Is StreamView::freeSectors needed?

[Numpsy]

I tried running the code through the whole solution code analysis in Rider and it determined that 'freeSectors' isn't mutated after creation, so I wonder if it's needed? (StreamView is an internal class, so if there are internal users then there shouldn't be any users at all).

As an extra test, I tried running a benchmark against the current code and with freeSectors removed and got

before:

| Method                  | Job      | Runtime  | Mean      | Error     | StdDev     | Median    | Gen0     | Gen1    | Allocated |
|------------------------ |--------- |--------- |----------:|----------:|-----------:|----------:|---------:|--------:|----------:|
| CreateCompoundDocument  | .NET 6.0 | .NET 6.0 |  50.47 us |  1.820 us |   5.251 us |  48.50 us |   6.8359 |  0.1221 |  42.19 KB |
| ReadDocFile             | .NET 6.0 | .NET 6.0 | 648.27 us | 12.958 us |  34.362 us | 645.34 us | 162.1094 | 24.4141 | 995.83 KB |
| ReadOnePropFromADocFile | .NET 6.0 | .NET 6.0 | 633.38 us | 12.618 us |  23.701 us | 631.44 us | 162.1094 | 25.3906 | 993.42 KB |
| CreateCompoundDocument  | .NET 8.0 | .NET 8.0 |  42.88 us |  0.931 us |   2.672 us |  43.08 us |   6.8359 |  0.1221 |   42.2 KB |
| ReadDocFile             | .NET 8.0 | .NET 8.0 | 599.77 us | 12.722 us |  37.311 us | 599.49 us | 160.1563 | 27.3438 | 995.86 KB |
| ReadOnePropFromADocFile | .NET 8.0 | .NET 8.0 | 527.57 us | 36.255 us | 103.437 us | 493.24 us | 162.1094 | 27.3438 | 993.44 KB |

after

| Method                  | Job      | Runtime  | Mean      | Error     | StdDev    | Median    | Gen0     | Gen1    | Allocated |
|------------------------ |--------- |--------- |----------:|----------:|----------:|----------:|---------:|--------:|----------:|
| CreateCompoundDocument  | .NET 6.0 | .NET 6.0 |  39.58 us |  0.635 us |  0.563 us |  39.57 us |   6.8359 |  0.1221 |  42.11 KB |
| ReadDocFile             | .NET 6.0 | .NET 6.0 | 512.33 us | 10.039 us | 15.630 us | 507.56 us | 156.2500 | 25.3906 | 957.85 KB |
| ReadOnePropFromADocFile | .NET 6.0 | .NET 6.0 | 528.27 us |  9.799 us | 19.794 us | 522.99 us | 155.2734 | 24.4141 | 955.42 KB |
| CreateCompoundDocument  | .NET 8.0 | .NET 8.0 |  39.19 us |  1.562 us |  4.455 us |  37.36 us |   6.8359 |  0.1221 |  42.12 KB |
| ReadDocFile             | .NET 8.0 | .NET 8.0 | 441.14 us |  8.335 us |  9.922 us | 440.31 us | 156.2500 | 30.2734 | 957.86 KB |
| ReadOnePropFromADocFile | .NET 8.0 | .NET 8.0 | 455.55 us |  9.087 us | 17.068 us | 449.14 us | 154.2969 | 25.3906 | 955.47 KB |

which seems a pretty substantial change in memory allocations.

[Numpsy]

The InMemory benchmark here only goes from

| Method | BufferSize | TotalStreamSize | Mean        | Error     | StdDev      | Median      | Gen0      | Gen1     | Gen2     | Allocated |
|------- |----------- |---------------- |------------:|----------:|------------:|------------:|----------:|---------:|---------:|----------:|
| Test   | 1048576    | 1048576         |    158.7 us |   3.12 us |     4.77 us |    158.1 us |  181.1523 |  90.5762 |        - |   1.09 MB |
| Test   | 524288     | 1048576         |    168.5 us |   2.68 us |     2.37 us |    168.1 us |  184.0820 |  92.0410 |        - |    1.1 MB |
| Test   | 262144     | 1048576         |    181.7 us |   3.41 us |     2.85 us |    180.7 us |  189.6973 |  88.1348 |        - |   1.14 MB |
| Test   | 131072     | 1048576         |    228.6 us |   3.97 us |     3.52 us |    227.4 us |  200.9277 | 100.3418 |        - |    1.2 MB |
| Test   | 4096       | 1048576         |  2,923.7 us |  47.46 us |    66.53 us |  2,907.0 us |  898.4375 | 398.4375 |        - |   5.39 MB |
| Test   | 1024       | 1048576         | 11,271.1 us | 208.83 us |   185.12 us | 11,246.9 us | 3062.5000 | 343.7500 | 171.8750 |  18.33 MB |
| Test   | 512        | 1048576         | 24,782.9 us | 596.95 us | 1,693.45 us | 24,280.3 us | 5937.5000 | 343.7500 | 156.2500 |   35.6 MB |

to

| Method | BufferSize | TotalStreamSize | Mean        | Error     | StdDev    | Median      | Gen0      | Gen1     | Gen2     | Allocated |
|------- |----------- |---------------- |------------:|----------:|----------:|------------:|----------:|---------:|---------:|----------:|
| Test   | 524288     | 1048576         |    171.0 us |   3.38 us |   7.71 us |    168.7 us |  184.0820 |  92.0410 |        - |    1.1 MB |
| Test   | 1048576    | 1048576         |    180.5 us |   9.76 us |  28.79 us |    188.8 us |  181.1523 |  90.5762 |        - |   1.09 MB |
| Test   | 262144     | 1048576         |    183.1 us |   3.61 us |   3.38 us |    183.4 us |  189.6973 |  87.1582 |        - |   1.14 MB |
| Test   | 131072     | 1048576         |    230.8 us |   4.57 us |   9.24 us |    227.9 us |  200.9277 | 100.3418 |        - |    1.2 MB |
| Test   | 4096       | 1048576         |  2,961.0 us |  58.71 us | 131.31 us |  2,910.7 us |  894.5313 | 378.9063 |        - |   5.37 MB |
| Test   | 1024       | 1048576         | 11,222.6 us | 219.51 us | 328.55 us | 11,231.8 us | 3046.8750 | 359.3750 | 171.8750 |  18.26 MB |
| Test   | 512        | 1048576         | 23,522.0 us | 461.55 us | 631.78 us | 23,304.1 us | 5906.2500 | 406.2500 | 187.5000 |  35.44 MB |

for another test

[jeremy-visionaid]

@Numpsy 3.0.0 is pretty close now, we could probably just close this one unless it's a problem for you to switch to the new API?

[Numpsy]

Was just an observation, I haven;t had the time to test the v3 test yet

[Numpsy]

unless it's a problem for you to switch to the new API

Personally I'd find it useful to have a new official v2 build to get #128 for maintenance purposes and take v3 after I do a major version bump and drop .NET 6.0 support.
This could go into such a build, but it's only a small allocation improvement so it's not a problem to not take the change

[jeremy-visionaid]

@Numpsy, I think we should get 2.4 out of the door too. @ironfede has granted me NuGet privileges, so I'll try and get that done now... I might leave this one here till after 3.0 is out, since it's probably easier for me to retarget this to a 2.4 branch.

[Numpsy]

Thanks