master: cache last RID. Closes #234

.gitignore

@@ -19,6 +19,7 @@ __pycache__/
 /artiq/test/results
 /artiq/test/h5types.h5
 /examples/master/results
+/examples/master/last_rid.pyon
 /examples/master/dataset_db.pyon
 /examples/sim/results
 /examples/sim/dataset_db.pyon
@@ -26,8 +27,9 @@ __pycache__/
 # recommended location for testbed
 /run
 # alternatively, when testing ad-hoc experiments at the root:
-/device_db.pyon
-/dataset_db.pyon
 /results
+/last_rid.pyon
+/dataset_db.pyon
+/device_db.pyon
 /h5types.h5
 /test*.py

artiq/frontend/artiq_master.py

@@ -12,7 +12,7 @@ from artiq.protocols.logging import Server as LoggingServer
 from artiq.master.log import log_args, init_log
 from artiq.master.databases import DeviceDB, DatasetDB
 from artiq.master.scheduler import Scheduler
-from artiq.master.worker_db import get_last_rid
+from artiq.master.worker_db import RIDCounter
 from artiq.master.experiments import FilesystemBackend, GitBackend, ExperimentDB
 
 
@@ -73,7 +73,7 @@ def main():
         "get_dataset": dataset_db.get,
         "update_dataset": dataset_db.update
     }
-    scheduler = Scheduler(get_last_rid() + 1, worker_handlers, experiment_db)
+    scheduler = Scheduler(RIDCounter(), worker_handlers, experiment_db)
     worker_handlers.update({
         "scheduler_submit": scheduler.submit,
         "scheduler_delete": scheduler.delete,

artiq/master/scheduler.py

@@ -116,16 +116,6 @@ class Run:
     write_results = _mk_worker_method("write_results")
 
 
-class RIDCounter:
-    def __init__(self, next_rid):
-        self._next_rid = next_rid
-
-    def get(self):
-        rid = self._next_rid
-        self._next_rid += 1
-        return rid
-
-
 class RunPool:
     def __init__(self, ridc, worker_handlers, notifier, experiment_db):
         self.runs = dict()
@@ -387,7 +377,7 @@ class Deleter(TaskObject):
 
 
 class Scheduler:
-    def __init__(self, next_rid, worker_handlers, experiment_db):
+    def __init__(self, ridc, worker_handlers, experiment_db):
         self.notifier = Notifier(dict())
 
         self._pipelines = dict()
@@ -395,7 +385,7 @@ class Scheduler:
         self._experiment_db = experiment_db
         self._terminated = False
 
-        self._ridc = RIDCounter(next_rid)
+        self._ridc = ridc
         self._deleter = Deleter(self._pipelines)
 
     def start(self):

artiq/master/worker_db.py

@@ -2,6 +2,7 @@ from collections import OrderedDict
 import importlib
 import logging
 import os
+import tempfile
 import time
 import re
 
@@ -15,6 +16,75 @@ from artiq.protocols.pc_rpc import AutoTarget, Client, BestEffortClient
 logger = logging.getLogger(__name__)
 
 
+class RIDCounter:
+    def __init__(self, cache_filename="last_rid.pyon", results_dir="results"):
+        self.cache_filename = cache_filename
+        self.results_dir = results_dir
+        self._next_rid = self._last_rid() + 1
+        logger.debug("Next RID is %d", self._next_rid)
+
+    def get(self):
+        rid = self._next_rid
+        self._next_rid += 1
+        self._update_cache(rid)
+        return rid
+
+    def _last_rid(self):
+        try:
+            rid = self._last_rid_from_cache()
+        except FileNotFoundError:
+            logger.debug("Last RID cache not found, scanning results")
+            rid = self._last_rid_from_results()
+            self._update_cache(rid)
+            return rid
+        else:
+            logger.debug("Using last RID from cache")
+            return rid
+
+    def _update_cache(self, rid):
+        contents = str(rid) + "\n"
+        directory = os.path.abspath(os.path.dirname(self.cache_filename))
+        with tempfile.NamedTemporaryFile("w", dir=directory, delete=False) as f:
+            f.write(contents)
+            tmpname = f.name
+        os.replace(tmpname, self.cache_filename)
+
+    def _last_rid_from_cache(self):
+        with open(self.cache_filename, "r") as f:
+            return int(f.read())
+
+    def _last_rid_from_results(self):
+        r = -1
+        try:
+            day_folders = os.listdir(self.results_dir)
+        except:
+            return r
+        day_folders = filter(lambda x: re.fullmatch('\d\d\d\d-\d\d-\d\d', x),
+                             day_folders)
+        for df in day_folders:
+            day_path = os.path.join(self.results_dir, df)
+            try:
+                minute_folders = os.listdir(day_path)
+            except:
+                continue
+            minute_folders = filter(lambda x: re.fullmatch('\d\d-\d\d', x),
+                                              minute_folders)
+            for mf in minute_folders:
+                minute_path = os.path.join(day_path, mf)
+                try:
+                    h5files = os.listdir(minute_path)
+                except:
+                    continue
+                for x in h5files:
+                    m = re.fullmatch('(\d\d\d\d\d\d\d\d\d)-.*\.h5', x)
+                    if m is None:
+                        continue
+                    rid = int(m.group(1))
+                    if rid > r:
+                        r = rid
+        return r
+
+
 def _create_device(desc, device_mgr):
     ty = desc["type"]
     if ty == "local":
@@ -87,38 +157,6 @@ def get_hdf5_output(start_time, rid, name):
     return h5py.File(os.path.join(dirname, filename), "w")
 
 
-def get_last_rid():
-    r = -1
-    try:
-        day_folders = os.listdir("results")
-    except:
-        return r
-    day_folders = filter(lambda x: re.fullmatch('\d\d\d\d-\d\d-\d\d', x),
-                         day_folders)
-    for df in day_folders:
-        day_path = os.path.join("results", df)
-        try:
-            minute_folders = os.listdir(day_path)
-        except:
-            continue
-        minute_folders = filter(lambda x: re.fullmatch('\d\d-\d\d', x),
-                                          minute_folders)
-        for mf in minute_folders:
-            minute_path = os.path.join(day_path, mf)
-            try:
-                h5files = os.listdir(minute_path)
-            except:
-                continue
-            for x in h5files:
-                m = re.fullmatch('(\d\d\d\d\d\d\d\d\d)-.*\.h5', x)
-                if m is None:
-                    continue
-                rid = int(m.group(1))
-                if rid > r:
-                    r = rid
-    return r
-
-
 _type_to_hdf5 = {
     int: h5py.h5t.STD_I64BE,
     float: h5py.h5t.IEEE_F64BE,