private void loadBuffers()

in vector/src/main/java/org/apache/arrow/vector/VectorLoader.java [102:164]
60 lines of code
12 McCabe index (conditional complexity)

  private void loadBuffers(
      FieldVector vector,
      Field field,
      Iterator<ArrowBuf> buffers,
      Iterator<ArrowFieldNode> nodes,
      CompressionCodec codec,
      Iterator<Long> variadicBufferCounts) {
    checkArgument(nodes.hasNext(), "no more field nodes for field %s and vector %s", field, vector);
    ArrowFieldNode fieldNode = nodes.next();
    // variadicBufferLayoutCount will be 0 for vectors of a type except BaseVariableWidthViewVector
    long variadicBufferLayoutCount = 0;
    if (vector instanceof BaseVariableWidthViewVector) {
      if (variadicBufferCounts.hasNext()) {
        variadicBufferLayoutCount = variadicBufferCounts.next();
      } else {
        throw new IllegalStateException(
            "No variadicBufferCounts available for BaseVariableWidthViewVector");
      }
    }
    int bufferLayoutCount =
        (int) (variadicBufferLayoutCount + TypeLayout.getTypeBufferCount(field.getType()));
    List<ArrowBuf> ownBuffers = new ArrayList<>(bufferLayoutCount);
    for (int j = 0; j < bufferLayoutCount; j++) {
      if (!buffers.hasNext()) {
        throw new IllegalArgumentException(
            "no more buffers for field " + field + ". Expected " + bufferLayoutCount);
      }
      ArrowBuf nextBuf = buffers.next();
      // for vectors without nulls, the buffer is empty, so there is no need to decompress it.
      ArrowBuf bufferToAdd =
          nextBuf.writerIndex() > 0 ? codec.decompress(vector.getAllocator(), nextBuf) : nextBuf;
      ownBuffers.add(bufferToAdd);
      if (decompressionNeeded) {
        // decompression performed
        nextBuf.getReferenceManager().retain();
      }
    }
    try {
      vector.loadFieldBuffers(fieldNode, ownBuffers);
      if (decompressionNeeded) {
        for (ArrowBuf buf : ownBuffers) {
          buf.close();
        }
      }
    } catch (RuntimeException e) {
      throw new IllegalArgumentException(
          "Could not load buffers for field " + field + ". error message: " + e.getMessage(), e);
    }
    List<Field> children = field.getChildren();
    if (children.size() > 0) {
      List<FieldVector> childrenFromFields = vector.getChildrenFromFields();
      checkArgument(
          children.size() == childrenFromFields.size(),
          "should have as many children as in the schema: found %s expected %s",
          childrenFromFields.size(),
          children.size());
      for (int i = 0; i < childrenFromFields.size(); i++) {
        Field child = children.get(i);
        FieldVector fieldVector = childrenFromFields.get(i);
        loadBuffers(fieldVector, child, buffers, nodes, codec, variadicBufferCounts);
      }
    }
  }