github.com/mysteriumnetwork/node@v0.0.0-20240516044423-365054f76801/core/discovery/reducer/field.go (about)

     1  /*
     2   * Copyright (C) 2019 The "MysteriumNetwork/node" Authors.
     3   *
     4   * This program is free software: you can redistribute it and/or modify
     5   * it under the terms of the GNU General Public License as published by
     6   * the Free Software Foundation, either version 3 of the License, or
     7   * (at your option) any later version.
     8   *
     9   * This program is distributed in the hope that it will be useful,
    10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    12   * GNU General Public License for more details.
    13   *
    14   * You should have received a copy of the GNU General Public License
    15   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    16   */
    17  
    18  package reducer
    19  
    20  import (
    21  	"github.com/mysteriumnetwork/node/market"
    22  )
    23  
    24  // FieldSelector callback to select field in proposal
    25  type FieldSelector func(proposal market.ServiceProposal) interface{}
    26  
    27  // FieldCondition returns flag if field value matches against it's rules
    28  type FieldCondition func(value interface{}) bool
    29  
    30  // Field returns a matcher for checking proposal's field value with custom callback
    31  func Field(field FieldSelector, reducer FieldCondition) func(market.ServiceProposal) bool {
    32  	return func(proposal market.ServiceProposal) bool {
    33  		return reducer(field(proposal))
    34  	}
    35  }
    36  
    37  // Empty returns a matcher for checking if given field is empty
    38  func Empty(field FieldSelector) func(market.ServiceProposal) bool {
    39  	return Field(field, func(value interface{}) bool {
    40  		switch valueTyped := value.(type) {
    41  		case string:
    42  			return valueTyped == ""
    43  		case int:
    44  			return valueTyped == 0
    45  		case byte:
    46  			return valueTyped == byte(0)
    47  		case bool:
    48  			return valueTyped == false
    49  		case []string:
    50  		case []int:
    51  		case []byte:
    52  		case []bool:
    53  			return len(valueTyped) == 0
    54  		}
    55  		return false
    56  	})
    57  }