/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* 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 eu.stratosphere.compiler.dataproperties;
import java.util.Arrays;
import eu.stratosphere.api.common.operators.Ordering;
import eu.stratosphere.api.common.operators.util.FieldList;
import eu.stratosphere.api.common.operators.util.FieldSet;
import eu.stratosphere.compiler.dag.OptimizerNode;
import eu.stratosphere.compiler.plan.Channel;
import eu.stratosphere.compiler.util.Utils;
import eu.stratosphere.pact.runtime.task.util.LocalStrategy;
/**
* This class represents local properties of the data. A local property is a property that exists
* within the data of a single partition.
*/
public class RequestedLocalProperties implements Cloneable {
public static final RequestedLocalProperties DEFAULT_PROPERTIES = null;
// --------------------------------------------------------------------------------------------
Ordering ordering; // order inside a partition, null if not ordered
FieldSet groupedFields; // fields by which the stream is grouped. null if not grouped.
// --------------------------------------------------------------------------------------------
/**
* Default constructor for trivial local properties. No order, no grouping, no uniqueness.
*/
public RequestedLocalProperties() {}
/**
* Creates interesting properties for the given ordering.
*
* @param ordering The interesting ordering.
*/
public RequestedLocalProperties(Ordering ordering) {
this.ordering = ordering;
}
/**
* Creates interesting properties for the given grouping.
*
* @param groupedFields The set of fields whose grouping is interesting.
*/
public RequestedLocalProperties(FieldSet groupedFields) {
this.groupedFields = groupedFields;
}
/**
* This constructor is used only for internal copy creation.
*
* @param ordering The ordering represented by these local properties.
* @param groupedFields The grouped fields for these local properties.
*/
private RequestedLocalProperties(Ordering ordering, FieldSet groupedFields) {
this.ordering = ordering;
this.groupedFields = groupedFields;
}
// --------------------------------------------------------------------------------------------
/**
* Gets the key order.
*
* @return The key order, or <code>null</code> if nothing is ordered.
*/
public Ordering getOrdering() {
return ordering;
}
/**
* Sets the order for these interesting local properties.
*
* @param ordering The order to set.
*/
public void setOrdering(Ordering ordering) {
this.ordering = ordering;
}
/**
* Gets the grouped fields.
*
* @return The grouped fields, or <code>null</code> if nothing is grouped.
*/
public FieldSet getGroupedFields() {
return this.groupedFields;
}
/**
* Sets the fields that are grouped in these data properties.
*
* @param groupedFields The fields that are grouped in these data properties.
*/
public void setGroupedFields(FieldSet groupedFields) {
this.groupedFields = groupedFields;
}
/**
* Checks, if the properties in this object are trivial, i.e. only standard values.
*/
public boolean isTrivial() {
return ordering == null && this.groupedFields == null;
}
/**
* This method resets the local properties to a state where no properties are given.
*/
public void reset() {
this.ordering = null;
this.groupedFields = null;
}
// --------------------------------------------------------------------------------------------
/**
* Filters these properties by what can be preserved through a user function's constant fields set.
* Since interesting properties are filtered top-down, anything that partially destroys the ordering
* makes the properties uninteresting.
*
* @param node The optimizer node that potentially modifies the properties.
* @param input The input of the node which is relevant.
*
* @return True, if the resulting properties are non trivial.
*/
public RequestedLocalProperties filterByNodesConstantSet(OptimizerNode node, int input) {
if (this.ordering != null) {
final FieldList involvedIndexes = this.ordering.getInvolvedIndexes();
for (int i = 0; i < involvedIndexes.size(); i++) {
if (!node.isFieldConstant(input, involvedIndexes.get(i))) {
return null;
}
}
} else if (this.groupedFields != null) {
// check, whether the local key grouping is preserved
for (Integer index : this.groupedFields) {
if (!node.isFieldConstant(input, index)) {
return null;
}
}
}
return this;
}
/**
* Checks, if this set of properties, as interesting properties, is met by the given
* properties.
*
* @param other
* The properties for which to check whether they meet these properties.
* @return True, if the properties are met, false otherwise.
*/
public boolean isMetBy(LocalProperties other) {
if (this.ordering != null) {
// we demand an ordering
return other.getOrdering() != null && this.ordering.isMetBy(other.getOrdering());
} else if (this.groupedFields != null) {
// check if the other fields are unique
if (other.getGroupedFields() != null && other.getGroupedFields().isValidUnorderedPrefix(this.groupedFields)) {
return true;
} else {
return other.areFieldsUnique(this.groupedFields);
}
} else {
return true;
}
}
/**
* Parameterizes the local strategy fields of a channel such that the channel produces the desired local properties.
*
* @param channel The channel to parameterize.
*/
public void parameterizeChannel(Channel channel) {
if (this.ordering != null) {
channel.setLocalStrategy(LocalStrategy.SORT, this.ordering.getInvolvedIndexes(), this.ordering.getFieldSortDirections());
} else if (this.groupedFields != null) {
boolean[] dirs = new boolean[this.groupedFields.size()];
Arrays.fill(dirs, true);
channel.setLocalStrategy(LocalStrategy.SORT, Utils.createOrderedFromSet(this.groupedFields), dirs);
}
}
// --------------------------------------------------------------------------------------------
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + (this.ordering == null ? 0 : this.ordering.hashCode());
result = prime * result + (this.groupedFields == null ? 0 : this.groupedFields.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (obj instanceof RequestedLocalProperties) {
final RequestedLocalProperties other = (RequestedLocalProperties) obj;
return (this.ordering == other.ordering || (this.ordering != null && this.ordering.equals(other.ordering))) &&
(this.groupedFields == other.groupedFields || (this.groupedFields != null && this.groupedFields.equals(other.groupedFields)));
} else {
return false;
}
}
@Override
public String toString() {
return "Requested Local Properties [ordering=" + this.ordering + ", grouped=" + this.groupedFields + "]";
}
@Override
public RequestedLocalProperties clone() {
return new RequestedLocalProperties(this.ordering, this.groupedFields);
}
}