sync: Implement per-type GetCommitIds

sync/engine/get_commit_ids_command.h

-// Copyright 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.
-
-#ifndef SYNC_ENGINE_GET_COMMIT_IDS_COMMAND_H_
-#define SYNC_ENGINE_GET_COMMIT_IDS_COMMAND_H_
-
-#include <utility>
-#include <vector>
-
-#include "base/compiler_specific.h"
-#include "sync/base/sync_export.h"
-#include "sync/engine/syncer_command.h"
-#include "sync/engine/syncer_util.h"
-#include "sync/sessions/sync_session.h"
-#include "sync/syncable/directory.h"
-
-using std::pair;
-using std::vector;
-
-namespace syncer {
-
-namespace sessions {
-class OrderedCommitSet;
-}
-
-// A class that contains the code used to search the syncable::Directory for
-// locally modified items that are ready to be committed to the server.
-//
-// See SyncerCommand documentation for more info.
-class SYNC_EXPORT_PRIVATE GetCommitIdsCommand : public SyncerCommand {
-  friend class SyncerTest;
-
- public:
-  // The batch_size parameter is the maximum number of entries we are allowed
-  // to commit in a single batch.  This value can be modified by the server.
-  //
-  // The ordered_commit_set parameter is an output parameter that will contain a
-  // set of items that are ready to commit.  Its size shall not exceed the
-  // provided batch_size.  This contents of this "set" will be ordered; see the
-  // comments in this class' implementation for details.
-  GetCommitIdsCommand(syncable::BaseTransaction* trans,
-                      ModelTypeSet requested_types,
-                      const size_t commit_batch_size,
-                      sessions::OrderedCommitSet* ordered_commit_set);
-  virtual ~GetCommitIdsCommand();
-
-  // SyncerCommand implementation.
-  virtual SyncerError ExecuteImpl(sessions::SyncSession* session) OVERRIDE;
-
-  // Builds a vector of IDs that should be committed.
-  void BuildCommitIds(syncable::BaseTransaction* write_transaction,
-                      const ModelSafeRoutingInfo& routes,
-                      const std::set<int64>& ready_unsynced_set);
-
-  // Fill |ready_unsynced_set| with all entries from |unsynced_handles| that
-  // are ready to commit.
-  // An entry is not considered ready for commit if any are true:
-  // 1. It's in conflict.
-  // 2. It requires encryption (either the type is encrypted but a passphrase
-  //    is missing from the cryptographer, or the entry itself wasn't properly
-  //    encrypted).
-  // 3. It's type is currently throttled.
-  // 4. It's a delete but has not been committed.
-  void FilterUnreadyEntries(
-      syncable::BaseTransaction* trans,
-      ModelTypeSet throttled_types,
-      ModelTypeSet encrypted_types,
-      bool passphrase_missing,
-      const syncable::Directory::Metahandles& unsynced_handles,
-      std::set<int64>* ready_unsynced_set);
-
- private:
-  // Add all the uncommitted parents of |item| to |result| if they are ready to
-  // commit. Entries are added in root->child order and predecessor->successor
-  // order.
-  // Returns values:
-  //    False: if a parent item was in conflict, and hence no child cannot be
-  //           committed.
-  //    True: if all parents were checked for commit readiness and were added to
-  //          |result| as necessary.
-  bool AddUncommittedParentsAndTheirPredecessors(
-      syncable::BaseTransaction* trans,
-      const ModelSafeRoutingInfo& routes,
-      const std::set<int64>& ready_unsynced_set,
-      const syncable::Entry& item,
-      sessions::OrderedCommitSet* result) const;
-
-  // OrderedCommitSet helpers for adding predecessors in order.
-
-  // Adds |item| to |result| if it's ready for committing and was not already
-  // present.
-  // Prereq: |item| is unsynced.
-  void TryAddItem(const std::set<int64>& ready_unsynced_set,
-                  const syncable::Entry& item,
-                  sessions::OrderedCommitSet* result) const;
-
-  // Adds |item| and all its unsynced predecessors to |result| as necessary.
-  // Entries that are unsynced but not ready to commit are not added to the
-  // list, though they do not stop the traversal.
-  void AddItemThenPredecessors(syncable::BaseTransaction* trans,
-                               const std::set<int64>& ready_unsynced_set,
-                               const syncable::Entry& item,
-                               sessions::OrderedCommitSet* result) const;
-
-  // Appends all commit ready predecessors of |item|, followed by |item| itself,
-  // to |commit_set|.
-  void AddPredecessorsThenItem(syncable::BaseTransaction* trans,
-                               const ModelSafeRoutingInfo& routes,
-                               const std::set<int64>& ready_unsynced_set,
-                               const syncable::Entry& item,
-                               sessions::OrderedCommitSet* commit_set) const;
-
-  bool IsCommitBatchFull() const;
-
-  void AddCreatesAndMoves(syncable::BaseTransaction* write_transaction,
-                          const ModelSafeRoutingInfo& routes,
-                          const std::set<int64>& ready_unsynced_set);
-
-  void AddDeletes(syncable::BaseTransaction* write_transaction,
-                  const std::set<int64>& ready_unsynced_set);
-
-  // A pointer to a valid transaction not owned by this class.
-  syncable::BaseTransaction* trans_;
-
-  // The set of types from which to draw commit IDs.
-  const ModelTypeSet requested_types_;
-
-  // Input parameter; see constructor comment.
-  const size_t requested_commit_batch_size_;
-
-  // Output parameter; see constructor comment.
-  sessions::OrderedCommitSet* commit_set_;
-
-  DISALLOW_COPY_AND_ASSIGN(GetCommitIdsCommand);
-};
-
-}  // namespace syncer
-
-#endif  // SYNC_ENGINE_GET_COMMIT_IDS_COMMAND_H_