add rpm: get_installed_package()

Signed-off-by: Jia Chao <jiachao2130@126.com>

src/lib.rs

@@ -1,14 +1,16 @@
-pub fn add(left: usize, right: usize) -> usize {
-    left + right
-}
+use std::sync::Once;
 
-#[cfg(test)]
-mod tests {
-    use super::*;
+use librpm::config;
 
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
+// use librpm
+pub mod rpm;
+
+// 使用 Once 对配置进行一次性地初始化
+static CONFIGURE: Once = Once::new();
+
+// 使用系统的默认配置
+pub fn configure() {
+    CONFIGURE.call_once(|| {
+        config::read_file(None).unwrap();
+    });
 }

src/rpm.rs

@@ -0,0 +1,37 @@
+use std::collections::HashMap;
+
+use librpm::db;
+use librpm::Package;
+
+// 获取当前系统已安装的所有 RPM 包
+// 最后返回一个 map，其键为包名，因有多个版本可并存的软件包如 kernel，故其值为 `Vec<Package>`
+pub fn get_installed_packages() -> HashMap<String, Vec<Package>> {
+    let mut installed: HashMap<String, Vec<Package>> = HashMap::new();
+    db::installed_packages().for_each(|pkg| {
+        if let Some(rpms) = installed.get_mut(pkg.name()) {
+            rpms.push(pkg.clone());
+        } else {
+            installed.insert(pkg.name().into(), vec![pkg.clone()]);
+        }
+    });
+
+    installed
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    
+    #[test]
+    fn get_installed_pkgs() {
+        crate::configure();
+
+        let pkgs = get_installed_packages();
+
+        if let Some(_) = pkgs.get("kernel") {
+            assert!(true);
+        } else {
+            assert_eq!("", "Package kernel not installed?");
+        }
+    }
+}