private static TypedFieldId getFieldIdIfMatches()

in exec/java-exec/src/main/java/org/apache/drill/exec/vector/complex/FieldIdUtil.java [77:203]
114 lines of code
36 McCabe index (conditional complexity)

  private static TypedFieldId getFieldIdIfMatches(ValueVector vector, TypedFieldId.Builder builder,
                                                  boolean addToBreadCrumb, PathSegment seg, int depth) {
    if (vector instanceof DictVector) {
      builder.setDict(depth);
    } else if (vector instanceof RepeatedMapVector && seg != null && seg.isArray() && !seg.isLastPath()) {
      if (addToBreadCrumb) {
        addToBreadCrumb = false;
        builder.remainder(seg);
      }
      // skip the first array segment as there is no corresponding child vector.
      seg = seg.getChild();
      depth++;

      // multi-level numbered access to a repeated map is not possible so return if the next part is also an array
      // segment.
      if (seg.isArray()) {
        return null;
      }
    }

    if (seg == null) {
      if (addToBreadCrumb) {
        builder.intermediateType(vector.getField().getType());
      }
      return builder.finalType(vector.getField().getType()).build();
    }

    if (seg.isArray()) {
      if (seg.isLastPath()) {
        MajorType type;
        if (vector instanceof AbstractContainerVector) {
          type = ((AbstractContainerVector) vector).getLastPathType();
        } else if (vector instanceof RepeatedValueVector) {
          type = ((RepeatedValueVector) vector).getDataVector().getField().getType();
          builder.listVector(vector.getField().getType().getMinorType() == MinorType.LIST);
        } else {
          throw new UnsupportedOperationException("FieldIdUtil does not support vector of type " + vector.getField().getType());
        }
        builder //
                .withIndex() //
                .finalType(type);

        // remainder starts with the 1st array segment in SchemaPath.
        // only set remainder when it's the only array segment.
        if (addToBreadCrumb) {
          addToBreadCrumb = false;
          builder.remainder(seg);
        }
        return builder.build();
      } else {
        if (addToBreadCrumb) {
          addToBreadCrumb = false;
          builder.remainder(seg);
        }
      }
    } else {
      if (vector instanceof ListVector) {
        return null;
      }
    }

    ValueVector v;
    MajorType finalType = null;
    if (vector instanceof DictVector) {
      v = ((DictVector) vector).getValues();
      if (addToBreadCrumb) {
        builder.remainder(seg);
        builder.intermediateType(vector.getField().getType());
        addToBreadCrumb = false;
        // reset bit set and depth as this Dict vector will be the first one in the schema
        builder.resetDictBitSet();
        depth = 0;
        builder.setDict(depth);
      }
      finalType = ((DictVector) vector).getLastPathType();
    } else if (vector instanceof AbstractContainerVector) {
      String fieldName = null;
      if (seg.isNamed()) {
        fieldName = seg.getNameSegment().getPath();
      }
      VectorWithOrdinal vord = ((AbstractContainerVector) vector).getChildVectorWithOrdinal(fieldName);
      if (vord == null) {
        return null;
      }
      v = vord.vector;
      if (addToBreadCrumb) {
        builder.intermediateType(v.getField().getType());
        builder.addId(vord.ordinal);
      }
    } else if (vector instanceof ListVector || vector instanceof RepeatedDictVector) {
      v = ((RepeatedValueVector) vector).getDataVector();
    } else {
      throw new UnsupportedOperationException("FieldIdUtil does not support vector of type " + vector.getField().getType());
    }

    if (v instanceof AbstractContainerVector || v instanceof ListVector || v instanceof RepeatedDictVector) {
      return getFieldIdIfMatches(v, builder, addToBreadCrumb, seg.getChild(), depth + 1);
    } else if (v instanceof UnionVector) {
      return getFieldIdIfMatchesUnion((UnionVector) v, builder, addToBreadCrumb, seg.getChild());
    } else {
      if (seg.isNamed()) {
        if(addToBreadCrumb) {
          builder.intermediateType(v.getField().getType());
        }
        builder.finalType(finalType != null ? finalType : v.getField().getType());
      } else {
        builder.finalType(v.getField().getType().toBuilder().setMode(DataMode.OPTIONAL).build());
      }

      if (seg.isLastPath()) {
        return builder.build();
      } else {
        PathSegment child = seg.getChild();
        if (child.isLastPath() && child.isArray()) {
          if (addToBreadCrumb) {
            builder.remainder(child);
          }
          builder.withIndex();
          builder.finalType(v.getField().getType().toBuilder().setMode(DataMode.OPTIONAL).build());
          return builder.build();
        } else {
          logger.warn("You tried to request a complex type inside a scalar object or path or type is wrong.");
          return null;
        }
      }
    }
  }