Fix review comment

- Add function name in error log
- Use sscanf to get index of ethx
- Handle the exception explicitly when reading previous inventory

Signed-off-by: Changlei Li <[email protected]>

Author: changlei-li

ocaml/networkd/bin/network_server.ml

@@ -36,11 +36,7 @@ let write_config () =
     with Network_config.Write_error -> ()
 
 let get_index_from_ethx name =
-  if String.starts_with ~prefix:"eth" name then
-    let index = String.sub name 3 (String.length name - 3) in
-    int_of_string_opt index
-  else
-    None
+  try Scanf.sscanf name "eth%d%!" Option.some with _ -> None
 
 let sort_based_on_ethx () =
   Sysfs.list ()
@@ -53,20 +49,32 @@ let sort_based_on_ethx () =
 
 let read_previous_inventory () =
   let previous_inventory = "/var/tmp/.previousInventory" in
-  Xapi_stdext_unix.Unixext.file_lines_fold
-    (fun acc line ->
-      match Inventory.parse_inventory_entry line with
-      | Some ("MANAGEMENT_INTERFACE", iface) ->
-          info "get management interface from previous inventory: %s" iface ;
-          (iface, snd acc)
-      | Some ("MANAGEMENT_ADDRESS_TYPE", addr_type) ->
-          info "get management address type from previous inventory: %s"
-            addr_type ;
-          (fst acc, addr_type)
-      | _ ->
-          acc
-    )
-    ("", "") previous_inventory
+  try
+    Xapi_stdext_unix.Unixext.file_lines_fold
+      (fun acc line ->
+        match Inventory.parse_inventory_entry line with
+        | Some ("MANAGEMENT_INTERFACE", iface) ->
+            info "get management interface from previous inventory: %s" iface ;
+            (iface, snd acc)
+        | Some ("MANAGEMENT_ADDRESS_TYPE", addr_type) ->
+            info "get management address type from previous inventory: %s"
+              addr_type ;
+            (fst acc, addr_type)
+        | _ ->
+            acc
+      )
+      ("", "") previous_inventory
+  with e ->
+    error "Failed to read previous inventory %s: %s" previous_inventory
+      (Printexc.to_string e) ;
+    raise
+      (Network_error
+         (Internal_error
+            (Printf.sprintf "Failed to read previous inventory: %s"
+               previous_inventory
+            )
+         )
+      )
 
 let update_inventory () =
   let iface, addr_type = read_previous_inventory () in
@@ -118,7 +126,7 @@ let sort last_order =
       (None, [])
   | true, Some _ ->
       (* Impossible *)
-      error "device renamed but order is not None" ;
+      error "%s: device renamed but order is not None" __FUNCTION__ ;
       raise
         (Network_error (Internal_error "device renamed but order is not None"))
   | false, None ->