1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_TABLE_H_
6 #define COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_TABLE_H_
7 
8 #include "base/macros.h"
9 #include "components/webdata/common/webdata_export.h"
10 
11 namespace sql {
12 class Database;
13 class MetaTable;
14 }
15 
16 // An abstract base class representing a table within a WebDatabase.
17 // Each table should subclass this, adding type-specific methods as needed.
18 class WEBDATA_EXPORT WebDatabaseTable {
19  public:
20   // To look up a WebDatabaseTable of a certain type from WebDatabase,
21   // we use a void* key, so that we can simply use the address of one
22   // of the type's statics.
23   typedef void* TypeKey;
24 
25   // The object is not ready for use until Init() has been called.
26   WebDatabaseTable();
27   virtual ~WebDatabaseTable();
28 
29   // Retrieves the TypeKey for the concrete subtype.
30   virtual TypeKey GetTypeKey() const = 0;
31 
32   // Stores the passed members as instance variables.
33   void Init(sql::Database* db, sql::MetaTable* meta_table);
34 
35   // Create all of the expected SQL tables if they do not already exist.
36   // Returns true on success, false on failure.
37   virtual bool CreateTablesIfNecessary() = 0;
38 
39   // In order to encourage developers to think about sync when adding or
40   // or altering new tables, this method must be implemented. Please get in
41   // contact with the sync team if you believe you're making a change that they
42   // should be aware of (or if you could break something).
43   // TODO(andybons): Implement something more robust.
44   virtual bool IsSyncable() = 0;
45 
46   // Migrates this table to |version|. Returns false if there was
47   // migration work to do and it failed, true otherwise.
48   //
49   // Implementations may set |*update_compatible_version| to true if the
50   // compatible version should be changed to |version|, i.e., if the change will
51   // break previous versions when they try to use the updated database.
52   // Implementations should otherwise not modify this parameter.
53   virtual bool MigrateToVersion(int version,
54                                 bool* update_compatible_version) = 0;
55 
56  protected:
57   // Non-owning. These are owned by WebDatabase, valid as long as that
58   // class exists. Since lifetime of WebDatabaseTable objects slightly
59   // exceeds that of WebDatabase, they should not be used in
60   // ~WebDatabaseTable.
61   sql::Database* db_;
62   sql::MetaTable* meta_table_;
63 
64  private:
65   DISALLOW_COPY_AND_ASSIGN(WebDatabaseTable);
66 };
67 
68 #endif  // COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_TABLE_H_
69