solver: add release support for bolt backend

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

solver-next/boltdbcachestorage/storage.go

@@ -13,6 +13,8 @@ const (
 	mainBucket      = "_main"
 	resultBucket    = "_result"
 	linksBucket     = "_links"
+	byResultBucket  = "_byresult"
+	backlinksBucket = "_backlinks"
 )
 
 type Store struct {
@@ -25,7 +27,7 @@ func NewStore(dbPath string) (*Store, error) {
 		return nil, errors.Wrapf(err, "failed to open database file %s", dbPath)
 	}
 	if err := db.Update(func(tx *bolt.Tx) error {
-		for _, b := range []string{mainBucket, resultBucket, linksBucket} {
+		for _, b := range []string{mainBucket, resultBucket, linksBucket, byResultBucket, backlinksBucket} {
 			if _, err := tx.CreateBucketIfNotExists([]byte(b)); err != nil {
 				return err
 			}
@@ -70,6 +72,25 @@ func (s *Store) Set(info solver.CacheKeyInfo) error {
 	})
 }
 
+func (s *Store) Walk(fn func(id string) error) error {
+	ids := make([]string, 0)
+	if err := s.db.View(func(tx *bolt.Tx) error {
+		b := tx.Bucket([]byte(mainBucket))
+		return b.ForEach(func(k, v []byte) error {
+			ids = append(ids, string(k))
+			return nil
+		})
+	}); err != nil {
+		return err
+	}
+	for _, id := range ids {
+		if err := fn(id); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func (s *Store) WalkResults(id string, fn func(solver.CacheResult) error) error {
 	return s.db.View(func(tx *bolt.Tx) error {
 		b := tx.Bucket([]byte(resultBucket))
@@ -119,11 +140,7 @@ func (s *Store) Load(id string, resultID string) (solver.CacheResult, error) {
 
 func (s *Store) AddResult(id string, res solver.CacheResult) error {
 	return s.db.Update(func(tx *bolt.Tx) error {
-		b := tx.Bucket([]byte(resultBucket))
+		b, err := tx.Bucket([]byte(resultBucket)).CreateBucketIfNotExists([]byte(id))
-		if b == nil {
-			return errors.WithStack(solver.ErrNotFound)
-		}
-		b, err := b.CreateBucketIfNotExists([]byte(id))
 		if err != nil {
 			return err
 		}
@@ -131,21 +148,129 @@ func (s *Store) AddResult(id string, res solver.CacheResult) error {
 		if err != nil {
 			return err
 		}
-		return b.Put([]byte(res.ID), dt)
+		if err := b.Put([]byte(res.ID), dt); err != nil {
+			return err
+		}
+
+		b, err = tx.Bucket([]byte(byResultBucket)).CreateBucketIfNotExists([]byte(res.ID))
+		if err != nil {
+			return err
+		}
+		if err := b.Put([]byte(id), []byte{}); err != nil {
+			return err
+		}
+
+		return nil
 	})
 }
 
-func (s *Store) Release(id, resultID string) error {
+func (s *Store) Release(resultID string) error {
-	return errors.Errorf("not-implemented")
+	return s.db.Update(func(tx *bolt.Tx) error {
+		b := tx.Bucket([]byte(byResultBucket))
+		if b == nil {
+			return errors.WithStack(solver.ErrNotFound)
+		}
+		b = b.Bucket([]byte(resultID))
+		if b == nil {
+			return errors.WithStack(solver.ErrNotFound)
+		}
+		if err := b.ForEach(func(k, v []byte) error {
+			return s.releaseHelper(tx, string(k), resultID)
+		}); err != nil {
+			return err
+		}
+		return nil
+	})
+}
+
+func (s *Store) releaseHelper(tx *bolt.Tx, id, resultID string) error {
+	results := tx.Bucket([]byte(resultBucket)).Bucket([]byte(id))
+	if results == nil {
+		return nil
+	}
+
+	if err := results.Delete([]byte(resultID)); err != nil {
+		return err
+	}
+
+	ids := tx.Bucket([]byte(byResultBucket))
+
+	ids = ids.Bucket([]byte(resultID))
+	if ids == nil {
+		return nil
+	}
+
+	if err := ids.Delete([]byte(resultID)); err != nil {
+		return err
+	}
+
+	if isEmptyBucket(ids) {
+		if err := tx.Bucket([]byte(byResultBucket)).DeleteBucket([]byte(resultID)); err != nil {
+			return err
+		}
+	}
+
+	links := tx.Bucket([]byte(resultBucket))
+	if results == nil {
+		return nil
+	}
+	links = links.Bucket([]byte(id))
+
+	return s.emptyBranchWithParents(tx, []byte(id))
+}
+
+func (s *Store) emptyBranchWithParents(tx *bolt.Tx, id []byte) error {
+	results := tx.Bucket([]byte(resultBucket)).Bucket(id)
+	if results == nil {
+		return nil
+	}
+
+	isEmptyLinks := true
+	links := tx.Bucket([]byte(linksBucket)).Bucket(id)
+	if links != nil {
+		isEmptyLinks = isEmptyBucket(links)
+	}
+
+	if !isEmptyBucket(results) || !isEmptyLinks {
+		return nil
+	}
+
+	if backlinks := tx.Bucket([]byte(backlinksBucket)).Bucket(id); backlinks != nil {
+		if err := backlinks.ForEach(func(k, v []byte) error {
+			if subLinks := tx.Bucket([]byte(linksBucket)).Bucket(k); subLinks != nil {
+				if err := subLinks.ForEach(func(k, v []byte) error {
+					parts := bytes.Split(k, []byte("@"))
+					if len(parts) != 2 {
+						return errors.Errorf("invalid key %s", k)
+					}
+					if bytes.Equal(id, parts[1]) {
+						return subLinks.Delete(k)
+					}
+					return nil
+				}); err != nil {
+					return err
+				}
+
+				if isEmptyBucket(subLinks) {
+					if err := tx.Bucket([]byte(linksBucket)).DeleteBucket(k); err != nil {
+						return err
+					}
+				}
+			}
+			return s.emptyBranchWithParents(tx, k)
+		}); err != nil {
+			return err
+		}
+		if err := tx.Bucket([]byte(backlinksBucket)).DeleteBucket(id); err != nil {
+			return err
+		}
+	}
+	return tx.Bucket([]byte(mainBucket)).Delete(id)
 }
 
 func (s *Store) AddLink(id string, link solver.CacheInfoLink, target string) error {
 	return s.db.Update(func(tx *bolt.Tx) error {
-		b := tx.Bucket([]byte(linksBucket))
+		b, err := tx.Bucket([]byte(linksBucket)).CreateBucketIfNotExists([]byte(id))
-		if b == nil {
-			return errors.WithStack(solver.ErrNotFound)
-		}
-		b, err := b.CreateBucketIfNotExists([]byte(id))
 		if err != nil {
 			return err
 		}
@@ -155,7 +280,20 @@ func (s *Store) AddLink(id string, link solver.CacheInfoLink, target string) err
 			return err
 		}
 
-		return b.Put(bytes.Join([][]byte{dt, []byte(target)}, []byte("@")), []byte{})
+		if err := b.Put(bytes.Join([][]byte{dt, []byte(target)}, []byte("@")), []byte{}); err != nil {
+			return err
+		}
+
+		b, err = tx.Bucket([]byte(backlinksBucket)).CreateBucketIfNotExists([]byte(target))
+		if err != nil {
+			return err
+		}
+
+		if err := b.Put([]byte(id), []byte{}); err != nil {
+			return err
+		}
+
+		return nil
 	})
 }
 
@@ -198,3 +336,8 @@ func (s *Store) WalkLinks(id string, link solver.CacheInfoLink, fn func(id strin
 	}
 	return nil
 }
+
+func isEmptyBucket(b *bolt.Bucket) bool {
+	k, _ := b.Cursor().First()
+	return k == nil
+}

solver-next/memorycachestorage.go

@@ -145,16 +145,14 @@ func (s *inMemoryStore) Release(resultID string) error {
 			delete(s.byResult, resultID)
 		}
 
-		if len(k.results) == 0 && len(k.links) == 0 {
 		s.emptyBranchWithParents(k)
 	}
-	}
 
 	return nil
 }
 
 func (s *inMemoryStore) emptyBranchWithParents(k *inMemoryKey) {
-	if len(k.results) != 0 && len(k.links) != 0 {
+	if len(k.results) != 0 || len(k.links) != 0 {
 		return
 	}
 	for id := range k.backlinks {