objectstore: Refresh v0.1.80

* Add manual Refresh for various objectstore's
* RefreshPolicy option
* Refreshable MRU and atomic snapshotting

1 files changed, 64 insertions, 9 deletions

diff --git a/objectstore/packed/store_lookup.go b/objectstore/packed/store_lookup.go
index cf5a580d..a1bd9b85 100644
--- a/objectstore/packed/store_lookup.go
+++ b/objectstore/packed/store_lookup.go
@@ -14,38 +14,93 @@ func (store *Store) lookup(id objectid.ObjectID) (location, error) {
 		return zero, errors.New("objectstore/packed: object id algorithm mismatch")
 	}
 
-	err := store.ensureCandidates()
+	snapshot, err := store.ensureCandidates()
 	if err != nil {
 		return zero, err
 	}
 
-	nextPackName := store.firstCandidatePackName()
+	loc, ok, err := store.lookupInCandidates(id, snapshot)
+	if err != nil {
+		return zero, err
+	}
+
+	if ok {
+		return loc, nil
+	}
+
+	if store.refreshPolicy == RefreshPolicyOnMissing {
+		err = store.Refresh()
+		if err != nil {
+			return zero, err
+		}
+
+		refreshed := store.candidates.Load()
+		if refreshed != nil && refreshed != snapshot {
+			loc, ok, err = store.lookupInCandidates(id, refreshed)
+			if err != nil {
+				return zero, err
+			}
+
+			if ok {
+				return loc, nil
+			}
+		}
+	}
+
+	return zero, objectstore.ErrObjectNotFound
+}
+
+func (store *Store) lookupInCandidates(
+	id objectid.ObjectID,
+	snapshot *candidateSnapshot,
+) (location, bool, error) {
+	var zero location
+
+	nextPackName := store.firstCandidatePackName(snapshot)
 	for nextPackName != "" {
-		candidate, ok := store.candidateForPack(nextPackName)
+		candidate, ok := snapshot.candidateByPack[nextPackName]
 		if !ok {
-			nextPackName = store.firstCandidatePackName()
+			nextPackName = store.firstCandidatePackName(snapshot)
 
 			continue
 		}
 
-		nextPackName = store.nextCandidatePackName(candidate.packName)
+		nextPackName = store.nextCandidatePackName(candidate.packName, snapshot)
 
 		index, err := store.openIndex(candidate)
 		if err != nil {
-			return zero, err
+			return zero, false, err
 		}
 
 		offset, ok, err := index.lookup(id)
 		if err != nil {
-			return zero, err
+			return zero, false, err
 		}
 
 		if ok {
 			store.touchCandidate(candidate.packName)
 
-			return location{packName: index.packName, offset: offset}, nil
+			return location{packName: index.packName, offset: offset}, true, nil
 		}
 	}
 
-	return zero, objectstore.ErrObjectNotFound
+	for _, candidate := range snapshot.candidates {
+		index, err := store.openIndex(candidate)
+		if err != nil {
+			return zero, false, err
+		}
+
+		offset, ok, err := index.lookup(id)
+		if err != nil {
+			return zero, false, err
+		}
+
+		if ok {
+			store.touchCandidate(candidate.packName)
+
+			return location{packName: index.packName, offset: offset}, true, nil
+		}
+	}
+
+	return zero, false, nil
 }