core, eth, ethdb, trie: simplify range proofs

ethdb/batch.go

@@ -25,9 +25,6 @@ const IdealBatchSize = 100 * 1024
 type Batch interface {
 	KeyValueWriter
 
-	// KeyCount retrieves the number of keys queued up for writing.
-	KeyCount() int
-
 	// ValueSize retrieves the amount of data queued up for writing.
 	ValueSize() int
 
@@ -47,3 +44,28 @@ type Batcher interface {
 	// until a final write is called.
 	NewBatch() Batch
 }
+
+// HookedBatch wraps an arbitrary batch where each operation may be hooked into
+// to monitor from black box code.
+type HookedBatch struct {
+	Batch
+
+	OnPut    func(key []byte, value []byte) // Callback if a key is inserted
+	OnDelete func(key []byte)               // Callback if a key is deleted
+}
+
+// Put inserts the given value into the key-value data store.
+func (b HookedBatch) Put(key []byte, value []byte) error {
+	if b.OnPut != nil {
+		b.OnPut(key, value)
+	}
+	return b.Batch.Put(key, value)
+}
+
+// Delete removes the key from the key-value data store.
+func (b HookedBatch) Delete(key []byte) error {
+	if b.OnDelete != nil {
+		b.OnDelete(key)
+	}
+	return b.Batch.Delete(key)
+}