github.com/iotexproject/iotex-core@v1.14.1-rc1/blockindex/contractstaking/delta_state.go (about)

     1  // Copyright (c) 2023 IoTeX Foundation
     2  // This source code is provided 'as is' and no warranties are given as to title or non-infringement, merchantability
     3  // or fitness for purpose and, to the extent permitted by law, all liability for your use of the code is disclaimed.
     4  // This source code is governed by Apache License 2.0 that can be found in the LICENSE file.
     5  
     6  package contractstaking
     7  
     8  import "github.com/pkg/errors"
     9  
    10  const (
    11  	// deltaState constants
    12  	// deltaStateUnchanged is the zero-value of the type deltaState
    13  	deltaStateUnchanged deltaState = iota
    14  	deltaStateAdded
    15  	deltaStateRemoved
    16  	deltaStateModified
    17  )
    18  
    19  type deltaState int
    20  
    21  var (
    22  	deltaStateTransferMap = map[deltaState]map[deltaAction]deltaState{
    23  		deltaStateUnchanged: {
    24  			deltaActionAdd:    deltaStateAdded,
    25  			deltaActionRemove: deltaStateRemoved,
    26  			deltaActionModify: deltaStateModified,
    27  		},
    28  		deltaStateAdded: {
    29  			deltaActionModify: deltaStateAdded,
    30  			deltaActionRemove: deltaStateUnchanged,
    31  		},
    32  		deltaStateModified: {
    33  			deltaActionModify: deltaStateModified,
    34  			deltaActionRemove: deltaStateRemoved,
    35  		},
    36  	}
    37  )
    38  
    39  func (s deltaState) Transfer(act deltaAction) (deltaState, error) {
    40  	if _, ok := deltaStateTransferMap[s]; !ok {
    41  		return s, errors.Errorf("invalid delta state %d", s)
    42  	}
    43  	if _, ok := deltaStateTransferMap[s][act]; !ok {
    44  		return s, errors.Errorf("invalid delta action %d on state %d", act, s)
    45  	}
    46  	return deltaStateTransferMap[s][act], nil
    47  }