[jas88]

Summary

• Add SlabMemoryPool for efficient 4KB slab allocation (avoids LOH pressure)
• Add SocketPipe wrapper with PipeReader/PipeWriter for zero-copy network I/O
• Includes 20 comprehensive tests

Test plan

• All Pipes tests pass (20 tests)
• Build succeeds across all target frameworks

High-level PR Summary

This PR introduces zero-copy network I/O infrastructure for efficient PDU handling in DICOM network operations. It adds a custom SlabMemoryPool for managing fixed 4KB memory slabs that avoid Large Object Heap (LOH) pressure during high-throughput scenarios, and a SocketPipe wrapper that integrates sockets with the PipeReader/PipeWriter pattern for zero-copy buffering with backpressure support. The implementation includes background read/write pumps for async socket operations, automatic memory pooling and reuse, and comprehensive test coverage with 20 tests validating concurrent access, bidirectional communication, large data handling, and proper resource cleanup.

⏱️ Estimated Review Time: 30-90 minutes

💡 Review Order Suggestion

Order	File Path
1	src/SharpDicom/Network/Pipes/SlabMemoryPool.cs
2	tests/SharpDicom.Tests/Network/Pipes/SlabMemoryPoolTests.cs
3	src/SharpDicom/Network/Pipes/SocketPipe.cs
4	tests/SharpDicom.Tests/Network/Pipes/SocketPipeTests.cs

---

Summary by cubic

Adds SlabMemoryPool and SocketPipe to enable zero-copy PDU network I/O with backpressure and pooled 4KB buffers. Meets Phase 15 requirements by reducing allocations and GC/LOH pressure while wiring sockets to PipeReader/PipeWriter.

• New Features

  • SlabMemoryPool: 4KB slab allocator with a capped pool (up to 1024 slabs), ArrayPool fallback for large requests, and thread-safe rent/return.
  • SocketPipe: Adapter exposing PipeReader/PipeWriter over a Socket with background pumps, configurable pause/resume thresholds, custom MemoryPool support, and clean cancellation/completion.

• Bug Fixes

  • Handle partial sends by looping until each segment is fully transmitted.
  • Shutdown and close the socket in DisposeAsync to unblock pending I/O and ensure pumps complete.

^{Written for commit 1e3a839. Summary will update on new commits.}

[recurseml]

Review by RecurseML

🔍 Review performed on c986ec5..d30c5d1

✨ No bugs found, your code is sparkling clean

✅ Files analyzed, no issues (4)

• src/SharpDicom/Network/Pipes/SlabMemoryPool.cs
• src/SharpDicom/Network/Pipes/SocketPipe.cs
• tests/SharpDicom.Tests/Network/Pipes/SlabMemoryPoolTests.cs
• tests/SharpDicom.Tests/Network/Pipes/SocketPipeTests.cs

[cubic-dev-ai]

1 issue found across 4 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="src/SharpDicom/Network/Pipes/SocketPipe.cs">

<violation number="1" location="src/SharpDicom/Network/Pipes/SocketPipe.cs:196">
P1: Handle partial sends: Socket.SendAsync may send fewer bytes than requested, so a single call can drop data when you advance the pipe to buffer.End. Loop until the entire segment is sent.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[codecov]

Codecov Report

❌ Patch coverage is 73.88060% with 35 lines in your changes missing coverage. Please review.
✅ Project coverage is 74.65%. Comparing base (c986ec5) to head (1e3a839).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/SharpDicom/Network/Pipes/SocketPipe.cs	68.42%	26 Missing and 4 partials ⚠️
src/SharpDicom/Network/Pipes/SlabMemoryPool.cs	87.17%	3 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #34      +/-   ##
==========================================
- Coverage   74.66%   74.65%   -0.01%     
==========================================
  Files         182      184       +2     
  Lines       13980    14114     +134     
  Branches     2611     2631      +20     
==========================================
+ Hits        10438    10537      +99     
- Misses       2777     2806      +29     
- Partials      765      771       +6     

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