pxp Library

The pxp library is a headless, consumer-agnostic Rust implementation of the Portal Transfer Protocol (PXP). It is decoupled from any specific user interface, making it suitable for command-line tools, desktop applications (such as Tauri or Electron wrappers), mobile applications, and background daemons.

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Key Design Principles

1. No Side Effects The library never writes to stdout/stderr or reads from stdin. All logger outputs use the standard tracing facade.
2. Standard Traits for UI Decoupling All user-facing behaviors — such as displaying progress bars, printing transfer status messages, and resolving filename conflicts — are abstracted into traits that the caller implements.
3. Pure Async/Await Built on top of tokio for non-blocking network I/O, UDP broadcasting, and filesystem streaming.
4. Strongly-Typed Errors Contains a comprehensive, typed error taxonomy (PxpError) built using thiserror (no anyhow dependencies).

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Crate Structure

The crate is organized into several modules representing protocol stages:

• discovery — Broadcasts and listens for UDP beacons.
• sender — Discovers receivers, establishes TCP handshakes, creates metadata manifests, and streams TAR archives.
• receiver — Binds listeners, receives handshake proofs, decodes manifests, stages streams to disk, and reconciles conflicts into the target directory.
• metadata — Shared models representing files, directories, manifests, and transfer items.
• error — Crate-wide error enum (PxpError) and Result type alias.