public sealed override DataViewRowCursor[] GetRowCursorSet(IEnumerable <DataViewSchema.Column> columnsNeeded, int n, Random rand = null)
{
Host.CheckValueOrNull(rand);
var predicate = RowCursorUtils.FromColumnsToPredicate(columnsNeeded, OutputSchema);
var inputCols = _bindings.GetDependencies(columnsNeeded);
var inputs = Source.GetRowCursorSet(inputCols, n, rand);
Host.AssertNonEmpty(inputs);
if (inputs.Length == 1 && n > 1 && WantParallelCursors(predicate))
{
inputs = DataViewUtils.CreateSplitCursors(Host, inputs[0], n);
}
Host.AssertNonEmpty(inputs);
var cursors = new DataViewRowCursor[inputs.Length];
var active = _bindings.GetActive(predicate);
for (int i = 0; i < inputs.Length; i++)
{
cursors[i] = new Cursor(Host, this, inputs[i], active);
}
return(cursors);
}
public sealed override IRowCursor[] GetRowCursorSet(out IRowCursorConsolidator consolidator,
Func <int, bool> predicate, int n, IRandom rand = null)
{
Host.CheckValue(predicate, nameof(predicate));
Host.CheckValueOrNull(rand);
var inputPred = _bindings.GetDependencies(predicate);
var active = _bindings.GetActive(predicate);
var inputs = Source.GetRowCursorSet(out consolidator, inputPred, n, rand);
Host.AssertNonEmpty(inputs);
if (inputs.Length == 1 && n > 1 && _bindings.AnyNewColumnsActive(predicate))
{
inputs = DataViewUtils.CreateSplitCursors(out consolidator, Host, inputs[0], n);
}
Host.AssertNonEmpty(inputs);
var cursors = new IRowCursor[inputs.Length];
for (int i = 0; i < inputs.Length; i++)
{
cursors[i] = new RowCursor(this, inputs[i], active);
}
return(cursors);
}
public override RowCursor[] GetRowCursorSet(IEnumerable <Schema.Column> columnsNeeded, int n, Random rand = null)
{
Host.CheckValueOrNull(rand);
var predicate = RowCursorUtils.FromColumnsToPredicate(columnsNeeded, OutputSchema);
var bindings = GetBindings();
Func <int, bool> inputPred;
Func <int, bool> predicateMapper;
var active = GetActive(bindings, predicate, out inputPred, out predicateMapper);
var inputCols = Source.Schema.Where(x => inputPred(x.Index));
var inputs = Source.GetRowCursorSet(inputCols, n, rand);
Contracts.AssertNonEmpty(inputs);
if (inputs.Length == 1 && n > 1 && WantParallelCursors(predicate) && (Source.GetRowCount() ?? int.MaxValue) > n)
{
inputs = DataViewUtils.CreateSplitCursors(Host, inputs[0], n);
}
Contracts.AssertNonEmpty(inputs);
var cursors = new RowCursor[inputs.Length];
for (int i = 0; i < inputs.Length; i++)
{
cursors[i] = new Cursor(Host, this, inputs[i], active, predicateMapper);
}
return(cursors);
}
public override RowCursor[] GetRowCursorSet(Func <int, bool> predicate, int n, Random rand = null)
{
Host.CheckValue(predicate, nameof(predicate));
Host.CheckValueOrNull(rand);
var bindings = GetBindings();
Func <int, bool> predicateInput;
Func <int, bool> predicateMapper;
var active = GetActive(bindings, predicate, out predicateInput, out predicateMapper);
var inputs = Source.GetRowCursorSet(predicateInput, n, rand);
Contracts.AssertNonEmpty(inputs);
if (inputs.Length == 1 && n > 1 && WantParallelCursors(predicate) && (Source.GetRowCount() ?? int.MaxValue) > n)
{
inputs = DataViewUtils.CreateSplitCursors(Host, inputs[0], n);
}
Contracts.AssertNonEmpty(inputs);
var cursors = new RowCursor[inputs.Length];
for (int i = 0; i < inputs.Length; i++)
{
cursors[i] = new Cursor(Host, this, inputs[i], active, predicateMapper);
}
return(cursors);
}
/// <summary>
/// Create a set of cursors with additional active columns.
/// </summary>
/// <param name="additionalColumnsPredicate">Predicate that denotes which additional columns to include in the cursor,
/// in addition to the columns that are needed for populating the <typeparamref name="TRow"/> object.</param>
/// <param name="n">Number of cursors to create</param>
/// <param name="rand">Random generator to use</param>
public RowCursor <TRow>[] GetCursorSet(Func <int, bool> additionalColumnsPredicate, int n, Random rand)
{
_host.CheckValue(additionalColumnsPredicate, nameof(additionalColumnsPredicate));
_host.CheckValueOrNull(rand);
var inputs = _data.GetRowCursorSet(_data.Schema.Where(col => _columnIndices.Contains(col.Index) || additionalColumnsPredicate(col.Index)), n, rand);
_host.AssertNonEmpty(inputs);
if (inputs.Length == 1 && n > 1)
{
inputs = DataViewUtils.CreateSplitCursors(_host, inputs[0], n);
}
_host.AssertNonEmpty(inputs);
return(inputs
.Select(rc => (RowCursor <TRow>)(new RowCursorImplementation(new TypedCursor(this, rc))))
.ToArray());
}
/// <summary>
/// Create a set of cursors with additional active columns.
/// </summary>
/// <param name="consolidator">The consolidator for the original row cursors</param>
/// <param name="additionalColumnsPredicate">Predicate that denotes which additional columns to include in the cursor,
/// in addition to the columns that are needed for populating the <typeparamref name="TRow"/> object.</param>
/// <param name="n">Number of cursors to create</param>
/// <param name="rand">Random generator to use</param>
public IRowCursor <TRow>[] GetCursorSet(out IRowCursorConsolidator consolidator,
Func <int, bool> additionalColumnsPredicate, int n, IRandom rand)
{
_host.CheckValue(additionalColumnsPredicate, nameof(additionalColumnsPredicate));
_host.CheckValueOrNull(rand);
Func <int, bool> inputPredicate = col => _columnIndices.Contains(col) || additionalColumnsPredicate(col);
var inputs = _data.GetRowCursorSet(out consolidator, inputPredicate, n, rand);
_host.AssertNonEmpty(inputs);
if (inputs.Length == 1 && n > 1)
{
inputs = DataViewUtils.CreateSplitCursors(out consolidator, _host, inputs[0], n);
}
_host.AssertNonEmpty(inputs);
return(inputs
.Select(rc => (IRowCursor <TRow>)(new TypedCursor(this, rc)))
.ToArray());
}