Replace ArrayList in ItemContainerGenerator with List<EmptyGroupItem>

[h3xds1nz]

Description

Replaces ArrayList with List<EmptyGroupItem> to hold empty group items when needed. Improves code quality by swapping to generic collection and decreases memory footprint.

Sample benchmark showing difference between ArrayList and List<EmptyGroupItem>.

10 additions comparison

Method	Mean [ns]	Error [ns]	StdDev [ns]	Gen0	Code Size [B]	Gen1	Allocated [B]
Original	103.59 ns	2.013 ns	3.578 ns	0.0483	740 B	0.0001	808 B
PR__EDIT	95.02 ns	1.907 ns	2.480 ns	0.0483	342 B	0.0001	808 B

Benchmark code

[Benchmark]
public void Original()
{
    ArrayList? _alEmptyGroupItems = null;

    for (int i = 0; i < 10; i++)
        BenchV1(ref _alEmptyGroupItems);
}

[Benchmark]
public void PR__EDIT()
{
    List<EmptyGroupItem>? _emptyGroupItems = null;

    for (int i = 0; i < 10; i++)
        BenchV2(ref _emptyGroupItems);
}

[MethodImpl(MethodImplOptions.AggressiveInlining)]
private void BenchV1(ref ArrayList? _alEmptyGroupItems)
{
    EmptyGroupItem emptyGroupItem = new EmptyGroupItem();

    if (_alEmptyGroupItems == null)
        _alEmptyGroupItems = new ArrayList();

    _alEmptyGroupItems.Add(emptyGroupItem);
}

[MethodImpl(MethodImplOptions.AggressiveInlining)]
private void BenchV2(ref List<EmptyGroupItem>? _emptyGroupItems)
{
    EmptyGroupItem emptyGroupItem = new EmptyGroupItem();

    if (_emptyGroupItems == null)
        _emptyGroupItems = new();

    _emptyGroupItems.Add(emptyGroupItem);
}

public class EmptyGroupItem
{
    public string? Item1 { get; set; }

    public Int32? Item2 { get; set; }

    public Int32? Item3 { get; set; }

    public List<int>? Item4 { get; set; }
}

Customer Impact

Improved performance, getting rid of ArrayList.

Regression

No.

Testing

Local build.

Risk

None, changes are minimal.

Microsoft Reviewers: Open in CodeFlow

[rchauhan18]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[siagupta0202]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[siagupta0202]

@h3xds1nz Thank you for your contribution!

[h3xds1nz]

@siagupta0202 Thank you for including it 👍