Allow any ArrowReader implementation to be use for reading Arrow data

#627

Author: fb64

dataframe-arrow/build.gradle.kts

@@ -24,6 +24,8 @@ dependencies {
     testImplementation(libs.kotestAssertions) {
         exclude("org.jetbrains.kotlin", "kotlin-stdlib-jdk8")
     }
+    testImplementation(libs.arrow.c.data)
+    testImplementation(libs.duckdb.jdbc)
 }
 
 kotlinPublications {

dataframe-arrow/src/main/kotlin/org/jetbrains/kotlinx/dataframe/io/arrowReadingImpl.kt

@@ -317,7 +317,7 @@ internal fun DataFrame.Companion.readArrowImpl(
                         add(df)
                     }
                 }
-                is ArrowStreamReader -> {
+                else -> {
                     val root = reader.vectorSchemaRoot
                     val schema = root.schema
                     while (reader.loadNextBatch()) {

dataframe-arrow/src/test/kotlin/org/jetbrains/kotlinx/dataframe/io/ArrowKtTest.kt

@@ -11,6 +11,7 @@ import org.apache.arrow.vector.TimeStampSecVector
 import org.apache.arrow.vector.VectorSchemaRoot
 import org.apache.arrow.vector.ipc.ArrowFileReader
 import org.apache.arrow.vector.ipc.ArrowFileWriter
+import org.apache.arrow.vector.ipc.ArrowReader
 import org.apache.arrow.vector.ipc.ArrowStreamReader
 import org.apache.arrow.vector.ipc.ArrowStreamWriter
 import org.apache.arrow.vector.types.FloatingPointPrecision
@@ -21,6 +22,9 @@ import org.apache.arrow.vector.types.pojo.FieldType
 import org.apache.arrow.vector.types.pojo.Schema
 import org.apache.arrow.vector.util.ByteArrayReadableSeekableByteChannel
 import org.apache.arrow.vector.util.Text
+import org.duckdb.DuckDBConnection
+import org.duckdb.DuckDBResultSet
+import org.jetbrains.kotlinx.dataframe.AnyFrame
 import org.jetbrains.kotlinx.dataframe.DataColumn
 import org.jetbrains.kotlinx.dataframe.DataFrame
 import org.jetbrains.kotlinx.dataframe.api.NullabilityOptions
@@ -34,12 +38,14 @@ import org.jetbrains.kotlinx.dataframe.api.pathOf
 import org.jetbrains.kotlinx.dataframe.api.remove
 import org.jetbrains.kotlinx.dataframe.api.toColumn
 import org.jetbrains.kotlinx.dataframe.exceptions.TypeConverterNotFoundException
+import org.junit.Assert
 import org.junit.Test
 import java.io.ByteArrayInputStream
 import java.io.ByteArrayOutputStream
 import java.io.File
 import java.net.URL
 import java.nio.channels.Channels
+import java.sql.DriverManager
 import java.time.LocalDate
 import java.time.LocalDateTime
 import java.time.ZoneOffset
@@ -558,23 +564,26 @@ internal class ArrowKtTest {
         }
     }
 
-    @Test
-    fun testArrowReaderExtension() {
+    private fun expectedSimpleDataFrame(): AnyFrame {
         val dates = listOf(
-            LocalDateTime.of(2023, 11, 23, 9, 30, 25),
+            LocalDateTime.of(2020, 11, 23, 9, 30, 25),
             LocalDateTime.of(2015, 5, 25, 14, 20, 13),
             LocalDateTime.of(2013, 6, 19, 11, 20, 13),
             LocalDateTime.of(2000, 1, 1, 0, 0, 0)
         )
 
-        val expected = dataFrameOf(
+        return dataFrameOf(
             "string" to listOf("a", "b", "c", "d"),
             "int" to listOf(1, 2, 3, 4),
             "float" to listOf(1.0f, 2.0f, 3.0f, 4.0f),
             "double" to listOf(1.0, 2.0, 3.0, 4.0),
             "datetime" to dates
         )
+    }
 
+    @Test
+    fun testArrowReaderExtension() {
+        val expected = expectedSimpleDataFrame()
         val featherChannel = ByteArrayReadableSeekableByteChannel(expected.saveArrowFeatherToByteArray())
         val arrowFileReader = ArrowFileReader(featherChannel, RootAllocator())
         arrowFileReader.toDataFrame() shouldBe expected
@@ -583,4 +592,24 @@ internal class ArrowKtTest {
         val arrowStreamReader = ArrowStreamReader(ipcInputStream, RootAllocator())
         arrowStreamReader.toDataFrame() shouldBe expected
     }
+
+    @Test
+    fun testDuckDBArrowIntegration() {
+        val expected = expectedSimpleDataFrame()
+        val query = """
+            select 'a' as string, 1 as int, CAST(1.0 as FLOAT) as float, CAST(1.0 as DOUBLE) as double, TIMESTAMP '2020-11-23 09:30:25'  as datetime
+            UNION ALL SELECT 'b', 2, 2.0, 2.0, TIMESTAMP '2015-05-25 14:20:13'
+            UNION ALL SELECT 'c', 3, 3.0, 3.0, TIMESTAMP '2013-06-19 11:20:13'
+            UNION ALL SELECT 'd', 4, 4.0, 4.0, TIMESTAMP '2000-01-01 00:00:00'
+        """.trimIndent()
+
+        Class.forName("org.duckdb.DuckDBDriver")
+        val conn = DriverManager.getConnection("jdbc:duckdb:") as DuckDBConnection
+        conn.use {
+            val resultSet = it.createStatement().executeQuery(query) as DuckDBResultSet
+            val dbArrowReader = resultSet.arrowExportStream(RootAllocator(), 256) as ArrowReader
+            Assert.assertTrue(dbArrowReader.javaClass.name.equals("org.apache.arrow.c.ArrowArrayStreamReader"))
+            DataFrame.readArrow(dbArrowReader) shouldBe expected
+        }
+    }
 }

gradle/libs.versions.toml

@@ -56,6 +56,7 @@ shadow = "8.1.1"
 android-gradle-api = "7.3.1" # Can't be updated to 7.4.0+ due to Java 8 compatibility
 ktor-server-netty = "2.3.8"
 kotlin-compile-testing = "1.5.0"
+duckdb = "0.10.0"
 
 [libraries]
 ksp-gradle = { group = "com.google.devtools.ksp", name = "symbol-processing-gradle-plugin", version.ref = "ksp" }
@@ -97,6 +98,8 @@ jsoup = { group = "org.jsoup", name = "jsoup", version.ref = "jsoup" }
 arrow-format = { group = "org.apache.arrow", name = "arrow-format", version.ref = "arrow" }
 arrow-vector = { group = "org.apache.arrow", name = "arrow-vector", version.ref = "arrow" }
 arrow-memory = { group = "org.apache.arrow", name = "arrow-memory-unsafe", version.ref = "arrow" }
+arrow-c-data = { group = "org.apache.arrow", name = "arrow-c-data", version.ref = "arrow" }
+
 
 kotlinpoet = { group = "com.squareup", name = "kotlinpoet", version.ref = "kotlinpoet" }
 swagger = { group = "io.swagger.parser.v3", name = "swagger-parser", version.ref = "openapi" }
@@ -120,6 +123,7 @@ kotlin-jupyter-test-kit = { group = "org.jetbrains.kotlinx", name = "kotlin-jupy
 
 dataframe-symbol-processor = { group = "org.jetbrains.kotlinx.dataframe", name = "symbol-processor-all" }
 
+duckdb-jdbc = { group = "org.duckdb", name = "duckdb_jdbc", version.ref= "duckdb"}
 
 [plugins]
 jupyter-api = { id = "org.jetbrains.kotlin.jupyter.api", version.ref = "kotlinJupyter" }