Fixing concurrency problems in history counter

- riak datatype for both riak modes
- old behaviour for sql with transaction

Change-Id: Ie89629e1cf8f02c8af532f4d5b53dced7059c3fc

.config

@@ -5,3 +5,4 @@ solar_db: sqlite:////tmp/solar.db
 # solar_db: riak://10.0.0.2:8087
 riak_ensemble: False
 lock_bucket_type: ''
+counters_bucket_type: ''

bootstrap/playbooks/solar.yaml

@@ -39,6 +39,11 @@
         line: "log_file: /var/log/solar/solar.log"
         state: present
         create: yes
+    - lineinfile:
+        dest: /.solar_config_override
+        line: "counter_bucket_type: counters"
+        state: present
+        create: yes
     - lineinfile:
         dest: /home/vagrant/.bashrc
         line: export PYTHONWARNINGS="ignore"
@@ -59,4 +64,11 @@
 
     - name: start riak container
       shell: docker-compose up -d riak chdir=/vagrant
+    # preconfigure docker container
+    # add counters datatype etc.
+    - shell: timeout 60 docker exec vagrant_riak_1 riak-admin wait_for_service riak_kv
+    - shell: timeout 10 docker exec vagrant_riak_1 riak-admin bucket-type create counters '{"props":{"datatype":"counter"}}'
+      ignore_errors: yes
+    - shell: timeout 10 docker exec vagrant_riak_1 riak-admin bucket-type activate counters
+
     - include: tasks/celery_init.yaml

solar/config.py

@@ -28,6 +28,7 @@ C.celery_broker = 'sqla+sqlite:////tmp/celery.db'
 C.celery_backend = 'db+sqlite:////tmp/celery.db'
 C.riak_ensemble = False
 C.lock_bucket_type = None
+C.counter_bucket_type = None
 C.log_file = 'solar.log'
 
 

solar/dblayer/solar_models.py

@@ -36,6 +36,7 @@ from solar.dblayer.model import NONE
 from solar.dblayer.model import SingleIndexCache
 from solar.dblayer.model import StrInt
 from solar.utils import detect_input_schema_by_value
+from solar.utils import parse_database_conn
 from solar.utils import solar_map
 
 
@@ -1060,7 +1061,8 @@ system log
 5. keep order of history
 """
 
-
+_connection, _connection_details = parse_database_conn(C.solar_db)
+if _connection.mode == 'sqlite':
     class NegativeCounter(Model):
 
         count = Field(int, default=int)
@@ -1069,6 +1071,33 @@ class NegativeCounter(Model):
             self.count -= 1
             self.save()
             return self.count
+else:
+    class NegativeCounter(Model):
+
+        bucket_type = C.counter_bucket_type
+
+        def next(self):
+            ro = self._riak_object
+            ro.decrement(1)
+            ro.store()
+            val = ro.value
+            return val
+
+        @property
+        def count(self):
+            return self._riak_object.value
+
+        @classmethod
+        def get_or_create(cls, key):
+            return cls.get(key)
+
+        @classmethod
+        def get(cls, key):
+            try:
+                return cls._c.obj_cache.get(key)
+            except KeyError:
+                riak_object = cls.bucket.get(key)
+                return cls.from_riakobj(riak_object)
 
 
 class LogItem(Model):