Import upstream v0.16.22, stripped

Upstream commit: 474dd0229cb20cf513036619781ed97bd8073c3f Enterprise-only files removed or emptied: 63 Enterprise-only snippets removed: 117 in 50 files Dangling module declarations removed: 5 Cargo edits turning enterprise off: 14 Verification: clean Enterprise feature gates left for rebuilt features: 19 in 18 files Produced by tools/fork/strip.py. The full report is in docs/fork/strip-reports/ on main.
2026-09-18 10:21:56 -07:00
commit 7dae9b29fd
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+/*
+ * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <[email protected]>
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ */
+
+use crate::classifier::model::FhClassifier;
+
+pub mod adam;
+pub mod feature;
+pub mod ftrl;
+pub mod model;
+pub mod reservoir;
+pub mod sgd;
+pub mod train;
+
+const MAX_DLOSS: f32 = 1e4;
+
+pub trait Optimizer {
+    fn step(&mut self);
+    fn update_param(&mut self, i: usize, g: f32);
+    fn update_bias(&mut self, g: f32);
+    fn get_param(&self, idx: usize) -> f32;
+    fn get_param_mut(&mut self, idx: usize) -> &mut f32;
+    fn get_bias(&self) -> f32;
+    fn build_classifier(&self) -> FhClassifier;
+    fn num_parameters(&self) -> usize;
+}
+
+#[inline(always)]
+fn sigmoid(z: f32) -> f32 {
+    let z = z.clamp(-35.0, 35.0);
+    if z >= 0.0 {
+        1.0 / (1.0 + (-z).exp())
+    } else {
+        let exp_z = z.exp();
+        exp_z / (1.0 + exp_z)
+    }
+}
+
+#[inline(always)]
+fn gradient(y: f32, p: f32) -> f32 {
+    if p > -16.0 {
+        let exp_tmp = (-p).exp();
+        ((1.0 - y) - y * exp_tmp) / (1.0 + exp_tmp)
+    } else {
+        p.exp() - y
+    }
+}