add a reload() (#1)

Cargo.toml

@@ -9,7 +9,7 @@ license = "MIT"
 name = "apt-pkg-native"
 readme = "README.md"
 repository = "https://github.com/FauxFaux/apt-pkg-native-rs"
-version = "0.2.1"
+version = "0.3.0"
 
 [badges.travis-ci]
 repository = "FauxFaux/apt-pkg-native-rs"

apt-pkg-c/lib.cpp

@@ -48,6 +48,7 @@ extern "C" {
     void init_config_system();
 
     PCache *pkg_cache_create();
+    void pkg_cache_release(PCache *cache);
 
     int32_t pkg_cache_compare_versions(PCache *cache, const char *left, const char *right);
 
@@ -133,7 +134,6 @@ PCache *pkg_cache_create() {
     return ret;
 }
 
-// TODO: we don't expose this so we always leak the wrapper.
 void pkg_cache_release(PCache *cache) {
     // TODO: is cache->cache cleaned up with cache->cache_file?
     delete cache->cache_file;

src/lib.rs

@@ -87,4 +87,13 @@ mod tests {
         assert_eq!(Ordering::Greater, cache.compare_versions("3.1", "3.0"));
         assert_eq!(Ordering::Equal, cache.compare_versions("3.0", "3.0"));
     }
+
+    #[test]
+    fn reload() {
+        let mut cache = Cache::get_singleton();
+        cache.reload();
+        cache.reload();
+        cache.reload();
+        cache.reload();
+    }
 }

src/raw.rs

@@ -20,6 +20,7 @@ extern "C" {
     /// Must be called exactly once, before anything else?
     fn init_config_system();
     fn pkg_cache_create() -> PCache;
+    fn pkg_cache_release(cache: PCache);
 
     pub fn pkg_cache_compare_versions(
         cache: PCache,
@@ -108,6 +109,15 @@ pub struct CacheHolder {
 
 unsafe impl Send for CacheHolder {}
 
+impl CacheHolder {
+    pub fn re_up(&mut self) {
+        unsafe {
+            pkg_cache_release(self.ptr);
+            self.ptr = pkg_cache_create();
+        }
+    }
+}
+
 lazy_static! {
     #[derive(Debug)]
     pub static ref CACHE_SINGLETON: Mutex<CacheHolder> = {

src/sane.rs

@@ -24,6 +24,16 @@ impl Cache {
         }
     }
 
+    /// Drop the cache, and re-create it from scratch.
+    ///
+    /// It's super important that there are no other outstanding
+    /// references to the cache at this point. Again, I remind you
+    /// not to try and outsmart the borrow checker. It doesn't know
+    /// how much trouble there is in here.
+    pub fn reload(&mut self) {
+        self.ptr_mutex.lock().expect("poisoned mutex").re_up()
+    }
+
     /// Walk through all of the packages, in a random order.
     ///
     /// If there are multiple architectures, multiple architectures will be returned.