[Sync] Move 'sync' target to sync/

chrome/browser/sync/sessions/sync_session.h

-// Copyright (c) 2012 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.
-
-// A class representing an attempt to synchronize the local syncable data
-// store with a sync server. A SyncSession instance is passed as a stateful
-// bundle to and from various SyncerCommands with the goal of converging the
-// client view of data with that of the server. The commands twiddle with
-// session status in response to events and hiccups along the way, set and
-// query session progress with regards to conflict resolution and applying
-// server updates, and access the SyncSessionContext for the current session
-// via SyncSession instances.
-
-#ifndef CHROME_BROWSER_SYNC_SESSIONS_SYNC_SESSION_H_
-#define CHROME_BROWSER_SYNC_SESSIONS_SYNC_SESSION_H_
-#pragma once
-
-#include <map>
-#include <set>
-#include <string>
-#include <utility>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/time.h"
-#include "chrome/browser/sync/engine/model_safe_worker.h"
-#include "chrome/browser/sync/sessions/ordered_commit_set.h"
-#include "chrome/browser/sync/sessions/session_state.h"
-#include "chrome/browser/sync/sessions/status_controller.h"
-#include "chrome/browser/sync/sessions/sync_session_context.h"
-#include "chrome/browser/sync/syncable/model_type.h"
-#include "chrome/browser/sync/util/extensions_activity_monitor.h"
-
-namespace syncable {
-class WriteTransaction;
-}
-
-namespace browser_sync {
-class ModelSafeWorker;
-
-namespace sessions {
-
-class SyncSession {
- public:
-  // The Delegate services events that occur during the session requiring an
-  // explicit (and session-global) action, as opposed to events that are simply
-  // recorded in per-session state.
-  class Delegate {
-   public:
-    // The client was throttled and should cease-and-desist syncing activity
-    // until the specified time.
-    virtual void OnSilencedUntil(const base::TimeTicks& silenced_until) = 0;
-
-    // Silenced intervals can be out of phase with individual sessions, so the
-    // delegate is the only thing that can give an authoritative answer for
-    // "is syncing silenced right now". This shouldn't be necessary very often
-    // as the delegate ensures no session is started if syncing is silenced.
-    // ** Note **  This will return true if silencing commenced during this
-    // session and the interval has not yet elapsed, but the contract here is
-    // solely based on absolute time values. So, this cannot be used to infer
-    // that any given session _instance_ is silenced.  An example of reasonable
-    // use is for UI reporting.
-    virtual bool IsSyncingCurrentlySilenced() = 0;
-
-    // The client has been instructed to change its short poll interval.
-    virtual void OnReceivedShortPollIntervalUpdate(
-        const base::TimeDelta& new_interval) = 0;
-
-    // The client has been instructed to change its long poll interval.
-    virtual void OnReceivedLongPollIntervalUpdate(
-        const base::TimeDelta& new_interval) = 0;
-
-    // The client has been instructed to change its sessions commit
-    // delay.
-    virtual void OnReceivedSessionsCommitDelay(
-        const base::TimeDelta& new_delay) = 0;
-
-    // The client needs to cease and desist syncing at once.  This occurs when
-    // the Syncer detects that the backend store has fundamentally changed or
-    // is a different instance altogether (e.g. swapping from a test instance
-    // to production, or a global stop syncing operation has wiped the store).
-    // TODO(lipalani) : Replace this function with the one below. This function
-    // stops the current sync cycle and purges the client. In the new model
-    // the former would be done by the |SyncProtocolError| and
-    // the latter(which is an action) would be done in ProfileSyncService
-    // along with the rest of the actions.
-    virtual void OnShouldStopSyncingPermanently() = 0;
-
-    // Called for the syncer to respond to the error sent by the server.
-    virtual void OnSyncProtocolError(
-        const sessions::SyncSessionSnapshot& snapshot) = 0;
-
-   protected:
-    virtual ~Delegate() {}
-  };
-
-  SyncSession(SyncSessionContext* context,
-              Delegate* delegate,
-              const SyncSourceInfo& source,
-              const ModelSafeRoutingInfo& routing_info,
-              const std::vector<ModelSafeWorker*>& workers);
-  ~SyncSession();
-
-  // Builds a thread-safe and read-only copy of the current session state.
-  SyncSessionSnapshot TakeSnapshot() const;
-
-  // Builds and sends a snapshot to the session context's listeners.
-  void SendEventNotification(SyncEngineEvent::EventCause cause);
-
-  // Returns true if this session contains data that should go through the sync
-  // engine again.
-  bool HasMoreToSync() const;
-
-  // Returns true if there we did not detect any errors in this session.
-  //
-  // There are many errors that could prevent a sync cycle from succeeding.
-  // These include invalid local state, inability to contact the server,
-  // inability to authenticate with the server, and server errors.  What they
-  // have in common is that the we either need to take some action and then
-  // retry the sync cycle or, in the case of transient errors, retry after some
-  // backoff timer has expired.  Most importantly, the SyncScheduler should not
-  // assume that the original action that triggered the sync cycle (ie. a nudge
-  // or a notification) has been properly serviced.
-  //
-  // This function also returns false if SyncShare has not been called on this
-  // session yet, or if ResetTransientState() has been called on this session
-  // since the last call to SyncShare.
-  bool Succeeded() const;
-
-  // Collects all state pertaining to how and why |s| originated and unions it
-  // with corresponding state in |this|, leaving |s| unchanged.  Allows |this|
-  // to take on the responsibilities |s| had (e.g. certain data types) in the
-  // next SyncShare operation using |this|, rather than needed two separate
-  // sessions.
-  void Coalesce(const SyncSession& session);
-
-  // Compares the routing_info_, workers and payload map with the passed in
-  // session. Purges types from the above 3 which are not in session. Useful
-  // to update the sync session when the user has disabled some types from
-  // syncing.
-  void RebaseRoutingInfoWithLatest(const SyncSession& session);
-
-  // Should be called any time |this| is being re-used in a new call to
-  // SyncShare (e.g., HasMoreToSync returned true).
-  void PrepareForAnotherSyncCycle();
-
-  // TODO(akalin): Split this into context() and mutable_context().
-  SyncSessionContext* context() const { return context_; }
-  Delegate* delegate() const { return delegate_; }
-  syncable::WriteTransaction* write_transaction() { return write_transaction_; }
-  const StatusController& status_controller() const {
-    return *status_controller_.get();
-  }
-  StatusController* mutable_status_controller() {
-    return status_controller_.get();
-  }
-
-  const ExtensionsActivityMonitor::Records& extensions_activity() const {
-    return extensions_activity_;
-  }
-  ExtensionsActivityMonitor::Records* mutable_extensions_activity() {
-    return &extensions_activity_;
-  }
-
-  const std::vector<ModelSafeWorker*>& workers() const { return workers_; }
-  const ModelSafeRoutingInfo& routing_info() const { return routing_info_; }
-  const SyncSourceInfo& source() const { return source_; }
-
-  // Returns the set of groups which have enabled types.
-  const std::set<ModelSafeGroup>& GetEnabledGroups() const;
-
-  // Returns the set of enabled groups that have conflicts.
-  std::set<ModelSafeGroup> GetEnabledGroupsWithConflicts() const;
-
-  // Returns the set of enabled groups that have verified updates.
-  std::set<ModelSafeGroup> GetEnabledGroupsWithVerifiedUpdates() const;
-
- private:
-  // Extend the encapsulation boundary to utilities for internal member
-  // assignments. This way, the scope of these actions is explicit, they can't
-  // be overridden, and assigning is always accompanied by unassigning.
-  friend class ScopedSetSessionWriteTransaction;
-
-  // The context for this session, guaranteed to outlive |this|.
-  SyncSessionContext* const context_;
-
-  // The source for initiating this sync session.
-  SyncSourceInfo source_;
-
-  // Information about extensions activity since the last successful commit.
-  ExtensionsActivityMonitor::Records extensions_activity_;
-
-  // Used to allow various steps to share a transaction. Can be NULL.
-  syncable::WriteTransaction* write_transaction_;
-
-  // The delegate for this session, must never be NULL.
-  Delegate* const delegate_;
-
-  // Our controller for various status and error counters.
-  scoped_ptr<StatusController> status_controller_;
-
-  // The set of active ModelSafeWorkers for the duration of this session.
-  // This can change if this session is Coalesce()'d with another.
-  std::vector<ModelSafeWorker*> workers_;
-
-  // The routing info for the duration of this session, dictating which
-  // datatypes should be synced and which workers should be used when working
-  // on those datatypes.
-  ModelSafeRoutingInfo routing_info_;
-
-  // The set of groups with enabled types.  Computed from
-  // |routing_info_|.
-  std::set<ModelSafeGroup> enabled_groups_;
-
-  DISALLOW_COPY_AND_ASSIGN(SyncSession);
-};
-
-// Installs a WriteTransaction to a given session and later clears it when the
-// utility falls out of scope. Transactions are not nestable, so it is an error
-// to try and use one of these if the session already has a transaction.
-class ScopedSetSessionWriteTransaction {
- public:
-  ScopedSetSessionWriteTransaction(SyncSession* session,
-                                   syncable::WriteTransaction* trans)
-      : session_(session) {
-    DCHECK(!session_->write_transaction_);
-    session_->write_transaction_ = trans;
-  }
-  ~ScopedSetSessionWriteTransaction() { session_->write_transaction_ = NULL; }
-
- private:
-  SyncSession* session_;
-  DISALLOW_COPY_AND_ASSIGN(ScopedSetSessionWriteTransaction);
-};
-
-}  // namespace sessions
-}  // namespace browser_sync
-
-#endif  // CHROME_BROWSER_SYNC_SESSIONS_SYNC_SESSION_H_