Exposed based Table implementation

dataforge-exposed/build.gradle.kts

@@ -0,0 +1,15 @@
+plugins {
+    id("ru.mipt.npm.gradle.jvm")
+}
+
+dependencies {
+    api("org.jetbrains.exposed:exposed-core:0.31.1")
+    testImplementation("org.jetbrains.exposed:exposed-jdbc:0.31.1")
+    testImplementation("com.h2database:h2:1.4.200")
+    testImplementation("org.slf4j:slf4j-simple:1.7.30")
+    api(project(":dataforge-tables"))
+}
+
+readme {
+    maturity = ru.mipt.npm.gradle.Maturity.PROTOTYPE
+}

dataforge-exposed/src/main/kotlin/space/kscience/dataforge/exposed/ExposedTable.kt

@@ -0,0 +1,84 @@
+package space.kscience.dataforge.exposed
+
+import org.jetbrains.exposed.dao.id.EntityID
+import org.jetbrains.exposed.dao.id.IntIdTable
+import org.jetbrains.exposed.sql.*
+import org.jetbrains.exposed.sql.transactions.transaction
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.tables.Column
+import space.kscience.dataforge.tables.Row
+import space.kscience.dataforge.tables.Table
+import kotlin.reflect.KType
+import kotlin.reflect.typeOf
+import org.jetbrains.exposed.sql.Column as SqlColumn
+
+public class ExposedColumn<T : Any>(
+    public val db: Database,
+    public val sqlTable: IntIdTable,
+    public val sqlColumn: SqlColumn<T>,
+    public override val type: KType,
+) : Column<T> {
+    public override val name: String
+        get() = sqlColumn.name
+
+    public override val meta: Meta
+        get() = Meta.EMPTY
+
+    public override val size: Int
+        get() = transaction(db) { sqlColumn.table.selectAll().count().toInt() }
+
+    public override fun get(index: Int): T? = transaction(db) {
+        sqlTable.select { sqlTable.id eq index + 1 }.firstOrNull()?.getOrNull(sqlColumn)
+    }
+}
+
+@Suppress("UNCHECKED_CAST")
+public class ExposedRow<T : Any>(
+    public val db: Database,
+    public val sqlTable: IntIdTable,
+    public val sqlRow: ResultRow,
+) :
+    Row<T> {
+    public override fun get(column: String): T? = transaction(db) {
+        val theColumn = sqlTable.columns.find { it.name == column } as SqlColumn<T>? ?: return@transaction null
+        sqlRow.getOrNull(theColumn)
+    }
+}
+
+@Suppress("UNCHECKED_CAST")
+public class ExposedTable<T : Any>(public val db: Database, public val sqlTable: IntIdTable, public val type: KType) :
+    Table<T> {
+    public override val columns: List<Column<T>> =
+        sqlTable.columns.filterNot { it.name == "id" }.map { ExposedColumn(db, sqlTable, it as SqlColumn<T>, type) }
+
+    public override val rows: List<Row<T>>
+        get() = transaction(db) {
+            sqlTable.selectAll().map { ExposedRow(db, sqlTable, it) }
+        }
+
+    public override operator fun get(row: Int, column: String): T? = transaction(db) {
+        val sqlColumn: SqlColumn<T> = sqlTable.columns.find { it.name == column } as SqlColumn<T>?
+            ?: return@transaction null
+
+        sqlTable.select { sqlTable.id eq row + 1 }.firstOrNull()?.getOrNull(sqlColumn)
+    }
+}
+
+public inline fun <reified T : Any> ExposedTable(db: Database, table: IntIdTable): ExposedTable<T> =
+    ExposedTable(db, table, typeOf<T>())
+
+public inline fun <reified T : Any> ExposedTable(
+    db: Database,
+    tableName: String,
+    columns: List<String>,
+    sqlColumnType: IColumnType,
+): ExposedTable<T> {
+    val table = object : IntIdTable(tableName) {
+        init {
+            columns.forEach { registerColumn<T>(it, sqlColumnType) }
+        }
+    }
+
+    transaction(db) { SchemaUtils.createMissingTablesAndColumns(table) }
+    return ExposedTable(db, table)
+}

dataforge-exposed/src/test/kotlin/space/kscience/dataforge/exposed/ExposedTableTest.kt

@@ -0,0 +1,40 @@
+package space.kscience.dataforge.exposed
+
+import org.jetbrains.exposed.sql.Column
+import org.jetbrains.exposed.sql.Database
+import org.jetbrains.exposed.sql.IntegerColumnType
+import org.jetbrains.exposed.sql.insert
+import org.jetbrains.exposed.sql.transactions.transaction
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+@Suppress("UNCHECKED_CAST")
+internal class ExposedTableTest {
+    @Test
+    fun exposedTable() {
+        val db = Database.connect("jdbc:h2:mem:test;DB_CLOSE_DELAY=-1", driver = "org.h2.Driver")
+
+        val table = ExposedTable<Int>(
+            db,
+            "test",
+            listOf("a", "b", "c"),
+            IntegerColumnType(),
+        )
+
+        transaction(db) {
+            table.sqlTable.insert {
+                it[table.sqlTable.columns.find { t -> t.name == "a" } as Column<Int>] = 42
+                it[table.sqlTable.columns.find { t -> t.name == "b" } as Column<Int>] = 3
+                it[table.sqlTable.columns.find { t -> t.name == "c" } as Column<Int>] = 7
+            }
+        }
+
+
+        assertEquals(42, table[0, "a"])
+        assertEquals(3, table[0, "b"])
+        assertEquals(7, table[0, "c"])
+        assertEquals(3, table.columns.size)
+        table.columns.forEach { assertEquals(1, it.size) }
+        assertEquals(1, table.rows.size)
+    }
+}

settings.gradle.kts

@@ -27,5 +27,6 @@ include(
 //    ":dataforge-output",
     ":dataforge-tables",
     ":dataforge-workspace",
+    ":dataforge-exposed",
     ":dataforge-scripting"
 )