Replace boxing Stacks in BamlReader, decrease allocs, improve performance

[h3xds1nz]

Description

Replaces boxing Stack with Stack<bool>, increasing overall performance and decreasing allocations/code-size.
Also replaces non-generic Stack with Stack<BamlNodeInfo> and makes it readonly.

For ilustration, here are some benchmarks:

1 boxing stack vs. generic

Method	Mean [ns]	Error [ns]	StdDev [ns]	Gen0	Code Size [B]	Allocated [B]
BoxingStack	67.83 ns	1.107 ns	0.981 ns	0.0238	869 B	400 B
GenericStack	22.23 ns	0.213 ns	0.189 ns	0.0038	210 B	64 B

Benchmark code

[Benchmark]
public void BoxingStack()
{
    Stack stack = new Stack();
    stack.Push(true);

    int i = 0;
    while (i < 10)
    {
        if ((bool)stack.Peek())
        {
            stack.Pop();
            stack.Push(true);
        }
        i++;
    }


}
[Benchmark]
public void GenericStack()
{
    Stack<bool> stack = new Stack<bool>();
    stack.Push(true);

    int i = 0;
    while (i < 10)
    {
        if (stack.Peek())
        {
            stack.Pop();
            stack.Push(true);
        }
        i++;
    }

3 boxing stacks vs. generic

Method	Mean [ns]	Error [ns]	StdDev [ns]	Gen0	Code Size [B]	Allocated [B]
BoxingStack	207.90 ns	3.092 ns	2.582 ns	0.0715	1,798 B	1200 B
GenericStack	59.11 ns	0.923 ns	0.863 ns	0.0114	441 B	192 B

Benchmark code

[Benchmark]
public void BoxingStack()
{
    Stack stack = new Stack();
    stack.Push(true);
    Stack stack2 = new Stack();
    stack2.Push(true);
    Stack stack3 = new Stack();
    stack3.Push(true);

    int i = 0;
    while (i < 10)
    {
        if ((bool)stack.Peek())
        {
            stack.Pop();
            stack.Push(true);
        }
        if ((bool)stack2.Peek())
        {
            stack2.Pop();
            stack2.Push(true);
        }
        if ((bool)stack3.Peek())
        {
            stack3.Pop();
            stack3.Push(true);
        }
        i++;
    }


}
[Benchmark]
public void GenericStack()
{
    Stack<bool> stack = new Stack<bool>();
    stack.Push(true);
    Stack<bool> stack2 = new Stack<bool>();
    stack2.Push(true);
    Stack<bool> stack3 = new Stack<bool>();
    stack3.Push(true);

    int i = 0;
    while (i < 10)
    {
        if (stack.Peek())
        {
            stack.Pop();
            stack.Push(true);
        }
        if (stack2.Peek())
        {
            stack2.Pop();
            stack2.Push(true);
        }
        if (stack3.Peek())
        {
            stack3.Pop();
            stack3.Push(true);
        }
        i++;
    }

Customer Impact

Increased performance, decreased allocations.

Regression

No.

Testing

Local build, app run.

Risk

Low.

Microsoft Reviewers: Open in CodeFlow

[harshit7962]

@h3xds1nz Thank you for active contributions.

[h3xds1nz]

@harshit7962 Happy to contribute!