RDB as a cache storage
libraryDependencies += "com.github.tototoshi" %% "dbcache-mysql" % "1.0.0"
// or
// libraryDependencies += "com.github.tototoshi" %% "dbcache-postgresql" % "1.0.0"dbcache is a cache library which uses RDB (mysql and postgresql) as backend. it uses a table named cache_entries which has columns named key, value, expired_at and created_at like below.
-- mysql
CREATE TABLE `cache_entries` (
`cache_key` varchar(191) PRIMARY KEY,
`cache_value` mediumblob NOT NULL,
`expired_at` datetime,
`created_at` datetime NOT NULL,
`updated_at` datetime NOT NULL,
INDEX (`expired_at`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
-- postgresql
CREATE TABLE cache_entries (
cache_key varchar(191) PRIMARY KEY,
cache_value bytea NOT NULL,
expired_at timestamp,
created_at timestamp NOT NULL,
updated_at timestamp NOT NULL
);
create index on cache_entries(expired_at);You can add more constraint and index (for example: expired_at as NOT NULL).
package example
import java.sql.{Connection, DriverManager}
import java.util.Date
import com.github.tototoshi.dbcache.mysql.MySQLCache
import com.github.tototoshi.dbcache.{ConnectionFactory, DBCache}
import scala.concurrent.duration.Duration
case class User(id: Int, name: String)
object Example {
class ExampleConnectionFactory extends ConnectionFactory {
val driver = "com.mysql.cj.jdbc.Driver"
val url = "jdbc:mysql//localhost/mydb"
val user = "user"
val password = "password"
Class.forName(driver)
override def get(): Connection = {
DriverManager.getConnection(url, user, password)
}
}
def main(args: Array[String]): Unit = {
val cache: DBCache = new MySQLCache(new ExampleConnectionFactory)
cache.set("key", User(1, "John"), Duration("5s"))
1.to(10).foreach { _ =>
val user = cache.get[User]("key")
val date = new Date()
println(s"$date: $user")
Thread.sleep(1000)
}
}
}
/* output
Tue Apr 26 22:26:48 JST 2016: Some(User(1,John))
Tue Apr 26 22:26:49 JST 2016: Some(User(1,John))
Tue Apr 26 22:26:50 JST 2016: Some(User(1,John))
Tue Apr 26 22:26:51 JST 2016: Some(User(1,John))
Tue Apr 26 22:26:52 JST 2016: Some(User(1,John))
Tue Apr 26 22:26:53 JST 2016: None
Tue Apr 26 22:26:54 JST 2016: None
Tue Apr 26 22:26:55 JST 2016: None
Tue Apr 26 22:26:56 JST 2016: None
Tue Apr 26 22:26:57 JST 2016: None
*/| dbcache-play version | Play version | Scala version |
|---|---|---|
| 1.0.0 | 3.0.x | 2.13/3.3 |
| 0.5.0 | 2.9.x | 2.13/3.3 |
| 0.4.0 | 2.8.x | 2.12/2.13 |
Add dbcache-play to dependencies.
libraryDependencies += "com.github.tototoshi" %% "dbcache-play" % "1.0.0"The code below is Play integration example with scalikejdbc
import java.sql.Connection
import com.github.tototoshi.dbcache.ConnectionFactory
import com.github.tototoshi.dbcache.mysql.MySQLCache
import com.github.tototoshi.dbcache.play.DBCacheApi
import javax.inject.{Inject, Provider}
import play.api.Environment
import play.api.cache.SyncCacheApi
import scalikejdbc.DB
class MySQLCacheApiProvider @Inject()(environment: Environment) extends Provider[SyncCacheApi] {
private val connectionFactory = new ConnectionFactory {
override def get(): Connection = {
DB.autoCommitSession().connection
}
}
override def get(): SyncCacheApi = {
val mysqlCache = new MySQLCache(connectionFactory, environment.classLoader)
new DBCacheApi(mysqlCache)
}
}Disable EhCache which is the default cache backend of Play.
play.modules.disabled += "play.api.cache.ehcache.EhCacheModule"