ballot.go

package BigBFT

import (
	"fmt"
	"strconv"
	"strings"

	"github.com/salemmohammed/BigBFT/log"
)

// Ballot is ballot number type combines 32 bits of natual number and 32 bits of node id into uint64
type Ballot uint64

// NewBallot generates ballot number in format <n, zone, node>
func NewBallot(n int, id ID) Ballot {
	return Ballot(n<<32 | id.Zone()<<16 | id.Node())
}

func NewBallotFromString(b string) Ballot {
	var s, id string
	if strings.Contains(b, ".") {
		split := strings.SplitN(b, ".", 2)
		s = split[0]
		id = split[1]
	} else {
		s = b
	}

	n, err := strconv.ParseUint(s, 10, 64)
	if err != nil {
		log.Errorf("Failed to convert counter %s to uint64\n", s)
	}

	return NewBallot(int(n), ID(id))
}

// N returns first 32 bit of ballot
func (b Ballot) N() int {
	return int(uint64(b) >> 32)
}

// ID return node id as last 32 bits of ballot
func (b Ballot) ID() ID {
	zone := int(uint32(b) >> 16)
	node := int(uint16(b))
	return NewID(zone, node)
}

// Next generates the next ballot number given node id
func (b *Ballot) Next(id ID) {
	*b = NewBallot(b.N()+1, id)
}

func (b Ballot) String() string {
	return fmt.Sprintf("%d.%s", b.N(), b.ID())
}

// NextBallot generates next ballot number given current ballot bumber and node id
func NextBallot(ballot int, id ID) int {
	n := id.Zone()<<16 | id.Node()
	return (ballot>>32+1)<<32 | n
}

// LeaderID return the node id from ballot number
func LeaderID(ballot int) ID {
	zone := uint32(ballot) >> 16
	node := uint16(ballot)
	return NewID(int(zone), int(node))
}