/tags/release-0.1-rc2/hive/external/serde/src/java/org/apache/hadoop/hive/serde2/typeinfo/StructTypeInfo.java

/**

 * 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.typeinfo;



import java.io.Serializable;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;



import org.apache.hadoop.hive.serde.Constants;

import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector.Category;



/**

 * StructTypeInfo represents the TypeInfo of a struct. A struct contains one or

 * more fields each of which has a unique name and its own TypeInfo. Different

 * fields can have the same or different TypeInfo.

 * 

 * Always use the TypeInfoFactory to create new TypeInfo objects, instead of

 * directly creating an instance of this class.

 */

public final class StructTypeInfo extends TypeInfo implements Serializable {



  private static final long serialVersionUID = 1L;



  private ArrayList<String> allStructFieldNames;

  private ArrayList<TypeInfo> allStructFieldTypeInfos;



  /**

   * For java serialization use only.

   */

  public StructTypeInfo() {

  }



  @Override

  public String getTypeName() {

    StringBuilder sb = new StringBuilder();

    sb.append(Constants.STRUCT_TYPE_NAME + "<");

    for (int i = 0; i < allStructFieldNames.size(); i++) {

      if (i > 0) {

        sb.append(",");

      }

      sb.append(allStructFieldNames.get(i));

      sb.append(":");

      sb.append(allStructFieldTypeInfos.get(i).getTypeName());

    }

    sb.append(">");

    return sb.toString();

  }



  /**

   * For java serialization use only.

   */

  public void setAllStructFieldNames(ArrayList<String> allStructFieldNames) {

    this.allStructFieldNames = allStructFieldNames;

  }



  /**

   * For java serialization use only.

   */

  public void setAllStructFieldTypeInfos(

      ArrayList<TypeInfo> allStructFieldTypeInfos) {

    this.allStructFieldTypeInfos = allStructFieldTypeInfos;

  }



  /**

   * For TypeInfoFactory use only.

   */

  StructTypeInfo(List<String> names, List<TypeInfo> typeInfos) {

    allStructFieldNames = new ArrayList<String>();

    allStructFieldNames.addAll(names);

    allStructFieldTypeInfos = new ArrayList<TypeInfo>();

    allStructFieldTypeInfos.addAll(typeInfos);

  }



  @Override

  public Category getCategory() {

    return Category.STRUCT;

  }



  public ArrayList<String> getAllStructFieldNames() {

    return allStructFieldNames;

  }



  public ArrayList<TypeInfo> getAllStructFieldTypeInfos() {

    return allStructFieldTypeInfos;

  }



  public TypeInfo getStructFieldTypeInfo(String field) {

    String fieldLowerCase = field.toLowerCase();

    for (int i = 0; i < allStructFieldNames.size(); i++) {

      if (fieldLowerCase.equals(allStructFieldNames.get(i))) {

        return allStructFieldTypeInfos.get(i);

      }

    }

    throw new RuntimeException("cannot find field " + field

        + "(lowercase form: " + fieldLowerCase + ") in " + allStructFieldNames);

    // return null;

  }



  @Override

  public boolean equals(Object other) {

    if (this == other) {

      return true;

    }

    if (!(other instanceof StructTypeInfo)) {

      return false;

    }

    StructTypeInfo o = (StructTypeInfo) other;

    Iterator<String> namesIterator = getAllStructFieldNames().iterator();

    Iterator<String> otherNamesIterator = o.getAllStructFieldNames().iterator();



    // Compare the field names using ignore-case semantics

    while (namesIterator.hasNext() && otherNamesIterator.hasNext()) {

      if (!namesIterator.next().equalsIgnoreCase(otherNamesIterator.next())) {

        return false;

      }

    }



    // Different number of field names

    if (namesIterator.hasNext() || otherNamesIterator.hasNext()) {

      return false;

    }



    // Compare the field types

    return o.getAllStructFieldTypeInfos().equals(getAllStructFieldTypeInfos());

  }



  @Override

  public int hashCode() {

    return allStructFieldNames.hashCode() ^ allStructFieldTypeInfos.hashCode();

  }



}