Store created elements in a local SQLite database

Closes #41 (closed)

arkindex_worker/cache.py

+# -*- coding: utf-8 -*-
+import os
+import sqlite3
+
+
+class LocalDB(object):
+    def __init__(self, path):
+        if not os.path.exists(path):
+            open(path, "x").close()
+
+        self.db = sqlite3.connect(path)
+        self.cursor = self.db.cursor()
+
+    def create_elements_table(self):
+        try:
+            self.cursor.execute(
+                """CREATE TABLE elements (
+                id TEXT PRIMARY KEY,
+                parent_id TEXT,
+                name TEXT NOT NULL,
+                type TEXT NOT NULL,
+                polygon TEXT,
+                worker_version_id TEXT
+            )"""
+            )
+        except sqlite3.OperationalError:
+            print("Table 'elements' already exists")
+
+    def insert(self, table, lines):
+        self.cursor.executemany(f"INSERT INTO {table} VALUES (?,?,?,?,?,?)", lines)
+        self.db.commit()