perf: EXPOSED-204 Performance problem with getConnection()

Switch unitialized Database.dataSourceIsolationLevel from nullable to -1.
JetBrains · Dec 14, 2023 · 1057508 · 1057508
1 parent 9a0a3e4
commit 1057508
Show file tree

Hide file tree

Showing 2 changed files with 6 additions and 6 deletions.
diff --git a/exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/Database.kt b/exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/Database.kt
@@ -79,9 +79,9 @@ class Database private constructor(
     /**
      * The transaction isolation level defined by a [DataSource] connection.
      *
-     * This should only hold a non-null value if [connectsViaDataSource] has been set to `true`.
+     * This should only hold a value other than -1 if [connectsViaDataSource] has been set to `true`.
      */
-    internal var dataSourceIsolationLevel: Int? = null
+    internal var dataSourceIsolationLevel: Int = -1
 
     companion object {
         internal val dialects = ConcurrentHashMap<String, () -> DatabaseDialect>()

diff --git a/...e/src/main/kotlin/org/jetbrains/exposed/sql/transactions/ThreadLocalTransactionManager.kt b/...e/src/main/kotlin/org/jetbrains/exposed/sql/transactions/ThreadLocalTransactionManager.kt
@@ -49,9 +49,9 @@ class ThreadLocalTransactionManager(
                     field = Database.getDefaultIsolationLevel(db)
                 }
                 db.connectsViaDataSource && loadDataSourceIsolationLevel -> {
-                    db.dataSourceIsolationLevel?.let {
+                    if (db.dataSourceIsolationLevel != -1) {
                         loadDataSourceIsolationLevel = false
-                        field = it
+                        field = db.dataSourceIsolationLevel
                     }
                 }
             }
@@ -123,12 +123,12 @@ class ThreadLocalTransactionManager(
                     // Transaction isolation should go first as readOnly or autoCommit can start transaction with wrong isolation level
                     // Some drivers start a transaction right after `setAutoCommit(false)`,
                     // which makes `setReadOnly` throw an exception if it is called after `setAutoCommit`
-                    if (db.connectsViaDataSource && loadDataSourceIsolationLevel && db.dataSourceIsolationLevel == null) {
+                    if (db.connectsViaDataSource && loadDataSourceIsolationLevel && db.dataSourceIsolationLevel == -1) {
                         // retrieves the setting of the datasource connection & caches it
                         db.dataSourceIsolationLevel = transactionIsolation
                     } else if (
                         !db.connectsViaDataSource ||
-                        db.dataSourceIsolationLevel?.equals(this@ThreadLocalTransaction.transactionIsolation) != true
+                        db.dataSourceIsolationLevel != this@ThreadLocalTransaction.transactionIsolation
                     ) {
                         // only set the level if there is no cached datasource value or if the value differs
                         transactionIsolation = this@ThreadLocalTransaction.transactionIsolation