tape: improve export media to directly export from drive, add CLI

src/tape/changer/mod.rs

@@ -10,7 +10,7 @@ pub use mtx_wrapper::*;
 mod mtx;
 pub use mtx::*;
 
-use anyhow::{bail, Error};
+use anyhow::Error;
 
 /// Interface to media change devices
 pub trait MediaChange {
@@ -80,34 +80,5 @@ pub trait MediaChange {
     /// By moving the media to an empty import-export slot. Returns
     /// Some(slot) if the media was exported. Returns None if the media is
     /// not online (already exported).
-    fn export_media(&mut self, changer_id: &str) -> Result<Option<u64>, Error> {
-        let status = self.status()?;
-
-        let mut from = None;
-        let mut to = None;
-
-        for (i, (import_export, element_status)) in status.slots.iter().enumerate() {
-            if *import_export {
-                if to.is_some() { continue; }
-                if let ElementStatus::Empty = element_status {
-                    to = Some(i as u64 + 1);
-                }
-            } else {
-                if let ElementStatus::VolumeTag(ref tag) = element_status {
-                    if tag == changer_id {
-                        from = Some(i as u64 + 1);
-                    }
-                }
-            }
-        }
-        match (from, to) {
-            (Some(from), Some(to)) => {
-                self.transfer_media(from, to)?;
-                Ok(Some(to))
-            }
-            (Some(_from), None) => bail!("unable to find free export slot"),
-            (None, _) => Ok(None), // not online
-        }
-    }
-
+    fn export_media(&mut self, changer_id: &str) -> Result<Option<u64>, Error>;
 }

src/tape/changer/mtx.rs

@@ -48,6 +48,7 @@ fn unload_to_free_slot(drive_name: &str, path: &str, status: &MtxStatus, drivenu
     }
     let drive_status = &status.drives[drivenum as usize];
     if let Some(slot) = drive_status.loaded_slot {
+        // fixme: check if slot is free
         mtx_unload(path, slot, drivenum)
     } else {
         let mut free_slot = None;
@@ -174,4 +175,54 @@ impl MediaChange for MtxMediaChanger {
 
         Ok(())
     }
+
+    fn export_media(&mut self, changer_id: &str) -> Result<Option<u64>, Error> {
+        let status = self.status()?;
+
+        let mut from_drive = None;
+        if let Some(drive_status) = status.drives.get(self.drivenum as usize) {
+            if let ElementStatus::VolumeTag(ref tag) = drive_status.status {
+                if tag == changer_id {
+                    from_drive = Some(self.drivenum);
+                }
+            }
+        }
+
+        let mut from = None;
+        let mut to = None;
+
+        for (i, (import_export, element_status)) in status.slots.iter().enumerate() {
+            if *import_export {
+                if to.is_some() { continue; }
+                if let ElementStatus::Empty = element_status {
+                    to = Some(i as u64 + 1);
+                }
+            } else {
+                if let ElementStatus::VolumeTag(ref tag) = element_status {
+                    if tag == changer_id {
+                        from = Some(i as u64 + 1);
+                    }
+                }
+            }
+        }
+
+        if let Some(drivenum) = from_drive {
+            match to {
+                Some(to) => {
+                    mtx_unload(&self.config.path, to, drivenum)?;
+                    Ok(Some(to))
+                }
+                None =>  bail!("unable to find free export slot"),
+            }
+        } else {
+            match (from, to) {
+                (Some(from), Some(to)) => {
+                    self.transfer_media(from, to)?;
+                    Ok(Some(to))
+                }
+                (Some(_from), None) => bail!("unable to find free export slot"),
+                (None, _) => Ok(None), // not online
+            }
+        }
+    }
 }

src/tape/drive/virtual_tape.rs

@@ -394,7 +394,11 @@ impl MediaChange for VirtualTapeHandle {
     }
 
     fn transfer_media(&mut self, _from: u64, _to: u64) -> Result<(), Error> {
-        bail!("medfia tranfer is not implemented!");
+        bail!("media tranfer is not implemented!");
+    }
+
+    fn export_media(&mut self, _changer_id: &str) -> Result<Option<u64>, Error> {
+        bail!("media export is not implemented!");
     }
 
     fn load_media_from_slot(&mut self, slot: u64) -> Result<(), Error> {
@@ -461,6 +465,11 @@ impl MediaChange for VirtualTapeDrive {
         handle.transfer_media(from, to)
     }
 
+    fn export_media(&mut self, changer_id: &str) -> Result<Option<u64>, Error> {
+        let mut handle = self.open()?;
+        handle.export_media(changer_id)
+    }
+
     fn load_media_from_slot(&mut self, slot: u64) -> Result<(), Error> {
         let mut handle = self.open()?;
         handle.load_media_from_slot(slot)