Relieve SyncerSession,SyncCycleState, SyncProcessState, SyncerSession, Syncer...

chrome/browser/sync/sessions/session_state.h

+// Copyright (c) 2009 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.
+
+// The 'sessions' namespace comprises all the pieces of state that are
+// combined to form a SyncSession instance. In that way, it can be thought of
+// as an extension of the SyncSession type itself. Session scoping gives
+// context to things like "conflict progress", "update progress", etc, and the
+// separation this file provides allows clients to only include the parts they
+// need rather than the entire session stack.
+
+#ifndef CHROME_BROWSER_SYNC_SESSIONS_SESSION_STATE_H_
+#define CHROME_BROWSER_SYNC_SESSIONS_SESSION_STATE_H_
+
+#include <set>
+
+#include "base/basictypes.h"
+#include "chrome/browser/sync/engine/syncer_types.h"
+#include "chrome/browser/sync/engine/syncproto.h"
+
+namespace syncable {
+class DirectoryManager;
+}
+
+namespace browser_sync {
+namespace sessions {
+
+class UpdateProgress;
+
+// Data describing the progress made relative to the changelog on the server.
+struct ChangelogProgress {
+  ChangelogProgress() : current_sync_timestamp(0),
+                        num_server_changes_remaining(0) {}
+  int64 current_sync_timestamp;
+  int64 num_server_changes_remaining;
+};
+
+// Data pertaining to the status of an active Syncer object.
+struct SyncerStatus {
+  SyncerStatus()
+      : over_quota(false), invalid_store(false), syncer_stuck(false),
+        syncing(false), num_successful_commits(0) {}
+  bool over_quota;
+  // True when we get such an INVALID_STORE error from the server.
+  bool invalid_store;
+  // True iff we're stuck.
+  bool syncer_stuck;
+  bool syncing;
+  int num_successful_commits;
+};
+
+// Counters for various errors that can occur repeatedly during a sync session.
+struct ErrorCounters {
+  ErrorCounters() : num_conflicting_commits(0),
+                    consecutive_problem_get_updates(0),
+                    consecutive_problem_commits(0),
+                    consecutive_transient_error_commits(0),
+                    consecutive_errors(0) {}
+  int num_conflicting_commits;
+  // Is reset when we get any updates (not on pings) and increments whenever
+  // the request fails.
+  int consecutive_problem_get_updates;
+
+  // Consecutive_problem_commits_ resets whenever we commit any number of items
+  // and increments whenever all commits fail for any reason.
+  int consecutive_problem_commits;
+
+  // Number of commits hitting transient errors since the last successful
+  // commit.
+  int consecutive_transient_error_commits;
+
+  // Incremented when get_updates fails, commit fails, and when hitting
+  // transient errors. When any of these succeed, this counter is reset.
+  // TODO(chron): Reduce number of weird counters we use.
+  int consecutive_errors;
+};
+
+// An immutable snapshot of state from a SyncSession.  Convenient to use as
+// part of notifications as it is inherently thread-safe.
+struct SyncSessionSnapshot {
+  SyncSessionSnapshot(const SyncerStatus& syncer_status,
+      const ErrorCounters& errors,
+      const ChangelogProgress& changelog_progress, bool is_share_usable,
+      bool more_to_sync, bool is_silenced, int64 unsynced_count,
+      int num_conflicting_updates, bool did_commit_items)
+      : syncer_status(syncer_status),
+        errors(errors),
+        changelog_progress(changelog_progress),
+        is_share_usable(is_share_usable),
+        has_more_to_sync(more_to_sync),
+        is_silenced(is_silenced),
+        unsynced_count(unsynced_count),
+        num_conflicting_updates(num_conflicting_updates),
+        did_commit_items(did_commit_items) {}
+  const SyncerStatus syncer_status;
+  const ErrorCounters errors;
+  const ChangelogProgress changelog_progress;
+  const bool is_share_usable;
+  const bool has_more_to_sync;
+  const bool is_silenced;
+  const int64 unsynced_count;
+  const int num_conflicting_updates;
+  const bool did_commit_items;
+};
+
+// Tracks progress of conflicts and their resolution using conflict sets.
+class ConflictProgress {
+ public:
+  ConflictProgress() : progress_changed_(false) {}
+  ~ConflictProgress() { CleanupSets(); }
+  // Various iterators, size, and retrieval functions for conflict sets.
+  IdToConflictSetMap::const_iterator IdToConflictSetBegin() const;
+  IdToConflictSetMap::const_iterator IdToConflictSetEnd() const;
+  IdToConflictSetMap::size_type IdToConflictSetSize() const;
+  IdToConflictSetMap::const_iterator IdToConflictSetFind(
+      const syncable::Id& the_id) const;
+  const ConflictSet* IdToConflictSetGet(const syncable::Id& the_id);
+  std::set<ConflictSet*>::const_iterator ConflictSetsBegin() const;
+  std::set<ConflictSet*>::const_iterator ConflictSetsEnd() const;
+  std::set<ConflictSet*>::size_type ConflictSetsSize() const;
+
+  // Various mutators for tracking commit conflicts.
+  void AddConflictingItemById(const syncable::Id& the_id);
+  void EraseConflictingItemById(const syncable::Id& the_id);
+  int ConflictingItemsSize() const { return conflicting_item_ids_.size(); }
+  std::set<syncable::Id>::iterator ConflictingItemsBegin();
+  std::set<syncable::Id>::const_iterator ConflictingItemsBeginConst() const;
+  std::set<syncable::Id>::const_iterator ConflictingItemsEnd() const;
+
+  void MergeSets(const syncable::Id& set1, const syncable::Id& set2);
+  void CleanupSets();
+
+  bool progress_changed() const { return progress_changed_; }
+  void reset_progress_changed() { progress_changed_ = false; }
+ private:
+  // TODO(sync): move away from sets if it makes more sense.
+  std::set<syncable::Id> conflicting_item_ids_;
+  std::map<syncable::Id, ConflictSet*> id_to_conflict_set_;
+  std::set<ConflictSet*> conflict_sets_;
+
+  // Whether a conflicting item was added or removed since
+  // the last call to reset_progress_changed(), if any.
+  bool progress_changed_;
+};
+
+typedef std::pair<VerifyResult, sync_pb::SyncEntity> VerifiedUpdate;
+typedef std::pair<UpdateAttemptResponse, syncable::Id> AppliedUpdate;
+
+// Tracks update application and verification.
+class UpdateProgress {
+ public:
+  void AddVerifyResult(const VerifyResult& verify_result,
+                       const sync_pb::SyncEntity& entity);
+
+  // Log a successful or failing update attempt.
+  void AddAppliedUpdate(const UpdateAttemptResponse& response,
+                        const syncable::Id& id);
+
+  // Various iterators.
+  std::vector<AppliedUpdate>::iterator AppliedUpdatesBegin();
+  std::vector<VerifiedUpdate>::const_iterator VerifiedUpdatesBegin() const;
+  std::vector<AppliedUpdate>::const_iterator AppliedUpdatesEnd() const;
+  std::vector<VerifiedUpdate>::const_iterator VerifiedUpdatesEnd() const;
+
+  // Returns the number of update application attempts.  This includes both
+  // failures and successes.
+  int AppliedUpdatesSize() const { return applied_updates_.size(); }
+  int VerifiedUpdatesSize() const { return verified_updates_.size(); }
+  bool HasVerifiedUpdates() const { return !verified_updates_.empty(); }
+  bool HasAppliedUpdates() const { return !applied_updates_.empty(); }
+
+  // Count the number of successful update applications that have happend this
+  // cycle. Note that if an item is successfully applied twice, it will be
+  // double counted here.
+  int SuccessfullyAppliedUpdateCount() const;
+
+  // Returns true if at least one update application failed due to a conflict
+  // during this sync cycle.
+  bool HasConflictingUpdates() const;
+
+ private:
+  // Some container for updates that failed verification.
+  std::vector<VerifiedUpdate> verified_updates_;
+
+  // Stores the result of the various ApplyUpdate attempts we've made.
+  // May contain duplicate entries.
+  std::vector<AppliedUpdate> applied_updates_;
+};
+
+// Transient state is a physical grouping of session state that can be reset
+// while that session is in flight.  This is useful when multiple
+// SyncShare operations take place during a session.
+struct TransientState {
+  TransientState()
+    : conflict_sets_built(false),
+      conflicts_resolved(false),
+      items_committed(false),
+      timestamp_dirty(false) {}
+  UpdateProgress update_progress;
+  ClientToServerMessage commit_message;
+  ClientToServerResponse commit_response;
+  ClientToServerResponse updates_response;
+  std::vector<int64> unsynced_handles;
+  std::vector<syncable::Id> commit_ids;
+  bool conflict_sets_built;
+  bool conflicts_resolved;
+  bool items_committed;
+  bool timestamp_dirty;
+};
+
+}  // namespace sessions
+}  // namespace browser_sync
+
+#endif  // CHROME_BROWSER_SYNC_SESSIONS_SESSION_STATE_H_