath() + " is not versionable");
}
return tree;
}
/**
* Returns {@code true} if the given {@code tree} is of type
* {@code mix:versionable}; {@code false} otherwise.
*
* @param tree the tree to check.
* @return whether the {@code tree} is versionable.
* @throws RepositoryException if an error occurs while checking the node
* type of the tree.
*/
protected boolean isVersionable(@Nonnull Tree tree) {
return getNodeTypeManager().isNodeType(
checkNotNull(tree), VersionConstants.MIX_VERSIONABLE);
}
}