Add sqlite engine

Closes #2808

searx/engines/sqlite.py

@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+"""
+ SQLite database (Offline)
+"""
+
+import sqlite3
+
+engine_type = 'offline'
+database = ""
+query_str = ""
+limit = 10
+paging = True
+result_template = 'key-value.html'
+
+
+def init(engine_settings):
+    if 'query_str' not in engine_settings:
+        raise ValueError('query_str cannot be empty')
+
+    if not engine_settings['query_str'].lower().startswith('select '):
+        raise ValueError('only SELECT query is supported')
+
+
+def search(query, params):
+    query_params = {'query': query}
+    query_to_run = query_str + ' LIMIT {0} OFFSET {1}'.format(limit, (params['pageno'] - 1) * limit)
+
+    connection = sqlite3.connect(database)
+    cur = connection.cursor()
+    cur.execute(query_to_run, query_params)
+    results = _fetch_results(cur)
+    cur.close()
+    connection.close()
+
+    return results
+
+
+def _fetch_results(cur):
+    results = []
+    titles = [name for (name, _, _, _, _, _, _) in cur.description]
+
+    res = cur.fetchone()
+    while res:
+        result = dict(zip(titles, map(str, res)))
+        result['template'] = result_template
+        results.append(result)
+        res = cur.fetchone()
+
+    return results
+

searx/settings.yml

@@ -1019,6 +1019,13 @@ engines:
     timeout : 3.0
     disabled : True
 
+#  - name : sqlite
+#    engine : sqlite
+#    shortcut: sq
+#    database : mydb
+#    query_str : 'SELECT * FROM mytable WHERE fieldname=:query'
+#    disabled : True
+
   - name : torrentz
     engine : torrentz
     shortcut : tor