Save suggestions in a database

app/suggestions.py

@@ -0,0 +1,31 @@
+import sqlite3
+import uuid
+
+from expiringdict import ExpiringDict
+
+DEFAULT_DB_PATH = "suggestions.db"
+
+
+class Database:
+    def __init__(self, db_path=DEFAULT_DB_PATH, max_cache_len=1000, max_cache_age=30):
+        self.db_path = db_path
+        self.cache = ExpiringDict(max_len=max_cache_len, max_age_seconds=max_cache_age)
+
+        # Make sure to do data synchronization on writes!
+        self.c = sqlite3.connect(db_path, check_same_thread=False)
+        self.c.execute(
+            """CREATE TABLE IF NOT EXISTS suggestions (
+            "q"	TEXT NOT NULL,
+            "s"	TEXT NOT NULL,
+            "source"	TEXT NOT NULL,
+            "target"	TEXT NOT NULL
+        );"""
+        )
+
+    def add(self, q, s, source, target):
+        self.c.execute(
+            "INSERT INTO suggestions (q, s, source, target) VALUES (?, ?, ?, ?)",
+            (q, s, source, target),
+        )
+        self.c.commit()
+        return True