DB functions tidyup

Added PRAGMAs for better DB performance on open. Integrated some Fake8 comments and eliminated some looping with more efficient pyton functions.

server/database.py

@@ -1,18 +1,16 @@
 """ all things database to support NetAlertX """
 
 import sqlite3
-import base64
-import json
 
 # Register NetAlertX modules 
-from const import fullDbPath, sql_devices_stats, sql_devices_all, sql_generateGuid
+from const import fullDbPath, sql_devices_stats, sql_devices_all
 
 from logger import mylog
-from helper import timeNowTZ
-from db.db_helper import row_to_json, get_table_json, json_obj
+from db.db_helper import get_table_json, json_obj
 from workflows.app_events import AppEvent_obj
 from db.db_upgrade import ensure_column, ensure_views, ensure_CurrentScan, ensure_plugins_tables, ensure_Parameters, ensure_Settings, ensure_Indexes
 
+
 class DB():
     """
     DB Class to provide the basic database interactions.
@@ -26,7 +24,7 @@ class DB():
     #-------------------------------------------------------------------------------
     def open(self):
         # Check if DB is open
-        if self.sql_connection != None :
+        if self.sql_connection is not None:
             mylog('debug', 'openDB: database already open')
             return
 
@@ -34,17 +32,27 @@ class DB():
         # Open DB and Cursor
         try:
             self.sql_connection = sqlite3.connect(fullDbPath, isolation_level=None)
-            self.sql_connection.execute('pragma journal_mode=wal') #
+
+            # The WAL journaling mode uses a write-ahead log instead of a
+            # rollback journal to implement transactions.
+            self.sql_connection.execute('pragma journal_mode=WAL;')
+            # When synchronous is NORMAL (1), the SQLite database engine will still sync
+            # at the most critical moments, but less often than in FULL mode.
+            self.sql_connection.execute('PRAGMA synchronous=NORMAL;')
+            # When temp_store is MEMORY (2) temporary tables and indices
+            # are kept as if they were in pure in-memory databases.
+            self.sql_connection.execute('PRAGMA temp_store=MEMORY;')
+
             self.sql_connection.text_factory = str
             self.sql_connection.row_factory = sqlite3.Row
             self.sql = self.sql_connection.cursor()
         except sqlite3.Error as e:
-            mylog('verbose',[ '[Database] - Open DB Error: ', e])
+            mylog('minimal', ['[Database] - Open DB Error: ', e])
 
 
     #-------------------------------------------------------------------------------
     def commitDB(self):
-        if self.sql_connection == None :
+        if self.sql_connection is None:
             mylog('debug', 'commitDB: database is not open')
             return False
 
@@ -59,7 +67,7 @@ class DB():
 
     #-------------------------------------------------------------------------------    
     def get_sql_array(self, query):
-        if self.sql_connection == None :
+        if self.sql_connection is None:
             mylog('debug', 'getQueryArray: database is not open')
             return
 
@@ -67,15 +75,11 @@ class DB():
         rows = self.sql.fetchall()
         # self.commitDB()
 
-        #  convert result into list of lists
-        arr = []
-        for row in rows:
-            r_temp = []
-            for column in row:
-                r_temp.append(column)
-            arr.append(r_temp)
+        # Convert result into list of lists
+        # Efficiently convert each row to a list
+
+        return [list(row) for row in rows]
 
-        return arr
 
     #-------------------------------------------------------------------------------
     def initDB(self):
@@ -150,7 +154,7 @@ class DB():
         try:
             result = get_table_json(self.sql, sqlQuery)
         except Exception as e:
-            mylog('verbose', ['[Database] - get_table_as_json ERROR:', e])
+            mylog('minimal', ['[Database] - get_table_as_json ERROR:', e])
             return json_obj({}, [])  # return empty object on failure
 
         # mylog('debug',[ '[Database] - get_table_as_json - returning ', len(rows), " rows with columns: ", columnNames])
@@ -171,9 +175,9 @@ class DB():
             rows = self.sql.fetchall()
             return rows
         except AssertionError:
-            mylog('verbose',[ '[Database] - ERROR: inconsistent query and/or arguments.', query, " params: ", args])
+            mylog('minimal', [ '[Database] - ERROR: inconsistent query and/or arguments.', query, " params: ", args])
         except sqlite3.Error as e:
-            mylog('verbose',[ '[Database] - SQL ERROR: ', e])
+            mylog('minimal', [ '[Database] - SQL ERROR: ', e])
         return None
 
     def read_one(self, query, *args):
@@ -199,10 +203,13 @@ class DB():
 def get_device_stats(db):
     # columns = ["online","down","all","archived","new","unknown"]
     return db.read_one(sql_devices_stats)
+
+
 #-------------------------------------------------------------------------------
 def get_all_devices(db):
     return db.read(sql_devices_all)
 
+
 #-------------------------------------------------------------------------------
 
 def get_array_from_sql_rows(rows):