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.arrow.vector;
  
  import static org.apache.arrow.vector.NullCheckingForGet.NULL_CHECKING_ENABLED;
  
  import org.apache.arrow.memory.BufferAllocator;
  import org.apache.arrow.memory.ReusableBuffer;
  import org.apache.arrow.vector.complex.impl.ViewVarCharReaderImpl;
  import org.apache.arrow.vector.complex.reader.FieldReader;
  import org.apache.arrow.vector.holders.NullableViewVarCharHolder;
  import org.apache.arrow.vector.holders.ViewVarCharHolder;
  import org.apache.arrow.vector.types.Types.MinorType;
  import org.apache.arrow.vector.types.pojo.Field;
  import org.apache.arrow.vector.types.pojo.FieldType;
  import org.apache.arrow.vector.util.Text;
  import org.apache.arrow.vector.util.TransferPair;
  import org.apache.arrow.vector.validate.ValidateUtil;
  
  /**
   * ViewVarCharVector implements a view of a variable width vector of VARCHAR values which could be
   * NULL. A validity buffer (bit vector) is maintained to track which elements in the vector are
   * null. A viewBuffer keeps track of all values in the vector, and an external data buffer is kept
   * to keep longer strings (>12).
   */
  public final class ViewVarCharVector extends BaseVariableWidthViewVector
      implements ValueIterableVector<Text> {
  
    /**
     * Instantiate a ViewVarCharVector. This doesn't allocate any memory for the data in vector.
     *
     * @param name name of the vector
     * @param allocator allocator for memory management.
     */
    public ViewVarCharVector(String name, BufferAllocator allocator) {
      this(name, FieldType.nullable(MinorType.VIEWVARCHAR.getType()), allocator);
    }
  
    /**
     * Instantiate a ViewVarCharVector. This doesn't allocate any memory for the data in vector.
     *
     * @param name name of the vector
     * @param fieldType type of Field materialized by this vector
     * @param allocator allocator for memory management.
     */
    public ViewVarCharVector(String name, FieldType fieldType, BufferAllocator allocator) {
      this(new Field(name, fieldType, null), allocator);
    }
  
    /**
     * Instantiate a ViewVarCharVector. This doesn't allocate any memory for the data in vector.
     *
     * @param field field materialized by this vector
     * @param allocator allocator for memory management.
     */
    public ViewVarCharVector(Field field, BufferAllocator allocator) {
      super(field, allocator);
    }
  
    @Override
    protected FieldReader getReaderImpl() {
      return new ViewVarCharReaderImpl(ViewVarCharVector.this);
    }
  
    /**
     * Get a minor type for this vector. The vector holds values belonging to a particular type.
     *
     * @return {@link org.apache.arrow.vector.types.Types.MinorType}
     */
    @Override
    public MinorType getMinorType() {
      return MinorType.VIEWVARCHAR;
    }
  
    /*----------------------------------------------------------------*
    |                                                                |
    |          vector value retrieval methods                        |
    |                                                                |
    *----------------------------------------------------------------*/
  
    /**
     * Get the variable length element at specified index as a byte array.
     *
     * @param index position of an element to get
     * @return array of bytes for a non-null element, null otherwise
     */
    public byte[] get(int index) {
      assert index >= 0;
      if (NULL_CHECKING_ENABLED && isSet(index) == 0) {
        return null;
      }
      return getData(index);
    }
  
    /**
     * Get the variable length element at specified index as Text.
     *
     * @param index position of an element to get
     * @return Text object for a non-null element, null otherwise
     */
    @Override
    public Text getObject(int index) {
      assert index >= 0;
      if (isSet(index) == 0) {
        return null;
      }
  
      final Text result = new Text();
      read(index, result);
      return result;
    }
  
    /**
     * Read the value at the given position to the given output buffer. The caller is responsible for
     * checking for nullity first.
     *
     * @param index position of an element.
     * @param buffer the buffer to write into.
     */
    @Override
    public void read(int index, ReusableBuffer<?> buffer) {
      getData(index, buffer);
    }
  
    /**
     * Get the variable length element at specified index and sets the state in provided holder.
     *
     * @param index position of an element to get
     * @param holder data holder to be populated by this function
     */
    public void get(int index, NullableViewVarCharHolder holder) {
      final int dataLength = getValueLength(index);
      if (isSet(index) == 0) {
        holder.isSet = 0;
        return;
      }
      holder.isSet = 1;
      if (dataLength > INLINE_SIZE) {
        // data is in the data buffer
        // get buffer index
        final int bufferIndex =
            viewBuffer.getInt(((long) index * ELEMENT_SIZE) + LENGTH_WIDTH + PREFIX_WIDTH);
        // get data offset
        final int dataOffset =
            viewBuffer.getInt(
                ((long) index * ELEMENT_SIZE) + LENGTH_WIDTH + PREFIX_WIDTH + BUF_INDEX_WIDTH);
        holder.buffer = dataBuffers.get(bufferIndex);
        holder.start = dataOffset;
        holder.end = dataOffset + dataLength;
      } else {
        final long dataOffset = ((long) index * ELEMENT_SIZE) + LENGTH_WIDTH;
        // data is in the value buffer
        holder.buffer = viewBuffer;
        holder.start = (int) dataOffset;
        holder.end = (int) dataOffset + dataLength;
      }
    }
  
    /*----------------------------------------------------------------*
    |                                                                |
    |          vector value setter methods                           |
    |                                                                |
    *----------------------------------------------------------------*/
  
    /**
     * Set the variable length element at the specified index to the data buffer supplied in the
     * holder.
     *
     * @param index position of the element to set
     * @param holder holder that carries data buffer.
     */
    public void set(int index, ViewVarCharHolder holder) {
      int start = holder.start;
      int length = holder.end - start;
      setBytes(index, holder.buffer, start, length);
      lastSet = index;
    }
  
    /**
     * Same as {@link #set(int, ViewVarCharHolder)} except that it handles the case where index and
     * length of a new element are beyond the existing capacity of the vector.
     *
     * @param index position of the element to set
     * @param holder holder that carries data buffer.
     */
    public void setSafe(int index, ViewVarCharHolder holder) {
      int length = holder.end - holder.start;
      handleSafe(index, length);
      set(index, holder);
    }
  
    /**
     * Set the variable length element at the specified index to the data buffer supplied in the
     * holder.
     *
     * @param index position of the element to set
     * @param holder holder that carries data buffer.
     */
    public void set(int index, NullableViewVarCharHolder holder) {
      if (holder.isSet == 0) {
        setNull(index);
      } else {
        BitVectorHelper.setBit(validityBuffer, index);
        int start = holder.start;
        int length = holder.end - start;
        setBytes(index, holder.buffer, start, length);
      }
      lastSet = index;
    }
  
    /**
     * Same as {@link #set(int, NullableViewVarCharHolder)} except that it handles the case where
     * index and length of a new element are beyond the existing capacity of the vector.
     *
     * @param index position of the element to set
     * @param holder holder that carries data buffer.
     */
    public void setSafe(int index, NullableViewVarCharHolder holder) {
      int length = holder.end - holder.start;
      handleSafe(index, length);
      set(index, holder);
    }
  
    /**
     * Set the variable length element at the specified index to the content in supplied Text.
     *
     * @param index position of the element to set
     * @param text Text object with data
     */
    public void set(int index, Text text) {
      set(index, text.getBytes(), 0, (int) text.getLength());
    }
  
    /**
     * Same as {@link #set(int, NullableViewVarCharHolder)} except that it handles the case where
     * index and length of a new element are beyond the existing capacity of the vector.
     *
     * @param index position of the element to set.
     * @param text Text object with data
     */
    public void setSafe(int index, Text text) {
      setSafe(index, text.getBytes(), 0, (int) text.getLength());
    }
  
    @Override
    public void validateScalars() {
      for (int i = 0; i < getValueCount(); ++i) {
        byte[] value = get(i);
        if (value != null) {
          ValidateUtil.validateOrThrow(
              Text.validateUTF8NoThrow(value),
              "Non-UTF-8 data in VarCharVector at position " + i + ".");
        }
      }
    }
  
    /*----------------------------------------------------------------*
    |                                                                |
    |                      vector transfer                           |
    |                                                                |
    *----------------------------------------------------------------*/
  
    /**
     * Construct a TransferPair comprising this and a target vector of the same type.
     *
     * @param ref name of the target vector
     * @param allocator allocator for the target vector
     * @return {@link TransferPair} (UnsupportedOperationException)
     */
    @Override
    public TransferPair getTransferPair(String ref, BufferAllocator allocator) {
      return new TransferImpl(ref, allocator);
    }
  
    /**
     * Construct a TransferPair with a desired target vector of the same type.
     *
     * @param field The field materialized by this vector.
     * @param allocator allocator for the target vector
     * @return {@link TransferPair} (UnsupportedOperationException)
     */
    @Override
    public TransferPair getTransferPair(Field field, BufferAllocator allocator) {
      return new TransferImpl(field, allocator);
    }
  
    /**
     * Construct a TransferPair with a desired target vector of the same type.
     *
     * @param to the target for the transfer
     * @return {@link TransferPair} (UnsupportedOperationException)
     */
    @Override
    public TransferPair makeTransferPair(ValueVector to) {
      return new TransferImpl((ViewVarCharVector) to);
    }
  
    private class TransferImpl implements TransferPair {
      ViewVarCharVector to;
  
      public TransferImpl(String ref, BufferAllocator allocator) {
        to = new ViewVarCharVector(ref, field.getFieldType(), allocator);
      }
  
      public TransferImpl(Field field, BufferAllocator allocator) {
        to = new ViewVarCharVector(field, allocator);
      }
  
      public TransferImpl(ViewVarCharVector to) {
        this.to = to;
      }
  
      @Override
      public ViewVarCharVector getTo() {
        return to;
      }
  
      @Override
      public void transfer() {
        transferTo(to);
      }
  
      @Override
      public void splitAndTransfer(int startIndex, int length) {
        splitAndTransferTo(startIndex, length, to);
      }
  
      @Override
      public void copyValueSafe(int fromIndex, int toIndex) {
        to.copyFromSafe(fromIndex, toIndex, ViewVarCharVector.this);
      }
    }
  }
  