content: /*
   * 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.asterix.dataflow.data.nontagged.serde;
  
  import java.io.DataInput;
  import java.io.DataOutput;
  import java.io.IOException;
  
  import org.apache.asterix.common.exceptions.CompilationException;
  import org.apache.asterix.common.exceptions.ErrorCode;
  import org.apache.asterix.dataflow.data.common.TaggedValueReference;
  import org.apache.asterix.om.base.AInt32;
  import org.apache.asterix.om.base.IAObject;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.om.types.EnumDeserializer;
  import org.apache.asterix.om.types.IAType;
  import org.apache.asterix.om.utils.NonTaggedFormatUtil;
  import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
  
  public final class SerializerDeserializerUtil {
  
      private SerializerDeserializerUtil() {
          throw new AssertionError("do not instantiate");
      }
  
      public static void writeIntToByteArray(byte[] array, int value, int offset) {
          array[offset] = (byte) (0xff & (value >> 24));
          array[offset + 1] = (byte) (0xff & (value >> 16));
          array[offset + 2] = (byte) (0xff & (value >> 8));
          array[offset + 3] = (byte) (0xff & value);
      }
  
      public static void writeShortToByteArray(byte[] array, short value, int offset) {
          array[offset] = (byte) (0xff & (value >> 8));
          array[offset + 1] = (byte) (0xff & value);
      }
  
      public static int readIntFromByteArray(byte[] array) {
          int value = 0;
          for (int i = 0; i < 4; i++) {
              int shift = (3 - i) * 8;
              value += (array[i] & 0x000000FF) << shift;
          }
          return value;
      }
  
      public static short readShortFromByteArray(byte[] array) {
          short value = 0;
          for (int i = 0; i < 2; i++) {
              int shift = (1 - i) * 8;
              value += (array[i] & 0x000000FF) << shift;
          }
          return value;
      }
  
      public static void serializeTag(IAObject instance, DataOutput out) throws HyracksDataException {
          IAType t = instance.getType();
          serializeTag(t.getTypeTag(), out);
      }
  
      public static void serializeTag(ATypeTag tag, DataOutput out) throws HyracksDataException {
          try {
              out.writeByte(tag.serialize());
          } catch (IOException e) {
              throw HyracksDataException.create(e);
          }
      }
  
      public static ATypeTag deserializeTag(DataInput in) throws HyracksDataException {
          try {
              return EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(in.readByte());
          } catch (IOException e) {
              throw HyracksDataException.create(e);
          }
      }
  
      /**
       * Computes and returns the byte array for an integer value.
       */
      public static byte[] computeByteArrayForIntValue(int value) throws AlgebricksException {
          ArrayBackedValueStorage castBuffer = new ArrayBackedValueStorage();
          try {
              AInt32 val = new AInt32(value);
              SerializerDeserializerUtil.serializeTag(val, castBuffer.getDataOutput());
              AInt32SerializerDeserializer.INSTANCE.serialize(val, castBuffer.getDataOutput());
          } catch (HyracksDataException e) {
              throw CompilationException.create(ErrorCode.CANNOT_SERIALIZE_A_VALUE, e);
          }
          return castBuffer.getByteArray();
      }
  
      public static int getNumberOfItemsNonTagged(TaggedValueReference list) {
          // 5 = itemTag (1) + list size (4)
          return AInt32SerializerDeserializer.getInt(list.getByteArray(), list.getStartOffset() + 5);
      }
  
      public static int getItemOffset(byte[] listBytes, int offset, int itemIndex) throws HyracksDataException {
          ATypeTag itemTag = EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(listBytes[offset + 1]);
          // 10 = tag (1) + itemTag (1) + list size (4) + number of items (4)
          if (NonTaggedFormatUtil.isFixedSizedCollection(itemTag)) {
              int valueLength = NonTaggedFormatUtil.getFieldValueLength(listBytes, offset + 1, itemTag, true);
              return offset + 10 + (valueLength * itemIndex);
          } else {
              return offset + AInt32SerializerDeserializer.getInt(listBytes, offset + 10 + (4 * itemIndex));
          }
      }
  
      public static int getItemOffsetNonTagged(TaggedValueReference list, int itemIndex) throws HyracksDataException {
          byte[] listValueBytes = list.getByteArray();
          int offset = list.getStartOffset();
          ATypeTag itemTag = EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(listValueBytes[offset]);
          // 9 = itemTag (1) + list size (4) + number of items (4)
          if (NonTaggedFormatUtil.isFixedSizedCollection(itemTag)) {
              int valueLength = NonTaggedFormatUtil.getFieldValueLength(listValueBytes, offset, itemTag, true);
              return offset + 9 + (valueLength * itemIndex);
          } else {
              // the -1 is due to the fact that the item encoded offset is measured from a tagged list
              return offset + AInt32SerializerDeserializer.getInt(listValueBytes, offset + 9 + (4 * itemIndex)) - 1;
          }
      }
  }
  