/// <summary>
/// Applies a document addition to the document tree. Returns the corresponding DocumentChange event.
/// </summary>
private DocumentChange AddDocument(DocumentSnapshot newDocument)
{
_documentSet = _documentSet.WithDocumentAdded(newDocument);
int newIndex = _documentSet.IndexOf(newDocument.Reference);
return(new DocumentChange(newDocument, DocumentChange.Type.Added, null, newIndex));
}
/// <summary>
/// Applies a document delete to the document tree. Returns the corresponding DocumentChange event.
/// </summary>
private DocumentChange DeleteDocument(DocumentSnapshot oldDocument)
{
int oldIndex = _documentSet.IndexOf(oldDocument.Reference);
_documentSet = _documentSet.WithDocumentRemoved(oldDocument.Reference);
return(new DocumentChange(oldDocument, DocumentChange.Type.Removed, oldIndex, null));
}
internal WatchState(Query query, Func <QuerySnapshot, CancellationToken, Task> callback)
{
_query = query;
_callback = callback;
_comparer = query.CreateDocumentSnapshotComparer();
_documentSet = DocumentSet.Empty(_comparer);
_changeMap = new Dictionary <DocumentReference, Document>();
}
internal DocumentSet WithDocumentAdded(DocumentSnapshot document)
{
// Remove any prior mapping of the document's key before adding, preventing sortedSet from
// accumulating values that aren't in the index.
DocumentSet removed = WithDocumentRemoved(document.Reference);
var newKeyIndex = removed._keyIndex.Add(document.Reference, document);
var newSortedSet = removed._sortedSet.Add(document);
return(new DocumentSet(newKeyIndex, newSortedSet));
}
/// <summary>
/// Applies a document modification to the document tree. Returns the DocumentChange event for
/// successful modifications, or null if the old and new documents have the same update timestamp.
/// </summary>
private DocumentChange ModifyDocument(DocumentSnapshot newDocument)
{
var docRef = newDocument.Reference;
if (!_documentSet.TryGetDocument(docRef, out var oldDocument))
{
// TODO: Is this appropriate? Java throws an NPE here...
throw new InvalidOperationException("Attempt to create a document modification, but document wasn't in set.");
}
if (oldDocument.UpdateTime == newDocument.UpdateTime)
{
return(null);
}
int oldIndex = _documentSet.IndexOf(docRef);
_documentSet = _documentSet.WithDocumentRemoved(docRef);
_documentSet = _documentSet.WithDocumentAdded(newDocument);
int newIndex = _documentSet.IndexOf(docRef);
return(new DocumentChange(newDocument, DocumentChange.Type.Modified, oldIndex, newIndex));
}
internal static QuerySnapshot ForChanges(Query query, DocumentSet documentSet, IReadOnlyList <DocumentChange> changes, Timestamp readTime) => new QuerySnapshot(query, () => documentSet.ToList().AsReadOnly(), () => changes, readTime);
