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binary_snowflake.go
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binary_snowflake.go
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// Copyright (C) 2019-2024, Ava Labs, Inc. All rights reserved.
// See the file LICENSE for licensing terms.
package snowball
import "fmt"
var _ Binary = (*binarySnowflake)(nil)
func newBinarySnowflake(beta, choice int) binarySnowflake {
return binarySnowflake{
binarySlush: newBinarySlush(choice),
beta: beta,
}
}
// binarySnowflake is the implementation of a binary snowflake instance
type binarySnowflake struct {
// wrap the binary slush logic
binarySlush
// confidence tracks the number of successful polls in a row that have
// returned the preference
confidence int
// beta is the number of consecutive successful queries required for
// finalization.
beta int
// finalized prevents the state from changing after the required number of
// consecutive polls has been reached
finalized bool
}
func (sf *binarySnowflake) RecordSuccessfulPoll(choice int) {
if sf.finalized {
return // This instance is already decided.
}
if preference := sf.Preference(); preference == choice {
sf.confidence++
} else {
// confidence is set to 1 because there has already been 1 successful
// poll, namely this poll.
sf.confidence = 1
}
sf.finalized = sf.confidence >= sf.beta
sf.binarySlush.RecordSuccessfulPoll(choice)
}
func (sf *binarySnowflake) RecordPollPreference(choice int) {
if sf.finalized {
return // This instance is already decided.
}
sf.confidence = 0
sf.binarySlush.RecordSuccessfulPoll(choice)
}
func (sf *binarySnowflake) RecordUnsuccessfulPoll() {
sf.confidence = 0
}
func (sf *binarySnowflake) Finalized() bool {
return sf.finalized
}
func (sf *binarySnowflake) String() string {
return fmt.Sprintf("SF(Confidence = %d, Finalized = %v, %s)",
sf.confidence,
sf.finalized,
&sf.binarySlush)
}