Class Database

ZezeJava/ZezeJava/src/main/java/Zeze/Transaction/Database.java:29–737

数据访问的效率主要来自TableCache的命中。根据以往的经验，命中率是很高的。 所以数据库层就不要求很高的效率。马马虎虎就可以了。

 * 所以数据库层就不要求很高的效率。马马虎虎就可以了。
 */
public abstract class Database extends ReentrantLock {
	protected static final @NotNull Logger logger = LogManager.getLogger(Database.class);

	// 当数据库对Key长度有限制时，使用这个常量。这个数字来自 PolarDb-X。其中MySql 8是3072.
	// 以后需要升级时，修改这个常量。但是对于已经存在的表，需要自己完成Alter。
	public static final int eMaxKeyLength = 3070;

	static {
		ShutdownHook.init();
	}

	private final ConcurrentHashMap<String, Zeze.Transaction.Table> tables = new ConcurrentHashMap<>();
	private final ArrayList<Storage<?, ?>> storages = new ArrayList<>();
	private final @NotNull DatabaseConf conf;
	private final @NotNull String databaseUrl;
	private Operates directOperates;
	private final Application zeze;

	public Database(@Nullable Application zeze, @NotNull DatabaseConf conf) {
		this.zeze = zeze;
		this.conf = conf;
		databaseUrl = conf.getDatabaseUrl();
	}

	public void __add_storage__(@Nullable Storage<?, ?> storage) {
		if (storage != null)
			storages.add(storage);
	}

	void replaceStorage(@Nullable Storage<?, ?> exist, @Nullable Storage<?, ?> replace) {
		if (replace == null) {
			for (var i = 0; i < storages.size(); ++i) {
				if (storages.get(i) == exist) {
					storages.remove(i);
					break;
				}
			}
		} else {
			for (var i = 0; i < storages.size(); ++i) {
				if (storages.get(i) == exist) {
					storages.set(i, replace);
					break;
				}
			}
		}
	}

	public @NotNull Application getZeze() {
		return zeze;
	}

	public final @NotNull Collection<Zeze.Transaction.Table> getTables() {
		return tables.values();
	}

	public final @Nullable Zeze.Transaction.Table getTable(@NotNull String name) {
		return tables.get(name);
	}