From 0e3927b01adb007024ae14000b57497137b0d77b Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Sun, 4 Oct 2015 17:38:07 +0800
Subject: [PATCH] master: support DDB rescan

---
 artiq/frontend/artiq_client.py | 38 ++++++++++++----------------------
 artiq/frontend/artiq_master.py |  3 ++-
 artiq/master/ddb.py            | 21 +++++++++++++++++++
 3 files changed, 36 insertions(+), 26 deletions(-)
 create mode 100644 artiq/master/ddb.py

diff --git a/artiq/frontend/artiq_client.py b/artiq/frontend/artiq_client.py
index 216c09809..f3a15fa24 100755
--- a/artiq/frontend/artiq_client.py
+++ b/artiq/frontend/artiq_client.py
@@ -61,16 +61,6 @@ def get_argparser():
     parser_delete.add_argument("rid", type=int,
                                help="run identifier (RID)")
 
-    parser_set_device = subparsers.add_parser(
-        "set-device", help="add or modify a device")
-    parser_set_device.add_argument("name", help="name of the device")
-    parser_set_device.add_argument("description",
-                                   help="description in PYON format")
-
-    parser_del_device = subparsers.add_parser(
-        "del-device", help="delete a device")
-    parser_del_device.add_argument("name", help="name of the device")
-
     parser_set_parameter = subparsers.add_parser(
         "set-parameter", help="add or modify a parameter")
     parser_set_parameter.add_argument("name", help="name of the parameter")
@@ -87,11 +77,14 @@ def get_argparser():
         "what",
         help="select object to show: schedule/log/devices/parameters")
 
-    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)")
+    subparsers.add_parser(
+        "scan-ddb", help="trigger a device database (re)scan")
+
+    parser_scan_repos = subparsers.add_parser(
+        "scan-repository", help="trigger a repository (re)scan")
+    parser_scan_repos.add_argument("revision", default=None, nargs="?",
+                                   help="use a specific repository revision "
+                                        "(defaults to head)")
 
     return parser
 
@@ -131,14 +124,6 @@ def _action_delete(remote, args):
     remote.delete(args.rid)
 
 
-def _action_set_device(remote, args):
-    remote.set(args.name, pyon.decode(args.description))
-
-
-def _action_del_device(remote, args):
-    remote.delete(args.name)
-
-
 def _action_set_parameter(remote, args):
     remote.set(args.name, pyon.decode(args.value))
 
@@ -147,6 +132,10 @@ def _action_del_parameter(remote, args):
     remote.delete(args.name)
 
 
+def _action_scan_ddb(remote, args):
+    remote.scan()
+
+
 def _action_scan_repository(remote, args):
     remote.scan_async(args.revision)
 
@@ -275,10 +264,9 @@ def main():
         target_name = {
             "submit": "master_schedule",
             "delete": "master_schedule",
-            "set_device": "master_ddb",
-            "del_device": "master_ddb",
             "set_parameter": "master_pdb",
             "del_parameter": "master_pdb",
+            "scan_ddb": "master_ddb",
             "scan_repository": "master_repository"
         }[action]
         remote = Client(args.server, port, target_name)
diff --git a/artiq/frontend/artiq_master.py b/artiq/frontend/artiq_master.py
index 2d6fffd18..0373873f9 100755
--- a/artiq/frontend/artiq_master.py
+++ b/artiq/frontend/artiq_master.py
@@ -7,6 +7,7 @@ import os
 
 from artiq.protocols.pc_rpc import Server
 from artiq.protocols.sync_struct import Notifier, Publisher, process_mod
+from artiq.master.ddb import DDB
 from artiq.protocols.file_db import FlatFileDB
 from artiq.master.scheduler import Scheduler
 from artiq.master.worker_db import get_last_rid
@@ -64,7 +65,7 @@ def main():
         loop = asyncio.get_event_loop()
     atexit.register(lambda: loop.close())
 
-    ddb = FlatFileDB(args.ddb)
+    ddb = DDB(args.ddb)
     pdb = FlatFileDB(args.pdb)
     rtr = Notifier(dict())
     log = Log(1000)
diff --git a/artiq/master/ddb.py b/artiq/master/ddb.py
new file mode 100644
index 000000000..9a2a1b34d
--- /dev/null
+++ b/artiq/master/ddb.py
@@ -0,0 +1,21 @@
+from artiq.protocols.sync_struct import Notifier
+from artiq.protocols import pyon
+
+
+class DDB:
+    def __init__(self, backing_file):
+        self.backing_file = backing_file
+        self.data = Notifier(pyon.load_file(self.backing_file))
+
+    def scan(self):
+        new_data = pyon.load_file(self.backing_file)
+
+        for k in list(self.data.read.keys()):
+            if k not in new_data:
+                del self.data[k]
+        for k in new_data.keys():
+            if k not in self.data.read or self.data.read[k] != new_data[k]:
+                self.data[k] = new_data[k]
+
+    def get(self, key):
+        return self.data.read[key]