/// <summary>
/// Fetch documents from enumerator and add to buffer. If cache recycle, stop read to execute in another read
/// </summary>
public void Fetch(TransactionService trans, DataService data, BsonReader bsonReader)
{
// empty document buffer
this.Documents.Clear();
// while until must cache not recycle
while (trans.CheckPoint() == false)
{
// read next node
this.HasMore = _nodes.MoveNext();
// if finish, exit loop
if (this.HasMore == false)
{
return;
}
// if run ONLY under index, skip/limit before deserialize
if (_query.UseIndex && _query.UseFilter == false)
{
if (--_skip >= 0)
{
continue;
}
if (--_limit <= -1)
{
this.HasMore = false;
return;
}
}
// get current node
var node = _nodes.Current;
// read document from data block
var buffer = data.Read(node.DataBlock);
var doc = bsonReader.Deserialize(buffer).AsDocument;
// if need run in full scan, execute full scan and test return
if (_query.UseFilter)
{
// execute query condition here - if false, do not add on final results
if (_query.FilterDocument(doc) == false)
{
continue;
}
// implement skip/limit after deserialize in full scan
if (--_skip >= 0)
{
continue;
}
if (--_limit <= -1)
{
this.HasMore = false;
return;
}
}
// increment position cursor
_position++;
// avoid lock again just to check limit
if (_limit == 0)
{
this.HasMore = false;
}
this.Documents.Add(doc);
}
}