stack allocated MemoryStream

[Xyncgas]

Although it can expand to overflow the stack, it gives 99% of object serialization an option to be allocation free simply writing the serialized result to stack allocated Span

[Xyncgas]

Maybe increase the stack size dynamically as needed, is to prevent stack overflow

[huoyaoyuan]

Stack is likely too small for Stream like operations.

[huoyaoyuan]

And also, dynamically adjusting stack allocated buffers would be impossible unless it's in the top frame.

[gfoidl]

object serialization an option to be allocation free

For object serialization there are other ways than using MemoryStream, like using IBufferWriter (or Pipelines) so it becomes also allocation-free.

Besides that it's not to difficult to write a Stream backed by stackallocated buffer.
And for .NET's point of view I think it's similar to #61456 (comment)

[Clockwork-Muse]

Besides that it's not to difficult to write a Stream backed by stackallocated buffer.

nit: you can't retain a stackallocated buffer between calls...

[gfoidl]

Why not? ref structs achieve this, look at ValueStringBuilder for example.

Sure, so it's not a stream-derived type, but a steam-like type 😉.

[Clockwork-Muse]

ValueStringBuilder has no internal stackalloc. ref structs are also stack-based - the moment execution leaves the method in which they're declared they get cleaned up.

You can pass them "down" the stack as parameters to methods that get called, but the moment you try to go "up" the stack they disappear.

[gfoidl]

I don't follow what you want to express in regards of the quote.

Is your problem "backed by stackallocated buffer"? Then wrap your head around, and just pass the buffer in quite as VSB does. I didn't state anything else, or did I?
Or where's the problem here? (I hope you don't believe that I don't know how the stack is working...).

[japasc]

https://dotnet.github.io/dotNext/api/DotNext.Buffers.BufferWriterSlim-1.html

Maybe its useful here.

[Clockwork-Muse]

... in what context do you need non-allocating serialization?