Merge pull request #1252 from ISISScientificComputing/threadsafe_experiment_creation

Author: Dimitar Tasev

WebApp/autoreduce_webapp/reduction_viewer/migrations/0005_auto_20210326_1628.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.1.2 on 2021-03-26 16:28
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('reduction_viewer', '0004_instrument_is_flat_output'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='experiment',
+            name='reference_number',
+            field=models.IntegerField(unique=True),
+        ),
+    ]

WebApp/autoreduce_webapp/reduction_viewer/models.py

@@ -48,7 +48,7 @@ class Experiment(models.Model):
     """
     Holds data about an Experiment
     """
-    reference_number = models.IntegerField()
+    reference_number = models.IntegerField(unique=True)
 
     def __str__(self):
         """

model/database/access.py

@@ -8,6 +8,7 @@
 Common functions for accessing and creating records in the database
 """
 from typing import List
+from django.db import transaction
 
 from utils.clients.django_database_client import DatabaseClient
 
@@ -22,6 +23,7 @@ def start_database():
     return database
 
 
+@transaction.atomic
 def get_instrument(instrument_name):
     """
     Find the instrument record associated with the name provided in the database
@@ -53,6 +55,7 @@ def get_all_instrument_names() -> List[str]:
     return list(database.data_model.Instrument.objects.values_list("name", flat=True))
 
 
+@transaction.atomic
 def get_status(status_value: str):
     """
     Find the status record associated with the value provided in the database
@@ -68,6 +71,7 @@ def get_status(status_value: str):
     return database.data_model.Status.objects.get_or_create(value=status_value)[0]
 
 
+@transaction.atomic
 def get_experiment(rb_number):
     """
     Find the Experiment record associated with the rb_number provided in the database
@@ -78,6 +82,7 @@ def get_experiment(rb_number):
     return database.data_model.Experiment.objects.get_or_create(reference_number=rb_number)[0]
 
 
+@transaction.atomic
 def get_software(name, version):
     """
     Find the Software record associated with the name and version provided
@@ -126,3 +131,7 @@ def save_record(record):
     Note: This is mostly a wrapper to aid unit testing
     """
     record.save()
+
+
+# Initialises the DjangoORM immediately on importing this module
+start_database()

queue_processors/queue_processor/handle_message.py

@@ -80,25 +80,31 @@ def _handle_error(self, reduction_run, message, err):
         message.reduction_log = str(err)
         self.reduction_error(reduction_run, message)
 
-    @transaction.atomic
     def create_run_records(self, message: Message):
         """
-        Creates or gets the necessary records to construct a ReductionRun
+        Creates or gets the necessary records to construct a ReductionRun.
         """
         # This must be done before looking up the run version to make sure the experiment record exists!
         rb_number = self.normalise_rb_number(message.rb_number)
         experiment = db_access.get_experiment(rb_number)
         run_version = db_access.find_highest_run_version(experiment, run_number=str(message.run_number))
         message.run_version = run_version
-
         instrument = db_access.get_instrument(str(message.instrument))
+        return self.do_create_reduction_record(message, experiment, instrument)
+
+    @transaction.atomic
+    def do_create_reduction_record(self, message: Message, experiment, instrument):
+        """
+        Creates the reduction record
+        """
         script = ReductionScript(instrument.name)
         script_text = script.text()
+
         # Make the new reduction run with the information collected so far
         reduction_run = db_records.create_reduction_run_record(experiment=experiment,
                                                                instrument=instrument,
                                                                message=message,
-                                                               run_version=run_version,
+                                                               run_version=message.run_version,
                                                                script_text=script_text,
                                                                status=self.status.get_queued())
         reduction_run.save()