/*
* 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.geode.cache.query.internal;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import org.apache.geode.cache.query.FunctionDomainException;
import org.apache.geode.cache.query.NameResolutionException;
import org.apache.geode.cache.query.QueryInvocationTargetException;
import org.apache.geode.cache.query.QueryService;
import org.apache.geode.cache.query.TypeMismatchException;
import org.apache.geode.cache.query.types.ObjectType;
import org.apache.geode.internal.cache.VMCachedDeserializable;
import org.apache.geode.pdx.internal.PdxString;
/**
* A generic comparator class which compares two Object/StructImpl according to their sort criterion
* specified in order by clause
*
*/
public class OrderByComparator implements Comparator {
private final ObjectType objType;
private final ExecutionContext context;
protected final List<CompiledSortCriterion> orderByAttrs;
public OrderByComparator(List<CompiledSortCriterion> orderByAttrs, ObjectType objType,
ExecutionContext context) {
this.objType = objType;
this.context = context;
this.orderByAttrs = orderByAttrs;
}
/**
* Yogesh : This methods evaluates sort criteria and returns a ArrayList of Object[] arrays of
* evaluated criteria
*
* @param value
* @return Object[]
*/
protected Object[] evaluateSortCriteria(Object value) {
CompiledSortCriterion csc;
Object[] array = null;
if (orderByAttrs != null) {
array = new Object[orderByAttrs.size()];
Iterator orderiter = orderByAttrs.iterator();
int i = 0;
while (orderiter.hasNext()) {
csc = (CompiledSortCriterion) orderiter.next();
Object[] arr = new Object[2];
arr[0] = csc.evaluate(value, context);
arr[1] = Boolean.valueOf(csc.getCriterion());
array[i++] = arr;
}
}
return array;
}
/**
* Compares its two arguments for order. Returns a negative integer, zero, or a positive integer
* as the first argument is less than, equal to, or greater than the second.
*
* @param obj1 the first object to be compared.
* @param obj2 the second object to be compared.
* @return a negative integer, zero, or a positive integer as the first argument is less than,
* equal to, or greater than the second.
* @throws ClassCastException if the arguments' types prevent them from being compared by this
* Comparator.
*/
public int compare(Object obj1, Object obj2) {
int result = -1;
if (obj1 == null && obj2 == null) {
return 0;
}
assert !(obj1 instanceof VMCachedDeserializable || obj2 instanceof VMCachedDeserializable);
if ((this.objType.isStructType() && obj1 instanceof Object[] && obj2 instanceof Object[])
|| !this.objType.isStructType()) { // obj1 instanceof Object && obj2
// instanceof Object){
Object[] list1 = this.evaluateSortCriteria(obj1);
Object[] list2 = this.evaluateSortCriteria(obj2);
if (list1.length != list2.length) {
Support.assertionFailed("Error Occured due to improper sort criteria evaluation ");
} else {
for (int i = 0; i < list1.length; i++) {
Object arr1[] = (Object[]) list1[i];
Object arr2[] = (Object[]) list2[i];
// check for null.
if (arr1[0] == null || arr2[0] == null) {
if (arr1[0] == null) {
result = (arr2[0] == null ? 0 : -1);
} else {
result = 1;
}
} else if (arr1[0] == QueryService.UNDEFINED || arr2[0] == QueryService.UNDEFINED) {
if (arr1[0] == QueryService.UNDEFINED) {
result = (arr2[0] == QueryService.UNDEFINED ? 0 : -1);
} else {
result = 1;
}
} else {
if (arr1[0] instanceof Number && arr2[0] instanceof Number) {
double diff = ((Number) arr1[0]).doubleValue() - ((Number) arr2[0]).doubleValue();
result = diff > 0 ? 1 : diff < 0 ? -1 : 0;
} else {
if (arr1[0] instanceof PdxString && arr2[0] instanceof String) {
arr2[0] = new PdxString((String) arr2[0]);
} else if (arr2[0] instanceof PdxString && arr1[0] instanceof String) {
arr1[0] = new PdxString((String) arr1[0]);
}
result = ((Comparable) arr1[0]).compareTo(arr2[0]);
}
}
// equals.
if (result == 0) {
continue;
} else {
// not equal, change the sign based on the order by type (asc,
// desc).
if (((Boolean) arr1[1]).booleanValue()) {
result = (result * -1);
}
return result;
}
}
QueryObserver observer = QueryObserverHolder.getInstance();
if (observer != null) {
observer.orderByColumnsEqual();
}
// The comparable fields are equal, so we check if the overall keys are
// equal or not
if (this.objType.isStructType()) {
int i = 0;
for (Object o1 : (Object[]) obj1) {
Object o2 = ((Object[]) obj2)[i++];
// Check for null value.
if (o1 == null || o2 == null) {
if (o1 == null) {
if (o2 == null) {
continue;
}
return -1;
} else {
return 1;
}
} else if (o1 == QueryService.UNDEFINED || o2 == QueryService.UNDEFINED) {
if (o1 == QueryService.UNDEFINED) {
if (o2 == QueryService.UNDEFINED) {
continue;
}
return -1;
} else {
return 1;
}
}
if (o1 instanceof Comparable) {
final int rslt;
if (o1 instanceof Number && o2 instanceof Number) {
double diff = ((Number) o1).doubleValue() - ((Number) o2).doubleValue();
rslt = diff > 0 ? 1 : diff < 0 ? -1 : 0;
} else {
if (o1 instanceof PdxString && o2 instanceof String) {
o2 = new PdxString((String) o2);
} else if (o2 instanceof PdxString && o1 instanceof String) {
o1 = new PdxString((String) o1);
}
rslt = ((Comparable) o1).compareTo(o2);
}
if (rslt == 0) {
continue;
} else {
return rslt;
}
} else if (!o1.equals(o2)) {
return -1;
}
}
return 0;
} else {
if (obj1 instanceof PdxString && obj2 instanceof String) {
obj2 = new PdxString((String) obj2);
} else if (obj2 instanceof PdxString && obj1 instanceof String) {
obj1 = new PdxString((String) obj1);
}
if (obj1 instanceof Comparable) {
return ((Comparable) obj1).compareTo(obj2);
} else {
return obj1.equals(obj2) ? 0 : -1;
}
}
}
}
return -1;
}
void addEvaluatedSortCriteria(Object row, ExecutionContext context)
throws FunctionDomainException, TypeMismatchException, NameResolutionException,
QueryInvocationTargetException {
// No op
}
}