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.validate;
  
  import static org.apache.arrow.vector.validate.ValidateUtil.validateOrThrow;
  
  import org.apache.arrow.memory.ArrowBuf;
  import org.apache.arrow.vector.BaseFixedWidthVector;
  import org.apache.arrow.vector.BaseLargeVariableWidthVector;
  import org.apache.arrow.vector.BaseVariableWidthVector;
  import org.apache.arrow.vector.BaseVariableWidthViewVector;
  import org.apache.arrow.vector.ExtensionTypeVector;
  import org.apache.arrow.vector.NullVector;
  import org.apache.arrow.vector.ValueVector;
  import org.apache.arrow.vector.compare.VectorVisitor;
  import org.apache.arrow.vector.complex.DenseUnionVector;
  import org.apache.arrow.vector.complex.FixedSizeListVector;
  import org.apache.arrow.vector.complex.LargeListVector;
  import org.apache.arrow.vector.complex.ListVector;
  import org.apache.arrow.vector.complex.NonNullableStructVector;
  import org.apache.arrow.vector.complex.UnionVector;
  
  /** Utility for validating vector data. */
  public class ValidateVectorDataVisitor implements VectorVisitor<Void, Void> {
  
    private void validateOffsetBuffer(ValueVector vector, int valueCount) {
      if (valueCount == 0) {
        return;
      }
      ArrowBuf offsetBuffer = vector.getOffsetBuffer();
  
      // verify that the values in the offset buffer is non-decreasing
      int prevValue = offsetBuffer.getInt(0);
      for (int i = 1; i <= valueCount; i++) {
        int curValue = offsetBuffer.getInt(i * 4);
        validateOrThrow(
            curValue >= 0,
            "The value at position %s of the offset buffer is negative: %s.",
            i,
            curValue);
        validateOrThrow(
            curValue >= prevValue,
            "The values in positions %s and %s of the offset buffer are decreasing: %s, %s.",
            i - 1,
            i,
            prevValue,
            curValue);
        prevValue = curValue;
      }
    }
  
    private void validateLargeOffsetBuffer(ValueVector vector, int valueCount) {
      if (valueCount == 0) {
        return;
      }
      ArrowBuf offsetBuffer = vector.getOffsetBuffer();
  
      // verify that the values in the large offset buffer is non-decreasing
      long prevValue = offsetBuffer.getLong(0);
      for (int i = 1; i <= valueCount; i++) {
        long curValue = offsetBuffer.getLong((long) i * 8);
        validateOrThrow(
            curValue >= 0L,
            "The value at position %s of the large offset buffer is negative: %s.",
            i,
            curValue);
        validateOrThrow(
            curValue >= prevValue,
            "The values in positions %s and %s of the large offset buffer are decreasing: %s, %s.",
            i - 1,
            i,
            prevValue,
            curValue);
        prevValue = curValue;
      }
    }
  
    private void validateTypeBuffer(ArrowBuf typeBuf, int valueCount) {
      for (int i = 0; i < valueCount; i++) {
        validateOrThrow(
            typeBuf.getByte(i) >= 0,
            "The type id at position %s is negative: %s.",
            i,
            typeBuf.getByte(i));
      }
    }
  
    @Override
    public Void visit(BaseFixedWidthVector vector, Void value) {
      vector.validateScalars();
      return null;
    }
  
    @Override
    public Void visit(BaseVariableWidthVector vector, Void value) {
      validateOffsetBuffer(vector, vector.getValueCount());
      vector.validateScalars();
      return null;
    }
  
    @Override
    public Void visit(BaseLargeVariableWidthVector vector, Void value) {
      validateLargeOffsetBuffer(vector, vector.getValueCount());
      vector.validateScalars();
      return null;
    }
  
    @Override
    public Void visit(BaseVariableWidthViewVector vector, Void value) {
      throw new UnsupportedOperationException("View vectors are not supported.");
    }
  
    @Override
    public Void visit(ListVector vector, Void value) {
      validateOffsetBuffer(vector, vector.getValueCount());
      ValueVector innerVector = vector.getDataVector();
      if (innerVector != null) {
        innerVector.accept(this, null);
      }
      return null;
    }
  
    @Override
    public Void visit(FixedSizeListVector vector, Void value) {
      validateOffsetBuffer(vector, vector.getValueCount());
      ValueVector innerVector = vector.getDataVector();
      if (innerVector != null) {
        innerVector.accept(this, null);
      }
      return null;
    }
  
    @Override
    public Void visit(LargeListVector vector, Void value) {
      validateLargeOffsetBuffer(vector, vector.getValueCount());
      ValueVector innerVector = vector.getDataVector();
      if (innerVector != null) {
        innerVector.accept(this, null);
      }
      return null;
    }
  
    @Override
    public Void visit(NonNullableStructVector vector, Void value) {
      for (ValueVector subVector : vector.getChildrenFromFields()) {
        subVector.accept(this, null);
      }
      return null;
    }
  
    @Override
    public Void visit(UnionVector vector, Void value) {
      validateTypeBuffer(vector.getTypeBuffer(), vector.getValueCount());
      for (ValueVector subVector : vector.getChildrenFromFields()) {
        subVector.accept(this, null);
      }
      return null;
    }
  
    @Override
    public Void visit(DenseUnionVector vector, Void value) {
      validateTypeBuffer(vector.getTypeBuffer(), vector.getValueCount());
  
      // validate offset buffer
      for (int i = 0; i < vector.getValueCount(); i++) {
        int offset = vector.getOffset(i);
        byte typeId = vector.getTypeId(i);
        ValueVector subVector = vector.getVectorByType(typeId);
        validateOrThrow(
            offset < subVector.getValueCount(),
            "Dense union vector offset exceeds sub-vector boundary. Vector offset %s, sub vector size %s",
            offset,
            subVector.getValueCount());
      }
  
      for (ValueVector subVector : vector.getChildrenFromFields()) {
        subVector.accept(this, null);
      }
      return null;
    }
  
    @Override
    public Void visit(NullVector vector, Void value) {
      ValidateUtil.validateOrThrow(
          vector.getNullCount() == vector.getValueCount(),
          "NullVector should have only null entries.");
      return null;
    }
  
    @Override
    public Void visit(ExtensionTypeVector<?> vector, Void value) {
      vector.getUnderlyingVector().accept(this, value);
      return null;
    }
  }
  