SPlit up

server-rs/src/data/property/quant.rs

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+//! u16 quantization: decoding stored feature values and encoding filter bounds.
+
+use crate::consts::{NAN_U16, QUANT_SCALE};
+
+/// Lightweight reference to quantization parameters for decoding u16 feature data.
+pub struct QuantRef<'a> {
+    pub dequant_a: &'a [f32],
+    pub quant_min: &'a [f32],
+    pub quant_range: &'a [f32],
+    pub num_numeric: usize,
+}
+
+impl QuantRef<'_> {
+    /// Decode a raw u16 value back to f32.
+    #[inline]
+    pub fn decode(&self, feat_idx: usize, raw: u16) -> f32 {
+        if raw == NAN_U16 {
+            return f32::NAN;
+        }
+        if feat_idx >= self.num_numeric {
+            raw as f32
+        } else {
+            raw as f32 * self.dequant_a[feat_idx] + self.quant_min[feat_idx]
+        }
+    }
+
+    /// Encode a filter minimum bound to u16 (floors to include boundary values).
+    #[inline]
+    pub fn encode_min(&self, feat_idx: usize, value: f32) -> u16 {
+        if !value.is_finite() || self.quant_range[feat_idx] == 0.0 {
+            return 0;
+        }
+        let norm = (value - self.quant_min[feat_idx]) / self.quant_range[feat_idx];
+        (norm * QUANT_SCALE).floor().clamp(0.0, QUANT_SCALE) as u16
+    }
+
+    /// Encode a filter maximum bound to u16 (ceils to include boundary values).
+    #[inline]
+    pub fn encode_max(&self, feat_idx: usize, value: f32) -> u16 {
+        if !value.is_finite() || self.quant_range[feat_idx] == 0.0 {
+            return QUANT_SCALE as u16;
+        }
+        let norm = (value - self.quant_min[feat_idx]) / self.quant_range[feat_idx];
+        (norm * QUANT_SCALE).ceil().clamp(0.0, QUANT_SCALE) as u16
+    }
+}