Free model

src/bindings.rs

@@ -54,6 +54,7 @@ extern "C" {
     pub fn mf_get_default_param() -> MfParameter;
     pub fn mf_save_model(model: *const MfModel, path: *const c_char) -> c_int;
     pub fn mf_load_model(path: *const c_char) -> *mut MfModel;
+    pub fn mf_destroy_model(model: *mut *mut MfModel);
     pub fn mf_train(prob: *const MfProblem, param: MfParameter) -> *mut MfModel;
     pub fn mf_train_with_validation(tr: *const MfProblem, va: *const MfProblem, param: MfParameter) -> *mut MfModel;
     pub fn mf_cross_validation(prob: *const MfProblem, nr_folds: c_int, param: MfParameter) -> c_double;

src/model.rs

@@ -3,7 +3,7 @@ use crate::Matrix;
 use std::ffi::CString;
 
 pub struct Model {
-    model: *const MfModel,
+    model: *mut MfModel,
     pub loss: i32,
     pub factors: i32,
     pub threads: i32,
@@ -22,7 +22,7 @@ pub struct Model {
 
 impl Model {
     pub fn new() -> Self {
-        Self::with_model(std::ptr::null())
+        Self::with_model(std::ptr::null_mut())
     }
 
     pub fn load(path: &str) -> Self {
@@ -32,12 +32,14 @@ impl Model {
 
     pub fn fit(&mut self, data: &Matrix) {
         let prob = data.to_problem();
+        self.destroy_model();
         self.model = unsafe { mf_train(&prob, self.param()) };
     }
 
     pub fn fit_eval(&mut self, train_set: &Matrix, eval_set: &Matrix) {
         let tr = train_set.to_problem();
         let va = eval_set.to_problem();
+        self.destroy_model();
         self.model = unsafe { mf_train_with_validation(&tr, &va, self.param()) };
     }
 
@@ -147,7 +149,7 @@ impl Model {
         unsafe { calc_auc(&prob, self.model, transpose) }
     }
 
-    fn with_model(model: *const MfModel) -> Self {
+    fn with_model(model: *mut MfModel) -> Self {
         let param = unsafe { mf_get_default_param() };
         Self {
             model: model,
@@ -190,6 +192,19 @@ impl Model {
     fn is_fit(&self) -> bool {
         !self.model.is_null()
     }
+
+    fn destroy_model(&mut self) {
+        if !self.model.is_null() {
+            unsafe { mf_destroy_model(&mut self.model) };
+            self.model = std::ptr::null_mut();
+        }
+    }
+}
+
+impl Drop for Model {
+    fn drop(&mut self) {
+        self.destroy_model();
+    }
 }
 
 #[cfg(test)]