package lib import ( "math" "time" "github.com/hashicorp/serf/coordinate" ) // ComputeDistance returns the distance between the two network coordinates in // seconds. If either of the coordinates is nil then this will return positive // infinity. func ComputeDistance(a *coordinate.Coordinate, b *coordinate.Coordinate) float64 { if a == nil || b == nil { return math.Inf(1.0) } return a.DistanceTo(b).Seconds() } // CoordinateSet holds all the coordinates for a given node, indexed by network // segment name. type CoordinateSet map[string]*coordinate.Coordinate // Intersect tries to return a pair of coordinates which are compatible with the // current set and a given set. We employ some special knowledge about network // segments to avoid doing a full intersection, since this is in several hot // paths. This might return nil for either coordinate in the output pair if an // intersection cannot be found. The ComputeDistance function above is designed // to deal with that. func (cs CoordinateSet) Intersect(other CoordinateSet) (*coordinate.Coordinate, *coordinate.Coordinate) { // Use the empty segment by default. segment := "" // If we have a single segment, then let our segment take priority since // we are possibly a client. Any node with more than one segment can only // be a server, which means it should be in all segments. if len(cs) == 1 { for s, _ := range cs { segment = s } } // Likewise for the other set. if len(other) == 1 { for s, _ := range other { segment = s } } return cs[segment], other[segment] } // GenerateCoordinate creates a new coordinate with the given distance from the // origin. This should only be used for tests. func GenerateCoordinate(rtt time.Duration) *coordinate.Coordinate { coord := coordinate.NewCoordinate(coordinate.DefaultConfig()) coord.Vec[0] = rtt.Seconds() coord.Height = 0 return coord }