B39pphg5

1package haven.Kerrigan;
2
3import java.io.File;
4import java.sql.Connection;
5import java.sql.DriverManager;
6import java.sql.SQLException;
7import java.sql.Statement;
8
9import org.sqlite.JDBC;
10
11public class DatabaseCache {
12    private static final String CONNECTION_NAME = "jdbc:sqlite:./cache/cache.db";
13    private static DatabaseCache cacheInstance = null;
14
15    private Connection connection;
16
17    private DatabaseCache() throws SQLException {
18        File file = new File("./cache");
19        if (file.mkdirs()) {
20            DriverManager.registerDriver(new JDBC());
21            this.connection = DriverManager.getConnection(CONNECTION_NAME);
22            createTables();
23        } else {
24            System.out.println("Failed to create cache database '/cache/cache.db'");
25        }
26    }
27
28    public static synchronized DatabaseCache instance() throws SQLException {
29        if (cacheInstance == null)
30            cacheInstance = new DatabaseCache();
31        return cacheInstance;
32    }
33
34    public void markContainer(long grid, int offset, String resource) {
35        try {
36            var prepared = this.connection.prepareStatement("SELECT id FROM containers WHERE grid = ? AND offset = ?;");
37            prepared.setLong(0, grid);
38            prepared.setInt(1, offset);
39            var result = prepared.executeQuery();
40            if (result.first()) {
41                // Updating
42                var id = result.getInt(0);
43                var updating = this.connection.prepareStatement("UPDATE containers SET resource = ? WHERE id = ?;");
44                updating.setString(0, resource);
45                updating.setInt(1, id);
46                updating.execute();
47            } else {
48                // Inserting
49                var inserting = this.connection.prepareStatement("INSERT INTO containers(grid, offset, resource) VALUES(?, ?, ?);");
50                inserting.setLong(0, grid);
51                inserting.setInt(1, offset);
52                inserting.setString(2, resource);
53                inserting.execute();
54            }
55        } catch (SQLException e) {
56            e.printStackTrace();
57        }
58    }
59
60    private void createTables() {
61        try (Statement statement = this.connection.createStatement()) {
62            statement.executeUpdate("""
63                CREATE TABLE IF NOT EXISTS "containers" (
64                        "id"	    INTEGER,
65                        "grid"	    INTEGER NOT NULL DEFAULT 0,
66                        "offset"	INTEGER NOT NULL DEFAULT 0,
67                        "resource"	TEXT,
68                        PRIMARY KEY("id")
69                );
70             """);
71        } catch (SQLException e) {
72            e.printStackTrace();
73        }
74    }
75}