cache.py

# -*- coding: utf-8 -*-
import sqlite3
from collections import namedtuple

from arkindex_worker import logger

SQL_ELEMENTS_TABLE_CREATION = """CREATE TABLE IF NOT EXISTS elements (
    id VARCHAR(32) PRIMARY KEY,
    parent_id VARCHAR(32),
    type TEXT NOT NULL,
    polygon TEXT,
    initial BOOLEAN DEFAULT 0 NOT NULL,
    worker_version_id VARCHAR(32)
)"""


CachedElement = namedtuple(
    "CachedElement",
    ["id", "type", "polygon", "worker_version_id", "parent_id", "initial"],
    defaults=[None, 0],
)


class LocalDB(object):
    def __init__(self, path):
        self.db = sqlite3.connect(path)
        self.db.row_factory = sqlite3.Row
        self.cursor = self.db.cursor()
        logger.info(f"Connection to local cache {path} established.")

    def create_tables(self):
        self.cursor.execute(SQL_ELEMENTS_TABLE_CREATION)

    def insert(self, table, lines):
        if not lines:
            return
        columns = ", ".join(lines[0]._fields)
        placeholders = ", ".join("?" * len(lines[0]))
        values = [tuple(line) for line in lines]
        self.cursor.executemany(
            f"INSERT INTO {table} ({columns}) VALUES ({placeholders})", values
        )
        self.db.commit()