/// <summary>
/// Adds an link with an item id to the address space.
/// </summary>
public bool AddItemAndLink(string browsePath, string itemID, IDevice device)
{
lock (this)
{
// validate browse path.
if (browsePath == null || browsePath.Length == 0)
{
return(false);
}
// check if item does not exists.
if (!m_items.Contains(itemID))
{
return(false);
}
// create the browse element.
BrowseElement element = m_addressSpace.Insert(browsePath, itemID);
if (element == null)
{
return(false);
}
// create new item and index by item id.
m_items[element.ItemID] = new CacheItem(itemID, device);
return(true);
}
}
/// <summary>
/// Removes an link (but not the item) from the address space only if it has no children.
/// </summary>
public bool RemoveEmptyLink(string browsePath)
{
lock (this)
{
// validate browse path.
if (browsePath == null || browsePath.Length == 0)
{
return(false);
}
// create the browse element.
BrowseElement element = m_addressSpace.Find(browsePath);
if (element != null)
{
if (element.Count == 0)
{
element.Remove();
return(true);
}
}
return(false);
}
}
/// <summary>
/// Removes an link and an item with the same id to the address space.
/// </summary>
public bool RemoveItemAndLink(string browsePath)
{
lock (this)
{
// validate browse path.
if (browsePath == null || browsePath.Length == 0)
{
return(false);
}
// find the browse element.
BrowseElement element = m_addressSpace.Find(browsePath);
if (element != null)
{
// remove item.
m_items.Remove(element.ItemID);
// remove element.
element.Remove();
}
return(true);
}
}
/// <summary>
/// Inserts a child with a specific item id into the correct place in the hierarchy.
/// </summary>
public BrowseElement Insert(string browsePath, string itemID)
{
BrowseElement child = Insert(browsePath);
if (child != null)
{
child.m_itemID = itemID;
}
return(child);
}
/// <summary>
/// Removes the child with the specified name from the element.
/// </summary>
public bool Remove(string name)
{
if (m_children != null)
{
for (int ii = 0; ii < m_children.Count; ii++)
{
BrowseElement child = (BrowseElement)m_children[ii];
if (child.Name == name)
{
m_children.RemoveAt(ii);
return(true);
}
}
}
return(false);
}
/// <summary>
/// Adds an link without an item to the address space.
/// </summary>
public bool AddLink(string browsePath)
{
lock (this)
{
// validate browse path.
if (browsePath == null || browsePath.Length == 0)
{
return(false);
}
// create the browse element.
BrowseElement element = m_addressSpace.Insert(browsePath);
if (element == null)
{
return(false);
}
return(true);
}
}
/// <summary>
/// Returns the set of elements in the address space that meet the specified criteria.
/// </summary>
public Opc.Da.BrowseElement[] Browse(
ItemIdentifier itemID,
BrowseFilters filters,
ref Opc.Da.BrowsePosition position)
{
lock (this)
{
if (m_disposed)
{
throw new ObjectDisposedException("Opc.Da.Cache");
}
BrowseElement element = m_addressSpace;
// find desired element.
string browsePath = (itemID != null)?itemID.ItemName:null;
if (browsePath != null && browsePath.Length > 0)
{
element = m_addressSpace.Find(browsePath);
if (element == null)
{
// check if browsing a property item.
PropertyID property = Property.VALUE;
string rootID = LookupProperty(browsePath, out property);
if (rootID != null)
{
element = m_addressSpace.Find(rootID);
}
if (element == null)
{
throw new ResultIDException(ResultID.Da.E_UNKNOWN_ITEM_NAME);
}
// property items never contain children.
return(new Opc.Da.BrowseElement[0]);
}
}
// check if no elements exist.
if (element.Count == 0)
{
return(new Opc.Da.BrowseElement[0]);
}
// determine start position.
int start = 0;
if (position != null)
{
start = ((BrowsePosition)position).Index;
position.Dispose();
position = null;
}
// process child nodes.
ArrayList results = new ArrayList();
for (int ii = start; ii < element.Count; ii++)
{
BrowseElement child = element.Child(ii);
// exclude elements without children.
if (filters.BrowseFilter == browseFilter.branch && child.Count == 0)
{
continue;
}
// check if an element is an item.
CacheItem item = (CacheItem)m_items[child.ItemID];
// exclude elements which are not items.
if (filters.BrowseFilter == browseFilter.item && item == null)
{
continue;
}
// apply name filter (using the SQL LIKE operator).
if (filters.ElementNameFilter != null && filters.ElementNameFilter.Length > 0)
{
if (!Opc.Convert.Match(child.Name, filters.ElementNameFilter, true))
{
continue;
}
}
// add element to list of results.
Opc.Da.BrowseElement result = new Opc.Da.BrowseElement();
result.Name = child.Name;
result.ItemName = child.ItemID;
result.ItemPath = null;
result.IsItem = item != null;
result.HasChildren = child.Count > 0;
result.Properties = null;
// add properties to results.
if (filters.ReturnAllProperties || filters.PropertyIDs != null)
{
result.Properties = GetProperties(item, (filters.ReturnAllProperties)?null:filters.PropertyIDs, filters.ReturnPropertyValues);
}
results.Add(result);
// check if max elements exceeded.
if (filters.MaxElementsReturned > 0 && results.Count >= filters.MaxElementsReturned)
{
if (ii + 1 < element.Count)
{
position = new BrowsePosition(itemID, filters);
((BrowsePosition)position).Index = ii + 1;
}
break;
}
}
// return results.
return((Opc.Da.BrowseElement[])results.ToArray(typeof(Opc.Da.BrowseElement)));
}
}
/// <summary>
/// Initializes the element with its parent and item id.
/// </summary>
public BrowseElement(BrowseElement parent, string name, string itemID)
{
m_parent = parent;
m_name = name;
m_itemID = itemID;
}
/// <summary>
/// Initializes the element with its parent.
/// </summary>
public BrowseElement(BrowseElement parent, string name)
{
m_parent = parent;
m_name = name;
}
/// <summary>
/// Inserts a child into the correct place in the hierarchy.
/// </summary>
public BrowseElement Insert(string browsePath)
{
if (browsePath == null) throw new ArgumentNullException("browsePath");
// extract the first path element from the browse path.
string name = browsePath;
string subpath = "";
do
{
int index = name.IndexOf(Separator);
if (index == -1)
{
break;
}
subpath = name.Substring(index + Separator.Length);
name = name.Substring(0, index);
// name may be empty if multiple separators defined.
if (name.Length > 0)
{
break;
}
name = subpath;
}
while (subpath.Length > 0);
// check for valid path.
if (name.Length == 0)
{
return null;
}
// find out if child element already exists.
if (m_children != null)
{
foreach (BrowseElement child in m_children)
{
if (child.Name == name)
{
// insert new element in child.
if (subpath.Length > 0)
{
return child.Insert(subpath);
}
// return existing child.
return child;
}
}
}
// create a new child element.
BrowseElement element = new BrowseElement(this, name);
// add new child to end of list.
if (m_children == null)
{
m_children = new ArrayList();
}
// add any children to the new element.
if (subpath.Length == 0)
{
m_children.Add(element);
return element;
}
// add any sub elements.
BrowseElement parent = element;
element = parent.Insert(subpath);
if (element != null)
{
m_children.Add(parent);
}
return element;
}
/// <summary>
/// Initializes the element with its parent and item id.
/// </summary>
public BrowseElement(BrowseElement parent, string name, string itemID)
{
m_parent = parent;
m_name = name;
m_itemID = itemID;
}
/// <summary>
/// Initializes the element with its parent.
/// </summary>
public BrowseElement(BrowseElement parent, string name)
{
m_parent = parent;
m_name = name;
}
/// <summary>
/// Inserts a child into the correct place in the hierarchy.
/// </summary>
public BrowseElement Insert(string browsePath)
{
if (browsePath == null)
{
throw new ArgumentNullException("browsePath");
}
// extract the first path element from the browse path.
string name = browsePath;
string subpath = "";
do
{
int index = name.IndexOf(Separator);
if (index == -1)
{
break;
}
subpath = name.Substring(index + Separator.Length);
name = name.Substring(0, index);
// name may be empty if multiple separators defined.
if (name.Length > 0)
{
break;
}
name = subpath;
}while (subpath.Length > 0);
// check for valid path.
if (name.Length == 0)
{
return(null);
}
// find out if child element already exists.
if (m_children != null)
{
foreach (BrowseElement child in m_children)
{
if (child.Name == name)
{
// insert new element in child.
if (subpath.Length > 0)
{
return(child.Insert(subpath));
}
// return existing child.
return(child);
}
}
}
// create a new child element.
BrowseElement element = new BrowseElement(this, name);
// add new child to end of list.
if (m_children == null)
{
m_children = new ArrayList();
}
// add any children to the new element.
if (subpath.Length == 0)
{
m_children.Add(element);
return(element);
}
// add any sub elements.
BrowseElement parent = element;
element = parent.Insert(subpath);
if (element != null)
{
m_children.Add(parent);
}
return(element);
}