Use a two-part data format version in IndexedDB metadata.

content/browser/indexed_db/indexed_db_backing_store.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_INDEXED_DB_BACKING_STORE_H_
 #define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_BACKING_STORE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 12 matching lines @@
 #include "base/strings/string_piece.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "content/browser/indexed_db/indexed_db.h"
 #include "content/browser/indexed_db/indexed_db_active_blob_registry.h"
 #include "content/browser/indexed_db/indexed_db_blob_info.h"
 #include "content/browser/indexed_db/indexed_db_leveldb_coding.h"
 #include "content/browser/indexed_db/leveldb/leveldb_iterator.h"
 #include "content/browser/indexed_db/leveldb/leveldb_transaction.h"
 #include "content/common/content_export.h"
+#include "content/common/indexed_db/indexed_db_data_format_version.h"
 #include "content/common/indexed_db/indexed_db_key.h"
 #include "content/common/indexed_db/indexed_db_key_path.h"
 #include "content/common/indexed_db/indexed_db_key_range.h"
 #include "content/common/indexed_db/indexed_db_metadata.h"
 #include "storage/browser/blob/blob_data_handle.h"
 #include "third_party/leveldatabase/src/include/leveldb/status.h"
 #include "url/gurl.h"
 #include "url/origin.h"
 
 namespace base {
@@ skipping 325 matching lines @@
     // NextNoDuplicate.
     ContinueResult ContinuePrevious(const IndexedDBKey* key,
                                     const IndexedDBKey* primary_key,
                                     IteratorState state,
                                     leveldb::Status*);
 
     DISALLOW_COPY_AND_ASSIGN(Cursor);
   };
 
   const url::Origin& origin() const { return origin_; }
+  const IndexedDBDataFormatVersion data_format_version() const {

[dcheng, 2017/04/04 19:59:21]

Nit: no const and return by value, or const and return by ref.

+    return data_format_version_;
+  }
   IndexedDBFactory* factory() const { return indexed_db_factory_; }
   base::SequencedTaskRunner* task_runner() const { return task_runner_.get(); }
   base::OneShotTimer* close_timer() { return &close_timer_; }
   IndexedDBActiveBlobRegistry* active_blob_registry() {
     return &active_blob_registry_;
   }
 
   static scoped_refptr<IndexedDBBackingStore> Open(
       IndexedDBFactory* indexed_db_factory,
       const url::Origin& origin,
       const base::FilePath& path_base,
+      const IndexedDBDataFormatVersion& data_format_version,
       scoped_refptr<net::URLRequestContextGetter> request_context_getter,
       IndexedDBDataLossInfo* data_loss_info,
       bool* disk_full,
       base::SequencedTaskRunner* task_runner,
       bool clean_journal,
       leveldb::Status* status);
   static scoped_refptr<IndexedDBBackingStore> Open(
       IndexedDBFactory* indexed_db_factory,
       const url::Origin& origin,
       const base::FilePath& path_base,
+      const IndexedDBDataFormatVersion& data_format_version,
       scoped_refptr<net::URLRequestContextGetter> request_context_getter,
       IndexedDBDataLossInfo* data_loss_info,
       bool* disk_full,
       LevelDBFactory* leveldb_factory,
       base::SequencedTaskRunner* task_runner,
       bool clean_journal,
       leveldb::Status* status);
   static scoped_refptr<IndexedDBBackingStore> OpenInMemory(
       const url::Origin& origin,
+      const IndexedDBDataFormatVersion& data_format_version,
       base::SequencedTaskRunner* task_runner,
       leveldb::Status* status);
   static scoped_refptr<IndexedDBBackingStore> OpenInMemory(
       const url::Origin& origin,
+      const IndexedDBDataFormatVersion& data_format_version,
       LevelDBFactory* leveldb_factory,
       base::SequencedTaskRunner* task_runner,
       leveldb::Status* status);
 
   void GrantChildProcessPermissions(int child_process_id);
 
   // Compact is public for testing.
   virtual void Compact();
   virtual std::vector<base::string16> GetDatabaseNames(leveldb::Status*);
   virtual leveldb::Status GetIDBDatabaseMetaData(
@@ skipping 161 matching lines @@
       blink::WebIDBCursorDirection,
       leveldb::Status*);
 
  protected:
   friend class base::RefCounted<IndexedDBBackingStore>;
 
   IndexedDBBackingStore(
       IndexedDBFactory* indexed_db_factory,
       const url::Origin& origin,
       const base::FilePath& blob_path,
+      const IndexedDBDataFormatVersion& data_format_version,
       scoped_refptr<net::URLRequestContextGetter> request_context_getter,
       std::unique_ptr<LevelDBDatabase> db,
       std::unique_ptr<LevelDBComparator> comparator,
       base::SequencedTaskRunner* task_runner);
   virtual ~IndexedDBBackingStore();
 
   bool is_incognito() const { return !indexed_db_factory_; }
 
   leveldb::Status SetUpMetadata();
 
@@ skipping 16 matching lines @@
   // via StartJournalCleaningTimer().
   void CleanPrimaryJournalIgnoreReturn();
 
  private:
   FRIEND_TEST_ALL_PREFIXES(IndexedDBBackingStoreTest, ReadCorruptionInfo);
 
   static scoped_refptr<IndexedDBBackingStore> Create(
       IndexedDBFactory* indexed_db_factory,
       const url::Origin& origin,
       const base::FilePath& blob_path,
+      const IndexedDBDataFormatVersion& data_format_version,
       scoped_refptr<net::URLRequestContextGetter> request_context_getter,
       std::unique_ptr<LevelDBDatabase> db,
       std::unique_ptr<LevelDBComparator> comparator,
       base::SequencedTaskRunner* task_runner,
       leveldb::Status* status);
 
   static bool ReadCorruptionInfo(const base::FilePath& path_base,
                                  const url::Origin& origin,
                                  std::string* message);
 
@@ skipping 21 matching lines @@
   leveldb::Status CleanUpBlobJournal(const std::string& level_db_key) const;
 
   // Synchronously delete the files and/or directories on disk referenced by
   // the blob journal.
   leveldb::Status CleanUpBlobJournalEntries(
       const BlobJournalType& journal) const;
 
   IndexedDBFactory* indexed_db_factory_;
   const url::Origin origin_;
   base::FilePath blob_path_;
+  const IndexedDBDataFormatVersion data_format_version_;
 
   // The origin identifier is a key prefix unique to the origin used in the
   // leveldb backing store to partition data by origin. It is a normalized
   // version of the origin URL with a versioning suffix appended, e.g.
   // "http_localhost_81@1" Since only one origin is stored per backing store
   // this is redundant but necessary for backwards compatibility; the suffix
   // provides for future flexibility.
   const std::string origin_identifier_;
 
   scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
@@ skipping 13 matching lines @@
   // complete. While > 0, temporary journal entries may exist so out-of-band
   // journal cleaning must be deferred.
   size_t committing_transaction_count_;
 
   DISALLOW_COPY_AND_ASSIGN(IndexedDBBackingStore);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_BACKING_STORE_H_