DB Store Abstractions

swarm/shed/db.go

@@ -71,23 +71,39 @@ func NewDB(path string) (db *DB, err error) {
 
 // Put wraps LevelDB Put method to increment metrics counter.
 func (db *DB) Put(key []byte, value []byte) (err error) {
+	err = db.ldb.Put(key, value, nil)
+	if err != nil {
+		metrics.GetOrRegisterCounter("DB.putFail", nil).Inc(1)
+		return err
+	}
 	metrics.GetOrRegisterCounter("DB.put", nil).Inc(1)
-
-	return db.ldb.Put(key, value, nil)
+	return nil
 }
 
 // Get wraps LevelDB Get method to increment metrics counter.
 func (db *DB) Get(key []byte) (value []byte, err error) {
+	value, err = db.ldb.Get(key, nil)
+	if err != nil {
+		if err == leveldb.ErrNotFound {
+			metrics.GetOrRegisterCounter("DB.getNotFound", nil).Inc(1)
+		} else {
+			metrics.GetOrRegisterCounter("DB.getFail", nil).Inc(1)
+		}
+		return nil, err
+	}
 	metrics.GetOrRegisterCounter("DB.get", nil).Inc(1)
-
-	return db.ldb.Get(key, nil)
+	return value, nil
 }
 
 // Delete wraps LevelDB Delete method to increment metrics counter.
-func (db *DB) Delete(key []byte) error {
+func (db *DB) Delete(key []byte) (err error) {
+	err = db.ldb.Delete(key, nil)
+	if err != nil {
+		metrics.GetOrRegisterCounter("DB.deleteFail", nil).Inc(1)
+		return err
+	}
 	metrics.GetOrRegisterCounter("DB.delete", nil).Inc(1)
-
-	return db.ldb.Delete(key, nil)
+	return nil
 }
 
 // NewIterator wraps LevelDB NewIterator method to increment metrics counter.
@@ -98,10 +114,14 @@ func (db *DB) NewIterator() iterator.Iterator {
 }
 
 // WriteBatch wraps LevelDB Write method to increment metrics counter.
-func (db *DB) WriteBatch(batch *leveldb.Batch) error {
+func (db *DB) WriteBatch(batch *leveldb.Batch) (err error) {
+	err = db.ldb.Write(batch, nil)
+	if err != nil {
+		metrics.GetOrRegisterCounter("DB.writebatchFail", nil).Inc(1)
+		return err
+	}
 	metrics.GetOrRegisterCounter("DB.writebatch", nil).Inc(1)
-
-	return db.ldb.Write(batch, nil)
+	return nil
 }
 
 // Close closes LevelDB database.

swarm/shed/example_store_test.go

@@ -297,8 +297,8 @@ func (s *Store) PutSchema(name string) (err error) {
 }
 
 // Close closes the underlying database.
-func (s *Store) Close() {
-	s.db.Close()
+func (s *Store) Close() error {
+	return s.db.Close()
 }
 
 // Example_store constructs a simple storage implementation using shed package.
@@ -313,6 +313,7 @@ func Example_store() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer s.Close()
 
 	ch := storage.GenerateRandomChunk(1024)
 	err = s.Put(context.Background(), ch)

swarm/shed/field_string.go

@@ -27,7 +27,7 @@ type StringField struct {
 	key []byte
 }
 
-// NewStringField retruns a new Instance fo StringField.
+// NewStringField retruns a new Instance of StringField.
 // It validates its name and type against the database schema.
 func (db *DB) NewStringField(name string) (f StringField, err error) {
 	key, err := db.schemaFieldKey(name, "string")

swarm/shed/field_struct.go

@@ -41,9 +41,9 @@ func (db *DB) NewStructField(name string) (f StructField, err error) {
 	}, nil
 }
 
-// Unmarshal unmarshals data fromt he database to a provided val.
+// Get unmarshals data from the database to a provided val.
 // If the data is not found leveldb.ErrNotFound is returned.
-func (f StructField) Unmarshal(val interface{}) (err error) {
+func (f StructField) Get(val interface{}) (err error) {
 	b, err := f.db.Get(f.key)
 	if err != nil {
 		return err

swarm/shed/field_struct_test.go

@@ -22,7 +22,7 @@ import (
 	"github.com/syndtr/goleveldb/leveldb"
 )
 
-// TestStructField validates put and unmarshal operations
+// TestStructField validates put and get operations
 // of the StructField.
 func TestStructField(t *testing.T) {
 	db, cleanupFunc := newTestDB(t)
@@ -37,9 +37,9 @@ func TestStructField(t *testing.T) {
 		A string
 	}
 
-	t.Run("unmarshal empty", func(t *testing.T) {
+	t.Run("get empty", func(t *testing.T) {
 		var s complexStructure
-		err := complexField.Unmarshal(&s)
+		err := complexField.Get(&s)
 		if err != leveldb.ErrNotFound {
 			t.Fatalf("got error %v, want %v", err, leveldb.ErrNotFound)
 		}
@@ -58,7 +58,7 @@ func TestStructField(t *testing.T) {
 			t.Fatal(err)
 		}
 		var got complexStructure
-		err = complexField.Unmarshal(&got)
+		err = complexField.Get(&got)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -75,7 +75,7 @@ func TestStructField(t *testing.T) {
 				t.Fatal(err)
 			}
 			var got complexStructure
-			err = complexField.Unmarshal(&got)
+			err = complexField.Get(&got)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -96,7 +96,7 @@ func TestStructField(t *testing.T) {
 			t.Fatal(err)
 		}
 		var got complexStructure
-		err := complexField.Unmarshal(&got)
+		err := complexField.Get(&got)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -115,7 +115,7 @@ func TestStructField(t *testing.T) {
 				t.Fatal(err)
 			}
 			var got complexStructure
-			err := complexField.Unmarshal(&got)
+			err := complexField.Get(&got)
 			if err != nil {
 				t.Fatal(err)
 			}

swarm/shed/index.go

@@ -37,15 +37,12 @@ type IndexItem struct {
 	Data            []byte
 	AccessTimestamp int64
 	StoreTimestamp  int64
-	// UseMockStore is a pointer to identify
-	// an unset state of the field in Join function.
-	UseMockStore *bool
 }
 
-// Join is a helper method to construct a new
+// Merge is a helper method to construct a new
 // IndexItem by filling up fields with default values
 // of a particular IndexItem with values from another one.
-func (i IndexItem) Join(i2 IndexItem) (new IndexItem) {
+func (i IndexItem) Merge(i2 IndexItem) (new IndexItem) {
 	if i.Address == nil {
 		i.Address = i2.Address
 	}
@@ -58,9 +55,6 @@ func (i IndexItem) Join(i2 IndexItem) (new IndexItem) {
 	if i.StoreTimestamp == 0 {
 		i.StoreTimestamp = i2.StoreTimestamp
 	}
-	if i.UseMockStore == nil {
-		i.UseMockStore = i2.UseMockStore
-	}
 	return i
 }
 
@@ -139,7 +133,7 @@ func (f Index) Get(keyFields IndexItem) (out IndexItem, err error) {
 	if err != nil {
 		return out, err
 	}
-	return out.Join(keyFields), nil
+	return out.Merge(keyFields), nil
 }
 
 // Put accepts IndexItem to encode information from it
@@ -173,7 +167,7 @@ func (f Index) PutInBatch(batch *leveldb.Batch, i IndexItem) (err error) {
 }
 
 // Delete accepts IndexItem to remove a key/value pair
-// form the database based on its fields.
+// from the database based on its fields.
 func (f Index) Delete(keyFields IndexItem) (err error) {
 	key, err := f.encodeKeyFunc(keyFields)
 	if err != nil {
@@ -218,7 +212,7 @@ func (f Index) IterateAll(fn IndexIterFunc) (err error) {
 		if err != nil {
 			return err
 		}
-		stop, err := fn(keyIndexItem.Join(valueIndexItem))
+		stop, err := fn(keyIndexItem.Merge(valueIndexItem))
 		if err != nil {
 			return err
 		}
@@ -252,7 +246,7 @@ func (f Index) IterateFrom(start IndexItem, fn IndexIterFunc) (err error) {
 		if err != nil {
 			return err
 		}
-		stop, err := fn(keyIndexItem.Join(valueIndexItem))
+		stop, err := fn(keyIndexItem.Merge(valueIndexItem))
 		if err != nil {
 			return err
 		}

swarm/shed/schema.go

@@ -56,10 +56,10 @@ type indexSpec struct {
 // a particular field form the schema definition.
 func (db *DB) schemaFieldKey(name, fieldType string) (key []byte, err error) {
 	if name == "" {
-		return nil, errors.New("filed name can not be blank")
+		return nil, errors.New("field name can not be blank")
 	}
 	if fieldType == "" {
-		return nil, errors.New("filed type can not be blank")
+		return nil, errors.New("field type can not be blank")
 	}
 	s, err := db.getSchema()
 	if err != nil {