ethdb, core: implement delete for db batch (#17101)

ethdb/database.go

@@ -388,6 +388,12 @@ func (b *ldbBatch) Put(key, value []byte) error {
 	return nil
 }
 
+func (b *ldbBatch) Delete(key []byte) error {
+	b.b.Delete(key)
+	b.size += 1
+	return nil
+}
+
 func (b *ldbBatch) Write() error {
 	return b.db.Write(b.b, nil)
 }
@@ -453,6 +459,10 @@ func (tb *tableBatch) Put(key, value []byte) error {
 	return tb.batch.Put(append([]byte(tb.prefix), key...), value)
 }
 
+func (tb *tableBatch) Delete(key []byte) error {
+	return tb.batch.Delete(append([]byte(tb.prefix), key...))
+}
+
 func (tb *tableBatch) Write() error {
 	return tb.batch.Write()
 }

ethdb/interface.go

@@ -25,12 +25,17 @@ type Putter interface {
 	Put(key []byte, value []byte) error
 }
 
+// Deleter wraps the database delete operation supported by both batches and regular databases.
+type Deleter interface {
+	Delete(key []byte) error
+}
+
 // Database wraps all database operations. All methods are safe for concurrent use.
 type Database interface {
 	Putter
+	Deleter
 	Get(key []byte) ([]byte, error)
 	Has(key []byte) (bool, error)
-	Delete(key []byte) error
 	Close()
 	NewBatch() Batch
 }
@@ -39,6 +44,7 @@ type Database interface {
 // when Write is called. Batch cannot be used concurrently.
 type Batch interface {
 	Putter
+	Deleter
 	ValueSize() int // amount of data in the batch
 	Write() error
 	// Reset resets the batch for reuse

ethdb/memory_database.go

@@ -110,11 +110,20 @@ func (b *memBatch) Put(key, value []byte) error {
 	return nil
 }
 
+func (b *memBatch) Delete(key []byte) error {
+	b.writes = append(b.writes, kv{common.CopyBytes(key), nil})
+	return nil
+}
+
 func (b *memBatch) Write() error {
 	b.db.lock.Lock()
 	defer b.db.lock.Unlock()
 
 	for _, kv := range b.writes {
+		if kv.v == nil {
+			delete(b.db.db, string(kv.k))
+			continue
+		}
 		b.db.db[string(kv.k)] = kv.v
 	}
 	return nil