| /* |
| * 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.hcatalog.data; |
| |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Properties; |
| import java.util.TreeMap; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.hive.serde.Constants; |
| import org.apache.hadoop.hive.serde2.SerDe; |
| import org.apache.hadoop.hive.serde2.SerDeException; |
| import org.apache.hadoop.hive.serde2.SerDeStats; |
| import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector; |
| import org.apache.hadoop.hive.serde2.objectinspector.MapObjectInspector; |
| import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector; |
| import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector; |
| import org.apache.hadoop.hive.serde2.objectinspector.StructField; |
| import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector; |
| import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector.Category; |
| import org.apache.hadoop.hive.serde2.typeinfo.StructTypeInfo; |
| import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo; |
| import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory; |
| import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoUtils; |
| import org.apache.hadoop.io.Writable; |
| import org.apache.hcatalog.common.HCatUtil; |
| |
| /** |
| * SerDe class for serializing to and from HCatRecord |
| */ |
| public class HCatRecordSerDe implements SerDe { |
| |
| public static final Log LOG = LogFactory |
| .getLog(HCatRecordSerDe.class.getName()); |
| |
| public HCatRecordSerDe() throws SerDeException{ |
| } |
| |
| private List<String> columnNames; |
| private List<TypeInfo> columnTypes; |
| private StructTypeInfo rowTypeInfo; |
| |
| private HCatRecordObjectInspector cachedObjectInspector; |
| |
| @Override |
| public void initialize(Configuration conf, Properties tbl) |
| throws SerDeException { |
| |
| if (LOG.isDebugEnabled()){ |
| LOG.debug("Initializing HCatRecordSerDe"); |
| HCatUtil.logEntrySet(LOG, "props to serde", tbl.entrySet()); |
| } |
| |
| // Get column names and types |
| String columnNameProperty = tbl.getProperty(Constants.LIST_COLUMNS); |
| String columnTypeProperty = tbl.getProperty(Constants.LIST_COLUMN_TYPES); |
| |
| // all table column names |
| if (columnNameProperty.length() == 0) { |
| columnNames = new ArrayList<String>(); |
| } else { |
| columnNames = Arrays.asList(columnNameProperty.split(",")); |
| } |
| |
| // all column types |
| if (columnTypeProperty.length() == 0) { |
| columnTypes = new ArrayList<TypeInfo>(); |
| } else { |
| columnTypes = TypeInfoUtils.getTypeInfosFromTypeString(columnTypeProperty); |
| } |
| |
| if (LOG.isDebugEnabled()){ |
| LOG.debug("columns:" + columnNameProperty); |
| for (String s : columnNames){ |
| LOG.debug("cn:"+s); |
| } |
| LOG.debug("types: " + columnTypeProperty); |
| for (TypeInfo t : columnTypes){ |
| LOG.debug("ct:"+t.getTypeName()+",type:"+t.getCategory()); |
| } |
| } |
| |
| |
| assert (columnNames.size() == columnTypes.size()); |
| |
| rowTypeInfo = (StructTypeInfo) TypeInfoFactory.getStructTypeInfo(columnNames, columnTypes); |
| |
| cachedObjectInspector = HCatRecordObjectInspectorFactory.getHCatRecordObjectInspector(rowTypeInfo); |
| |
| } |
| |
| /** |
| * The purpose of a deserialize method is to turn a data blob |
| * which is a writable representation of the data into an |
| * object that can then be parsed using the appropriate |
| * ObjectInspector. In this case, since HCatRecord is directly |
| * already the Writable object, there's no extra work to be done |
| * here. Most of the logic resides in the ObjectInspector to be |
| * able to return values from within the HCatRecord to hive when |
| * it wants it. |
| */ |
| @Override |
| public Object deserialize(Writable data) throws SerDeException { |
| if (!(data instanceof HCatRecord)) { |
| throw new SerDeException(getClass().getName() + ": expects HCatRecord!"); |
| } |
| |
| return (HCatRecord) data; |
| } |
| |
| /** |
| * The purpose of the serialize method is to turn an object-representation |
| * with a provided ObjectInspector into a Writable format, which |
| * the underlying layer can then use to write out. |
| * |
| * In this case, it means that Hive will call this method to convert |
| * an object with appropriate objectinspectors that it knows about, |
| * to write out a HCatRecord. |
| */ |
| @Override |
| public Writable serialize(Object obj, ObjectInspector objInspector) |
| throws SerDeException { |
| if (objInspector.getCategory() != Category.STRUCT) { |
| throw new SerDeException(getClass().toString() |
| + " can only serialize struct types, but we got: " |
| + objInspector.getTypeName()); |
| } |
| return new DefaultHCatRecord((List<Object>)serializeStruct(obj,(StructObjectInspector)objInspector)); |
| } |
| |
| |
| /** |
| * Return serialized HCatRecord from an underlying |
| * object-representation, and readable by an ObjectInspector |
| * @param obj : Underlying object-representation |
| * @param soi : StructObjectInspector |
| * @return HCatRecord |
| */ |
| private List<?> serializeStruct(Object obj, StructObjectInspector soi) |
| throws SerDeException { |
| |
| List<? extends StructField> fields = soi.getAllStructFieldRefs(); |
| List<Object> list = soi.getStructFieldsDataAsList(obj); |
| |
| List<Object> l = new ArrayList<Object>(fields.size()); |
| |
| if (fields != null){ |
| for (int i = 0; i < fields.size(); i++) { |
| |
| // Get the field objectInspector and the field object. |
| ObjectInspector foi = fields.get(i).getFieldObjectInspector(); |
| Object f = (list == null ? null : list.get(i)); |
| Object res = serializeField(f, foi); |
| l.add(i, res); |
| } |
| } |
| return l; |
| } |
| |
| /** |
| * Return underlying Java Object from an object-representation |
| * that is readable by a provided ObjectInspector. |
| */ |
| private Object serializeField(Object field, |
| ObjectInspector fieldObjectInspector) throws SerDeException { |
| Object res = null; |
| if (fieldObjectInspector.getCategory() == Category.PRIMITIVE){ |
| res = ((PrimitiveObjectInspector)fieldObjectInspector).getPrimitiveJavaObject(field); |
| } else if (fieldObjectInspector.getCategory() == Category.STRUCT){ |
| res = serializeStruct(field,(StructObjectInspector)fieldObjectInspector); |
| } else if (fieldObjectInspector.getCategory() == Category.LIST){ |
| res = serializeList(field,(ListObjectInspector)fieldObjectInspector); |
| } else if (fieldObjectInspector.getCategory() == Category.MAP){ |
| res = serializeMap(field,(MapObjectInspector)fieldObjectInspector); |
| } else { |
| throw new SerDeException(getClass().toString() |
| + " does not know what to do with fields of unknown category: " |
| + fieldObjectInspector.getCategory() + " , type: " + fieldObjectInspector.getTypeName()); |
| } |
| return res; |
| } |
| |
| /** |
| * Helper method to return underlying Java Map from |
| * an object-representation that is readable by a provided |
| * MapObjectInspector |
| */ |
| private Map<?,?> serializeMap(Object f, MapObjectInspector moi) throws SerDeException { |
| ObjectInspector koi = moi.getMapKeyObjectInspector(); |
| ObjectInspector voi = moi.getMapValueObjectInspector(); |
| Map<Object,Object> m = new TreeMap<Object, Object>(); |
| |
| Map<?, ?> readMap = moi.getMap(f); |
| if (readMap == null) { |
| return null; |
| } else { |
| for (Map.Entry<?, ?> entry: readMap.entrySet()) { |
| m.put(serializeField(entry.getKey(),koi), serializeField(entry.getValue(),voi)); |
| } |
| } |
| return m; |
| } |
| |
| private List<?> serializeList(Object f, ListObjectInspector loi) throws SerDeException { |
| List l = loi.getList(f); |
| ObjectInspector eloi = loi.getListElementObjectInspector(); |
| if (eloi.getCategory() == Category.PRIMITIVE){ |
| List<Object> list = new ArrayList<Object>(l.size()); |
| for(int i = 0; i < l.size(); i++){ |
| list.add(((PrimitiveObjectInspector)eloi).getPrimitiveJavaObject(l.get(i))); |
| } |
| return list; |
| } else if (eloi.getCategory() == Category.STRUCT){ |
| List<List<?>> list = new ArrayList<List<?>>(l.size()); |
| for (int i = 0 ; i < l.size() ; i++ ){ |
| list.add(serializeStruct(l.get(i), (StructObjectInspector) eloi)); |
| } |
| return list; |
| } else if (eloi.getCategory() == Category.LIST){ |
| List<List<?>> list = new ArrayList<List<?>>(l.size()); |
| for (int i = 0 ; i < l.size() ; i++ ){ |
| list.add(serializeList(l.get(i), (ListObjectInspector) eloi)); |
| } |
| return list; |
| } else if (eloi.getCategory() == Category.MAP){ |
| List<Map<?,?>> list = new ArrayList<Map<?,?>>(l.size()); |
| for (int i = 0 ; i < l.size() ; i++ ){ |
| list.add(serializeMap(l.get(i), (MapObjectInspector) eloi)); |
| } |
| return list; |
| } else { |
| throw new SerDeException(getClass().toString() |
| + " does not know what to do with fields of unknown category: " |
| + eloi.getCategory() + " , type: " + eloi.getTypeName()); |
| } |
| } |
| |
| /** |
| * Return an object inspector that can read through the object |
| * that we return from deserialize(). To wit, that means we need |
| * to return an ObjectInspector that can read HCatRecord, given |
| * the type info for it during initialize(). This also means |
| * that this method cannot and should not be called before initialize() |
| */ |
| @Override |
| public ObjectInspector getObjectInspector() throws SerDeException { |
| return (ObjectInspector) cachedObjectInspector; |
| } |
| |
| @Override |
| public Class<? extends Writable> getSerializedClass() { |
| return HCatRecord.class; |
| } |
| |
| @Override |
| public SerDeStats getSerDeStats() { |
| // no support for statistics yet |
| return null; |
| } |
| |
| } |