Zero-Copy Loading

Zero-copy loading eliminates memory copies when loading models, reducing latency and memory usage.

How It Works

Traditional loading:

File → Read to buffer → Parse → Copy to model struct → Use
        ↓                        ↓
     Allocation              Allocation

Zero-copy loading:

Memory (file/include_bytes!) → Interpret in place → Use
                                    ↓
                              No allocations

The include_bytes!() Pattern

// Model bytes are in the binary's .rodata section
const MODEL: &[u8] = include_bytes!("model.apr");

fn main() {
    // BundledModel borrows from MODEL, no copies
    let model = BundledModel::from_bytes(MODEL).unwrap();

    // model.as_bytes() returns the original slice
    assert!(std::ptr::eq(MODEL.as_ptr(), model.as_bytes().as_ptr()));
}

Memory Layout

Binary .rodata section:
┌──────────────────────────────────────────┐
│ ... other static data ...                │
│ MODEL: [APRN header | metadata | payload]│
│ ... other static data ...                │
└──────────────────────────────────────────┘
         ↑
         │ BundledModel references this directly
         │ No heap allocations

Benefits

When to Use

✅ Use zero-copy when:

• Model is embedded via include_bytes!()
• Model is memory-mapped
• Model lifetime matches application lifetime

❌ Don't use when:

• Model needs modification
• Model comes from untrusted source (validate first)
• Model needs to outlive source buffer