Replace LinearFifo with builtin ArrayList API

[bomanaps]

#110. Replaced custom LinearFifo with simple buffer types using std.ArrayList for dynamic mode and direct slice management for fixed mode. Added bounds checking, unit tests, and reset functionality.

[gemini-code-assist]

Summary of Changes

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This pull request refactors the internal buffer management by replacing a custom FIFO implementation with more idiomatic Zig approaches. It introduces dedicated fixed-size and dynamic buffer types built upon standard library components, enhancing the clarity, maintainability, and reliability of byte stream handling throughout the codebase. This change directly addresses a reported issue by adopting standard and well-tested mechanisms for buffer operations.

Highlights

• Buffer Implementation Replacement: The custom LinearFifo implementation has been replaced with two new buffer types: SliceBuffer for fixed-size buffers using direct slice management, and DynamicBuffer for growable buffers leveraging std.ArrayList(u8).
• Enhanced Buffer Functionality: The new buffer types include comprehensive methods for read, write, unget, discard, readableLength, readableSlice, and reset, ensuring robust FIFO operations.
• Improved Robustness and Testing: Bounds checking has been added to buffer operations, and extensive unit tests are now in place for both SliceBuffer and DynamicBuffer to ensure correctness and prevent common buffer-related issues.
• Integration Across Modules: Existing modules such as multistream/multistream.zig, protocols/mss.zig, and protocols/pubsub/semiduplex.zig have been updated to utilize the new SliceBuffer and DynamicBuffer types, replacing the deprecated LinearFifo.

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Changelog

• src/byte_buffer.zig
  • Added SliceBuffer for fixed-size FIFO buffering using direct slice management.
  • Added DynamicBuffer for growable FIFO buffering using std.ArrayList(u8).
  • Implemented init, deinit, readableLength, readableSlice, read, discard, unget, write, and reset methods for both buffer types.
  • Included comprehensive unit tests for SliceBuffer and DynamicBuffer.
• src/linear_fifo.zig
  • Removed the LinearFifo module, as its functionality is now provided by SliceBuffer and DynamicBuffer.
• src/multistream/multistream.zig
  • Updated import from linear_fifo.zig to byte_buffer.zig.
  • Replaced LinearFifo(u8, .Slice) with SliceBuffer in the Negotiator struct definition.
  • Updated Negotiator.init to use SliceBuffer.init.
  • Replaced linear_fifo.LinearFifo(u8, .Slice) with byte_buffer.SliceBuffer in the MultistreamSelectHandler struct definition.
  • Updated MultistreamSelectHandler.NegotiationSession.init to use byte_buffer.SliceBuffer.init.
• src/protocols/mss.zig
  • Updated import from linear_fifo.zig to byte_buffer.zig.
  • Replaced *linear_fifo.LinearFifo(u8, .Slice) with *byte_buffer.SliceBuffer in the Negotiator struct.
  • Replaced linear_fifo.LinearFifo(u8, .Slice) with byte_buffer.SliceBuffer in the MultistreamSelectHandler.NegotiationSession struct.
• src/protocols/pubsub/semiduplex.zig
  • Updated import from linear_fifo.zig to byte_buffer.zig.
  • Replaced linear_fifo.LinearFifo(u8, .Dynamic) with byte_buffer.DynamicBuffer for received_buffer initialization in PubSubPeerProtocolHandler.addStream.
  • Replaced linear_fifo.LinearFifo(u8, .Dynamic) with byte_buffer.DynamicBuffer in the PubSubPeerResponder struct.

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[gemini-code-assist]

Code Review

This pull request is a nice refactoring that replaces a custom LinearFifo implementation with SliceBuffer and DynamicBuffer, which are built on top of standard Zig features like slices and std.ArrayList. This simplifies the codebase and improves maintainability. The new implementations are well-tested.

My review includes a couple of suggestions for the new DynamicBuffer to make it even more robust and idiomatic by using more of the std.ArrayList public API, reducing the need to manually manage its internal state.

[GrapeBaBa]

since linear_fifo removed from std, can you check the official release notes to see what can be used to instead it which probably not need introduce this

[bomanaps]

Zig 0.15 recommends std.Io.Reader/Writer as LinearFifo replacements, but those serve stream I/O with underlying sources (files, sockets), not in-memory accumulation buffers requiring unget and readableSlice operations. We use std.ArrayList(u8) with fromOwnedSlice, replaceRange, and clearRetainingCapacity all public stdlib APIs which fits this protocol parsing use case idiomatically any idea on how to properly go about this considering this?

[anshalshukla]

I think there are plans to reintroduce in zig 0.16, so maybe we can just wait for the release

[GrapeBaBa]

I think there are plans to reintroduce in zig 0.16, so maybe we can just wait for the release

Great.

[GrapeBaBa]

@bomanaps we may not need this change and wait until it back