JarCastingFlex Lock
Flexible lock interface for locking shared network resources using a database or for simple locking with-in an application.
Build status:
Maven Setup
<dependency>
<groupId>com.nofacepress</groupId>
<artifactId>flex-lock</artifactId>
<version>1.0.1</version>
</dependency>
Usage Example
FlexLockRegistry<String> registry = new DatabaseFlexLockRegistry<String>(DB_DRIVER, DB_URL, DB_USER, DB_PASSWORD, DB_TABLE_NAME);
FlexLockHandle<String> handle = registry.lock("key", 1000);
registry.unlock(handle);
Database Setup
Default Setup
CREATE TABLE IF NOT EXISTS `AnyTableName` (
`mutex_id` VARCHAR(128) NOT NULL,
`expire_time` LONG DEFAULT 0 NOT NULL,
`owner` VARCHAR(36),
PRIMARY KEY (`mutex_id`)
);
Integration with an existing table
In this case, the lock table is a part of an existing table.
CREATE TABLE IF NOT EXISTS `AnotherTableName` (
`another_id` LONG NOT NULL,
-- Other fields
`expires` LONG DEFAULT 0 NOT NULL,
`owner` VARCHAR(36),
PRIMARY KEY (`another_id`)
);
To work with this table, specify the primary key
FlexLockRegistry<Long> registry = new DatabaseFlexLockRegistry<Long>(DB_DRIVER, DB_URL, DB_USER, DB_PASSWORD, "AnotherTableName", "another_id", "expires", "owner");
FlexLockHandle<Long> handle = registry.lock(101L, 1000);
registry.unlock(handle);
The registry keeps locks in memory. If there is going to be a very large number of keys, it is best to use the adapter directly.
final FlexLockAdapter<Long> adapter = new DatabaseFlexLockAdapter<Long>(DB_DRIVER, DB_URL, DB_USER, DB_PASSWORD, "AnotherTableName", "another_id", "expires", "owner");
final FlexLockHandle handle = new FlexLockHandle(); // used to uniquely identify the owner
final long now = System.currentTimeMillis();
final boolean success = adapter.tryLock(101L, handle, now, now + 10000);
adapter.unlock(101L, handle);
