ferrox_models/
hybrid_engine.rs

1//! Hybrid attn+SSM engine stub (Jamba / LFM2 / Nemotron-H / Qwen3.5 GDN / …).
2//!
3//! Fail-closed at load via [`HybridEngine::reject`] (used by
4//! [`crate::engine_factory`] for `nemotron_h` and other hybrid arches).
5//! Qwen-style GDN math: [`crate::gdn`]. GGUF hparams + GDN weight load
6//! skeleton: [`crate::hybrid_gguf_loader`] (`try_load` still
7//! `UnsupportedFeature` until this engine assembles layers for serve).
8
9use thiserror::Error;
10
11#[derive(Debug, Error)]
12#[error("hybrid engine not implemented for architecture {arch}")]
13pub struct HybridUnavailable {
14    pub arch: String,
15}
16
17/// Placeholder hybrid serve handle.
18///
19/// Holds the GGUF arch string and an optional note. Construction is via
20/// [`Self::stub`]; the factory still calls [`Self::reject`]. GGUF→GDN
21/// weight probing lives in [`crate::hybrid_gguf_loader::try_load`].
22#[derive(Debug)]
23pub struct HybridEngine {
24    pub arch: String,
25    /// e.g. that GDN + loader skeleton exist but assemble/serve is incomplete.
26    pub note: Option<String>,
27}
28
29impl HybridEngine {
30    /// Fail-closed entry used by the engine factory until HybridEngine assemble lands.
31    pub fn reject(arch: &str) -> Result<(), HybridUnavailable> {
32        Err(HybridUnavailable {
33            arch: arch.to_string(),
34        })
35    }
36
37    /// Non-serving stub: records arch + note that GDN + hybrid_gguf_loader
38    /// exist but serve assemble is not wired.
39    pub fn stub(arch: &str) -> Self {
40        Self {
41            arch: arch.to_string(),
42            note: Some(
43                "GDN + hybrid_gguf_loader skeleton exist; HybridEngine assemble/serve not wired — factory still reject()"
44                    .into(),
45            ),
46        }
47    }
48}
49
50#[cfg(test)]
51mod tests {
52    use super::*;
53
54    #[test]
55    fn reject_is_fail_closed() {
56        assert!(HybridEngine::reject("jamba").is_err());
57        assert!(HybridEngine::reject("nemotron_h").is_err());
58    }
59
60    #[test]
61    fn stub_holds_arch_and_gdn_note() {
62        let eng = HybridEngine::stub("qwen35");
63        assert_eq!(eng.arch, "qwen35");
64        let note = eng.note.expect("note");
65        assert!(note.contains("GDN"));
66        assert!(note.contains("hybrid_gguf_loader"));
67    }
68}
ferrox_models/hybrid_engine.rs

ferrox_models/
hybrid_engine.rs
