From 400b4148859058cae7a898500b39a13372b487f2 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Sat, 8 Aug 2015 23:23:25 +0800
Subject: [PATCH] master,client: support scanning specific repo revisions

---
 artiq/frontend/artiq_client.py |  9 ++++++---
 artiq/master/repository.py     | 21 +++++++++++----------
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/artiq/frontend/artiq_client.py b/artiq/frontend/artiq_client.py
index 49fa91651..216c09809 100755
--- a/artiq/frontend/artiq_client.py
+++ b/artiq/frontend/artiq_client.py
@@ -87,8 +87,11 @@ def get_argparser():
         "what",
         help="select object to show: schedule/log/devices/parameters")
 
-    subparsers.add_parser("scan-repository",
-                          help="trigger a repository rescan")
+    parser_scan = subparsers.add_parser("scan-repository",
+                                        help="trigger a repository (re)scan")
+    parser_scan.add_argument("revision", default=None, nargs="?",
+                             help="use a specific repository revision "
+                                  "(defaults to head)")
 
     return parser
 
@@ -145,7 +148,7 @@ def _action_del_parameter(remote, args):
 
 
 def _action_scan_repository(remote, args):
-    remote.scan_async()
+    remote.scan_async(args.revision)
 
 
 def _show_schedule(schedule):
diff --git a/artiq/master/repository.py b/artiq/master/repository.py
index 73ff9cde0..fdb131c9d 100644
--- a/artiq/master/repository.py
+++ b/artiq/master/repository.py
@@ -57,33 +57,34 @@ class Repository:
         self.backend = backend
         self.log_fn = log_fn
 
-        self.head_rev = self.backend.get_head_rev()
-        self.backend.request_rev(self.head_rev)
+        self.cur_rev = self.backend.get_head_rev()
+        self.backend.request_rev(self.cur_rev)
         self.explist = Notifier(dict())
 
         self._scanning = False
 
     def close(self):
         # The object cannot be used anymore after calling this method.
-        self.backend.release_rev(self.head_rev)
+        self.backend.release_rev(self.cur_rev)
 
     @asyncio.coroutine
-    def scan(self):
+    def scan(self, new_cur_rev=None):
         if self._scanning:
             return
         self._scanning = True
 
-        new_head_rev = self.backend.get_head_rev()
-        wd, _ = self.backend.request_rev(new_head_rev)
-        self.backend.release_rev(self.head_rev)
-        self.head_rev = new_head_rev
+        if new_cur_rev is None:
+            new_cur_rev = self.backend.get_head_rev()
+        wd, _ = self.backend.request_rev(new_cur_rev)
+        self.backend.release_rev(self.cur_rev)
+        self.cur_rev = new_cur_rev
         new_explist = yield from _scan_experiments(wd, self.log_fn)
 
         _sync_explist(self.explist, new_explist)
         self._scanning = False
 
-    def scan_async(self):
-        asyncio.async(self.scan())
+    def scan_async(self, new_cur_rev=None):
+        asyncio.async(self.scan(new_cur_rev))
 
 
 class FilesystemBackend: