// getStoreList returns a store list matching the required attributes.
// Results are cached for performance.
//
// If it cannot retrieve a StoreDescriptor from the Store's gossip, it
// garbage collects the failed key.
//
// TODO(embark, spencer): consider using a reverse index map from
// Attr->stores, for efficiency. Ensure that entries in this map still
// have an opportunity to be garbage collected.
func (a *allocator) getStoreList(required proto.Attributes) *storeList {
if a.storeLists == nil {
a.storeLists = map[string]*storeList{}
}
key := required.SortedString()
if sl, ok := a.storeLists[key]; ok {
return sl
}
sl := &storeList{}
a.storeLists[key] = sl
updateStoreList := func(key string) {
storeDesc, err := storeDescFromGossip(key, a.gossip)
if err != nil {
// We can no longer retrieve this key from the gossip store,
// perhaps it expired.
delete(a.capacityKeys, key)
} else if required.IsSubset(*storeDesc.CombinedAttrs()) {
sl.Add(storeDesc)
}
}
if a.deterministic {
var keys []string
for key := range a.capacityKeys {
keys = append(keys, key)
}
sort.Strings(keys)
for _, key := range keys {
updateStoreList(key)
}
return sl
}
for key := range a.capacityKeys {
updateStoreList(key)
}
return sl
}
