Add collapser for the Visual Studio built in profiler

[KnapSac]

Recently, I wanted to create a FlameGraph of the output of the Visual Studio profiler, but as it turns out, there is no stackcollapser for that yet. Since the original project does have a stackcollapser for this profiler, I was wondering if this would be a welcome contribution? I implemented my own stackcollapser before I found out there was an original, so I'd need to check that I haven't missed anything, but besides some polishing (and some tests) I think it should be pretty much good to go.

[jonhoo]

Absolutely, that'd be great!

[KnapSac]

If a method calls a few other methods, is the callers sample count the sample counts of the called methods combined?

So if we have a method Run( ) which calls A( ) 500 times, and B( ) 500 times, the sample count of Run( ) would be 1000, even though Run( ) itself may be called only once?

[jonhoo]

That depends on the collection format. I think in general the profilers report the number of samples in that function specifically, so if the sample count for A is 500, and the sample count for Run is 600, then that means the width of the stack frame for Run should be 1100 samples wide (and A's frame on top of that would be 500 wide).

[KnapSac]

That is what I was getting, both A and B were called 500 times, while Run was called only once, so Run had 1001 samples. Just wanted to double check that the sample count for Run was indeed correct :).