github.com/m3db/m3@v1.5.0/src/cluster/services/leader/campaign/state.go (about)

     1  // Copyright (c) 2017 Uber Technologies, Inc.
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     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
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    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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    19  // THE SOFTWARE.
    20  
    21  // Package campaign encapsulates the state of a campaign.
    22  package campaign
    23  
    24  //go:generate stringer -type State
    25  
    26  // State describes the state of a campaign as its relates to the
    27  // caller's leadership.
    28  type State int
    29  
    30  const (
    31  	// Follower indicates the caller has called Campaign but has not yet been
    32  	// elected.
    33  	Follower State = iota
    34  
    35  	// Leader indicates the caller has called Campaign and was elected.
    36  	Leader
    37  
    38  	// Error indicates the call to Campaign returned an error.
    39  	Error
    40  
    41  	// Closed indicates the campaign has been closed.
    42  	Closed
    43  )
    44  
    45  // Status encapsulates campaign state and any error encountered to
    46  // provide a consistent type for the campaign watch.
    47  type Status struct {
    48  	State State
    49  	Err   error
    50  }
    51  
    52  // NewStatus returns a non-error status with the given State.
    53  func NewStatus(s State) Status {
    54  	return Status{State: s}
    55  }
    56  
    57  // NewErrorStatus returns an error Status with the given State.
    58  func NewErrorStatus(err error) Status {
    59  	return Status{
    60  		State: Error,
    61  		Err:   err,
    62  	}
    63  }