/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* 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 com.hazelcast.query.impl;
import com.hazelcast.core.TypeConverter;
import com.hazelcast.internal.serialization.InternalSerializationService;
import com.hazelcast.nio.serialization.Data;
import com.hazelcast.nio.serialization.Portable;
import com.hazelcast.query.QueryException;
import com.hazelcast.query.impl.getters.Extractors;
import com.hazelcast.query.impl.getters.MultiResult;
import com.hazelcast.query.impl.getters.ReflectionHelper;
import java.util.Map;
import static com.hazelcast.query.QueryConstants.KEY_ATTRIBUTE_NAME;
import static com.hazelcast.query.QueryConstants.THIS_ATTRIBUTE_NAME;
import static com.hazelcast.query.impl.TypeConverters.IDENTITY_CONVERTER;
import static com.hazelcast.query.impl.TypeConverters.NULL_CONVERTER;
/**
* This abstract class contains methods related to Queryable Entry, which means searched an indexed by SQL query or predicate.
* <p/>
* If the object, which is used as the extraction target, is not of Data or Portable type the serializationService
* will not be touched at all.
*/
public abstract class QueryableEntry<K, V> implements Extractable, Map.Entry<K, V> {
protected InternalSerializationService serializationService;
protected Extractors extractors;
@Override
public Object getAttributeValue(String attributeName) throws QueryException {
return extractAttributeValue(attributeName);
}
@Override
public AttributeType getAttributeType(String attributeName) throws QueryException {
return extractAttributeType(attributeName);
}
public abstract V getValue();
public abstract K getKey();
public abstract Data getKeyData();
public abstract Data getValueData();
protected abstract Object getTargetObject(boolean key);
TypeConverter getConverter(String attributeName) {
Object attribute = getAttributeValue(attributeName);
if (attribute == null) {
return NULL_CONVERTER;
} else {
AttributeType attributeType = extractAttributeType(attributeName, attribute);
return attributeType == null ? IDENTITY_CONVERTER : attributeType.getConverter();
}
}
private Object extractAttributeValue(String attributeName) throws QueryException {
Object result = extractAttributeValueIfAttributeQueryConstant(attributeName);
if (result == null) {
boolean isKey = startsWithKeyConstant(attributeName);
attributeName = getAttributeName(isKey, attributeName);
Object target = getTargetObject(isKey);
result = extractAttributeValueFromTargetObject(extractors, serializationService, attributeName, target);
}
return result;
}
/**
* Optimized version of the other extractAttributeValueIfAttributeQueryConstant() method that uses getKey() and
* getValue() calls that may cache their results internally - like in CachedQueryEntry.
*/
private Object extractAttributeValueIfAttributeQueryConstant(String attributeName) {
if (KEY_ATTRIBUTE_NAME.value().equals(attributeName)) {
return getKey();
} else if (THIS_ATTRIBUTE_NAME.value().equals(attributeName)) {
return getValue();
}
return null;
}
/**
* Static version of the extractAttributeValue() method used when the caller does not have
* an instance of the QueryableEntry, but is in possession of key and value.
*/
static Object extractAttributeValue(Extractors extractors, InternalSerializationService serializationService,
String attributeName, Data key, Object value) throws QueryException {
Object result = extractAttributeValueIfAttributeQueryConstant(serializationService, attributeName, key, value);
if (result == null) {
boolean isKey = startsWithKeyConstant(attributeName);
attributeName = getAttributeName(isKey, attributeName);
Object target = isKey ? key : value;
result = extractAttributeValueFromTargetObject(extractors, serializationService, attributeName, target);
}
return result;
}
/**
* Static version of the extractAttributeValueIfAttributeQueryConstant() method that needs key and value upfront.
*/
private static Object extractAttributeValueIfAttributeQueryConstant(InternalSerializationService serializationService,
String attributeName, Data key, Object value) {
if (KEY_ATTRIBUTE_NAME.value().equals(attributeName)) {
return serializationService.toObject(key);
} else if (THIS_ATTRIBUTE_NAME.value().equals(attributeName)) {
return value instanceof Data ? serializationService.toObject(value) : value;
}
return null;
}
private static boolean startsWithKeyConstant(String attributeName) {
return attributeName.startsWith(KEY_ATTRIBUTE_NAME.value());
}
private static String getAttributeName(boolean isKey, String attributeName) {
if (isKey) {
return attributeName.substring(KEY_ATTRIBUTE_NAME.value().length() + 1);
} else {
return attributeName;
}
}
private static Object extractAttributeValueFromTargetObject(Extractors extractors,
InternalSerializationService serializationService,
String attributeName, Object target) {
return extractors.extract(serializationService, target, attributeName);
}
private AttributeType extractAttributeType(String attributeName) {
AttributeType result = extractAttributeTypeIfAttributeQueryConstant(attributeName);
if (result == null) {
Object attributeValue = extractAttributeValue(attributeName);
result = extractAttributeType(attributeValue);
}
return result;
}
/**
* Optimization of the extractAttributeType that accepts extracted attribute value to skip double extraction.
*/
private AttributeType extractAttributeType(String attributeName, Object attributeValue) {
AttributeType result = extractAttributeTypeIfAttributeQueryConstant(attributeName);
if (result == null) {
result = extractAttributeType(attributeValue);
}
return result;
}
private AttributeType extractAttributeTypeIfAttributeQueryConstant(String attributeName) {
if (KEY_ATTRIBUTE_NAME.value().equals(attributeName)) {
return ReflectionHelper.getAttributeType(getKey().getClass());
} else if (THIS_ATTRIBUTE_NAME.value().equals(attributeName)) {
return ReflectionHelper.getAttributeType(getValue().getClass());
}
return null;
}
private AttributeType extractAttributeType(Object attributeValue) {
if (attributeValue instanceof MultiResult) {
return extractAttributeTypeFromMultiResult((MultiResult) attributeValue);
} else {
return extractAttributeTypeFromSingleResult(attributeValue);
}
}
private AttributeType extractAttributeTypeFromSingleResult(Object extractedSingleResult) {
if (extractedSingleResult == null) {
return null;
}
if (extractedSingleResult instanceof Portable) {
return AttributeType.PORTABLE;
}
return ReflectionHelper.getAttributeType(extractedSingleResult.getClass());
}
private AttributeType extractAttributeTypeFromMultiResult(MultiResult extractedMultiResult) {
Object firstNonNullResult = null;
for (Object result : extractedMultiResult.getResults()) {
if (result != null) {
firstNonNullResult = result;
break;
}
}
if (firstNonNullResult == null) {
return null;
}
return ReflectionHelper.getAttributeType(firstNonNullResult.getClass());
}
}