ferroalloc

Real-time Rust heap memory visualization directly in VS Code.

What it does

Ferroalloc shows live heap memory stats inside VS Code as your Rust program runs:

• CodeLens — allocation count and total bytes above each line that allocates
• Heatmap — lines colored green → red by allocation volume
• Leak detection — lines with unfreed allocations flagged with ⚠
• Snapshot diff — compare memory state before and after a workload

Quick Start

1 — Install the VS Code extension

Search "ferroalloc" in the VS Code Extensions panel, or:

ext install hichammh.ferroalloc

2 — Install the analyzer

cargo install ferroalloc-analyzer

3 — Add the probe to your Rust project

# Cargo.toml
[dependencies]
ferroalloc-probe = "0.1"

// src/main.rs
use ferroalloc_probe::{FerroAllocator, start_flush_thread};

#[global_allocator]
static ALLOC: FerroAllocator = FerroAllocator;

fn main() {
    start_flush_thread(7777);
    // ... rest of your program
}

4 — Run

# Terminal 1 — start the analyzer
ferroalloc-analyzer

# Terminal 2 — run your program
cargo run

Then in VS Code: Cmd+Shift+P → Ferroalloc: Start Memory Tracking

Architecture

Your Rust app                Analyzer              VS Code Extension
─────────────────            ────────────          ──────────────────
FerroAllocator               ferroalloc-           ferroalloc
  (GlobalAlloc)   ─TCP:7777─▶ analyzer   ─HTTP:7778─▶ extension
  captures every             aggregates            CodeLens + heatmap
  alloc/dealloc              by file:line          + leak panel
  resolves symbol
  at runtime

Project structure

ferroalloc/
├── probe/             # ferroalloc-probe crate (add to your project)
├── analyzer/          # ferroalloc-analyzer binary (install on your machine)
└── vscode-extension/  # VS Code extension (install from marketplace)

Configuration

Setting	Default	Description
ferroalloc.analyzerPort	7778	HTTP port of the analyzer API
ferroalloc.refreshIntervalMs	1000	Poll interval in milliseconds
ferroalloc.heatmapEnabled	true	Enable/disable background heatmap

License

MIT