Move some files from sync/engine to internal_api

chrome/browser/sync/engine/change_reorder_buffer.cc

-// Copyright (c) 2011 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.
-
-#include "chrome/browser/sync/engine/change_reorder_buffer.h"
-
-#include <limits>
-#include <queue>
-#include <set>
-#include <utility>  // for pair<>
-#include <vector>
-
-#include "chrome/browser/sync/internal_api/read_node.h"
-#include "chrome/browser/sync/syncable/model_type.h"
-#include "chrome/browser/sync/syncable/syncable.h"
-
-using std::numeric_limits;
-using std::pair;
-using std::queue;
-using std::set;
-using std::vector;
-
-namespace sync_api {
-
-// Traversal provides a way to collect a set of nodes from the syncable
-// directory structure and then traverse them, along with any intermediate
-// nodes, in a top-down fashion, starting from a single common ancestor.  A
-// Traversal starts out empty and is grown by means of the ExpandToInclude
-// method.  Once constructed, the top(), begin_children(), and end_children()
-// methods can be used to explore the nodes in root-to-leaf order.
-class ChangeReorderBuffer::Traversal {
- public:
-  typedef pair<int64, int64> ParentChildLink;
-  typedef set<ParentChildLink> LinkSet;
-
-  Traversal() : top_(kInvalidId) { }
-
-  // Expand the traversal so that it includes the node indicated by
-  // |child_handle|.
-  void ExpandToInclude(syncable::BaseTransaction* trans,
-                       int64 child_handle) {
-    // If |top_| is invalid, this is the first insertion -- easy.
-    if (top_ == kInvalidId) {
-      top_ = child_handle;
-      return;
-    }
-
-    int64 node_to_include = child_handle;
-    while (node_to_include != kInvalidId && node_to_include != top_) {
-      int64 node_parent = 0;
-
-      syncable::Entry node(trans, syncable::GET_BY_HANDLE, node_to_include);
-      CHECK(node.good());
-      if (node.Get(syncable::ID).IsRoot()) {
-        // If we've hit the root, and the root isn't already in the tree
-        // (it would have to be |top_| if it were), start a new expansion
-        // upwards from |top_| to unite the original traversal with the
-        // path we just added that goes from |child_handle| to the root.
-        node_to_include = top_;
-        top_ = node.Get(syncable::META_HANDLE);
-      } else {
-        // Otherwise, get the parent ID so that we can add a ParentChildLink.
-        syncable::Entry parent(trans, syncable::GET_BY_ID,
-                             node.Get(syncable::PARENT_ID));
-        CHECK(parent.good());
-        node_parent = parent.Get(syncable::META_HANDLE);
-
-        ParentChildLink link(node_parent, node_to_include);
-
-        // If the link exists in the LinkSet |links_|, we don't need to search
-        // any higher; we are done.
-        if (links_.find(link) != links_.end())
-          return;
-
-        // Otherwise, extend |links_|, and repeat on the parent.
-        links_.insert(link);
-        node_to_include = node_parent;
-      }
-    }
-  }
-
-  // Return the top node of the traversal.  Use this as a starting point
-  // for walking the tree.
-  int64 top() const { return top_; }
-
-  // Return an iterator corresponding to the first child (in the traversal)
-  // of the node specified by |parent_id|.  Iterate this return value until
-  // it is equal to the value returned by end_children(parent_id).  The
-  // enumeration thus provided is unordered.
-  LinkSet::const_iterator begin_children(int64 parent_id) const {
-    return links_.upper_bound(
-        ParentChildLink(parent_id, numeric_limits<int64>::min()));
-  }
-
-  // Return an iterator corresponding to the last child in the traversal
-  // of the node specified by |parent_id|.
-  LinkSet::const_iterator end_children(int64 parent_id) const {
-    return begin_children(parent_id + 1);
-  }
-
- private:
-  // The topmost point in the directory hierarchy that is in the traversal,
-  // and thus the first node to be traversed.  If the traversal is empty,
-  // this is kInvalidId.  If the traversal contains exactly one member, |top_|
-  // will be the solitary member, and |links_| will be empty.
-  int64 top_;
-  // A set of single-level links that compose the traversal below |top_|.  The
-  // (parent, child) ordering of values enables efficient lookup of children
-  // given the parent handle, which is used for top-down traversal.  |links_|
-  // is expected to be connected -- every node that appears as a parent in a
-  // link must either appear as a child of another link, or else be the
-  // topmost node, |top_|.
-  LinkSet links_;
-
-  DISALLOW_COPY_AND_ASSIGN(Traversal);
-};
-
-ChangeReorderBuffer::ChangeReorderBuffer() {
-}
-
-ChangeReorderBuffer::~ChangeReorderBuffer() {
-}
-
-void ChangeReorderBuffer::GetAllChangesInTreeOrder(
-    const BaseTransaction* sync_trans,
-    vector<ChangeRecord>* changelist) {
-  syncable::BaseTransaction* trans = sync_trans->GetWrappedTrans();
-
-  // Step 1: Iterate through the operations, doing three things:
-  // (a) Push deleted items straight into the |changelist|.
-  // (b) Construct a traversal spanning all non-deleted items.
-  // (c) Construct a set of all parent nodes of any position changes.
-  set<int64> parents_of_position_changes;
-  Traversal traversal;
-
-  OperationMap::const_iterator i;
-  for (i = operations_.begin(); i != operations_.end(); ++i) {
-    if (i->second == OP_DELETE) {
-      ChangeRecord record;
-      record.id = i->first;
-      record.action = ChangeRecord::ACTION_DELETE;
-      if (specifics_.find(record.id) != specifics_.end())
-        record.specifics = specifics_[record.id];
-      if (extra_data_.find(record.id) != extra_data_.end())
-        record.extra = extra_data_[record.id];
-      changelist->push_back(record);
-    } else {
-      traversal.ExpandToInclude(trans, i->first);
-      if (i->second == OP_ADD ||
-          i->second == OP_UPDATE_POSITION_AND_PROPERTIES) {
-        ReadNode node(sync_trans);
-        CHECK(node.InitByIdLookup(i->first));
-
-        // We only care about parents of entry's with position-sensitive models.
-        if (syncable::ShouldMaintainPosition(
-                node.GetEntry()->GetModelType())) {
-          parents_of_position_changes.insert(node.GetParentId());
-        }
-      }
-    }
-  }
-
-  // Step 2: Breadth-first expansion of the traversal, enumerating children in
-  // the syncable sibling order if there were any position updates.
-  queue<int64> to_visit;
-  to_visit.push(traversal.top());
-  while (!to_visit.empty()) {
-    int64 next = to_visit.front();
-    to_visit.pop();
-
-    // If the node has an associated action, output a change record.
-    i = operations_.find(next);
-    if (i != operations_.end()) {
-      ChangeRecord record;
-      record.id = next;
-      if (i->second == OP_ADD)
-        record.action = ChangeRecord::ACTION_ADD;
-      else
-        record.action = ChangeRecord::ACTION_UPDATE;
-      if (specifics_.find(record.id) != specifics_.end())
-        record.specifics = specifics_[record.id];
-      if (extra_data_.find(record.id) != extra_data_.end())
-        record.extra = extra_data_[record.id];
-      changelist->push_back(record);
-    }
-
-    // Now add the children of |next| to |to_visit|.
-    if (parents_of_position_changes.find(next) ==
-        parents_of_position_changes.end()) {
-        // No order changes on this parent -- traverse only the nodes listed
-        // in the traversal (and not in sibling order).
-        Traversal::LinkSet::const_iterator j = traversal.begin_children(next);
-        Traversal::LinkSet::const_iterator end = traversal.end_children(next);
-        for (; j != end; ++j) {
-          CHECK(j->first == next);
-          to_visit.push(j->second);
-        }
-    } else {
-      // There were ordering changes on the children of this parent, so
-      // enumerate all the children in the sibling order.
-      syncable::Entry parent(trans, syncable::GET_BY_HANDLE, next);
-      syncable::Id id = trans->directory()->
-          GetFirstChildId(trans, parent.Get(syncable::ID));
-      while (!id.IsRoot()) {
-        syncable::Entry child(trans, syncable::GET_BY_ID, id);
-        CHECK(child.good());
-        int64 handle = child.Get(syncable::META_HANDLE);
-        to_visit.push(handle);
-        // If there is no operation on this child node, record it as as an
-        // update, so that the listener gets notified of all nodes in the new
-        // ordering.
-        if (operations_.find(handle) == operations_.end())
-          operations_[handle] = OP_UPDATE_POSITION_AND_PROPERTIES;
-        id = child.Get(syncable::NEXT_ID);
-      }
-    }
-  }
-}
-
-}  // namespace sync_api