/// <summary>
/// Instead of filling the JoinCollector with iterators from all
/// data sources, fill only the rightmost for this key.
/// </summary>
/// <remarks>
/// Instead of filling the JoinCollector with iterators from all
/// data sources, fill only the rightmost for this key.
/// This not only saves space by discarding the other sources, but
/// it also emits the number of key-value pairs in the preferred
/// RecordReader instead of repeating that stream n times, where
/// n is the cardinality of the cross product of the discarded
/// streams for the given key.
/// </remarks>
/// <exception cref="System.IO.IOException"/>
/// <exception cref="System.Exception"/>
protected internal override void FillJoinCollector(K iterkey)
{
PriorityQueue <ComposableRecordReader <K, object> > q = GetRecordReaderQueue();
if (q != null && !q.IsEmpty())
{
int highpos = -1;
AList <ComposableRecordReader <K, object> > list = new AList <ComposableRecordReader <
K, object> >(kids.Length);
q.Peek().Key(iterkey);
WritableComparator cmp = GetComparator();
while (0 == cmp.Compare(q.Peek().Key(), iterkey))
{
ComposableRecordReader <K, object> t = q.Poll();
if (-1 == highpos || list[highpos].Id() < t.Id())
{
highpos = list.Count;
}
list.AddItem(t);
if (q.IsEmpty())
{
break;
}
}
ComposableRecordReader <K, object> t_1 = list.Remove(highpos);
t_1.Accept(jc, iterkey);
foreach (ComposableRecordReader <K, object> rr in list)
{
rr.Skip(iterkey);
}
list.AddItem(t_1);
foreach (ComposableRecordReader <K, object> rr_1 in list)
{
if (rr_1.HasNext())
{
q.AddItem(rr_1);
}
}
}
}
/// <summary>
/// For all child RRs offering the key provided, obtain an iterator
/// at that position in the JoinCollector.
/// </summary>
/// <exception cref="System.IO.IOException"/>
/// <exception cref="System.Exception"/>
protected internal virtual void FillJoinCollector(K iterkey)
{
if (!q.IsEmpty())
{
q.Peek().Key(iterkey);
while (0 == cmp.Compare(q.Peek().Key(), iterkey))
{
ComposableRecordReader <K, object> t = q.Poll();
t.Accept(jc, iterkey);
if (t.HasNext())
{
q.AddItem(t);
}
else
{
if (q.IsEmpty())
{
return;
}
}
}
}
}
/// <summary>
/// Implement Comparable contract (compare key at head of proxied RR
/// with that of another).
/// </summary>
public override int CompareTo(ComposableRecordReader <K, object> other)
{
return(cmp.Compare(Key(), other.Key()));
}
public abstract int CompareTo(ComposableRecordReader <K, object> arg1);
public int Compare(ComposableRecordReader <K, object> o1, ComposableRecordReader <K
, object> o2)
{
return(this._enclosing.cmp.Compare(o1.Key(), o2.Key()));
}
/// <summary>Add a RecordReader to this collection.</summary>
/// <remarks>
/// Add a RecordReader to this collection.
/// The id() of a RecordReader determines where in the Tuple its
/// entry will appear. Adding RecordReaders with the same id has
/// undefined behavior.
/// </remarks>
/// <exception cref="System.IO.IOException"/>
/// <exception cref="System.Exception"/>
public virtual void Add(ComposableRecordReader <K, V> rr)
{
kids[rr.Id()] = rr;
}
