Method incr_float

nodedb/src/engine/kv/engine_atomic.rs:109–145

Atomically increment an f64 value by `delta`. Returns the new value. - If key doesn't exist: initializes to 0.0, adds delta, returns delta. - If value is not a MessagePack float or integer: returns `TypeMismatch`. - f64 does not overflow in the traditional sense (it goes to infinity), but NaN/Infinity results are rejected as `Overflow`.

(
        &mut self,
        tenant_id: u64,
        collection: &str,
        key: &[u8],
        delta: f64,
        now_ms: u64,
    )

    /// - f64 does not overflow in the traditional sense (it goes to infinity),
    ///   but NaN/Infinity results are rejected as `Overflow`.
    pub fn incr_float(
        &mut self,
        tenant_id: u64,
        collection: &str,
        key: &[u8],
        delta: f64,
        now_ms: u64,
    ) -> Result<f64, AtomicError> {
        let tkey = table_key(tenant_id, collection);
        let table = self.ensure_table(tkey, tenant_id, collection);

        let current = table.get(key, now_ms).map(|v| v.to_vec());
        let old_f64 = match &current {
            None => 0.0f64,
            Some(bytes) => decode_msgpack_f64(bytes)?,
        };

        let new_f64 = old_f64 + delta;
        if new_f64.is_nan() || new_f64.is_infinite() {
            return Err(AtomicError::Overflow);
        }

        let new_bytes = zerompk::to_msgpack_vec(&new_f64).expect("f64 always serializes");
        // incr_float always preserves existing TTL (ttl_ms = 0).
        self.atomic_put(
            tenant_id,
            collection,
            tkey,
            key,
            &new_bytes,
            0,
            now_ms,
            current.is_none(),
        );

        Ok(new_f64)
    }

    /// Atomic compare-and-swap.
    ///