Add HikariCP connection pool

CHANGELOG.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 ### Changed
+- [2021-01-29] Add HikariCP connection pool [@carbotaniuman].
 
 ### Deprecated
 

build.gradle

@@ -44,6 +44,7 @@ dependencies {
     testImplementation group: "org.http4k", name: "http4k-testing-kotest", version: "$http_4k_version"
     runtimeOnly group: "io.netty", name: "netty-tcnative-boringssl-static", version: "2.0.34.Final"
 
+    implementation group: 'com.zaxxer', name: 'HikariCP', version: '4.0.1'
     implementation group: "com.h2database", name: "h2", version: "1.4.200"
     implementation "org.ktorm:ktorm-core:$ktorm_version"
     implementation "org.ktorm:ktorm-jackson:$ktorm_version"

src/main/kotlin/mdnet/MangaDexClient.kt

@@ -24,6 +24,8 @@ import com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException
 import com.fasterxml.jackson.dataformat.yaml.YAMLFactory
 import com.fasterxml.jackson.module.kotlin.KotlinModule
 import com.fasterxml.jackson.module.kotlin.readValue
+import com.zaxxer.hikari.HikariConfig
+import com.zaxxer.hikari.HikariDataSource
 import mdnet.Main.dieWithError
 import mdnet.cache.ImageStorage
 import mdnet.logging.info
@@ -51,6 +53,8 @@ class MangaDexClient(private val settingsFile: File, databaseFile: File, cacheFo
 
     private val database: Database
     private val storage: ImageStorage
+    private val dataSource: HikariDataSource
+
     private var settings: ClientSettings
 
     // state that must only be accessed from the thread on the executor
@@ -72,7 +76,14 @@ class MangaDexClient(private val settingsFile: File, databaseFile: File, cacheFo
 
         LOGGER.info { "Client settings loaded: $settings" }
 
-        database = Database.connect("jdbc:h2:$databaseFile", "org.h2.Driver")
+        val config = HikariConfig()
+        config.jdbcUrl = "jdbc:h2:$databaseFile"
+        config.addDataSourceProperty("cachePrepStmts", "true")
+        config.addDataSourceProperty("prepStmtCacheSize", "100")
+        config.addDataSourceProperty("prepStmtCacheSqlLimit", "1000")
+        dataSource = HikariDataSource(config)
+
+        database = Database.connect(dataSource)
         storage = ImageStorage(
             maxSize = (settings.maxCacheSizeInMebibytes * 1024 * 1024 * 0.95).toLong(), /* MiB to bytes */
             cacheFolder,
@@ -133,6 +144,7 @@ class MangaDexClient(private val settingsFile: File, databaseFile: File, cacheFo
                 }
 
                 storage.close()
+                dataSource.close()
                 latch.countDown()
             },
             0, TimeUnit.SECONDS