Implement AffiliationDatabase to cache affiliation information in a SQLite DB.

components/password_manager/core/browser/affiliation_database.h

+// Copyright 2014 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 COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_AFFILIATION_DATABASE_H_
+#define COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_AFFILIATION_DATABASE_H_
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/time/time.h"
+#include "components/password_manager/core/browser/affiliation_utils.h"
+
+namespace base {
+class FilePath;
+}  // namespace base
+
+namespace sql {
+class Connection;
+class Statement;
+}  // namespace sql
+
+namespace password_manager {
+
+// Stores equivalence classes of facets, i.e., facets that are affiliated with
+// each other, in an SQLite database. See affiliation_utils.h for a more
+// detailed definition of what this means.
+//
+// Under the assumption that there is most likely not much the caller can do in
+// case of database errors, most methods silently ignore them. Nevertheless, the
+// caller must plan ahead for this rare but non-negligible scenario, and expect
+// that in odd cases basic database invariants will not hold.
+class AffiliationDatabase {
+ public:
+  AffiliationDatabase();
+  ~AffiliationDatabase();
+
+  // Opens an existing database at |path|, or creates a new one if none exists,
+  // and returns true on success.
+  bool Init(const base::FilePath& path);
+
+  // Looks up the equivalence class containing |facet_uri|, and returns true if
+  // such a class is found, in which case it is also stored into |result|.
+  bool GetAffiliationsForFacet(const FacetURI& facet_uri,
+                               AffiliatedFacetsWithUpdateTime* result) const;
+
+  // Retrieves all stored equivalence classes.
+  void GetAllAffiliations(
+      std::vector<AffiliatedFacetsWithUpdateTime>* results) const;
+
+  // Removes the stored equivalence class, if any, containing |facet_uri|.
+  void DeleteAffiliationsForFacet(const FacetURI& facet_uri);
+
+  // Removes stored equivalence classes that were last updated before the
+  // |cutoff_threshold|.
+  void DeleteAffiliationsOlderThan(const base::Time& cutoff_threshold);
+
+  // Removes all records from all tables of the database.
+  void DeleteAllAffiliations();
+
+  // Stores the equivalence class defined by |affiliated_facets| to the DB and
+  // returns true unless it has a non-empty subset with a preexisting class, in
+  // which case no changes are made and the function returns false.
+  bool Store(const AffiliatedFacetsWithUpdateTime& affiliated_facets);
+
+  // Stores the equivalence class defined by |affiliated_facets| to the DB,
+  // database, and removes any other equivalence classes that are in conflict
+  // with |affiliated_facets|, i.e. those that are neither equal nor disjoint to
+  // it. Removed equivalence classes are stored into |removed_affiliations|.
+  void StoreAndRemoveConflicting(
+      const AffiliatedFacetsWithUpdateTime& affiliated_facets,
+      std::vector<AffiliatedFacetsWithUpdateTime>* removed_affiliations);
+
+ private:
+  // Creates any tables and indices that do not already exist in the database.
+  bool CreateTablesAndIndicesIfNeeded();
+
+  // Called when SQLite encounters an error.
+  void SQLErrorCallback(int error_number, sql::Statement* statement);
+
+  // The SQL connection to the database.
+  scoped_ptr<sql::Connection> sql_connection_;
+
+  DISALLOW_COPY_AND_ASSIGN(AffiliationDatabase);
+};
+
+}  // namespace password_manager
+
+#endif  // COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_AFFILIATION_DATABASE_H_