/// <summary>
/// Walks BSON tokens and validates and fires events on the supplied events instance.
/// </summary>
/// <param name="tokens"></param>
/// <param name="events"></param>
public void Walk(BSONTokenStream tokens, BSONWalkingEvents events)
{
_Start(tokens, events);
tokens.MoveNext();
if (BSONTokenType.EOF != tokens.Current.Type)
{
throw new BSONValidationException("Expected EOF but got: " + tokens.Current.Type);
}
}
/// <summary>
/// Walk a Document. Fires DocumentStart and DocumentEnd
/// </summary>
/// <param name="tokens"></param>
/// <param name="events"></param>
/// <param name="docType"></param>
private void _Document(BSONTokenStream tokens, BSONWalkingEvents events, BSONTypes docType)
{
if (null != events)
{
events.RaiseDocumentStart(docType);
}
BSONToken next = tokens.Current;
while (true)
{
tokens.MoveNext();
next = tokens.Current;
if (BSONTokenType.END != next.Type && BSONTokenType.EOF != next.Type)
{
_DocumentElement(next, tokens, events);
}
else
{
break;
}
}
if (BSONTokenType.END == next.Type)
{
if (null != events)
{
events.RaiseDocumentEnd(docType);
}
return;
}
else
{
throw new BSONValidationException("Expected value or end of document but got: " + next.Type);
}
}
/// <summary>
/// Start walking the BSON structure.
/// </summary>
/// <param name="tokens"></param>
/// <param name="events"></param>
private void _Start(BSONTokenStream tokens, BSONWalkingEvents events)
{
tokens.MoveNext();
BSONToken next = tokens.Current;
if (BSONTokenType.DOCUMENT_START == next.Type)
{
_Document(tokens, events, BSONTypes.DOCUMENT);
}
else if (BSONTokenType.ARRAY_START == next.Type)
{
_Document(tokens, events, BSONTypes.ARRAY);
}
else
{
throw new BSONValidationException("Expected DOCUMENT or ARRAY but got: " + next.Type);
}
}
private void _DocumentElement(BSONToken token, BSONTokenStream tokens, BSONWalkingEvents events)
{
if (BSONTokenType.END == token.Type
|| BSONTokenType.EOF == token.Type)
{
throw new BSONValidationException("Unexpected BSON token type encountered: " + token.Type);
}
if (BSONTokenType.DOCUMENT_START == token.Type)
{
events.RaiseElement(token.Name, token.Type);
_Document(tokens, events, BSONTypes.DOCUMENT);
}
else if (BSONTokenType.ARRAY_START == token.Type)
{
events.RaiseElement(token.Name, token.Type);
_Document(tokens, events, BSONTypes.ARRAY);
}
else if (BSONTokenType.CODE_WITH_SCOPE == token.Type)
{
events.RaiseElement(token.Name, token.Type);
events.RaiseValue(token);
tokens.MoveNext();
token = tokens.Current;
if (BSONTokenType.END == token.Type
|| BSONTokenType.EOF == token.Type)
{
throw new BSONValidationException("Expected DOCUMENT but got: " + token.Type);
}
if (BSONTokenType.DOCUMENT_START == token.Type)
{
_Document(tokens, events, BSONTypes.DOCUMENT);
}
else if (BSONTokenType.ARRAY_START == token.Type)
{
_Document(tokens, events, BSONTypes.ARRAY);
}
}
else
{
events.RaiseElement(token.Name, token.Type);
events.RaiseValue(token);
}
}
public BSONSelector(BSONWalkingEvents events, string[] paths, BSONSelectorOptions options)
{
if (null == events)
{
throw new ArgumentNullException("events");
}
_events = events;
paths = paths ?? new string[0];
if (options.IgnoreArrays())
{
// Filter out paths containing array specifiers
_paths = paths.Where(p => -1 == p.IndexOf(ArraySpecifier))
.ToDictionary<string, string>(p => p);
}
else
{
_paths = paths.ToDictionary<string, string>(p => p);
}
_selectedValues = new List<SelectedValue>();
_options = options;
_documentPathStack = new Stack<string>();
_docTypeStack = new Stack<BSONTypes>();
_docPath = string.Empty;
_memberPath = string.Empty;
_arrayIndex = -1;
_arrayIndexStack = new Stack<int>();
_events.DocumentStart += new BSONEventHandler(_events_DocumentStart);
_events.DocumentEnd += new BSONEventHandler(_events_DocumentEnd);
_events.Element += new BSONElementEventHandler(_events_Element);
_events.ArrayStart += new BSONEventHandler(_events_ArrayStart);
_events.ArrayEnd += new BSONEventHandler(_events_ArrayEnd);
_events.String += new BSONValueEventHandler<string>(_events_String);
_events.Int32 += new BSONValueEventHandler<Int32>(_events_Int32);
_events.Int64 += new BSONValueEventHandler<Int64>(_events_Int64);
_events.Double += new BSONValueEventHandler<double>(_events_Double);
_events.DateTime += new BSONValueEventHandler<DateTime>(_events_DateTime);
_events.Value += new BSONValueEventHandler(_events_Value);
_events.Null += new BSONEventHandler(_events_Null);
_events.Boolean += new BSONValueEventHandler<bool>(_events_Boolean);
}
public BSONSelector(BSONWalkingEvents events, string[] paths)
: this(events, paths, DefaultOptions)
{
}
public static SelectedValue[] SelectValues(BinaryReader bson, string[] selectors, BSONSelectorOptions options)
{
if (null == bson)
{
return new SelectedValue[0];
}
// Create tokenizer for the BSON document - this is fed to a Tree Walking Validator
BSONTokenizer tokenizer = new BSONTokenizer(bson);
// Create an events object for the Tree Walker - events are fired as the walker
// traverses nodes in the tree.
BSONWalkingEvents events = new BSONWalkingEvents();
// The selector subscribes to the Walker Events and selects the appropriate values from the
// BSON tree.
BSONSelector selector = new BSONSelector(events, selectors);
// A BSON Tree Walker that validates the structure of the BSON and also fires events
// while traversing the document.
BSONWalkingValidator walker = new BSONWalkingValidator();
walker.Walk(tokenizer.GetEnumerator(), events);
// Retrieve the values selected from the BSON.
return selector.SelectedValues;
}
