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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.lens.cube.metadata;
import java.util.*;
import org.apache.lens.cube.metadata.join.JoinPath;
import org.apache.lens.cube.metadata.join.TableRelationship;
import org.apache.lens.server.api.error.LensException;
import org.apache.commons.lang.StringUtils;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import lombok.EqualsAndHashCode;
import lombok.Getter;
import lombok.ToString;
@EqualsAndHashCode
@ToString
public class JoinChain implements Named {
@Getter
private final String name;
@Getter
private final String displayString;
@Getter
private final String description;
// There can be more than one path associated with same name.
// c1.r1->t1.k1
// c1.r2->t1.k2
@Getter
private final List paths;
public void addProperties(AbstractCubeTable tbl) {
if (tbl instanceof Cube) {
addProperties((Cube) tbl);
} else {
addProperties((Dimension) tbl);
}
}
public void addProperties(Cube cube) {
Map props = cube.getProperties();
props.put(MetastoreUtil.getCubeJoinChainNumChainsKey(getName()), String.valueOf(paths.size()));
for (int i = 0; i < paths.size(); i++) {
props.put(MetastoreUtil.getCubeJoinChainFullChainKey(getName(), i),
MetastoreUtil.getReferencesString(paths.get(i).getReferences()));
}
if (displayString != null) {
props.put(MetastoreUtil.getCubeJoinChainDisplayKey(getName()), displayString);
}
if (description != null) {
props.put(MetastoreUtil.getCubeJoinChainDescriptionKey(getName()), description);
}
}
public void addProperties(Dimension dimension) {
Map props = dimension.getProperties();
props.put(MetastoreUtil.getDimensionJoinChainNumChainsKey(getName()), String.valueOf(paths.size()));
for (int i = 0; i < paths.size(); i++) {
props.put(MetastoreUtil.getDimensionJoinChainFullChainKey(getName(), i),
MetastoreUtil.getReferencesString(paths.get(i).getReferences()));
}
if (displayString != null) {
props.put(MetastoreUtil.getDimensionJoinChainDisplayKey(getName()), displayString);
}
if (description != null) {
props.put(MetastoreUtil.getDimensionJoinChainDescriptionKey(getName()), description);
}
}
/**
* Construct join chain
*
* @param name
* @param display
* @param description
*/
public JoinChain(String name, String display, String description) {
this.name = name.toLowerCase();
this.displayString = display;
this.description = description;
this.paths = new ArrayList();
}
/**
* This is used only for serializing
*
* @param table
* @param name
*/
public JoinChain(AbstractBaseTable table, String name) {
boolean isCube = (table instanceof Cube);
this.name = name;
this.paths = new ArrayList();
int numChains = 0;
Map props = table.getProperties();
if (isCube) {
numChains = Integer.parseInt(props.get(MetastoreUtil.getCubeJoinChainNumChainsKey(getName())));
} else {
numChains = Integer.parseInt(props.get(MetastoreUtil.getDimensionJoinChainNumChainsKey(getName())));
}
for (int i = 0; i < numChains; i++) {
Path chain = new Path();
String refListStr;
if (isCube) {
refListStr = props.get(MetastoreUtil.getCubeJoinChainFullChainKey(getName(), i));
} else {
refListStr = props.get(MetastoreUtil.getDimensionJoinChainFullChainKey(getName(), i));
}
String[] refListDims = StringUtils.split(refListStr, ",");
TableReference from = null;
for (String refDimRaw : refListDims) {
if (from == null) {
from = new TableReference(refDimRaw);
} else {
chain.addLink(new Edge(from, new TableReference(refDimRaw)));
from = null;
}
}
paths.add(chain);
}
if (isCube) {
this.description = props.get(MetastoreUtil.getCubeJoinChainDescriptionKey(name));
this.displayString = props.get(MetastoreUtil.getCubeJoinChainDisplayKey(name));
} else {
this.description = props.get(MetastoreUtil.getDimensionJoinChainDescriptionKey(name));
this.displayString = props.get(MetastoreUtil.getDimensionJoinChainDisplayKey(name));
}
}
/**
* Copy constructor for JoinChain
*
* @param other JoinChain
*/
public JoinChain(JoinChain other) {
this.name = other.name;
this.displayString = other.displayString;
this.description = other.description;
this.paths = new ArrayList(other.paths);
}
@EqualsAndHashCode(exclude = {"relationShip"})
@ToString
public static class Edge {
@Getter
private final TableReference from;
@Getter
private final TableReference to;
transient TableRelationship relationShip = null;
Edge(TableReference from, TableReference to) {
this.from = from;
this.to = to;
}
TableRelationship toDimToDimRelationship(CubeMetastoreClient client) throws HiveException, LensException {
if (relationShip == null) {
relationShip = new TableRelationship(from.getDestColumn(),
client.getDimension(from.getDestTable()),
to.getDestColumn(),
client.getDimension(to.getDestTable()),
to.isMapsToMany());
}
return relationShip;
}
/**
* return Cube or Dimension relationship depending on the source table of the join chain.
*
* @param client
* @return
* @throws HiveException
*/
TableRelationship toCubeOrDimRelationship(CubeMetastoreClient client) throws HiveException, LensException {
if (relationShip == null) {
AbstractCubeTable fromTable = null;
if (client.isCube(from.getDestTable())) {
fromTable = (AbstractCubeTable) client.getCube(from.getDestTable());
} else if (client.isDimension(from.getDestTable())) {
fromTable = client.getDimension(from.getDestTable());
}
if (fromTable != null) {
relationShip = new TableRelationship(from.getDestColumn(),
fromTable,
to.getDestColumn(),
client.getDimension(to.getDestTable()),
to.isMapsToMany());
}
}
return relationShip;
}
}
@EqualsAndHashCode(exclude = {"refs"})
@ToString
public static class Path {
@Getter
final List links = new ArrayList();
transient List refs = null;
private void addLink(Edge edge) {
links.add(edge);
}
public List getReferences() {
if (refs == null) {
refs = new ArrayList();
for (Edge edge : links) {
refs.add(edge.from);
refs.add(edge.to);
}
}
return refs;
}
Path() {
}
Path(List refs) {
for (int i = 0; i < refs.size() - 1; i += 2) {
addLink(new Edge(refs.get(i), refs.get(i + 1)));
}
}
String getDestTable() {
return links.get(links.size() - 1).to.getDestTable();
}
String getSrcColumn() {
return links.get(0).from.getDestColumn();
}
}
public void addPath(List refs) {
if (refs.size() <= 1 || refs.size() % 2 != 0) {
throw new IllegalArgumentException("Path should contain both from and to links");
}
this.paths.add(new Path(refs));
}
private transient String destTable = null;
/**
* Get final destination table
*
* @return
*/
public String getDestTable() {
if (destTable == null) {
for (Path path : paths) {
if (destTable == null) {
destTable = path.getDestTable();
} else {
String temp = path.getDestTable();
if (!destTable.equalsIgnoreCase(temp)) {
throw new IllegalArgumentException("Paths have different destination tables :" + destTable + "," + temp);
}
}
}
}
return destTable;
}
/**
* Get all source columns from cube
*
* @return
*/
public Set getSourceColumns() {
Set srcFields = new HashSet();
for (Path path : paths) {
srcFields.add(path.getSrcColumn());
}
return srcFields;
}
/**
* Get all dimensions involved in paths, except destination table
*
* @return
*/
public Set getIntermediateDimensions() {
Set dimNames = new HashSet();
for (Path path : paths) {
// skip last entry in all paths, as that would be a destination
for (int i = 0; i < path.links.size() - 1; i++) {
dimNames.add(path.links.get(i).to.getDestTable());
}
}
return dimNames;
}
/**
* Convert join chain paths to JoinPath objects
*
* @param client
* @return List<JoinPath>
* @throws HiveException
*/
public List getRelationEdges(CubeMetastoreClient client) throws HiveException, LensException {
List joinPaths = new ArrayList<>();
for (Path path : paths) {
JoinPath jp = new JoinPath();
// Add edges from dimension to cube
for (int i = path.links.size() - 1; i > 0; i -= 1) {
jp.addEdge(path.links.get(i).toDimToDimRelationship(client));
}
jp.addEdge(path.links.get(0).toCubeOrDimRelationship(client));
joinPaths.add(jp);
}
return joinPaths;
}
}
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