column_filter_factory.h

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#ifndef CS_COLUMN_FILTER_FACTORY_H
#define CS_COLUMN_FILTER_FACTORY_H
 
#include "sql/changestreams/misc/column_filters/column_filter_inbound_func_indexes.h"
#include "sql/changestreams/misc/column_filters/column_filter_inbound_gipk.h"
#include "sql/changestreams/misc/column_filters/column_filter_outbound_func_indexes.h"
 
namespace cs {
namespace util {
/**
  @class ColumnFilterFactory
 
  This class allows the developer to create a filter instance given a type
 */
class ColumnFilterFactory {
 public:
  /**
    @brief The different types of filters for column iteration
  */
  enum class ColumnFilterType {
    outbound_func_index,  // filter functional indexes when outputting an event
    inbound_func_index,   // filter functional indexes when receiving an event
    inbound_gipk          // Filter GIPK when only present on the replica
  };
 
  /**
   @brief Create a filter object
 
   @param filter_type the filter to be created
   @return a unique pointer to a sub class of ColumnFilter
  */
  static std::unique_ptr<ColumnFilter> create_filter(
      ColumnFilterType filter_type) {
    switch (filter_type) {
      case ColumnFilterType::outbound_func_index:
        return std::make_unique<
            cs::util::ColumnFilterOutboundFunctionalIndexes>();
      case ColumnFilterType::inbound_func_index:
        return std::make_unique<ColumnFilterInboundFunctionalIndexes>();
      case ColumnFilterType::inbound_gipk:
        return std::make_unique<ColumnFilterInboundGipk>();
      default:
        /* This shall never happen. */
        assert(0); /* purecov: inspected */
        break;
    }
    return nullptr;
  }
 
  /**
    @brief Returns if a filter is needed given the parameters
 
    @param thd The thread being used in this context
    @param table The table being filtered
    @param tabledef The replicated table context if applicable
    @param filter_type The filter type being tested
    @return true if the filter should be used
    @return false if the filter is not needed
   */
  static bool is_filter_needed(THD const &thd, TABLE *table,
                               table_def const *tabledef,
                               ColumnFilterType filter_type) {
    switch (filter_type) {
      case ColumnFilterType::outbound_func_index:
        return ColumnFilterOutboundFunctionalIndexes::is_filter_needed(
            thd, table, tabledef);
      case ColumnFilterType::inbound_func_index:
        return ColumnFilterInboundFunctionalIndexes::is_filter_needed(
            thd, table, tabledef);
      case ColumnFilterType::inbound_gipk:
        return ColumnFilterInboundGipk::is_filter_needed(thd, table, tabledef);
      default:
        /* This shall never happen. */
        assert(0); /* purecov: inspected */
        break;
    }
    return false;
  }
};
}  // namespace util
}  // namespace cs
#endif  // CS_COLUMN_FILTER_FACTORY_H