private string PathFromRoot(SimpleCacheItem root)
{
var size = 1;
while (root.Name != null)
{
size += root.Name.Length + 1;
_pathFromRootList.AddFirst(root);
root = root.Parent;
}
if (_pathFromRootList.Count == 0)
{
return("/");
}
var sb = new StringBuilder(size);
foreach (var d in _pathFromRootList)
{
sb.AppendFormat("/{0}", d.Name);
}
_pathFromRootList.Clear();
return(sb.ToString());
}
private bool RemoveChildFromParent(SimpleCacheItem child)
{
if (child.Parent != null)
{
return(child.Parent.Children.Remove(child));
}
return(false);
}
private static SimpleCacheItem GetNamedChild(SimpleCacheItem root, string segment)
{
var newRoot = root.Children.FirstOrDefault(c => c.Name == segment);
if (newRoot == null)
{
newRoot = new SimpleCacheItem {Name = segment, Parent = root, Created = true};
root.Children.Add(newRoot);
}
return newRoot;
}
private void DeleteRootOrChildren(SimpleCacheItem root)
{
if (root.Parent == null && root.Children.Count == 0)
{
// We don't have other choices than removing root
root = null;
OnRemoved(new ValueRemovedEventArgs("/"));
}
else
{
DeleteChild(root);
}
}
private void UpdateChildren(SimpleCacheItem root, JsonReader reader, bool replace = false)
{
if (replace)
{
DeleteChild(root);
if (root.Parent != null)
{
root.Parent.Children.Add(root);
}
}
while (reader.Read())
{
switch (reader.TokenType)
{
case JsonToken.PropertyName:
var segment = reader.Value.ToString();
var child = GetNamedChild(root, segment);
UpdateChildren(child, reader); // Re-entrant, child become new cached root.
break;
case JsonToken.Boolean:
case JsonToken.Bytes:
case JsonToken.Date:
case JsonToken.Float:
case JsonToken.Integer:
case JsonToken.String:
if (root.Created)
{
root.Value = reader.Value.ToString();
var rootPath = PathFromRoot(root);
OnAdded(new ValueAddedEventArgs(rootPath, root.Value));
root.Created = false;
}
else
{
var oldData = root.Value;
root.Value = reader.Value.ToString();
var rootPath = PathFromRoot(root);
OnChanged(new ValueChangedEventArgs(rootPath, root.Value, oldData));
}
return;
case JsonToken.Null:
DeleteRootOrChildren(root);
return;
}
}
}
private void UpdateChildren(SimpleCacheItem root, JsonReader reader, bool replace = false)
{
if (replace)
{
DeleteChild(root);
if (root.Parent != null)
{
root.Parent.Children.Add(root);
}
}
while (reader.Read())
{
switch (reader.TokenType)
{
case JsonToken.PropertyName:
UpdateChildren(GetNamedChild(root, reader.Value.ToString()), reader);
break;
case JsonToken.Boolean:
case JsonToken.Bytes:
case JsonToken.Date:
case JsonToken.Float:
case JsonToken.Integer:
case JsonToken.String:
if (root.Created)
{
root.Value = reader.Value.ToString();
OnAdded(new ValueAddedEventArgs(PathFromRoot(root), reader.Value.ToString()));
root.Created = false;
}
else
{
var oldData = root.Value;
root.Value = reader.Value.ToString();
OnUpdated(new ValueChangedEventArgs(PathFromRoot(root), root.Value, oldData));
}
return;
case JsonToken.Null:
DeleteChild(root);
return;
case JsonToken.EndObject:
root = root.Parent;
return;
}
}
}
private static SimpleCacheItem GetNamedChild(SimpleCacheItem root, string segment)
{
var newRoot = root.Children.FirstOrDefault(c => c.Name == segment);
if (newRoot == null)
{
newRoot = new SimpleCacheItem {
Name = segment, Parent = root, Created = true
};
root.Children.Add(newRoot);
}
return(newRoot);
}
private void UpdateChildren(SimpleCacheItem root, JsonReader reader, bool replace = false)
{
if (replace)
{
DeleteChild(root);
if (root.Parent != null)
{
root.Parent.Children.Add(root);
}
}
while (reader.Read())
{
switch (reader.TokenType)
{
case JsonToken.PropertyName:
UpdateChildren(GetNamedChild(root, reader.Value.ToString()), reader);
break;
case JsonToken.Boolean:
case JsonToken.Bytes:
case JsonToken.Date:
case JsonToken.Float:
case JsonToken.Integer:
case JsonToken.String:
if (root.Created)
{
root.Value = reader.Value.ToString();
OnAdded(new ValueAddedEventArgs(PathFromRoot(root), reader.Value.ToString()));
root.Created = false;
}
else
{
var oldData = root.Value;
root.Value = reader.Value.ToString();
OnUpdated(new ValueChangedEventArgs(PathFromRoot(root), root.Value, oldData));
}
return;
case JsonToken.Null:
DeleteChild(root);
return;
}
}
}
private void DeleteChild(SimpleCacheItem root)
{
if (root.Parent != null)
{
if (RemoveChildFromParent(root))
{
OnRemoved(new ValueRemovedEventArgs(PathFromRoot(root)));
}
}
else
{
foreach (var child in root.Children.ToArray())
{
RemoveChildFromParent(child);
OnRemoved(new ValueRemovedEventArgs(PathFromRoot(child)));
}
}
}
private void Replace(SimpleCacheItem root, JsonReader reader)
{
UpdateChildren(root, reader, true);
}
private void DeleteChild(SimpleCacheItem root)
{
if (root.Parent != null)
{
if (RemoveChildFromParent(root))
{
OnRemoved(new ValueRemovedEventArgs(PathFromRoot(root)));
}
}
else
{
foreach (var child in root.Children.ToArray())
{
RemoveChildFromParent(child);
OnRemoved(new ValueRemovedEventArgs(PathFromRoot(child)));
}
}
}
private void Replace(SimpleCacheItem root, JsonReader reader)
{
UpdateChildren(root, reader, true);
}
private bool RemoveChildFromParent(SimpleCacheItem child)
{
if (child.Parent != null)
{
return child.Parent.Children.Remove(child);
}
return false;
}
private string PathFromRoot(SimpleCacheItem root)
{
var size = 1;
while (root.Name != null)
{
size += root.Name.Length + 1;
_pathFromRootList.AddFirst(root);
root = root.Parent;
}
if (_pathFromRootList.Count == 0)
{
return "/";
}
var sb = new StringBuilder(size);
foreach (var d in _pathFromRootList)
{
sb.Append($"/{d.Name}");
}
_pathFromRootList.Clear();
return sb.ToString();
}
