func (l *Layer) LinearizeOn(name string) error {
// We map names to smaller keys to bound the size of the linearizing data set.
// When this mapping causes extra collisions, that's only more restrictive,
// so it affects performance (slightly) but not correctness.
name = compressLinearizabilityKey(name)
key, _ := tuple.Append(nil, "linearizability", name)
pair, err := l.inner.Get(key)
if err != nil {
if err != kvl.ErrNotFound {
return err
}
pair.Key = key
pair.Value = make([]byte, 8)
// A random value is highly likely to conflict with another random value
// if we race on the initial linearizability key writes, which will cause
// the transaction to restart.
rand.Read(pair.Value)
}
newValue := make([]byte, 8)
copy(newValue, pair.Value)
// Big-endian integer increment
for i := 7; i >= 0; i-- {
newValue[i]++
if newValue[i] != 0 {
break
}
}
return l.inner.Set(kvl.Pair{pair.Key, newValue})
}
func (l *Layer) AllLocations() ([]Location, error) {
var query kvl.RangeQuery
key, _ := tuple.Append(nil, "location")
query.Low, query.High = keys.PrefixRange(key)
pairs, err := l.inner.Range(query)
if err != nil {
return nil, err
}
locations := make([]Location, len(pairs))
for i, pair := range pairs {
err := locations[i].fromPair(pair)
if err != nil {
return nil, err
}
}
return locations, nil
}
