/// <summary>
/// Exposes the ContentDirectory's Search action (for returning sorted results) as a method of a container.
/// </summary>
/// <param name="expression">IMediaComparer object that will indicate if a media object is a match</param>
/// <param name="sorter">IMediaSorter object that determines the sorting criteria for the results</param>
/// <param name="startingIndex">starting index for the search results, 0-based index</param>
/// <param name="requestedCount">maximum number of children requested</param>
/// <param name="totalMatches">total number of possible matches, sometimes has uint.MaxValue if the total possible is unknown</param>
/// <returns></returns>
public virtual IList SearchSorted(IMediaComparer expression, IMediaSorter sorter, UInt32 startingIndex, UInt32 requestedCount, out UInt32 totalMatches)
{
SortedList sorted = null;
ArrayList results = null;
if (this.m_Listing != null)
{
sorted = new SortedList(sorter, this.m_Listing.Count);
this.SearchCollection(expression, ref sorted);
int size = Convert.ToInt32(requestedCount);
if (sorted.Count < size) size = sorted.Count;
results = new ArrayList(size);
int i=0;
foreach (IUPnPMedia entry in sorted.Values)
{
if (i >= startingIndex)
{
results.Add(entry);
}
i++;
if ((results.Count >= requestedCount) && (requestedCount != 0))
{
break;
}
}
totalMatches = Convert.ToUInt32(sorted.Count);
}
else
{
results = new ArrayList(0);
totalMatches = 0;
}
return results;
}
/// <summary>
/// Implements the core logic for a sorted Search.
/// </summary>
/// <param name="exoression">IMediaComparer object that will indicate if a media object is a match</param>
/// <param name="sorted">sorted list of IUPnPMedia objects that make up result set</param>
private void SearchCollection(IMediaComparer expression, ref SortedList sorted)
{
this.m_LockListing.AcquireReaderLock(-1);
ArrayList containers = null;
if (this.m_Listing != null)
{
containers = new ArrayList(this.m_Listing.Count);
foreach (IUPnPMedia entry in this.m_Listing)
{
// If the item is a match, add it to the list of results.
//
if (expression.IsMatch(entry))
{
sorted.Add(entry,entry);
}
if (entry.IsContainer)
{
containers.Add(entry);
}
}
}
this.m_LockListing.ReleaseReaderLock();
if (containers != null)
{
foreach (MediaContainer container in containers)
{
container.SearchCollection(expression, ref sorted);
}
}
}
/// <summary>
/// Exposes the ContentDirectory's Search action (for returning unsorted results) as a method of a container.
/// </summary>
/// <param name="expression">IMediaComparer object that will indicate if a media object is a match</param>
/// <param name="startingIndex">starting index for the search results, 0-based index</param>
/// <param name="requestedCount">maximum number of children requested</param>
/// <param name="totalMatches">
/// total number of possible matches, sometimes has uint.MaxValue if the total possible is unknown.
/// CHANGED PER DHWG: Returns 0 if total is unknown.
/// </param>
/// <returns></returns>
public virtual IList Search(IMediaComparer expression, UInt32 startingIndex, UInt32 requestedCount, out UInt32 totalMatches)
{
ArrayList results = new ArrayList(2500);
bool searchedSubtree;
this.SearchCollection(expression, startingIndex, requestedCount, out searchedSubtree, ref results);
if (searchedSubtree)
{
totalMatches = Convert.ToUInt32(results.Count);
}
else
{
//totalMatches = UInt32.MaxValue;
totalMatches = 0;
}
return results;
}
/// <summary>
/// Implements the core logic for packaging up the results for a Search.
/// </summary>
/// <param name="expression">IMediaComparer object that will indicate if a media object is a match</param>
/// <param name="startingIndex">starting index for the search results, 0-based index</param>
/// <param name="requestedCount">maximum number of children requested</param>
/// <param name="searchedEntireSubtree">True, if the entire subtree was searched.</param>
/// <param name="results">ArrayList of the desired results.</param>
private void SearchCollection(IMediaComparer expression, UInt32 startingIndex, UInt32 requestedCount, out bool searchedEntireSubtree, ref ArrayList results)
{
searchedEntireSubtree = true;
if (this.m_Listing != null)
{
ArrayList containers = new ArrayList(this.m_Listing.Count);
this.m_LockListing.AcquireReaderLock(-1);
foreach (IUPnPMedia entry in this.m_Listing)
{
// If the item is a match, add it to the list of results.
//
if (expression.IsMatch(entry))
{
results.Add(entry);
}
// If we've reached the max number of results, then indicate
// that we will not end up searching the entire subtree.
//
if ((results.Count >= requestedCount) && (requestedCount != 0))
{
searchedEntireSubtree = false;
break;
}
if (entry.IsContainer)
{
containers.Add(entry);
}
}
this.m_LockListing.ReleaseReaderLock();
// If we're still intent on searching the entire subtree, then
// recurse through each sub-container.
//
if (searchedEntireSubtree)
{
foreach (MediaContainer container in containers)
{
// After recursing each subtree, check to see if we stopped
// searching the entire subtee. If so, then do not continue.
if (searchedEntireSubtree)
{
container.SearchCollection(expression, startingIndex, requestedCount, out searchedEntireSubtree, ref results);
}
else
{
break;
}
}
}
}
}
