private void allocateVectorBasedOnTypeName()

in arrow/src/main/java/org/apache/iceberg/arrow/vectorized/VectorizedArrowReader.java [346:429]
80 lines of code
10 McCabe index (conditional complexity)

  private void allocateVectorBasedOnTypeName(PrimitiveType primitive, Field arrowField) {
    switch (primitive.getPrimitiveTypeName()) {
      case FIXED_LEN_BYTE_ARRAY:
        int len;
        if (icebergField.type() instanceof Types.UUIDType) {
          len = 16;
          this.readType = ReadType.UUID;
        } else {
          len = ((Types.FixedType) icebergField.type()).length();
          this.readType = ReadType.FIXED_WIDTH_BINARY;
        }
        this.vec = arrowField.createVector(rootAlloc);
        vec.setInitialCapacity(batchSize * len);
        vec.allocateNew();
        this.typeWidth = len;
        break;
      case BINARY:
        this.vec = arrowField.createVector(rootAlloc);
        // TODO: Possibly use the uncompressed page size info to set the initial capacity
        vec.setInitialCapacity(batchSize * AVERAGE_VARIABLE_WIDTH_RECORD_SIZE);
        vec.allocateNewSafe();
        this.readType = ReadType.VARBINARY;
        this.typeWidth = UNKNOWN_WIDTH;
        break;
      case INT32:
        Field intField =
            new Field(
                icebergField.name(),
                new FieldType(
                    icebergField.isOptional(), new ArrowType.Int(Integer.SIZE, true), null, null),
                null);
        this.vec = intField.createVector(rootAlloc);
        ((IntVector) vec).allocateNew(batchSize);
        this.readType = ReadType.INT;
        this.typeWidth = (int) IntVector.TYPE_WIDTH;
        break;
      case INT96:
        // Impala & Spark used to write timestamps as INT96 by default. For backwards
        // compatibility we try to read INT96 as timestamps. But INT96 is not recommended
        // and deprecated (see https://issues.apache.org/jira/browse/PARQUET-323)
        int length = BigIntVector.TYPE_WIDTH;
        this.readType = ReadType.TIMESTAMP_INT96;
        this.vec = arrowField.createVector(rootAlloc);
        vec.setInitialCapacity(batchSize * length);
        vec.allocateNew();
        this.typeWidth = length;
        break;
      case FLOAT:
        Field floatField =
            new Field(
                icebergField.name(),
                new FieldType(
                    icebergField.isOptional(),
                    new ArrowType.FloatingPoint(FloatingPointPrecision.SINGLE),
                    null,
                    null),
                null);
        this.vec = floatField.createVector(rootAlloc);
        ((Float4Vector) vec).allocateNew(batchSize);
        this.readType = ReadType.FLOAT;
        this.typeWidth = (int) Float4Vector.TYPE_WIDTH;
        break;
      case BOOLEAN:
        this.vec = arrowField.createVector(rootAlloc);
        ((BitVector) vec).allocateNew(batchSize);
        this.readType = ReadType.BOOLEAN;
        this.typeWidth = UNKNOWN_WIDTH;
        break;
      case INT64:
        this.vec = arrowField.createVector(rootAlloc);
        ((BigIntVector) vec).allocateNew(batchSize);
        this.readType = ReadType.LONG;
        this.typeWidth = (int) BigIntVector.TYPE_WIDTH;
        break;
      case DOUBLE:
        this.vec = arrowField.createVector(rootAlloc);
        ((Float8Vector) vec).allocateNew(batchSize);
        this.readType = ReadType.DOUBLE;
        this.typeWidth = (int) Float8Vector.TYPE_WIDTH;
        break;
      default:
        throw new UnsupportedOperationException("Unsupported type: " + primitive);
    }
  }