components/subresource_filter/content/browser/ruleset_version.h

// Copyright 2018 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_SUBRESOURCE_FILTER_CONTENT_BROWSER_RULESET_VERSION_H_
#define COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_RULESET_VERSION_H_

#include <memory>
#include <string>

#include "base/files/file_path.h"

class PrefRegistrySimple;
class PrefService;

namespace base {
namespace trace_event {
class TracedValue;
}  // namespace trace_event
}  // namespace base

namespace subresource_filter {

// Encapsulates information about a version of unindexed subresource
// filtering rules on disk.
struct UnindexedRulesetInfo {
  UnindexedRulesetInfo();
  ~UnindexedRulesetInfo();

  // The version of the ruleset contents. Because the wire format of unindexed
  // rules is expected to be stable over time (at least backwards compatible),
  // the unindexed ruleset is uniquely identified by its content version.
  //
  // The version string must not be empty, but can be any string otherwise.
  // There is no ordering defined on versions.
  std::string content_version;

  // The path to the file containing the unindexed subresource filtering rules.
  base::FilePath ruleset_path;

  // The (optional) path to a file containing the applicable license, which will
  // be copied next to the indexed ruleset. For convenience, the lack of license
  // can be indicated not only by setting |license_path| to empty, but also by
  // setting it to any non existent path.
  base::FilePath license_path;
};

// Encapsulates the combination of the binary format version of the indexed
// ruleset, and the version of the ruleset contents.
//
// In contrast to the unindexed ruleset, the binary format of the index data
// structures is expected to evolve over time, so the indexed ruleset is
// identified by a pair of versions: the content version of the rules that have
// been indexed; and the binary format version of the indexed data structures.
// It also contains a checksum of the data, to ensure it hasn't been corrupted.
struct IndexedRulesetVersion {
  IndexedRulesetVersion();
  IndexedRulesetVersion(const std::string& content_version, int format_version);
  ~IndexedRulesetVersion();
  IndexedRulesetVersion& operator=(const IndexedRulesetVersion&);

  static void RegisterPrefs(PrefRegistrySimple* registry);
  static int CurrentFormatVersion();

  bool IsValid() const;
  bool IsCurrentFormatVersion() const;

  void SaveToPrefs(PrefService* local_state) const;
  void ReadFromPrefs(PrefService* local_state);

  std::unique_ptr<base::trace_event::TracedValue> ToTracedValue() const;

  std::string content_version;
  int format_version = 0;
  int checksum = 0;
};

}  // namespace subresource_filter

#endif  // COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_RULESET_VERSION_H_