/// <summary>
/// Direct commit of data is appended on the existing nodes
/// </summary>
/// <param name="changeSet">Changes</param>
private void CommitDirect(AppendableChangeSet <Guid, object, EdgeData> changeSet)
{
// Add all nodes to the provider
foreach (Guid nodeId in changeSet.Nodes.EnumerateNodes())
{
var node = changeSet.Nodes.GetNode(nodeId, NodeAccess.Read);
nodes.SetNode(nodeId, node);
}
// Store the change set in the change set provider
changeSetProvider.SetChangeSet(changeSet);
// Calculate collected nodes in the source changeset
collectedNodesProvider.StoreChangeset(changeSet, mutableParentProvider, immutableParentProvider);
// Update parent information in the parent map provider
mutableParentProvider.UpdateParents(changeSet, collectedNodesProvider);
// Update parent information in the immutable parent map provider
immutableParentProvider.UpdateParents(changeSet, collectedNodesProvider);
// Add new snapshot making it visible
snapshotsService.AddSnapshot(changeSet.DestinationSnapshotId);
#if DEBUG
Debug.WriteLine("Created snapshot " + changeSet.DestinationSnapshotId);
Utils.LogNodesRecursive(changeSet.DestinationSnapshotId, nodes, changeSet.Nodes, 0, new Hashtable(), typesService);
Debug.WriteLine("---------------------------------------------");
Debug.WriteLine("Collected nodes are:");
var enumerator = collectedNodesProvider.GetEdges(changeSet.SourceSnapshotId);
if (enumerator != null)
{
using (enumerator)
{
while (enumerator.MoveNext())
{
Debug.WriteLine(enumerator.Current.ToNodeId);
}
}
}
Debug.WriteLine("---------------------------------------------");
#endif
}
/// <summary>
/// Performs cleanup of historic data which is not used
/// </summary>
public void Cleanup()
{
lock (cleanupSync)
{
// Clean expired workspaces
trackingWorkspaceStateProvider.Cleanup();
// Determine which snapshots are used
var usedSnapshots = trackingWorkspaceStateProvider.UsedSnapshotIds();
// Ensure that last is always used
var lastSnapshot = snapshotsService.GetLatestSnapshotId();
if (!usedSnapshots.Contains(lastSnapshot))
{
usedSnapshots.Add(lastSnapshot);
}
// Determine which snapshots are not used, remove them from shapshots list
var unusedSnapshots = snapshotsService.RemoveUnusedSnapshots(usedSnapshots);
// Process removed snapshots
foreach (var snapshotId in unusedSnapshots)
{
// Garbage collect nodes which are not used
var collectedNodesEnumerator = collectedNodesProvider.GetEdges(snapshotId);
if (collectedNodesEnumerator != null)
{
using (collectedNodesEnumerator)
{
while (collectedNodesEnumerator.MoveNext())
{
provider.Remove(collectedNodesEnumerator.Current.ToNodeId);
}
}
}
// Remove change set history information
changeSetProvider.RemoveChangeSet(snapshotId);
// Remove information about collected nodes in the snapshot
collectedNodesProvider.Cleanup(snapshotId);
// Remove the snapshot node
provider.Remove(snapshotId);
}
}
}
/// <summary>
/// Updates parent information based on change set
/// </summary>
/// <param name="changeSet">Data change description</param>
public void UpdateParents(AppendableChangeSet <Guid, object, EdgeData> changeSet, ICollectedNodesProvider <Guid, object, EdgeData> collectedNodesProvider)
{
lock (dataSync)
{
if (changeSet.SourceSnapshotId != lastSnapshotId)
{
// If the last snapshot is not in the memory, clear and return
nodes.Clear();
createdNodes = false;
return;
}
using (var enumerator = collectedNodesProvider.GetEdges(changeSet.SourceSnapshotId))
{
if (enumerator != null)
{
while (enumerator.MoveNext())
{
if (nodes.Contains(enumerator.Current.ToNodeId))
{
DeleteTree(enumerator.Current.ToNodeId);
}
// Get the old node
var node = dataNodeProvider.GetNode(enumerator.Current.ToNodeId, NodeAccess.Read);
// For every edge in old node
foreach (var edge in node.Edges.Values)
{
if (EdgeFilter(edge))
{
// Find holder in destination snapshot for referenced node
if (nodes.Contains(edge.ToNodeId))
{
BPlusTreeOperations.RemoveEdge(nodes, edge.ToNodeId, new EdgeData(EdgeType.Contains, enumerator.Current.ToNodeId), ParentsTreeOrder);
}
}
}
}
}
}
// Add new node ids to map
foreach (Guid nodeId in changeSet.Nodes.EnumerateNodes())
{
var holderNode = BPlusTreeOperations.CreateRootNode(NodeType.Collection, nodeId);
nodes.SetNode(nodeId, holderNode);
}
// Add reused nodes if needed
foreach (Guid nodeId in changeSet.ReusedNodes.Keys)
{
if (!nodes.Contains(nodeId))
{
var holderNode = BPlusTreeOperations.CreateRootNode(NodeType.Collection, nodeId);
nodes.SetNode(nodeId, holderNode);
}
}
// Add new node edges to map
foreach (Guid nodeId in changeSet.Nodes.EnumerateNodes())
{
var node = changeSet.Nodes.GetNode(nodeId, NodeAccess.Read);
// Add this id into all referenced nodes
foreach (var edge in node.Edges.Values)
{
if (EdgeFilter(edge))
{
var edgeData = new EdgeData(EdgeType.Contains, nodeId);
Edge <Guid, EdgeData> existingEdge = null;
if (!BPlusTreeOperations.TryFindEdge(nodes, edge.ToNodeId, edgeData, out existingEdge))
{
BPlusTreeOperations.InsertEdge(nodes, edge.ToNodeId, new Edge <Guid, EdgeData>(nodeId, edgeData), ParentsTreeOrder);
}
}
}
}
// Set last snapshot as the destination ID
lastSnapshotId = changeSet.DestinationSnapshotId;
}
}
