try to optimize getting all controllers

rust/agama-lib/src/storage/client/zfcp.rs

@@ -34,8 +34,71 @@ use crate::{
     },
 };
 
+pub async fn get_wwpns(controller_id: &str) -> Result<Vec<String>, ServiceError> {
+    let output = std::process::Command::new("zfcp_san_disc")
+        .arg("-b")
+        .arg(controller_id)
+        .arg("-W")
+        .output()
+        .expect("zfcp_san_disc failed"); // TODO: real error handling
+    Ok(String::from_utf8_lossy(&output.stdout)
+        .split_whitespace()
+        .map(|s| s.to_string())
+        .collect())
+}
+
+pub async fn get_luns(controller_id: String, wwpn: String) -> Result<Vec<String>, ServiceError> {
+    let output = std::process::Command::new("zfcp_san_disc")
+        .arg("-b")
+        .arg(controller_id)
+        .arg("-p")
+        .arg(wwpn)
+        .arg("-L")
+        .output()
+        .expect("zfcp_san_disc failed"); // TODO: real error handling
+    Ok(String::from_utf8_lossy(&output.stdout)
+        .split_whitespace()
+        .map(|s| s.to_string())
+        .collect())
+}
+
+/// Obtains a LUNs map for the given controller
+///
+/// Given a controller id it returns a HashMap with each of its WWPNs as keys and the list of
+/// LUNS corresponding to that specific WWPN as values.
+///
+/// Arguments:
+///
+/// `controller_id`: controller id
+pub async fn get_luns_map(
+    controller_id: String,
+) -> Result<HashMap<String, Vec<String>>, ServiceError> {
+    let wwpns = get_wwpns(controller_id.as_str()).await?;
+    let mut tasks = vec![];
+    for wwpn in wwpns {
+        tasks.push((
+            wwpn.clone(),
+            tokio::spawn(get_luns(controller_id.to_string(), wwpn.clone())),
+        ));
+    }
+    let mut result = HashMap::with_capacity(tasks.len());
+    for (wwpn, task) in tasks {
+        result.insert(wwpn.clone(), task.await.expect("thread join failed")?);
+    }
+    Ok(result)
+}
+
 const ZFCP_CONTROLLER_PREFIX: &'static str = "/org/opensuse/Agama/Storage1/zfcp_controllers";
 
+/// Partial zfcp controller data used for thread processing
+/// TODO: for final version move all those thread related methods to this struct to procude final result
+struct PartialZFCPController {
+    pub id: String,
+    pub channel: String,
+    pub lun_scan: bool,
+    pub active: bool
+}
+
 /// Client to connect to Agama's D-Bus API for zFCP management.
 #[derive(Clone)]
 pub struct ZFCPClient<'a> {
@@ -99,23 +162,40 @@ impl<'a> ZFCPClient<'a> {
     ) -> Result<Vec<(OwnedObjectPath, ZFCPController)>, ServiceError> {
         let managed_objects = self.object_manager_proxy.get_managed_objects().await?;
 
-        let mut devices: Vec<(OwnedObjectPath, ZFCPController)> = vec![];
+        let mut devices: Vec<(OwnedObjectPath, PartialZFCPController)> = vec![];
         for (path, ifaces) in managed_objects {
             if let Some(properties) = ifaces.get("org.opensuse.Agama.Storage1.ZFCP.Controller") {
                 let id = extract_id_from_path(&path)?.to_string();
+                let channel: String = get_property(properties, "Channel")?;
                 devices.push((
                     path,
-                    ZFCPController {
-                        id: id.clone(),
-                        channel: get_property(properties, "Channel")?,
+                    PartialZFCPController {
+                        id: id,
+                        channel: channel,
                         lun_scan: get_property(properties, "LUNScan")?,
                         active: get_property(properties, "Active")?,
-                        luns_map: self.get_luns_map(id.as_str()).await?,
                     },
                 ))
             }
         }
-        Ok(devices)
+        let mut tasks = vec![];
+        for (_path, partial_controller) in &devices {
+            tasks.push(
+                tokio::spawn(get_luns_map(partial_controller.channel.clone()))
+            )
+        }
+        let mut result = Vec::with_capacity(devices.len());
+        for (index, task) in tasks.into_iter().enumerate() {
+            let (path, partial) = devices.get(index).unwrap();
+            result.push((path.clone(), ZFCPController {
+                id: partial.id.clone(),
+                channel: partial.channel.clone(),
+                lun_scan: partial.lun_scan,
+                active: partial.active,
+                luns_map: task.await.expect("thread join failed")?,
+            }));
+        }
+        Ok(result)
     }
 
     async fn get_controller_proxy(
@@ -129,12 +209,6 @@ impl<'a> ZFCPClient<'a> {
         Ok(dbus)
     }
 
-    pub async fn activate_controller(&self, controller_id: &str) -> Result<(), ServiceError> {
-        let controller = self.get_controller_proxy(controller_id).await?;
-        controller.activate().await?;
-        Ok(())
-    }
-
     pub async fn get_wwpns(&self, controller_id: &str) -> Result<Vec<String>, ServiceError> {
         let controller = self.get_controller_proxy(controller_id).await?;
         let result = controller.get_wwpns().await?;
@@ -176,6 +250,12 @@ impl<'a> ZFCPClient<'a> {
             .collect::<Result<HashMap<String, Vec<String>>, _>>()
     }
 
+    pub async fn activate_controller(&self, controller_id: &str) -> Result<(), ServiceError> {
+        let controller = self.get_controller_proxy(controller_id).await?;
+        controller.activate().await?;
+        Ok(())
+    }
+
     pub async fn activate_disk(
         &self,
         controller_id: &str,