Return number of values deleted by IDBObjectStore.delete(range)

content/browser/indexed_db/leveldb/leveldb_transaction.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_INDEXED_DB_LEVELDB_LEVELDB_TRANSACTION_H_
 #define CONTENT_BROWSER_INDEXED_DB_LEVELDB_LEVELDB_TRANSACTION_H_
 
 #include <map>
 #include <memory>
 #include <set>
 #include <string>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/string_piece.h"
 #include "content/browser/indexed_db/leveldb/leveldb_comparator.h"
 #include "content/browser/indexed_db/leveldb/leveldb_database.h"
 #include "content/browser/indexed_db/leveldb/leveldb_iterator.h"
 
 namespace content {
 
 class LevelDBWriteBatch;
 
 class CONTENT_EXPORT LevelDBTransaction
     : public base::RefCounted<LevelDBTransaction> {
  public:
   void Put(const base::StringPiece& key, std::string* value);
-  void Remove(const base::StringPiece& key);
+
+  // Returns true if this operation performs a change, where the value wasn't
+  // already deleted.
+  bool Remove(const base::StringPiece& key);
   virtual leveldb::Status Get(const base::StringPiece& key,
                               std::string* value,
                               bool* found);
   virtual leveldb::Status Commit();
   void Rollback();
 
   std::unique_ptr<LevelDBIterator> CreateIterator();
 
  protected:
   virtual ~LevelDBTransaction();
@@ skipping 82 matching lines @@
     const LevelDBComparator* comparator_;
     mutable std::unique_ptr<DataIterator> data_iterator_;
     std::unique_ptr<LevelDBIterator> db_iterator_;
     LevelDBIterator* current_;
 
     Direction direction_;
     mutable bool data_changed_;
 
     DISALLOW_COPY_AND_ASSIGN(TransactionIterator);
   };
-
-  void Set(const base::StringPiece& key, std::string* value, bool deleted);
+  // Returns true if the key was originally marked deleted, false otherwise.
+  bool Set(const base::StringPiece& key, std::string* value, bool deleted);
   void Clear();
   void RegisterIterator(TransactionIterator* iterator);
   void UnregisterIterator(TransactionIterator* iterator);
   void NotifyIterators();
 
   LevelDBDatabase* db_;
   const LevelDBSnapshot snapshot_;
   const LevelDBComparator* comparator_;
   Comparator data_comparator_;
   DataType data_;
@@ skipping 23 matching lines @@
   LevelDBDatabase* db_;
   std::unique_ptr<LevelDBWriteBatch> write_batch_;
   bool finished_;
 
   DISALLOW_COPY_AND_ASSIGN(LevelDBDirectTransaction);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_INDEXED_DB_LEVELDB_LEVELDB_TRANSACTION_H_