hivesterix/hivesterix-dist/src/main/java/org/apache/hadoop/hive/serde2/lazy/objectinspector/LazyObjectInspectorFactory.java

/*
 * Copyright 2009-2013 by The Regents of the University of California
 * 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 from
 * 
 *     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.
 */
/**
 * 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.hadoop.hive.serde2.lazy.objectinspector;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.io.Text;

/**
 * ObjectInspectorFactory is the primary way to create new ObjectInspector
 * instances.
 * SerDe classes should call the static functions in this library to create an
 * ObjectInspector to return to the caller of SerDe2.getObjectInspector().
 * The reason of having caches here is that ObjectInspectors do not have an
 * internal state - so ObjectInspectors with the same construction parameters
 * should result in exactly the same ObjectInspector.
 */
public final class LazyObjectInspectorFactory {

    static ConcurrentHashMap<ArrayList<Object>, LazySimpleStructObjectInspector> cachedLazySimpleStructObjectInspector = new ConcurrentHashMap<ArrayList<Object>, LazySimpleStructObjectInspector>();

    public static LazySimpleStructObjectInspector getLazySimpleStructObjectInspector(List<String> structFieldNames,
            List<ObjectInspector> structFieldObjectInspectors, byte separator, Text nullSequence,
            boolean lastColumnTakesRest, boolean escaped, byte escapeChar) {
        ArrayList<Object> signature = new ArrayList<Object>();
        signature.add(structFieldNames);
        signature.add(structFieldObjectInspectors);
        signature.add(Byte.valueOf(separator));
        signature.add(nullSequence.toString());
        signature.add(Boolean.valueOf(lastColumnTakesRest));
        signature.add(Boolean.valueOf(escaped));
        signature.add(Byte.valueOf(escapeChar));
        LazySimpleStructObjectInspector result = cachedLazySimpleStructObjectInspector.get(signature);
        if (result == null) {
            result = new LazySimpleStructObjectInspector(structFieldNames, structFieldObjectInspectors, separator,
                    nullSequence, lastColumnTakesRest, escaped, escapeChar);
            cachedLazySimpleStructObjectInspector.put(signature, result);
        }
        return result;
    }

    static ConcurrentHashMap<ArrayList<Object>, LazyListObjectInspector> cachedLazySimpleListObjectInspector = new ConcurrentHashMap<ArrayList<Object>, LazyListObjectInspector>();

    public static LazyListObjectInspector getLazySimpleListObjectInspector(ObjectInspector listElementObjectInspector,
            byte separator, Text nullSequence, boolean escaped, byte escapeChar) {
        ArrayList<Object> signature = new ArrayList<Object>();
        signature.add(listElementObjectInspector);
        signature.add(Byte.valueOf(separator));
        signature.add(nullSequence.toString());
        signature.add(Boolean.valueOf(escaped));
        signature.add(Byte.valueOf(escapeChar));
        LazyListObjectInspector result = cachedLazySimpleListObjectInspector.get(signature);
        if (result == null) {
            result = new LazyListObjectInspector(listElementObjectInspector, separator, nullSequence, escaped,
                    escapeChar);
            cachedLazySimpleListObjectInspector.put(signature, result);
        }
        return result;
    }

    static ConcurrentHashMap<ArrayList<Object>, LazyMapObjectInspector> cachedLazySimpleMapObjectInspector = new ConcurrentHashMap<ArrayList<Object>, LazyMapObjectInspector>();

    public static LazyMapObjectInspector getLazySimpleMapObjectInspector(ObjectInspector mapKeyObjectInspector,
            ObjectInspector mapValueObjectInspector, byte itemSeparator, byte keyValueSeparator, Text nullSequence,
            boolean escaped, byte escapeChar) {
        ArrayList<Object> signature = new ArrayList<Object>();
        signature.add(mapKeyObjectInspector);
        signature.add(mapValueObjectInspector);
        signature.add(Byte.valueOf(itemSeparator));
        signature.add(Byte.valueOf(keyValueSeparator));
        signature.add(nullSequence.toString());
        signature.add(Boolean.valueOf(escaped));
        signature.add(Byte.valueOf(escapeChar));
        LazyMapObjectInspector result = cachedLazySimpleMapObjectInspector.get(signature);
        if (result == null) {
            result = new LazyMapObjectInspector(mapKeyObjectInspector, mapValueObjectInspector, itemSeparator,
                    keyValueSeparator, nullSequence, escaped, escapeChar);
            cachedLazySimpleMapObjectInspector.put(signature, result);
        }
        return result;
    }

    static ConcurrentHashMap<List<Object>, LazyUnionObjectInspector> cachedLazyUnionObjectInspector = new ConcurrentHashMap<List<Object>, LazyUnionObjectInspector>();

    public static LazyUnionObjectInspector getLazyUnionObjectInspector(List<ObjectInspector> ois, byte separator,
            Text nullSequence, boolean escaped, byte escapeChar) {
        List<Object> signature = new ArrayList<Object>();
        signature.add(ois);
        signature.add(Byte.valueOf(separator));
        signature.add(nullSequence.toString());
        signature.add(Boolean.valueOf(escaped));
        signature.add(Byte.valueOf(escapeChar));
        LazyUnionObjectInspector result = cachedLazyUnionObjectInspector.get(signature);
        if (result == null) {
            result = new LazyUnionObjectInspector(ois, separator, nullSequence, escaped, escapeChar);
            cachedLazyUnionObjectInspector.put(signature, result);
        }
        return result;
    }

    private LazyObjectInspectorFactory() {
        // prevent instantiation
    }
}