Model Bundling
Bundling converts model weights into the APR format for deployment.
The ModelBundle Builder
use apr_cookbook::bundle::ModelBundle;
let bundle = ModelBundle::new()
.with_name("sentiment-v1")
.with_description("BERT-based sentiment classifier")
.with_compression(true)
.with_payload(model_weights)
.build();Builder Methods
| Method | Description |
|---|---|
with_name(s) | Set model name (max 255 chars) |
with_description(s) | Set description (optional) |
with_compression(bool) | Enable zstd compression |
with_payload(bytes) | Set model weights |
build() | Create the APR bundle |
Loading Bundles
use apr_cookbook::bundle::BundledModel;
// From bytes (zero-copy)
let model = BundledModel::from_bytes(&bundle_bytes)?;
// Access metadata
println!("Name: {}", model.name());
println!("Version: {:?}", model.version());
println!("Size: {} bytes", model.size());
// Check flags
if model.is_compressed() {
println!("Payload is compressed");
}BundledModel Methods
| Method | Returns | Description |
|---|---|---|
name() | &str | Model name |
version() | (u8, u8) | Format version |
size() | usize | Total size in bytes |
is_compressed() | bool | Compression flag |
is_encrypted() | bool | Encryption flag |
is_signed() | bool | Signature flag |
as_bytes() | &[u8] | Raw bundle bytes |
Compile-Time Embedding
The recommended pattern for production:
// Embed at compile time
const MODEL: &[u8] = include_bytes!("models/classifier.apr");
fn get_model() -> BundledModel<'static> {
// This never fails if the file is valid APR
BundledModel::from_bytes(MODEL).expect("embedded model is valid")
}Benefits:
- No file I/O at runtime
- Model integrity verified at compile time
- Single binary deployment