private def extractQueryAndLiterals()

in hudi-spark-datasource/hudi-spark-common/src/main/scala/org/apache/hudi/ExpressionIndexSupport.scala [440:490]
51 lines of code
53 McCabe index (conditional complexity)

  private def extractQueryAndLiterals(queryFilters: Seq[Expression], indexDefinition: HoodieIndexDefinition): Option[(Expression, List[String])] = {
    val attributeFetcher = (expr: Expression) => {
      expr match {
        case expression: UnaryExpression => expression.child
        case expression: DateFormatClass if expression.right.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexFormatOption()) =>
          expression.left
        case expression: FromUnixTime
          if expression.format.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexFormatOption(TimestampFormatter.defaultPattern())) =>
          expression.sec
        case expression: UnixTimestamp if expression.right.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexFormatOption(TimestampFormatter.defaultPattern())) =>
          expression.timeExp
        case expression: ParseToDate if (expression.format.isEmpty && StringUtils.isNullOrEmpty(indexDefinition.getExpressionIndexFormatOption()))
          || (expression.format.isDefined && expression.format.get.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexFormatOption())) =>
          expression.left
        case expression: ParseToTimestamp if (expression.format.isEmpty && StringUtils.isNullOrEmpty(indexDefinition.getExpressionIndexFormatOption()))
          || (expression.format.isDefined && expression.format.get.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexFormatOption())) =>
          expression.left
        case expression: DateAdd if expression.days.isInstanceOf[Literal] && expression.days.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexDaysOption) =>
          expression.startDate
        case expression: DateSub if expression.days.isInstanceOf[Literal] && expression.days.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexDaysOption) =>
          expression.startDate
        case expression: Substring if expression.pos.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexPositionOption)
          && expression.len.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexLengthOption)=>
          expression.str
        case expression: StringTrim if (expression.trimStr.isEmpty && StringUtils.isNullOrEmpty(indexDefinition.getExpressionIndexTrimStringOption))
          || (expression.trimStr.isDefined && expression.trimStr.get.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexTrimStringOption))  => expression.srcStr
        case expression: StringTrimLeft if (expression.trimStr.isEmpty && StringUtils.isNullOrEmpty(indexDefinition.getExpressionIndexTrimStringOption))
          || (expression.trimStr.isDefined && expression.trimStr.get.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexTrimStringOption))  => expression.srcStr
        case expression: StringTrimRight if (expression.trimStr.isEmpty && StringUtils.isNullOrEmpty(indexDefinition.getExpressionIndexTrimStringOption))
          || (expression.trimStr.isDefined && expression.trimStr.get.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexTrimStringOption)) => expression.srcStr
        case expression: RegExpReplace if expression.pos.asInstanceOf[Literal].value.toString.equals("1")
          && expression.regexp.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexPatternOption)
          && expression.rep.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexReplacementOption) =>
          expression.subject
        case expression: RegExpExtract if expression.regexp.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexPatternOption)
          && expression.idx.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexIndexOption) =>
          expression.subject
        case expression: StringSplit if expression.limit.asInstanceOf[Literal].value.toString.equals("-1")
          && expression.regex.asInstanceOf[Literal].value.toString.equals(indexDefinition.getExpressionIndexPatternOption) =>
          expression.str
        case other => other
      }
    }
    val expressionIndexQueries = filterQueriesWithFunctionalFilterKey(queryFilters, Option.apply(indexDefinition.getSourceFields.get(0)), attributeFetcher)
    var queryAndLiteralsOpt: Option[(Expression, List[String])] = Option.empty
    expressionIndexQueries.foreach { tuple =>
      val (expr, literals) = (tuple._1, tuple._2)
      queryAndLiteralsOpt = Option.apply(Tuple2.apply(expr, literals))
    }
    queryAndLiteralsOpt
  }