Improve async support for Cursors

drivers/android-driver/src/main/java/app/cash/sqldelight/driver/android/AndroidSqliteDriver.kt

@@ -141,7 +141,7 @@ class AndroidSqliteDriver private constructor(
     createStatement: () -> AndroidStatement,
     binders: (SqlPreparedStatement.() -> Unit)?,
     result: AndroidStatement.() -> T,
-  ): QueryResult<T> {
+  ): QueryResult.Value<T> {
     var statement: AndroidStatement? = null
     if (identifier != null) {
       statement = statements.remove(identifier)
@@ -171,7 +171,7 @@ class AndroidSqliteDriver private constructor(
   override fun <R> executeQuery(
     identifier: Int?,
     sql: String,
-    mapper: (SqlCursor) -> R,
+    mapper: (SqlCursor) -> QueryResult<R>,
     parameters: Int,
     binders: (SqlPreparedStatement.() -> Unit)?,
   ) = execute(identifier, { AndroidQuery(sql, database, parameters) }, binders) { executeQuery(mapper) }
@@ -207,7 +207,7 @@ class AndroidSqliteDriver private constructor(
 
 internal interface AndroidStatement : SqlPreparedStatement {
   fun execute(): Long
-  fun <R> executeQuery(mapper: (SqlCursor) -> R): R
+  fun <R> executeQuery(mapper: (SqlCursor) -> QueryResult<R>): R
   fun close()
 }
 
@@ -238,7 +238,7 @@ private class AndroidPreparedStatement(
     }
   }
 
-  override fun <R> executeQuery(mapper: (SqlCursor) -> R): R = throw UnsupportedOperationException()
+  override fun <R> executeQuery(mapper: (SqlCursor) -> QueryResult<R>): R = throw UnsupportedOperationException()
 
   override fun execute(): Long {
     return statement.executeUpdateDelete().toLong()
@@ -284,9 +284,9 @@ private class AndroidQuery(
 
   override fun execute() = throw UnsupportedOperationException()
 
-  override fun <R> executeQuery(mapper: (SqlCursor) -> R): R {
+  override fun <R> executeQuery(mapper: (SqlCursor) -> QueryResult<R>): R {
     return database.query(this)
-      .use { cursor -> mapper(AndroidCursor(cursor)) }
+      .use { cursor -> mapper(AndroidCursor(cursor)).value }
   }
 
   override fun bindTo(statement: SupportSQLiteProgram) {
@@ -303,7 +303,7 @@ private class AndroidQuery(
 private class AndroidCursor(
   private val cursor: Cursor,
 ) : SqlCursor {
-  override fun next() = cursor.moveToNext()
+  override fun next(): QueryResult.Value<Boolean> = QueryResult.Value(cursor.moveToNext())
   override fun getString(index: Int) = if (cursor.isNull(index)) null else cursor.getString(index)
   override fun getLong(index: Int) = if (cursor.isNull(index)) null else cursor.getLong(index)
   override fun getBytes(index: Int) = if (cursor.isNull(index)) null else cursor.getBlob(index)

drivers/android-driver/src/test/java/com/squareup/sqldelight/android/AndroidDriverTest.kt

@@ -26,12 +26,12 @@ class AndroidDriverTest : DriverTest() {
   fun `cached statement can be reused`() {
     val driver = AndroidSqliteDriver(schema, getApplicationContext(), cacheSize = 1)
     lateinit var bindable: SqlPreparedStatement
-    driver.executeQuery(1, "SELECT * FROM test", {}, 0, { bindable = this })
+    driver.executeQuery(1, "SELECT * FROM test", { QueryResult.Unit }, 0, { bindable = this })
 
     driver.executeQuery(
       1,
       "SELECT * FROM test",
-      {},
+      { QueryResult.Unit },
       0,
       {
         assertSame(bindable, this)
@@ -43,14 +43,14 @@ class AndroidDriverTest : DriverTest() {
   fun `cached statement is evicted and closed`() {
     val driver = AndroidSqliteDriver(schema, getApplicationContext(), cacheSize = 1)
     lateinit var bindable: SqlPreparedStatement
-    driver.executeQuery(1, "SELECT * FROM test", {}, 0, { bindable = this })
+    driver.executeQuery(1, "SELECT * FROM test", { QueryResult.Unit }, 0, { bindable = this })
 
-    driver.executeQuery(2, "SELECT * FROM test", {}, 0)
+    driver.executeQuery(2, "SELECT * FROM test", { QueryResult.Unit }, 0)
 
     driver.executeQuery(
       1,
       "SELECT * FROM test",
-      {},
+      { QueryResult.Unit },
       0,
       {
         assertNotSame(bindable, this)

drivers/driver-test/src/commonMain/kotlin/com/squareup/sqldelight/driver/test/DriverTest.kt

@@ -64,9 +64,9 @@ abstract class DriverTest {
   private fun changes(): Long? {
     // wrap in a transaction to ensure read happens on transaction thread/connection
     return transacter.value!!.transactionWithResult {
-      val mapper: (SqlCursor) -> Long? = {
+      val mapper: (SqlCursor) -> QueryResult<Long?> = {
         it.next()
-        it.getLong(0)
+        QueryResult.Value(it.getLong(0))
       }
       driver.executeQuery(null, "SELECT changes()", mapper, 0).value
     }
@@ -87,12 +87,13 @@ abstract class DriverTest {
     val insert = { binders: SqlPreparedStatement.() -> Unit ->
       driver.execute(2, "INSERT INTO test VALUES (?, ?);", 2, binders)
     }
-    fun query(mapper: (SqlCursor) -> Unit) {
+    fun query(mapper: (SqlCursor) -> QueryResult<Unit>) {
       driver.executeQuery(3, "SELECT * FROM test", mapper, 0)
     }
 
     query {
-      assertFalse(it.next())
+      assertFalse(it.next().value)
+      QueryResult.Unit
     }
 
     insert {
@@ -101,16 +102,18 @@ abstract class DriverTest {
     }
 
     query {
-      assertTrue(it.next())
-      assertFalse(it.next())
+      assertTrue(it.next().value)
+      assertFalse(it.next().value)
+      QueryResult.Unit
     }
 
     assertEquals(1, changes())
 
     query {
-      assertTrue(it.next())
+      assertTrue(it.next().value)
       assertEquals(1, it.getLong(0))
       assertEquals("Alec", it.getString(1))
+      QueryResult.Unit
     }
 
     insert {
@@ -120,19 +123,21 @@ abstract class DriverTest {
     assertEquals(1, changes())
 
     query {
-      assertTrue(it.next())
+      assertTrue(it.next().value)
       assertEquals(1, it.getLong(0))
       assertEquals("Alec", it.getString(1))
-      assertTrue(it.next())
+      assertTrue(it.next().value)
       assertEquals(2, it.getLong(0))
       assertEquals("Jake", it.getString(1))
+      QueryResult.Unit
     }
 
     driver.execute(5, "DELETE FROM test", 0)
     assertEquals(2, changes())
 
     query {
-      assertFalse(it.next())
+      assertFalse(it.next().value)
+      QueryResult.Unit
     }
   }
 
@@ -153,7 +158,7 @@ abstract class DriverTest {
     }
     assertEquals(1, changes())
 
-    fun query(binders: SqlPreparedStatement.() -> Unit, mapper: (SqlCursor) -> Unit) {
+    fun query(binders: SqlPreparedStatement.() -> Unit, mapper: (SqlCursor) -> QueryResult<Unit>) {
       driver.executeQuery(6, "SELECT * FROM test WHERE value = ?", mapper, 1, binders)
     }
 
@@ -162,9 +167,10 @@ abstract class DriverTest {
         bindString(0, "Jake")
       },
       mapper = {
-        assertTrue(it.next())
+        assertTrue(it.next().value)
         assertEquals(2, it.getLong(0))
         assertEquals("Jake", it.getString(1))
+        QueryResult.Unit
       },
     )
 
@@ -174,9 +180,10 @@ abstract class DriverTest {
         bindString(0, "Jake")
       },
       mapper = {
-        assertTrue(it.next())
+        assertTrue(it.next().value)
         assertEquals(2, it.getLong(0))
         assertEquals("Jake", it.getString(1))
+        QueryResult.Unit
       },
     )
   }
@@ -194,13 +201,14 @@ abstract class DriverTest {
     }
     assertEquals(1, changes())
 
-    val mapper: (SqlCursor) -> Unit = {
-      assertTrue(it.next())
+    val mapper: (SqlCursor) -> QueryResult<Unit> = {
+      assertTrue(it.next().value)
       assertEquals(1, it.getLong(0))
       assertNull(it.getLong(1))
       assertNull(it.getString(2))
       assertNull(it.getBytes(3))
       assertNull(it.getDouble(4))
+      QueryResult.Unit
     }
     driver.executeQuery(8, "SELECT * FROM nullability_test", mapper, 0)
   }

drivers/driver-test/src/commonMain/kotlin/com/squareup/sqldelight/driver/test/QueryTest.kt

@@ -174,7 +174,7 @@ abstract class QueryTest {
 
   private fun testDataQuery(): Query<TestData> {
     return object : Query<TestData>(mapper) {
-      override fun <R> execute(mapper: (SqlCursor) -> R): QueryResult<R> {
+      override fun <R> execute(mapper: (SqlCursor) -> QueryResult<R>): QueryResult<R> {
         return driver.executeQuery(0, "SELECT * FROM test", mapper, 0, null)
       }
 

drivers/jdbc-driver/src/main/kotlin/app/cash/sqldelight/driver/jdbc/JdbcDriver.kt

@@ -141,17 +141,15 @@ abstract class JdbcDriver : SqlDriver, ConnectionManager {
   override fun <R> executeQuery(
     identifier: Int?,
     sql: String,
-    mapper: (SqlCursor) -> R,
+    mapper: (SqlCursor) -> QueryResult<R>,
     parameters: Int,
     binders: (SqlPreparedStatement.() -> Unit)?,
   ): QueryResult<R> {
     val (connection, onClose) = connectionAndClose()
     try {
-      return QueryResult.Value(
-        JdbcPreparedStatement(connection.prepareStatement(sql))
-          .apply { if (binders != null) this.binders() }
-          .executeQuery(mapper),
-      )
+      return JdbcPreparedStatement(connection.prepareStatement(sql))
+        .apply { if (binders != null) this.binders() }
+        .executeQuery(mapper)
     } finally {
       onClose()
     }
@@ -310,5 +308,5 @@ class JdbcCursor(val resultSet: ResultSet) : SqlCursor {
   private fun <T> getAtIndex(index: Int, converter: (Int) -> T): T? =
     converter(index + 1).takeUnless { resultSet.wasNull() }
 
-  override fun next() = resultSet.next()
+  override fun next(): QueryResult.Value<Boolean> = QueryResult.Value(resultSet.next())
 }

drivers/native-driver/src/nativeMain/kotlin/app/cash/sqldelight/driver/native/NativeSqlDatabase.kt

@@ -63,14 +63,12 @@ sealed class ConnectionWrapper : SqlDriver {
   final override fun <R> executeQuery(
     identifier: Int?,
     sql: String,
-    mapper: (SqlCursor) -> R,
+    mapper: (SqlCursor) -> QueryResult<R>,
     parameters: Int,
     binders: (SqlPreparedStatement.() -> Unit)?,
-  ): QueryResult<R> = QueryResult.Value(
-    accessStatement(true, identifier, sql, binders) { statement ->
-      mapper(SqliterSqlCursor(statement.query()))
-    },
-  )
+  ): QueryResult<R> = accessStatement(true, identifier, sql, binders) { statement ->
+    mapper(SqliterSqlCursor(statement.query()))
+  }
 }
 
 /**

drivers/native-driver/src/nativeMain/kotlin/app/cash/sqldelight/driver/native/SqliterSqlCursor.kt

@@ -1,5 +1,6 @@
 package app.cash.sqldelight.driver.native
 
+import app.cash.sqldelight.db.QueryResult
 import app.cash.sqldelight.db.SqlCursor
 import co.touchlab.sqliter.Cursor
 import co.touchlab.sqliter.getBytesOrNull
@@ -25,5 +26,5 @@ internal class SqliterSqlCursor(private val cursor: Cursor) : SqlCursor {
     return (cursor.getLongOrNull(index) ?: return null) == 1L
   }
 
-  override fun next(): Boolean = cursor.next()
+  override fun next(): QueryResult.Value<Boolean> = QueryResult.Value(cursor.next())
 }

drivers/native-driver/src/nativeTest/kotlin/com/squareup/sqldelight/drivers/native/connectionpool/BaseConcurrencyTest.kt

@@ -20,7 +20,7 @@ abstract class BaseConcurrencyTest {
     return myDriver.executeQuery(
       0,
       "SELECT count(*) FROM test",
-      { it.next(); it.getLong(0)!! },
+      { it.next(); QueryResult.Value(it.getLong(0)!!) },
       0,
     ).value
   }

drivers/native-driver/src/nativeTest/kotlin/com/squareup/sqldelight/drivers/native/connectionpool/WalConcurrencyTest.kt

@@ -103,7 +103,7 @@ class WalConcurrencyTest : BaseConcurrencyTest() {
 
   private fun testDataQuery(): Query<TestData> {
     return object : Query<TestData>(mapper) {
-      override fun <R> execute(mapper: (SqlCursor) -> R): QueryResult<R> {
+      override fun <R> execute(mapper: (SqlCursor) -> QueryResult<R>): QueryResult<R> {
         return driver.executeQuery(0, "SELECT * FROM test", mapper, 0, null)
       }
 

drivers/r2dbc-driver/src/main/kotlin/app/cash/sqldelight/driver/r2dbc/R2dbcDriver.kt

@@ -17,7 +17,7 @@ class R2dbcDriver(val connection: Connection) : SqlDriver {
   override fun <R> executeQuery(
     identifier: Int?,
     sql: String,
-    mapper: (SqlCursor) -> R,
+    mapper: (SqlCursor) -> QueryResult<R>,
     parameters: Int,
     binders: (SqlPreparedStatement.() -> Unit)?,
   ): QueryResult<R> {
@@ -32,7 +32,7 @@ class R2dbcDriver(val connection: Connection) : SqlDriver {
         List(rowMetadata.columnMetadatas.size) { index -> row.get(index) }
       }.asFlow().toList()
 
-      return@AsyncValue mapper(R2dbcCursor(rowSet))
+      return@AsyncValue mapper(R2dbcCursor(rowSet)).await()
     }
   }
 
@@ -157,7 +157,7 @@ class R2dbcCursor(val rowSet: List<List<Any?>>) : SqlCursor {
   var row = -1
     private set
 
-  override fun next(): Boolean = ++row < rowSet.size
+  override fun next(): QueryResult.Value<Boolean> = QueryResult.Value(++row < rowSet.size)
 
   override fun getString(index: Int): String? = rowSet[row][index] as String?
 

drivers/sqljs-driver/src/jsMain/kotlin/app/cash/sqldelight/driver/sqljs/JsSqlDriver.kt

@@ -50,7 +50,7 @@ class JsSqlDriver(private val db: Database) : SqlDriver {
   override fun <R> executeQuery(
     identifier: Int?,
     sql: String,
-    mapper: (SqlCursor) -> R,
+    mapper: (SqlCursor) -> QueryResult<R>,
     parameters: Int,
     binders: (SqlPreparedStatement.() -> Unit)?,
   ): QueryResult<R> {
@@ -60,7 +60,7 @@ class JsSqlDriver(private val db: Database) : SqlDriver {
     }
 
     return try {
-      QueryResult.Value(mapper(cursor))
+      mapper(cursor)
     } finally {
       cursor.close()
     }
@@ -120,7 +120,7 @@ class JsSqlDriver(private val db: Database) : SqlDriver {
 }
 
 private class JsSqlCursor(private val statement: Statement) : SqlCursor {
-  override fun next(): Boolean = statement.step()
+  override fun next(): QueryResult.Value<Boolean> = QueryResult.Value(statement.step())
   override fun getString(index: Int): String? = statement.get()[index]
   override fun getLong(index: Int): Long? = (statement.get()[index] as? Double)?.toLong()
   override fun getBytes(index: Int): ByteArray? = (statement.get()[index] as? Uint8Array)?.let {