From 03b83c1a4bab53d8914c6946ad892bca30df09d0 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Wed, 29 Feb 2012 15:53:04 +0000
Subject: [PATCH] Add 'whenjobs --tail <serial>' to tail output messages from
 jobs.

---
 TODO               |  3 ---
 daemon/daemon.ml   | 13 +++++++++++++
 lib/whenproto.x    |  1 +
 tools/whenjobs.ml  | 22 ++++++++++++++++++++++
 tools/whenjobs.pod |  6 ++++++
 5 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/TODO b/TODO
index 88bd0ad..391136b 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,3 @@
-Allow the output of a job to be listed.  This is pretty easy since we
-know the tmpdir and the output file.
-
 For Whentools.once and Whentools.max:
 
  - Add a ~group parameter so we can run no more than "n" jobs in one
diff --git a/daemon/daemon.ml b/daemon/daemon.ml
index 925ad7e..6e6a5fd 100644
--- a/daemon/daemon.ml
+++ b/daemon/daemon.ml
@@ -78,6 +78,7 @@ let rec init j d =
       ~proc_get_jobs
       ~proc_cancel_job
       ~proc_start_job
+      ~proc_get_job
       (Rpc_server.Unix addr)
       Rpc.Tcp (* not TCP, this is the same as SOCK_STREAM *)
       Rpc.Socket
@@ -167,6 +168,18 @@ and proc_start_job jobname =
   | Not_found -> `error "job not found"
   | exn -> `error (Printexc.to_string exn)
 
+and proc_get_job serial =
+  try
+    let serial = big_int_of_string serial in
+    let pid = BigIntMap.find serial !serialmap in
+    let job, dir, serial, start_time = IntMap.find pid !runningmap in
+    { Whenproto_aux.job_name = job.job_name;
+      job_serial = string_of_big_int serial;
+      job_tmpdir = dir; job_start_time = Int64.of_float start_time }
+  with
+  | Not_found -> failwith "job not found"
+  | exn -> failwith (Printexc.to_string exn)
+
 (* Reload the jobs file. *)
 and reload_file () =
   let file = sprintf "%s/jobs.cmo" !jobsdir in
diff --git a/lib/whenproto.x b/lib/whenproto.x
index 280265d..5754821 100644
--- a/lib/whenproto.x
+++ b/lib/whenproto.x
@@ -90,5 +90,6 @@ program When {
     job_list get_jobs (void) = 6;
     status cancel_job (string_big_int) = 7;
     status start_job (job_name) = 8;
+    job get_job (string_big_int) = 9;
   } = 1;
 } = 0x20008081;
diff --git a/tools/whenjobs.ml b/tools/whenjobs.ml
index c792e26..be38f67 100644
--- a/tools/whenjobs.ml
+++ b/tools/whenjobs.ml
@@ -95,6 +95,7 @@ let rec main () =
     "--lib", Arg.Set_string libdir, "dir Specify directory that contains pa_when.cmo";
     "--set", Arg.Unit (set_mode `Set), " Set the variable";
     "--start", Arg.Unit (set_mode `Start), "name Start a job manually";
+    "--tail", Arg.Unit (set_mode `Tail), "serial Tail job output";
     "--type", Arg.Set_string typ, "bool|int|float|string|unit Set the variable type";
     "--upload", Arg.Unit (set_mode `Upload), " Upload the script";
     "--variables", Arg.Unit (set_mode `Variables), " Display all variables and values";
@@ -220,6 +221,14 @@ Options:
     );
     start_job (List.hd args)
 
+  | Some `Tail ->
+    if List.length args != 1 then (
+      eprintf "whenjobs --tail serial\n";
+      suggest_help ();
+      exit 1
+    );
+    tail (List.hd args)
+
 and edit_file () =
   (* If there is no initial file, create an empty one containing the
    * tutorial.
@@ -421,6 +430,19 @@ and start_job name =
   );
   stop_client client
 
+  (* This only works for local.  If we ever make whenjobs work
+   * remotely we'll have to change the implementation to use
+   * the server.
+   *)
+and tail serial =
+  let client = start_client () in
+  let job = Whenproto_clnt.When.V1.get_job client serial in
+  stop_client client;
+  let cmd =
+    sprintf "tail -f %s/output.txt"
+      (Filename.quote job.Whenproto_aux.job_tmpdir) in
+  exit (Sys.command cmd)
+
 and unused_error args op =
   if args <> [] then (
     eprintf "whenjobs %s: unused parameters on the command line.\n" op;
diff --git a/tools/whenjobs.pod b/tools/whenjobs.pod
index 25dff40..466bdb1 100644
--- a/tools/whenjobs.pod
+++ b/tools/whenjobs.pod
@@ -29,6 +29,7 @@ Examine running jobs:
  whenjobs --jobs
  whenjobs --cancel serial
  whenjobs --start "name"
+ whenjobs --tail serial
 
 =head1 DESCRIPTION
 
@@ -176,6 +177,11 @@ Start the job immediately and unconditionally.
 This runs the job even if its normal preconditions are not met.  This
 may cause unexpected results, so use with caution.
 
+=item B<--tail> serial
+
+Tail the output of the running job identified by its serial number.
+Use the I<--jobs> flag to get a list of running jobs.
+
 =item B<--upload>
 
 Compile the jobs script and upload it to the daemon, without editing.
-- 
1.8.3.1