IndexedDB: Optimize range deletion operations (e.g. clearing a store)

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>
@@ skipping 12 matching lines @@
 class LevelDBWriteBatch;
 
 class CONTENT_EXPORT LevelDBTransaction
     : public base::RefCounted<LevelDBTransaction> {
  public:
   void Put(const base::StringPiece& key, std::string* value);
 
   // Returns true if this operation performs a change, where the value wasn't
   // already deleted.
   bool Remove(const base::StringPiece& key);
+
+  leveldb::Status RemoveRange(const base::StringPiece& begin,
+                              const base::StringPiece& end,
+                              bool upper_open);
+
   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();
   explicit LevelDBTransaction(LevelDBDatabase* db);
   friend class IndexedDBClassFactory;
 
  private:
   friend class base::RefCounted<LevelDBTransaction>;
-  FRIEND_TEST_ALL_PREFIXES(LevelDBDatabaseTest, Transaction);
-  FRIEND_TEST_ALL_PREFIXES(LevelDBDatabaseTest, TransactionCommitTest);
-  FRIEND_TEST_ALL_PREFIXES(LevelDBDatabaseTest, TransactionIterator);
+  FRIEND_TEST_ALL_PREFIXES(LevelDBTransactionTest, GetAndPut);
+  FRIEND_TEST_ALL_PREFIXES(LevelDBTransactionTest, Commit);
+  FRIEND_TEST_ALL_PREFIXES(LevelDBTransactionTest, Iterator);
+  FRIEND_TEST_ALL_PREFIXES(LevelDBTransactionTest, RemoveRangeBackingData);
+  FRIEND_TEST_ALL_PREFIXES(LevelDBTransactionTest,
+                           RemoveRangeBackingDataUpperOpen);
+  FRIEND_TEST_ALL_PREFIXES(LevelDBTransactionTest, RemoveRangeMemoryData);
+  FRIEND_TEST_ALL_PREFIXES(LevelDBTransactionTest,
+                           RemoveRangeMemoryDataUpperOpen);
 
   struct Record {
     Record();
     ~Record();
     std::string key;
     std::string value;
-    bool deleted;
+    bool deleted = false;
   };
 
   class Comparator {
    public:
     explicit Comparator(const LevelDBComparator* comparator)
         : comparator_(comparator) {}
     bool operator()(const base::StringPiece& a,
                     const base::StringPiece& b) const {
       return comparator_->Compare(a, b) < 0;
     }
@@ skipping 102 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_