All db operations now should go thru Database object

brmbar3/brmbar/Database.py

@@ -0,0 +1,50 @@
+"""self-reconnecting database object"""
+
+import psycopg2
+from contextlib import closing
+import time
+
+class Database:
+    """self-reconnecting database object"""
+    def __init__(self, dsn):
+        self.db_conn = psycopg2.connect(dsn)
+        self.dsn = dsn
+
+    def execute(self, query, attrs = None):
+        """execute a query and return one result"""
+        with closing(self.db_conn.cursor()) as cur:
+            cur = self._execute(cur, query, attrs)
+
+    def execute_and_fetch(self, query, attrs = None):
+        """execute a query and return one result"""
+        with closing(self.db_conn.cursor()) as cur:
+            cur = self._execute(cur, query, attrs)
+            return cur.fetchone()
+
+    def execute_and_fetchall(self, query, attrs = None):
+        """execute a query and return all results"""
+        with closing(self.db_conn.cursor()) as cur:
+            cur = self._execute(cur, query, attrs)
+            return cur.fetchall()
+
+    def _execute(self, cur, query, attrs, level=1):
+        """execute a query, and in case of OperationalError (db restart)
+        reconnect to database. Recurses with increasig pause between tries"""
+        try:
+            if attrs is None:
+                cur.execute(query)
+            else:
+                cur.execute(query, attrs)
+            return cur
+        except psycopg2.OperationalError as error:
+            print("Sleeping: level %s (%s) @%s" % (
+                level, error, time.strftime("%Y%m%d %a %I:%m %p")
+                ))
+            time.sleep(2 ** level)
+            self.db_conn = psycopg2.connect(self.dsn)
+            cur = self.db_conn.cursor()  #how ugly is this?
+            return self._execute(cur, query, attrs, level+1)
+
+    def commit(self):
+        """passes commit to db"""
+        self.db_conn.commit()