Renumber the jobs file so that it can be reloaded in native code.

[whenjobs.git] / daemon / daemon.ml

diff --git a/daemon/daemon.ml b/daemon/daemon.ml
index bc4f51a..64d4012 100644 (file)
--- a/daemon/daemon.ml
+++ b/daemon/daemon.ml
@@ -292,13 +292,38 @@ and proc_whisper_variables vars =
 
 (* Reload the jobs file(s). *)
 and reload_files () =
-  (* Get dir/*.cmo (bytecode) or dir/*.cmxs (native code) *)
-  let suffix = if not Dynlink.is_native then ".cmo" else ".cmxs" in
-  let dir = !jobsdir in
-  let files = Array.to_list (Sys.readdir dir) in
-  let files = List.filter (fun file -> string_endswith file suffix) files in
-  let files = List.map (fun file -> dir // file) files in
-  let files = List.sort compare files in
+  (* Get the highest numbered dir/jobs__*.cmo (bytecode) or
+   * dir/jobs__*.cmxs (native code) file and load it.  Delete
+   * lower-numbered (== older) files.
+   *)
+  let filename =
+    let suffix, slen =
+      if not Dynlink.is_native then ".cmo", 4 else ".cmxs", 5 in
+    let dir = !jobsdir in
+    let files = Array.to_list (Sys.readdir dir) in
+    let times = filter_map (
+      fun file ->
+        if not (string_startswith file "jobs__") ||
+          not (string_endswith file suffix) then
+          None
+        else (
+          let len = String.length file in
+          let t = String.sub file 6 (len-slen-6) in
+          try Some (int_of_string t) with Failure "int_of_string" -> None
+        )
+    ) files in
+    let times = List.rev (List.sort compare times) in
+    match times with
+    | [] -> None
+    | x::xs ->
+      (* Unlink the older files. *)
+      List.iter (
+        fun t ->
+          try unlink (dir // sprintf "jobs__%d%s" t suffix)
+          with Unix_error _ -> ()
+      ) xs;
+      (* Return the newest (highest numbered) file. *)
+      Some (dir // sprintf "jobs__%d%s" x suffix) in
 
   (* As we are reloading the file, we want to create a new state
    * that has no jobs, but has all the variables from the previous
@@ -308,19 +333,24 @@ and reload_files () =
   Whenfile.init s;
 
   let s =
-    try
-      List.iter Dynlink.loadfile files;
-      let s = Whenfile.get_state () in
-      Syslog.notice "loaded %d job(s) from %d file(s)"
-        (Whenstate.nr_jobs s) (List.length files);
+    match filename with
+    | None ->
+      (* no jobs file, return the same state *)
+      Syslog.notice "no jobs file found";
       s
-    with
-    | Dynlink.Error err ->
-      let err = Dynlink.error_message err in
-      Syslog.error "error loading jobs: %s" err;
-      failwith err
-    | exn ->
-      failwith (Printexc.to_string exn) in
+    | Some filename ->
+      try
+        Dynlink.loadfile filename;
+        let s = Whenfile.get_state () in
+        Syslog.notice "loaded %d job(s)" (Whenstate.nr_jobs s);
+        s
+      with
+      | Dynlink.Error err ->
+        let err = Dynlink.error_message err in
+        Syslog.error "error loading jobs: %s" err;
+        failwith err
+      | exn ->
+        failwith (Printexc.to_string exn) in
 
   let s = Whenstate.copy_prev_state !state s in
   state := s;