From 3c8f1c58c551d8cc227b06fd142449e0df42d84a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20P=C3=A9pin?= <martin.pepin@ens.fr>
Date: Tue, 23 May 2017 05:56:29 +0100
Subject: [PATCH] Use transaction.atomic instead of lock_table

lock_table used LOCK which is mysql-specific
---
 gestioncof/petits_cours_views.py | 44 +++++++++++++++-----------------
 gestioncof/shared.py             | 29 ---------------------
 2 files changed, 21 insertions(+), 52 deletions(-)

diff --git a/gestioncof/petits_cours_views.py b/gestioncof/petits_cours_views.py
index 3fa0dc57..087c9cef 100644
--- a/gestioncof/petits_cours_views.py
+++ b/gestioncof/petits_cours_views.py
@@ -12,15 +12,15 @@ from django.views.decorators.csrf import csrf_exempt
 from django.conf import settings
 from django.contrib.auth.decorators import login_required
 from django.contrib import messages
+from django.db import transaction
 
 from gestioncof.models import CofProfile
 from gestioncof.petits_cours_models import (
     PetitCoursDemande, PetitCoursAttribution, PetitCoursAttributionCounter,
-    PetitCoursAbility, PetitCoursSubject
+    PetitCoursAbility
 )
 from gestioncof.petits_cours_forms import DemandeForm, MatieresFormSet
 from gestioncof.decorators import buro_required
-from gestioncof.shared import lock_table, unlock_tables
 
 
 class DemandeListView(ListView):
@@ -274,17 +274,17 @@ def _traitement_post(request, demande):
                                            headers={'Reply-To': replyto}))
     connection = mail.get_connection(fail_silently=False)
     connection.send_messages(mails_to_send)
-    lock_table(PetitCoursAttributionCounter, PetitCoursAttribution, User)
-    for matiere in proposals:
-        for rank, user in enumerate(proposals[matiere]):
-            counter = PetitCoursAttributionCounter.objects.get(user=user,
-                                                               matiere=matiere)
-            counter.count += 1
-            counter.save()
-            attrib = PetitCoursAttribution(user=user, matiere=matiere,
-                                           demande=demande, rank=rank + 1)
-            attrib.save()
-    unlock_tables()
+    with transaction.atomic():
+        for matiere in proposals:
+            for rank, user in enumerate(proposals[matiere]):
+                counter = PetitCoursAttributionCounter.objects.get(
+                    user=user, matiere=matiere
+                )
+                counter.count += 1
+                counter.save()
+                attrib = PetitCoursAttribution(user=user, matiere=matiere,
+                                               demande=demande, rank=rank + 1)
+                attrib.save()
     demande.traitee = True
     demande.traitee_par = request.user
     demande.processed = datetime.now()
@@ -309,17 +309,15 @@ def inscription(request):
             profile.petits_cours_accept = "receive_proposals" in request.POST
             profile.petits_cours_remarques = request.POST["remarques"]
             profile.save()
-            lock_table(PetitCoursAttributionCounter, PetitCoursAbility, User,
-                       PetitCoursSubject)
-            abilities = (
-                PetitCoursAbility.objects.filter(user=request.user).all()
-            )
-            for ability in abilities:
-                PetitCoursAttributionCounter.get_uptodate(
-                    ability.user,
-                    ability.matiere
+            with transaction.atomic():
+                abilities = (
+                    PetitCoursAbility.objects.filter(user=request.user).all()
                 )
-            unlock_tables()
+                for ability in abilities:
+                    PetitCoursAttributionCounter.get_uptodate(
+                        ability.user,
+                        ability.matiere
+                    )
             success = True
             formset = MatieresFormSet(instance=request.user)
     else:
diff --git a/gestioncof/shared.py b/gestioncof/shared.py
index 63aceae5..e4180b49 100644
--- a/gestioncof/shared.py
+++ b/gestioncof/shared.py
@@ -1,15 +1,8 @@
-# -*- coding: utf-8 -*-
-
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-
 from django.contrib.sites.models import Site
 from django.conf import settings
 from django_cas_ng.backends import CASBackend
 from django_cas_ng.utils import get_cas_client
 from django.contrib.auth import get_user_model
-from django.db import connection
 
 from gestioncof.models import CofProfile
 
@@ -74,25 +67,3 @@ def context_processor(request):
         "site": Site.objects.get_current(),
     }
     return data
-
-
-def lock_table(*models):
-    query = "LOCK TABLES "
-    for i, model in enumerate(models):
-        table = model._meta.db_table
-        if i > 0:
-            query += ", "
-        query += "%s WRITE" % table
-    cursor = connection.cursor()
-    cursor.execute(query)
-    row = cursor.fetchone()
-    return row
-
-
-def unlock_tables(*models):
-    cursor = connection.cursor()
-    cursor.execute("UNLOCK TABLES")
-    row = cursor.fetchone()
-    return row
-
-unlock_table = unlock_tables