[history] Scopes for transaction and prepared statement

src/jvmMain/kotlin/ru/landgrafhomyak/db/jdbc_kotlin_extensions/PreparedStatementPrepareAndFetch.kt

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+package ru.landgrafhomyak.db.jdbc_kotlin_extensions
+
+import java.sql.PreparedStatement
+import java.sql.ResultSet
+
+public interface PreparedStatementPrepareAndFetch<R> {
+    public fun prepare(ps: PreparedStatement)
+    public fun mapOne(rs: ResultSet): R
+}

src/jvmMain/kotlin/ru/landgrafhomyak/db/jdbc_kotlin_extensions/extensions.kt

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+@file:JvmName("ExtensionsKt")
+@file:Suppress("SqlSourceToSinkFlow")
+@file:OptIn(ExperimentalContracts::class)
+
+package ru.landgrafhomyak.db.jdbc_kotlin_extensions
+
+import java.sql.Connection
+import java.sql.PreparedStatement
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.contract
+
+public fun <R> Connection.mapQuery(sql: String, action: PreparedStatementPrepareAndFetch<R>, to: MutableList<R>) {
+	this.prepareStatement(sql).use { ps ->
+		action.prepare(ps)
+		ps.executeQuery().use { rs ->
+			while (rs.next()) {
+				to.add(action.mapOne(rs))
+			}
+		}
+	}
+}
+
+public fun <R> Connection.mapQuery(sql: String, action: PreparedStatementPrepareAndFetch<R>): List<R> {
+	val out = ArrayList<R>()
+	this.mapQuery(sql, action, out)
+	return out
+}
+
+public inline fun <R> Connection.transaction(t: (Connection) -> R): R {
+	contract {
+		callsInPlace(t)
+	}
+
+	this.prepareStatement("BEGIN TRANSACTION").use { ps -> ps.executeUpdate() }
+	val r: R
+	try {
+		r = t(this)
+	} catch (e1: Throwable) {
+		try {
+			this.prepareStatement("ROLLBACK TRANSACTION").use { ps -> ps.executeUpdate() }
+		} catch (e2: Throwable) {
+			e1.addSuppressed(e2)
+		}
+		throw e1
+	}
+	this.prepareStatement("COMMIT TRANSACTION").use { ps -> ps.executeUpdate() }
+	return r
+}
+
+
+public inline fun <R> Connection.prepareStatement(sql: String, action: (PreparedStatement) -> R): R {
+	contract {
+		callsInPlace(action)
+	}
+	this.prepareStatement(sql).use { ps -> return action(ps) }
+}