// ClosestDigest returns the closest digest of type 'label' to 'digest', or "" if there aren't any positive digests.
//
// If no digest of type 'label' is found then Closest.Digest is the empty string.
func ClosestDigest(test string, digest string, exp *expstorage.Expectations, tallies tally.Tally, diffStore diff.DiffStore, label types.Label) *Closest {
ret := newClosest()
unavailableDigests := diffStore.UnavailableDigests()
if unavailableDigests[digest] {
return ret
}
selected := []string{}
for d, _ := range tallies {
if !unavailableDigests[d] && (exp.Classification(test, d) == label) {
selected = append(selected, d)
}
}
if len(selected) == 0 {
return ret
}
if diffMetrics, err := diffStore.Get(digest, selected); err != nil {
glog.Errorf("ClosestDigest: Failed to get diff: %s", err)
return ret
} else {
for digest, diff := range diffMetrics {
if delta := combinedDiffMetric(diff.PixelDiffPercent, diff.MaxRGBADiffs); delta < ret.Diff {
ret.Digest = digest
ret.Diff = delta
ret.DiffPixels = diff.PixelDiffPercent
ret.MaxRGBA = diff.MaxRGBADiffs
}
}
return ret
}
}
