/// <summary>
/// Performs a commit
/// </summary>
/// <param name="workspaceId">Workspace ID</param>
/// <param name="changeSet">Changes to commit</param>
/// <returns>Changes which were commited</returns>
public CommitResult <Guid> Commit(Guid workspaceId, IsolatedChangeSet <Guid, object, EdgeData> changeSet)
{
bool isSnapshotIsolation = workspaceStateProvider.WorkspaceIsolationLevel(workspaceId) == IsolationLevel.Snapshot;
if (isSnapshotIsolation)
{
workspaceExclusiveLockProvider.EnterLockExclusive();
}
try
{
lock (commitSync)
{
if (!workspaceStateProvider.IsWorkspaceExpired(workspaceId))
{
var result = commitDataService.AcceptCommit(changeSet);
workspaceStateProvider.UpdateWorspace(workspaceId, result.ResultSnapshotId);
subscriptionManagerService.InvokeEvents(workspaceId, result);
return(result);
}
else
{
throw new TimeoutException("Workspace timeout has elapsed");
}
}
}
finally
{
if (isSnapshotIsolation)
{
workspaceExclusiveLockProvider.ExitLockExclusive();
}
}
}
public RecursiveResolutionParameters(Hashtable subTree, IsolatedNodeProvider destinationProvider, IsolatedNodeProvider sourceProvider, IsolatedChangeSet <Guid, object, EdgeData> changeSet, Dictionary <Guid, Guid> intermediateChanges, Hashtable visitedNodes)
{
this.SubTree = subTree;
this.DestinationProvider = destinationProvider;
this.SourceProvider = sourceProvider;
this.ChangeSet = changeSet;
this.IntermediateChanges = intermediateChanges;
this.VisitedNodes = visitedNodes;
}
/// <summary>
/// Returns node from the nodes list. If node does not exist in the nodes list node from the changeSet is returned.
/// </summary>
/// <param name="nodeId"></param>
/// <param name="changeSet"></param>
/// <returns></returns>
private Node <Guid, object, EdgeData> GetNode(Guid nodeId, IsolatedChangeSet <Guid, object, EdgeData> changeSet)
{
var childNode = nodes.GetNode(nodeId, NodeAccess.ReadWrite);
if (childNode != null)
{
return(childNode);
}
return(changeSet.Nodes.GetNode(nodeId, NodeAccess.ReadWrite));
}
/// <summary>
/// Accepts incoming isolated commit
/// </summary>
/// <param name="isolatedChangeSet">Isolated changeset</param>
/// <returns>Appended changes</returns>
public CommitResult <Guid> AcceptCommit(IsolatedChangeSet <Guid, object, EdgeData> isolatedChangeSet)
{
lock (commitSync)
{
var latestSnapshot = snapshotsService.GetLatestSnapshotId();
if (latestSnapshot.Equals(isolatedChangeSet.SourceSnapshotId))
{
AppendableChangeSet <Guid, object, EdgeData> appendableChangeSet = CreateAppendableChangeSet(isolatedChangeSet.SourceSnapshotId, Guid.NewGuid(), isolatedChangeSet);
// Commit is directly on the last snapshot
CommitDirect(appendableChangeSet);
return(new CommitResult <Guid>(appendableChangeSet.DestinationSnapshotId, appendableChangeSet.Mapping));
}
else
{
// There are snapshots in between
#if DEBUG
Debug.WriteLine("Source snapshot = " + isolatedChangeSet.SourceSnapshotId);
#endif
// Calculate changes between last snapshot and source snapshot
var intermediateChanges = ChangesBetween(isolatedChangeSet.SourceSnapshotId, latestSnapshot);
// Isolate portion of the last snapshot which is relevant for the change set
var subTree = IsolateSubTree(latestSnapshot, isolatedChangeSet, intermediateChanges);
// Create a brand new changeset which is compatible with last snapshot
// Do this by recursive walk through the last snapshot and perform the "compatible" operations done in the incomming changeset
var mergedChangeSet = CreateMergedChangeSet(latestSnapshot, subTree, isolatedChangeSet, intermediateChanges);
// When complete perform the CommitDirect of the new changeset
CommitDirect(mergedChangeSet);
// Start with created change mapping
var mapping = mergedChangeSet.Mapping;
// Merge intermediate changes items to it
foreach (var item in intermediateChanges)
{
AddChangeItem(mapping, item.Key, item.Value);
}
return(new CommitResult <Guid>(mergedChangeSet.DestinationSnapshotId, mapping));
}
}
}
/// <summary>
/// Creates map of node ids in the last snapshot which are affected by changes in the change set.
/// </summary>
/// <param name="snapshotId">Last snapshot</param>
/// <param name="changeSet">Change set which is created</param>
/// <param name="intermediateChanges">Intermediate changes</param>
/// <returns>Table of IDs for nodes which are modified in the last snapshot</returns>
private Hashtable IsolateSubTree(Guid snapshotId, IsolatedChangeSet <Guid, object, EdgeData> changeSet, Dictionary <Guid, Guid> intermediateChanges)
{
Hashtable result = new Hashtable();
Collection <Guid> changes = new Collection <Guid>();
foreach (Guid item in changeSet.Nodes.EnumerateNodes())
{
// Test if item is new or modified
if (changeSet.NodeStates[item] == NodeState.Modified)
{
Guid nodeId = Guid.Empty;
Guid oldNodeId = Guid.Empty;
// Try finding the latest id of the changed item
if (intermediateChanges.TryGetValue(item, out nodeId))
{
oldNodeId = item;
}
else
{
// It was not changed in the meantime, so the original ID should be still in use
nodeId = item;
}
// Remember new node ID with old node ID as value
result.Add(nodeId, oldNodeId);
// Changes
changes.Add(nodeId);
}
}
foreach (var item in changes)
{
AddSubTreeParentsRecursive(snapshotId, item, result);
}
return(result);
}
public string Commit(string workspaceId, object changeSet)
{
Guid guidWorkspaceId = Guid.Parse(workspaceId);
//transform changeSet into IsolatedChangeSet object
IsolatedChangeSet <Guid, object, EdgeData> serverChangeSet = ChangeSetParser.Parse(changeSet);
//commit changes
CommitResult <Guid> commitResult =
ServerContextSingleton.Instance.ServerContext.Commit(guidWorkspaceId, serverChangeSet);
String resultSnapshotId = commitResult.ResultSnapshotId.ToString();
Dictionary <string, string> mapping = new Dictionary <string, string>();
foreach (KeyValuePair <Guid, Guid> mapObject in commitResult.Mapping)
{
mapping.Add(mapObject.Key.ToString(), mapObject.Value.ToString());
}
CommitResult <String> commitResultString = new CommitResult <string>(resultSnapshotId, mapping);
Dictionary <String, CommitResult <String> > rez = new Dictionary <string, CommitResult <string> >();
rez.Add(RESULT, commitResultString);
return(rez.ToJSON());
}
/// <summary>
/// Adds node to delta with recursive pass through node parents
/// </summary>
/// <param name="delta">Provider which will accept new nodes</param>
/// <param name="nodeId">Node ID to add</param>
/// <param name="nodeMapping">Mapping between (old ID)->(new ID)</param>
private void AddNodeToAppendableTreeRecursive(DirectNodeProviderUnsafe<Guid, object, EdgeData> delta, Guid nodeId, Dictionary<Guid, Guid> nodeMapping, Dictionary<Guid, NodeState> nodeStates, IsolatedChangeSet<Guid, object, EdgeData> changeSet)
{
// Skip already added nodes
if (!nodeMapping.ContainsKey(nodeId))
{
// Generate new ID
Guid newId = Guid.NewGuid();
// Check node state
NodeState nodeState = NodeState.None;
changeSet.NodeStates.TryGetValue(nodeId, out nodeState);
switch (nodeState)
{
case NodeState.None:
{
// Register in the mapping
nodeMapping.Add(nodeId, newId);
// Get undelrying node
var node = nodes.GetNode(nodeId, NodeAccess.Read);
var newNode = CloneNode(node);
// Set node to commited
newNode.Commited = true;
// Create edge to previous node
newNode.Previous = nodeId;
// New node is created which is copied from underlying provider
delta.SetNode(newId, newNode);
// This change is defined as modification
nodeStates.Add(newId, NodeState.Modified);
// Add node parents from the current snapshot
using (var enumerator = mutableParentProvider.ParentEdges(changeSet.SourceSnapshotId, nodeId))
{
if (enumerator != null)
{
while (enumerator.MoveNext())
{
AddNodeToAppendableTreeRecursive(delta, enumerator.Current.ToNodeId, nodeMapping, nodeStates, changeSet);
}
}
}
// Update parent nodes
UpdateParentNodes(newId, newNode, nodeState, delta, changeSet);
}
break;
case NodeState.Created:
{
// Read the node
var node = changeSet.Nodes.GetNode(nodeId, NodeAccess.ReadWrite);
// Set node to commited
node.Commited = true;
// There is no previous
node.Previous = Guid.Empty;
// Store to delta
delta.SetNode(nodeId, node);
// This change is defined as creation
nodeStates.Add(nodeId, NodeState.Created);
// Update parent nodes
UpdateParentNodes(nodeId, node, nodeState, delta, changeSet);
}
break;
case NodeState.Modified:
{
// Register in the mapping
nodeMapping.Add(nodeId, newId);
// Read the node
var node = changeSet.Nodes.GetNode(nodeId, NodeAccess.ReadWrite);
// Set node to commited
node.Commited = true;
// Set the previous
node.Previous = nodeId;
// Store to delta
delta.SetNode(newId, node);
// This change is defined as modification
nodeStates.Add(newId, NodeState.Modified);
// Add node parents from the current snapshot
using (var enumerator = mutableParentProvider.ParentEdges(changeSet.SourceSnapshotId, nodeId))
{
while (enumerator.MoveNext())
{
AddNodeToAppendableTreeRecursive(delta, enumerator.Current.ToNodeId, nodeMapping, nodeStates, changeSet);
}
}
// Update parent nodes
UpdateParentNodes(newId, node, nodeState, delta, changeSet);
}
break;
case NodeState.Removed:
{
// Update parent nodes
var node = GetNode(nodeId, changeSet);
UpdateParentNodes(nodeId, node, nodeState, delta, changeSet);
}
break;
default:
throw new ArgumentException(nodeState.ToString());
}
}
}
/// <summary>
/// Accepts incoming isolated commit
/// </summary>
/// <param name="isolatedChangeSet">Isolated changeset</param>
/// <returns>Appended changes</returns>
public CommitResult<Guid> AcceptCommit(IsolatedChangeSet<Guid, object, EdgeData> isolatedChangeSet)
{
lock (commitSync)
{
var latestSnapshot = snapshotsService.GetLatestSnapshotId();
if (latestSnapshot.Equals(isolatedChangeSet.SourceSnapshotId))
{
AppendableChangeSet<Guid, object, EdgeData> appendableChangeSet = CreateAppendableChangeSet(isolatedChangeSet.SourceSnapshotId, Guid.NewGuid(), isolatedChangeSet);
// Commit is directly on the last snapshot
CommitDirect(appendableChangeSet);
return new CommitResult<Guid>(appendableChangeSet.DestinationSnapshotId, appendableChangeSet.Mapping);
}
else
{
// There are snapshots in between
#if DEBUG
Debug.WriteLine("Source snapshot = " + isolatedChangeSet.SourceSnapshotId);
#endif
// Calculate changes between last snapshot and source snapshot
var intermediateChanges = ChangesBetween(isolatedChangeSet.SourceSnapshotId, latestSnapshot);
// Isolate portion of the last snapshot which is relevant for the change set
var subTree = IsolateSubTree(latestSnapshot, isolatedChangeSet, intermediateChanges);
// Create a brand new changeset which is compatible with last snapshot
// Do this by recursive walk through the last snapshot and perform the "compatible" operations done in the incomming changeset
var mergedChangeSet = CreateMergedChangeSet(latestSnapshot, subTree, isolatedChangeSet, intermediateChanges);
// When complete perform the CommitDirect of the new changeset
CommitDirect(mergedChangeSet);
// Start with created change mapping
var mapping = mergedChangeSet.Mapping;
// Merge intermediate changes items to it
foreach(var item in intermediateChanges)
{
AddChangeItem(mapping, item.Key, item.Value);
}
return new CommitResult<Guid>(mergedChangeSet.DestinationSnapshotId, mapping);
}
}
}
public CommitResult <Guid> Commit(Guid workspaceId, IsolatedChangeSet <Guid, object, EdgeData> changeSet)
{
throw new NotImplementedException();
}
/// <summary>
/// Creates map of node ids in the last snapshot which are affected by changes in the change set.
/// </summary>
/// <param name="snapshotId">Last snapshot</param>
/// <param name="changeSet">Change set which is created</param>
/// <param name="intermediateChanges">Intermediate changes</param>
/// <returns>Table of IDs for nodes which are modified in the last snapshot</returns>
private Hashtable IsolateSubTree(Guid snapshotId, IsolatedChangeSet<Guid, object, EdgeData> changeSet, Dictionary<Guid, Guid> intermediateChanges)
{
Hashtable result = new Hashtable();
Collection<Guid> changes = new Collection<Guid>();
foreach (Guid item in changeSet.Nodes.EnumerateNodes())
{
// Test if item is new or modified
if (changeSet.NodeStates[item] == NodeState.Modified)
{
Guid nodeId = Guid.Empty;
Guid oldNodeId = Guid.Empty;
// Try finding the latest id of the changed item
if (intermediateChanges.TryGetValue(item, out nodeId))
{
oldNodeId = item;
}
else
{
// It was not changed in the meantime, so the original ID should be still in use
nodeId = item;
}
// Remember new node ID with old node ID as value
result.Add(nodeId, oldNodeId);
// Changes
changes.Add(nodeId);
}
}
foreach (var item in changes)
{
AddSubTreeParentsRecursive(snapshotId, item, result);
}
return result;
}
private AppendableChangeSet<Guid, object, EdgeData> CreateMergedChangeSet(Guid latestSnapshot, Hashtable subTree, IsolatedChangeSet<Guid, object, EdgeData> changeSet, Dictionary<Guid, Guid> intermediateChanges)
{
#if DEBUG
Debug.WriteLine("Merging over intermediate changes");
#endif
// We create node provider which will host changes to the last snapshot made by the merge process
var isolatedNodes = new DirectNodeProviderUnsafe<Guid,object, EdgeData>(new MemoryStorageUnsafe<Guid, object>(), false);
// Perform merging on the current thread
IsolatedNodeProvider destinationProvider = new IsolatedNodeProvider(nodes, isolatedNodes, Thread.CurrentThread);
IsolatedNodeProvider sourceProvider = new IsolatedNodeProvider(nodes, changeSet.Nodes, Thread.CurrentThread);
// Make changes from incoming changes within a subtree
MergeRecursive(latestSnapshot, new RecursiveResolutionParameters(subTree, destinationProvider, sourceProvider, changeSet, intermediateChanges, new Hashtable()));
// We create an appendable change set from changes made to last snapshot, defining a new snapshot
return CreateAppendableChangeSet(latestSnapshot, Guid.NewGuid(), destinationProvider.GetChanges(latestSnapshot));
}
/// <summary>
/// For the given nod, goes through all the child nodes and adds that node to the parent node list of the child nodes.
/// </summary>
/// <param name="newId"></param>
/// <param name="parentNode"></param>
/// <param name="nodeState"></param>
/// <param name="delta">Node provider which contains nodes which will be saved at the end of the commit process</param>
private void UpdateParentNodes(Guid newId, Node <Guid, object, EdgeData> parentNode, NodeState nodeState, DirectNodeProviderUnsafe <Guid, object, EdgeData> delta, IsolatedChangeSet <Guid, object, EdgeData> changeSet)
{
foreach (Edge <Guid, EdgeData> edge in parentNode.Edges.Values)
{
if ((edge.Data as EdgeData).Semantic == EdgeType.Property && (edge.Data.Flags & EdgeFlags.StoreParentNodes) == EdgeFlags.StoreParentNodes)
{
var childNode = GetNode(edge.ToNodeId, changeSet);
if (childNode != null)
{
switch (childNode.NodeType)
{
case NodeType.Object:
UpdateParentNode(newId, nodeState, delta, edge, childNode, parentNode);
break;
case NodeType.Collection:
case NodeType.Dictionary:
foreach (Edge <Guid, EdgeData> collectionEdge in childNode.Edges.Values)
{
if (collectionEdge.Data.Semantic.Equals(EdgeType.ListItem))
{
UpdateParentNode(newId, nodeState, delta, collectionEdge, GetNode(collectionEdge.ToNodeId, changeSet), parentNode);
}
}
break;
default:
throw new NotImplementedException("NodeType=" + childNode.NodeType);
}
}
}
}
}
/// <summary>
/// Adds node to delta with recursive pass through node parents
/// </summary>
/// <param name="delta">Provider which will accept new nodes</param>
/// <param name="nodeId">Node ID to add</param>
/// <param name="nodeMapping">Mapping between (old ID)->(new ID)</param>
private void AddNodeToAppendableTreeRecursive(DirectNodeProviderUnsafe <Guid, object, EdgeData> delta, Guid nodeId, Dictionary <Guid, Guid> nodeMapping, Dictionary <Guid, NodeState> nodeStates, IsolatedChangeSet <Guid, object, EdgeData> changeSet)
{
// Skip already added nodes
if (!nodeMapping.ContainsKey(nodeId))
{
// Generate new ID
Guid newId = Guid.NewGuid();
// Check node state
NodeState nodeState = NodeState.None;
changeSet.NodeStates.TryGetValue(nodeId, out nodeState);
switch (nodeState)
{
case NodeState.None:
{
// Register in the mapping
nodeMapping.Add(nodeId, newId);
// Get undelrying node
var node = nodes.GetNode(nodeId, NodeAccess.Read);
var newNode = CloneNode(node);
// Set node to commited
newNode.Commited = true;
// Create edge to previous node
newNode.Previous = nodeId;
// New node is created which is copied from underlying provider
delta.SetNode(newId, newNode);
// This change is defined as modification
nodeStates.Add(newId, NodeState.Modified);
// Add node parents from the current snapshot
using (var enumerator = mutableParentProvider.ParentEdges(changeSet.SourceSnapshotId, nodeId))
{
if (enumerator != null)
{
while (enumerator.MoveNext())
{
AddNodeToAppendableTreeRecursive(delta, enumerator.Current.ToNodeId, nodeMapping, nodeStates, changeSet);
}
}
}
// Update parent nodes
UpdateParentNodes(newId, newNode, nodeState, delta, changeSet);
}
break;
case NodeState.Created:
{
// Read the node
var node = changeSet.Nodes.GetNode(nodeId, NodeAccess.ReadWrite);
// Set node to commited
node.Commited = true;
// There is no previous
node.Previous = Guid.Empty;
// Store to delta
delta.SetNode(nodeId, node);
// This change is defined as creation
nodeStates.Add(nodeId, NodeState.Created);
// Update parent nodes
UpdateParentNodes(nodeId, node, nodeState, delta, changeSet);
}
break;
case NodeState.Modified:
{
// Register in the mapping
nodeMapping.Add(nodeId, newId);
// Read the node
var node = changeSet.Nodes.GetNode(nodeId, NodeAccess.ReadWrite);
// Set node to commited
node.Commited = true;
// Set the previous
node.Previous = nodeId;
// Store to delta
delta.SetNode(newId, node);
// This change is defined as modification
nodeStates.Add(newId, NodeState.Modified);
// Add node parents from the current snapshot
using (var enumerator = mutableParentProvider.ParentEdges(changeSet.SourceSnapshotId, nodeId))
{
while (enumerator.MoveNext())
{
AddNodeToAppendableTreeRecursive(delta, enumerator.Current.ToNodeId, nodeMapping, nodeStates, changeSet);
}
}
// Update parent nodes
UpdateParentNodes(newId, node, nodeState, delta, changeSet);
}
break;
case NodeState.Removed:
{
// Update parent nodes
var node = GetNode(nodeId, changeSet);
UpdateParentNodes(nodeId, node, nodeState, delta, changeSet);
}
break;
default:
throw new ArgumentException(nodeState.ToString());
}
}
}
/// <summary>
/// Creates new delta tree describing the new snapshot
/// </summary>
/// <param name="baseSnapshotId">Base snapshot of the change set</param>
/// <param name="newSnapshotId">New snapshot of the change set</param>
/// <returns>Delta tree nodes</returns>
private INodeProvider <Guid, object, EdgeData> CreateAppendableChangeSetTree(Guid baseSnapshotId, Guid newSnapshotId, IKeyValueStorage <Guid, object> storage, Dictionary <Guid, Guid> nodeMapping, Dictionary <Guid, NodeState> nodeStates, IsolatedChangeSet <Guid, object, EdgeData> changeSet, Hashtable reusedNodes)
{
DirectNodeProviderUnsafe <Guid, object, EdgeData> delta = new DirectNodeProviderUnsafe <Guid, object, EdgeData>(storage, storage is IForceUpdateStorage);
// Create snapshot in delta
nodeMapping.Add(baseSnapshotId, newSnapshotId);
var snapshotNode = new Node <Guid, object, EdgeData>(NodeType.Snapshot, null);
snapshotNode.Previous = baseSnapshotId;
// Link to root object
snapshotNode.AddEdge(new Edge <Guid, EdgeData>(snapshotsService.GetRootObjectId(baseSnapshotId), new EdgeData(EdgeType.RootObject, null)));
// Set node to provider
delta.SetNode(newSnapshotId, snapshotNode);
// Add all changes and parent nodes
foreach (Guid nodeId in changeSet.Nodes.EnumerateNodes())
{
AddNodeToAppendableTreeRecursive(delta, nodeId, nodeMapping, nodeStates, changeSet);
}
// Prepare list of unreferenced node IDs
Dictionary <Guid, Collection <Guid> > references = new Dictionary <Guid, Collection <Guid> >();
// Resolve edges based on mapping
foreach (Guid nodeId in delta.EnumerateNodes())
{
references.Add(nodeId, new Collection <Guid>());
}
// Resolve edges based on mapping
foreach (Guid nodeId in delta.EnumerateNodes())
{
var node = delta.GetNode(nodeId, NodeAccess.ReadWrite);
foreach (var edge in node.Edges.Values)
{
// Permanent edges should not be touched
if (!Utils.IsPermanentEdge(edge))
{
// Reroute based on node mapping
if (nodeMapping.ContainsKey(edge.ToNodeId))
{
edge.ToNodeId = nodeMapping[edge.ToNodeId];
}
else
{
if (!reusedNodes.ContainsKey(edge.ToNodeId))
{
reusedNodes.Add(edge.ToNodeId, null);
}
}
// Change edge data if it points to changed node
if (edge.Data.Data != null && edge.Data.Data is Guid)
{
if (nodeMapping.ContainsKey((Guid)edge.Data.Data))
{
edge.Data = new EdgeData(edge.Data.Semantic, nodeMapping[(Guid)edge.Data.Data]);
}
}
}
else
{
if (!reusedNodes.ContainsKey(edge.ToNodeId))
{
reusedNodes.Add(edge.ToNodeId, null);
}
}
if (references.ContainsKey(edge.ToNodeId))
{
references[edge.ToNodeId].Add(nodeId);
}
}
}
// Remove remaining unreferenced nodes
bool removed = false;
do
{
removed = false;
foreach (Guid key in delta.EnumerateNodes())
{
// There are no references to the key
if ((key != newSnapshotId) && (references[key].Count == 0))
{
#if DEBUG
Debug.WriteLine("Removed unreferenced key " + key);
#endif
delta.Remove(key);
reusedNodes.Remove(key);
nodeStates.Remove(key);
foreach (Guid otherKey in references.Keys)
{
references[otherKey].Remove(key);
}
foreach (var mappingKey in nodeMapping.Keys)
{
if (nodeMapping[mappingKey] == key)
{
nodeMapping.Remove(mappingKey);
break;
}
}
removed = true;
break;
}
}
}while (removed);
// Isolated provider nodes have been corrupted, perform clear
changeSet.Nodes.Clear();
changeSet.NodeStates.Clear();
return(delta);
}
/// <summary>
/// Creates a changeset from isolated changes
/// </summary>
/// <param name="baseSnapshotId">Base snapshot of the change set</param>
/// <returns>Change set object</returns>
private AppendableChangeSet <Guid, object, EdgeData> CreateAppendableChangeSet(Guid baseSnapshotId, Guid newSnapshotId, IsolatedChangeSet <Guid, object, EdgeData> changeSet)
{
Dictionary <Guid, Guid> nodeMapping = new Dictionary <Guid, Guid>(); // Mapping old->new node id
Dictionary <Guid, NodeState> nodeStates = new Dictionary <Guid, NodeState>();
Hashtable reusedNodes = new Hashtable();
var tree = CreateAppendableChangeSetTree(baseSnapshotId, newSnapshotId, new MemoryStorageUnsafe <Guid, object>(), nodeMapping, nodeStates, changeSet, reusedNodes);
return(new AppendableChangeSet <Guid, object, EdgeData>(baseSnapshotId, newSnapshotId, tree, nodeMapping, nodeStates, reusedNodes));
}
/// <summary>
/// Creates a changeset from isolated changes
/// </summary>
/// <param name="baseSnapshotId">Base snapshot of the change set</param>
/// <returns>Change set object</returns>
private AppendableChangeSet<Guid, object, EdgeData> CreateAppendableChangeSet(Guid baseSnapshotId, Guid newSnapshotId, IsolatedChangeSet<Guid, object, EdgeData> changeSet)
{
Dictionary<Guid, Guid> nodeMapping = new Dictionary<Guid, Guid>(); // Mapping old->new node id
Dictionary<Guid, NodeState> nodeStates = new Dictionary<Guid, NodeState>();
Hashtable reusedNodes = new Hashtable();
var tree = CreateAppendableChangeSetTree(baseSnapshotId, newSnapshotId, new MemoryStorageUnsafe<Guid, object>(), nodeMapping, nodeStates, changeSet, reusedNodes);
return new AppendableChangeSet<Guid, object, EdgeData>(baseSnapshotId, newSnapshotId, tree, nodeMapping, nodeStates, reusedNodes);
}
/// <summary>
/// Creates new delta tree describing the new snapshot
/// </summary>
/// <param name="baseSnapshotId">Base snapshot of the change set</param>
/// <param name="newSnapshotId">New snapshot of the change set</param>
/// <returns>Delta tree nodes</returns>
private INodeProvider<Guid, object, EdgeData> CreateAppendableChangeSetTree(Guid baseSnapshotId, Guid newSnapshotId, IKeyValueStorage<Guid, object> storage, Dictionary<Guid, Guid> nodeMapping, Dictionary<Guid, NodeState> nodeStates, IsolatedChangeSet<Guid, object, EdgeData> changeSet, Hashtable reusedNodes)
{
DirectNodeProviderUnsafe<Guid, object, EdgeData> delta = new DirectNodeProviderUnsafe<Guid, object, EdgeData>(storage, storage is IForceUpdateStorage);
// Create snapshot in delta
nodeMapping.Add(baseSnapshotId, newSnapshotId);
var snapshotNode = new Node<Guid, object, EdgeData>(NodeType.Snapshot, null);
snapshotNode.Previous = baseSnapshotId;
// Link to root object
snapshotNode.AddEdge(new Edge<Guid, EdgeData>(snapshotsService.GetRootObjectId(baseSnapshotId), new EdgeData(EdgeType.RootObject, null)));
// Set node to provider
delta.SetNode(newSnapshotId, snapshotNode);
// Add all changes and parent nodes
foreach (Guid nodeId in changeSet.Nodes.EnumerateNodes())
{
AddNodeToAppendableTreeRecursive(delta, nodeId, nodeMapping, nodeStates, changeSet);
}
// Prepare list of unreferenced node IDs
Dictionary<Guid, Collection<Guid>> references = new Dictionary<Guid, Collection<Guid>>();
// Resolve edges based on mapping
foreach (Guid nodeId in delta.EnumerateNodes())
{
references.Add(nodeId, new Collection<Guid>());
}
// Resolve edges based on mapping
foreach (Guid nodeId in delta.EnumerateNodes())
{
var node = delta.GetNode(nodeId, NodeAccess.ReadWrite);
foreach (var edge in node.Edges.Values)
{
// Permanent edges should not be touched
if (!Utils.IsPermanentEdge(edge))
{
// Reroute based on node mapping
if (nodeMapping.ContainsKey(edge.ToNodeId))
{
edge.ToNodeId = nodeMapping[edge.ToNodeId];
}
else
{
if (!reusedNodes.ContainsKey(edge.ToNodeId))
{
reusedNodes.Add(edge.ToNodeId, null);
}
}
// Change edge data if it points to changed node
if (edge.Data.Data != null && edge.Data.Data is Guid)
{
if (nodeMapping.ContainsKey((Guid)edge.Data.Data))
{
edge.Data = new EdgeData(edge.Data.Semantic, nodeMapping[(Guid)edge.Data.Data]);
}
}
}
else
{
if (!reusedNodes.ContainsKey(edge.ToNodeId))
{
reusedNodes.Add(edge.ToNodeId, null);
}
}
if (references.ContainsKey(edge.ToNodeId))
{
references[edge.ToNodeId].Add(nodeId);
}
}
}
// Remove remaining unreferenced nodes
bool removed = false;
do
{
removed = false;
foreach (Guid key in delta.EnumerateNodes())
{
// There are no references to the key
if ((key!=newSnapshotId) && (references[key].Count == 0))
{
#if DEBUG
Debug.WriteLine("Removed unreferenced key " + key);
#endif
delta.Remove(key);
reusedNodes.Remove(key);
nodeStates.Remove(key);
foreach (Guid otherKey in references.Keys)
{
references[otherKey].Remove(key);
}
foreach (var mappingKey in nodeMapping.Keys)
{
if (nodeMapping[mappingKey] == key)
{
nodeMapping.Remove(mappingKey);
break;
}
}
removed = true;
break;
}
}
}
while (removed);
// Isolated provider nodes have been corrupted, perform clear
changeSet.Nodes.Clear();
changeSet.NodeStates.Clear();
return delta;
}
/// <summary>
/// Performs a commit
/// </summary>
/// <param name="workspaceId">Workspace ID</param>
/// <param name="changeSet">Changes to commit</param>
/// <returns>Changes which were commited</returns>
public CommitResult<Guid> Commit(Guid workspaceId, IsolatedChangeSet<Guid, object, EdgeData> changeSet)
{
bool isSnapshotIsolation = workspaceStateProvider.WorkspaceIsolationLevel(workspaceId) == IsolationLevel.Snapshot;
if (isSnapshotIsolation)
{
workspaceExclusiveLockProvider.EnterLockExclusive();
}
try
{
lock (commitSync)
{
if (!workspaceStateProvider.IsWorkspaceExpired(workspaceId))
{
var result = commitDataService.AcceptCommit(changeSet);
workspaceStateProvider.UpdateWorspace(workspaceId, result.ResultSnapshotId);
subscriptionManagerService.InvokeEvents(workspaceId, result);
return result;
}
else
{
throw new TimeoutException("Workspace timeout has elapsed");
}
}
}
finally
{
if (isSnapshotIsolation)
{
workspaceExclusiveLockProvider.ExitLockExclusive();
}
}
}
/// <summary>
/// Returns node from the nodes list. If node does not exist in the nodes list node from the changeSet is returned.
/// </summary>
/// <param name="nodeId"></param>
/// <param name="changeSet"></param>
/// <returns></returns>
private Node<Guid, object, EdgeData> GetNode(Guid nodeId, IsolatedChangeSet<Guid, object, EdgeData> changeSet)
{
var childNode = nodes.GetNode(nodeId, NodeAccess.ReadWrite);
if (childNode != null)
{
return childNode;
}
return changeSet.Nodes.GetNode(nodeId, NodeAccess.ReadWrite);
}
/// <summary>
/// Method is used for getting data from object to IsolatedChangeSet.
/// Object containing dictionaries that contain data. If object is not
/// formated in right way, this method is throwing exception.
/// </summary>
/// <param name="objectForParsing">object that is containg data that is commited from client</param>
/// <returns>IsolatedChangeSet that is created from objectForParsing</returns>
public static IsolatedChangeSet <Guid, object, EdgeData> Parse(Object objectForParsing)
{
Guid sourceSnapshotId = Guid.Empty;
if (objectForParsing == null)
{
throw new Exception("Object is not valid!");
}
Dictionary <Guid, NodeState> nodeState = null;
DirectNodeProviderSafe <Guid, object, EdgeData> nodes = null;
if (objectForParsing is Dictionary <String, Object> )
{
Dictionary <String, Object> dictFromObject = (Dictionary <String, Object>)objectForParsing;
//finding sourceSnapshotId property from dictionary
if (dictFromObject.ContainsKey(SOURCE_SNAPSHOT_ID))
{
Object objectSourceId = dictFromObject[SOURCE_SNAPSHOT_ID];
if (objectSourceId is Dictionary <String, Object> )
{
Dictionary <String, Object> dSourceId = objectSourceId as Dictionary <String, Object>;
if (dSourceId != null)
{
Object sSourceId = dSourceId[VALUE];
//checking if object is string. If it is then this is guid
if (sSourceId is String)
{
sourceSnapshotId = new Guid(sSourceId as String);
}
else
{
//sSourceId is not string so this is not right type and object that is being
//parsed is not formated as he should.
throw new Exception("Field SourceSnapshotId is not in right format!");
}
}
else
{
throw new Exception("Field SourceSnapshotId is not in right format!");
}
}
}
else
{
//case when SourceSnapshotId is missing in objectForParsing
throw new Exception("There is not field SourceSnapshotId!");
}
nodes = ParseNodes(dictFromObject);
nodeState = ParseNodeStates(dictFromObject);
}
else
{
throw new Exception("Object is not valid!");
}
//in case some data is missing here we will throw exception
if (sourceSnapshotId == null || nodes == null || nodeState == null)
{
throw new ArgumentNullException();
}
// creating IsolatedChangeSet object with parsed data
IsolatedChangeSet <Guid, object, EdgeData> result =
new IsolatedChangeSet <Guid, object, EdgeData>(sourceSnapshotId, nodes, nodeState);
return(result);
}
/// <summary>
/// For the given nod, goes through all the child nodes and adds that node to the parent node list of the child nodes.
/// </summary>
/// <param name="newId"></param>
/// <param name="parentNode"></param>
/// <param name="nodeState"></param>
/// <param name="delta">Node provider which contains nodes which will be saved at the end of the commit process</param>
private void UpdateParentNodes(Guid newId, Node<Guid, object, EdgeData> parentNode, NodeState nodeState, DirectNodeProviderUnsafe<Guid, object, EdgeData> delta, IsolatedChangeSet<Guid, object, EdgeData> changeSet)
{
foreach (Edge<Guid, EdgeData> edge in parentNode.Edges.Values)
{
if ((edge.Data as EdgeData).Semantic == EdgeType.Property && (edge.Data.Flags & EdgeFlags.StoreParentNodes) == EdgeFlags.StoreParentNodes)
{
var childNode = GetNode(edge.ToNodeId, changeSet);
if (childNode != null)
{
switch (childNode.NodeType)
{
case NodeType.Object:
UpdateParentNode(newId, nodeState, delta, edge, childNode, parentNode);
break;
case NodeType.Collection:
case NodeType.Dictionary:
foreach (Edge<Guid, EdgeData> collectionEdge in childNode.Edges.Values)
{
if (collectionEdge.Data.Semantic.Equals(EdgeType.ListItem))
{
UpdateParentNode(newId, nodeState, delta, collectionEdge, GetNode(collectionEdge.ToNodeId, changeSet), parentNode);
}
}
break;
default:
throw new NotImplementedException("NodeType=" + childNode.NodeType);
}
}
}
}
}
public CommitResult<Guid> Commit(Guid workspaceId, IsolatedChangeSet<Guid, object, EdgeData> changeSet)
{
throw new NotImplementedException();
}
/// <summary>
/// Method is used for getting data from object to IsolatedChangeSet.
/// Object containing dictionaries that contain data. If object is not
/// formated in right way, this method is throwing exception.
/// </summary>
/// <param name="objectForParsing">object that is containg data that is commited from client</param>
/// <returns>IsolatedChangeSet that is created from objectForParsing</returns>
public static IsolatedChangeSet<Guid, object, EdgeData> Parse(Object objectForParsing)
{
Guid sourceSnapshotId = Guid.Empty;
if (objectForParsing == null)
throw new Exception("Object is not valid!");
Dictionary<Guid, NodeState> nodeState = null;
DirectNodeProviderSafe<Guid, object, EdgeData> nodes = null;
if (objectForParsing is Dictionary<String, Object>)
{
Dictionary<String, Object> dictFromObject = (Dictionary<String, Object>)objectForParsing;
//finding sourceSnapshotId property from dictionary
if (dictFromObject.ContainsKey(SOURCE_SNAPSHOT_ID))
{
Object objectSourceId = dictFromObject[SOURCE_SNAPSHOT_ID];
if (objectSourceId is Dictionary<String, Object>)
{
Dictionary<String, Object> dSourceId = objectSourceId as Dictionary<String, Object>;
if (dSourceId != null)
{
Object sSourceId = dSourceId[VALUE];
//checking if object is string. If it is then this is guid
if (sSourceId is String)
{
sourceSnapshotId = new Guid(sSourceId as String);
}
else
{
//sSourceId is not string so this is not right type and object that is being
//parsed is not formated as he should.
throw new Exception("Field SourceSnapshotId is not in right format!");
}
}
else
{
throw new Exception("Field SourceSnapshotId is not in right format!");
}
}
}
else
{
//case when SourceSnapshotId is missing in objectForParsing
throw new Exception("There is not field SourceSnapshotId!");
}
nodes = ParseNodes(dictFromObject);
nodeState = ParseNodeStates(dictFromObject);
}
else
throw new Exception("Object is not valid!");
//in case some data is missing here we will throw exception
if (sourceSnapshotId == null || nodes == null || nodeState == null)
{
throw new ArgumentNullException();
}
// creating IsolatedChangeSet object with parsed data
IsolatedChangeSet<Guid, object, EdgeData> result =
new IsolatedChangeSet<Guid, object, EdgeData>(sourceSnapshotId, nodes, nodeState);
return result;
}
private AppendableChangeSet <Guid, object, EdgeData> CreateMergedChangeSet(Guid latestSnapshot, Hashtable subTree, IsolatedChangeSet <Guid, object, EdgeData> changeSet, Dictionary <Guid, Guid> intermediateChanges)
{
#if DEBUG
Debug.WriteLine("Merging over intermediate changes");
#endif
// We create node provider which will host changes to the last snapshot made by the merge process
var isolatedNodes = new DirectNodeProviderUnsafe <Guid, object, EdgeData>(new MemoryStorageUnsafe <Guid, object>(), false);
// Perform merging on the current thread
IsolatedNodeProvider destinationProvider = new IsolatedNodeProvider(nodes, isolatedNodes, Thread.CurrentThread);
IsolatedNodeProvider sourceProvider = new IsolatedNodeProvider(nodes, changeSet.Nodes, Thread.CurrentThread);
// Make changes from incoming changes within a subtree
MergeRecursive(latestSnapshot, new RecursiveResolutionParameters(subTree, destinationProvider, sourceProvider, changeSet, intermediateChanges, new Hashtable()));
// We create an appendable change set from changes made to last snapshot, defining a new snapshot
return(CreateAppendableChangeSet(latestSnapshot, Guid.NewGuid(), destinationProvider.GetChanges(latestSnapshot)));
}