From 15987f51f109002078d1edc529dfb7817f626c4c Mon Sep 17 00:00:00 2001
From: Abhishek Radhakrishnan <abhishek.rb19@gmail.com>
Date: Mon, 30 Sep 2024 07:22:49 -0700
Subject: [PATCH] Update Delta Kernel to 3.2.1 (#17179)

Updated Delta Kernel from 3.2.0 to 3.2.1. This upstream version bump contains fixes to reading long columns, class loader and better retry mechanism when reading checkpoint files.
---
 .../druid-deltalake-extensions/pom.xml        |  8 +-------
 .../druid/delta/input/DeltaInputSource.java   | 19 ++++---------------
 2 files changed, 5 insertions(+), 22 deletions(-)

diff --git a/extensions-contrib/druid-deltalake-extensions/pom.xml b/extensions-contrib/druid-deltalake-extensions/pom.xml
index 6a2b7cc0646c..6b923106e46b 100644
--- a/extensions-contrib/druid-deltalake-extensions/pom.xml
+++ b/extensions-contrib/druid-deltalake-extensions/pom.xml
@@ -35,7 +35,7 @@
   <modelVersion>4.0.0</modelVersion>
 
   <properties>
-    <delta-kernel.version>3.2.0</delta-kernel.version>
+    <delta-kernel.version>3.2.1</delta-kernel.version>
   </properties>
 
   <dependencies>
@@ -49,12 +49,6 @@
       <artifactId>delta-kernel-defaults</artifactId>
       <version>${delta-kernel.version}</version>
     </dependency>
-    <dependency>
-      <groupId>io.delta</groupId>
-      <artifactId>delta-storage</artifactId>
-      <version>${delta-kernel.version}</version>
-    </dependency>
-
     <dependency>
       <groupId>org.apache.hadoop</groupId>
       <artifactId>hadoop-client-api</artifactId>
diff --git a/extensions-contrib/druid-deltalake-extensions/src/main/java/org/apache/druid/delta/input/DeltaInputSource.java b/extensions-contrib/druid-deltalake-extensions/src/main/java/org/apache/druid/delta/input/DeltaInputSource.java
index c4c2f2668b04..4f255d020f76 100644
--- a/extensions-contrib/druid-deltalake-extensions/src/main/java/org/apache/druid/delta/input/DeltaInputSource.java
+++ b/extensions-contrib/druid-deltalake-extensions/src/main/java/org/apache/druid/delta/input/DeltaInputSource.java
@@ -42,7 +42,6 @@
 import io.delta.kernel.types.StructType;
 import io.delta.kernel.utils.CloseableIterator;
 import io.delta.kernel.utils.FileStatus;
-import io.delta.storage.LogStore;
 import org.apache.druid.data.input.ColumnsFilter;
 import org.apache.druid.data.input.InputFormat;
 import org.apache.druid.data.input.InputRowSchema;
@@ -340,20 +339,10 @@ private CloseableIterator<FilteredColumnarBatch> getTransformedDataIterator(
 
   private Snapshot getSnapshotForTable(final Table table, final Engine engine)
   {
-    // Setting the LogStore class loader before calling the Delta Kernel snapshot API is required as a workaround with
-    // the 3.2.0 Delta Kernel because the Kernel library cannot instantiate the LogStore class otherwise. Please see
-    // https://github.com/delta-io/delta/issues/3299 for details. This workaround can be removed once the issue is fixed.
-    final ClassLoader currCtxCl = Thread.currentThread().getContextClassLoader();
-    try {
-      Thread.currentThread().setContextClassLoader(LogStore.class.getClassLoader());
-      if (snapshotVersion != null) {
-        return table.getSnapshotAsOfVersion(engine, snapshotVersion);
-      } else {
-        return table.getLatestSnapshot(engine);
-      }
-    }
-    finally {
-      Thread.currentThread().setContextClassLoader(currCtxCl);
+    if (snapshotVersion != null) {
+      return table.getSnapshotAsOfVersion(engine, snapshotVersion);
+    } else {
+      return table.getLatestSnapshot(engine);
     }
   }