kotlin-orm · sigmanil · Jan 19, 2021 · Jan 19, 2021 · Jan 19, 2021 · Jan 20, 2021
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -7,6 +7,6 @@ Pull requests are always welcome and can be a quick way to get your fix or impro
 
 - By contributing to Ktorm, you agree to uphold our [Code of Conduct](CODE_OF_CONDUCT.md).
 - By contributing to Ktorm, you agree that your contributions will be licensed under [Apache License 2.0](LICENSE).
-- Coding Conventions are very import. Refer to the [Kotlin Style Guide](https://kotlinlang.org/docs/reference/coding-conventions.html) for the recommended coding standards of Ktorm.
+- Coding Conventions are very important. Refer to the [Kotlin Style Guide](https://kotlinlang.org/docs/reference/coding-conventions.html) for the recommended coding standards of Ktorm.
 - If you've added code that should be tested, add tests and ensure they all pass. If you've changed APIs, update the documentation. 
 - If it's your first time contributing to Ktorm, please also update the `build.gradle` file, add your GitHub ID to the developers info, which will let more people know your contributions.
diff --git a/build.gradle b/build.gradle
@@ -2,7 +2,7 @@
 buildscript {
     ext {
         kotlinVersion = "1.4.21"
-        detektVersion = "1.12.0-RC1"
+        detektVersion = "1.14.2"
     }
     repositories {
         jcenter()
@@ -162,6 +162,11 @@ subprojects { project ->
                             name = "Pedro Domingues"
                             email = "pedro.domingues.pt@gmail.com"
                         }
+                        developer {
+                            id = "sigmanil"
+                            name = "Sigmund M. Nilssen"
+                            email = "sigmundn@gmail.com"
+                        }
                     }
                     scm {
                         url = "https://github.com/kotlin-orm/ktorm.git"

diff --git a/ktorm-support-mysql/ktorm-support-mysql.gradle b/ktorm-support-mysql/ktorm-support-mysql.gradle
@@ -5,5 +5,5 @@ dependencies {
     testImplementation project(path: ":ktorm-core", configuration: "testOutput")
     testImplementation project(":ktorm-jackson")
     testImplementation "mysql:mysql-connector-java:8.0.13"
-    testImplementation "org.testcontainers:mysql:1.11.3"
+    testImplementation "org.testcontainers:mysql:1.15.1"
 }
diff --git a/ktorm-support-oracle/ktorm-support-oracle.gradle b/ktorm-support-oracle/ktorm-support-oracle.gradle
@@ -4,5 +4,5 @@ dependencies {
 
     testImplementation project(path: ":ktorm-core", configuration: "testOutput")
     testImplementation fileTree(dir: "lib", includes: ["*.jar"])
-    testImplementation "org.testcontainers:oracle-xe:1.11.3"
+    testImplementation "org.testcontainers:oracle-xe:1.15.1"
 }
diff --git a/ktorm-support-postgresql/ktorm-support-postgresql.gradle b/ktorm-support-postgresql/ktorm-support-postgresql.gradle
@@ -4,5 +4,5 @@ dependencies {
 
     testImplementation project(path: ":ktorm-core", configuration: "testOutput")
     testImplementation "org.postgresql:postgresql:42.2.5"
-    testImplementation "org.testcontainers:postgresql:1.11.3"
+    testImplementation "org.testcontainers:postgresql:1.15.1"
 }
diff --git a/ktorm-support-postgresql/src/main/kotlin/org/ktorm/support/postgresql/PostgreSqlDialect.kt b/ktorm-support-postgresql/src/main/kotlin/org/ktorm/support/postgresql/PostgreSqlDialect.kt
@@ -146,6 +146,14 @@ public open class PostgreSqlFormatter(
         return expr
     }
 
+    override fun visitSelect(expr: SelectExpression): SelectExpression {
+        super.visitSelect(expr)
+        if (expr.extraProperties[SKIP_LOCKED] == true) {
+            writeKeyword("skip locked ")
+        }
+        return expr
+    }
+
     protected open fun visitInsertOrUpdate(expr: InsertOrUpdateExpression): InsertOrUpdateExpression {
         writeKeyword("insert into ")
         visitTable(expr.table)

diff --git a/ktorm-support-postgresql/src/main/kotlin/org/ktorm/support/postgresql/SkipLocked.kt b/ktorm-support-postgresql/src/main/kotlin/org/ktorm/support/postgresql/SkipLocked.kt
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2018-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.ktorm.support.postgresql
+
+import org.ktorm.dsl.Query
+import org.ktorm.entity.EntitySequence
+import org.ktorm.expression.SelectExpression
+import org.ktorm.expression.UnionExpression
+import org.ktorm.schema.BaseTable
+
+internal const val SKIP_LOCKED = "skipLocked"
+
+/**
+ * Indicate that this query should skip locked records, the generated SQL would be `select ... skip locked`.
+ */
+public fun Query.skipLocked(): Query {
+    val expr = when (expression) {
+        is SelectExpression ->
+            (expression as SelectExpression)
+                .copy(extraProperties = expression.extraProperties + (SKIP_LOCKED to true))
+        is UnionExpression ->
+            throw IllegalStateException("SELECT SKIP LOCKS is not supported in a union expression.")
+    }
+
+    return this.withExpression(expr)
+}
+
+/**
+ * Indicate that the generated query should skip locked records, the generated SQL would be `select ... skip locked`.
+ */
+public fun <E : Any, T : BaseTable<E>> EntitySequence<E, T>.skipLocked(): EntitySequence<E, T> {
+    return this.withExpression(expression.copy(extraProperties = expression.extraProperties + (SKIP_LOCKED to true)))
+}
diff --git a/ktorm-support-postgresql/src/test/kotlin/org/ktorm/support/postgresql/PostgreSqlTest.kt b/ktorm-support-postgresql/src/test/kotlin/org/ktorm/support/postgresql/PostgreSqlTest.kt
@@ -2,11 +2,12 @@ package org.ktorm.support.postgresql
 
 import org.hamcrest.CoreMatchers.equalTo
 import org.hamcrest.CoreMatchers.nullValue
-import org.junit.Assert.assertThat
+import org.junit.Assert.*
 import org.junit.ClassRule
 import org.junit.Test
 import org.ktorm.BaseTest
 import org.ktorm.database.Database
+import org.ktorm.database.TransactionIsolation
 import org.ktorm.database.use
 import org.ktorm.dsl.*
 import org.ktorm.entity.*
@@ -17,19 +18,17 @@ import org.ktorm.schema.Table
 import org.ktorm.schema.int
 import org.ktorm.schema.varchar
 import org.testcontainers.containers.PostgreSQLContainer
+import org.testcontainers.utility.DockerImageName
 import java.time.LocalDate
-import java.util.concurrent.ExecutionException
-import java.util.concurrent.Executors
-import java.util.concurrent.TimeUnit
-import java.util.concurrent.TimeoutException
+import java.util.concurrent.*
 
 /**
  * Created by vince on Feb 13, 2019.
  */
 class PostgreSqlTest : BaseTest() {
 
     companion object {
-        class KPostgreSqlContainer : PostgreSQLContainer<KPostgreSqlContainer>()
+        class KPostgreSqlContainer : PostgreSQLContainer<KPostgreSqlContainer>("postgres:13.1-alpine")
 
         @ClassRule
         @JvmField
@@ -493,4 +492,48 @@ class PostgreSqlTest : BaseTest() {
 
         assertThat(count, equalTo(1))
     }
+
+    @Test
+    fun testSelectForUpdateSkipLocked() {
+        val readyToTestSkipLocksLatch = CountDownLatch(1)
+        val testSkipLocksDoneLatch = CountDownLatch(1)
+
+        val skippedFuture = Executors.newSingleThreadExecutor().submit {
+            assertTrue(readyToTestSkipLocksLatch.await(5, TimeUnit.SECONDS))
+            val employees = database.useTransaction(isolation = TransactionIsolation.REPEATABLE_READ) {
+                database
+                    .sequenceOf(Employees, withReferences = false)
+                    .filter { it.id eq 1 }
+                    .forUpdate()
+                    .skipLocked()
+                    .toList()
+            }
+            testSkipLocksDoneLatch.countDown()
+            if (employees.isNotEmpty()) {
+                throw java.lang.IllegalStateException("Entry should have been skipped due to being locked.")
+            }
+        }
+
+        val selectedFuture = Executors.newSingleThreadExecutor().submit {
+            val employees = database.useTransaction(isolation = TransactionIsolation.REPEATABLE_READ) {
+                val employeeList = database
+                    .sequenceOf(Employees, withReferences = false)
+                    .filter { it.id eq 1 }
+                    .forUpdate()
+                    .skipLocked()
+                    .toList()
+
+                readyToTestSkipLocksLatch.countDown()
+                assertTrue(testSkipLocksDoneLatch.await(10, TimeUnit.SECONDS))
+                employeeList
+            }
+            if (employees.size != 1) {
+                throw java.lang.IllegalStateException("Entry should be available.")
+            }
+        }
+
+        assertNull(selectedFuture.get(5, TimeUnit.SECONDS))
+        assertNull(skippedFuture.get(5, TimeUnit.SECONDS))
+
+    }
 }
diff --git a/ktorm-support-sqlserver/ktorm-support-sqlserver.gradle b/ktorm-support-sqlserver/ktorm-support-sqlserver.gradle
@@ -4,5 +4,5 @@ dependencies {
     api "com.microsoft.sqlserver:mssql-jdbc:7.2.2.jre8"
 
     testImplementation project(path: ":ktorm-core", configuration: "testOutput")
-    testImplementation "org.testcontainers:mssqlserver:1.11.3"
+    testImplementation "org.testcontainers:mssqlserver:1.15.1"
 }