From c5644d5c8b3699a28a83d751af9df5aaeeb9e9b5 Mon Sep 17 00:00:00 2001
From: Pavlo Tkach <3469726+ptkach@users.noreply.github.com>
Date: Wed, 16 Jul 2025 14:56:20 -0400
Subject: [PATCH] Add stream to the console dum download (#2783)

---
 .../console/ConsoleDumDownloadAction.java     | 36 ++++++++++---------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/core/src/main/java/google/registry/ui/server/console/ConsoleDumDownloadAction.java b/core/src/main/java/google/registry/ui/server/console/ConsoleDumDownloadAction.java
index 50586f3a3..1db652e2f 100644
--- a/core/src/main/java/google/registry/ui/server/console/ConsoleDumDownloadAction.java
+++ b/core/src/main/java/google/registry/ui/server/console/ConsoleDumDownloadAction.java
@@ -14,7 +14,6 @@
 
 package google.registry.ui.server.console;
 
-import static com.google.common.collect.ImmutableList.toImmutableList;
 import static google.registry.persistence.transaction.TransactionManagerFactory.tm;
 import static google.registry.request.Action.Method.GET;
 import static org.joda.time.DateTimeZone.UTC;
@@ -34,7 +33,6 @@ import google.registry.util.Clock;
 import jakarta.inject.Inject;
 import jakarta.servlet.http.HttpServletResponse;
 import java.io.IOException;
-import java.util.List;
 import org.apache.commons.csv.CSVFormat;
 import org.apache.commons.csv.CSVPrinter;
 import org.joda.time.DateTime;
@@ -106,21 +104,27 @@ public class ConsoleDumDownloadAction extends ConsoleApiAction {
   private void writeCsv(CSVPrinter printer) throws IOException {
     String sql = SQL_TEMPLATE.replaceAll(":now", clock.nowUtc().toString());
 
-    // We deliberately don't want to use ImmutableList.copyOf because underlying list may contain
-    // large amount of records and that will degrade performance.
-    List<String> queryResult =
-        tm().transact(
-                () ->
-                    tm().getEntityManager()
-                        .createNativeQuery(sql)
-                        .setParameter("registrarId", registrarId)
-                        .setHint("org.hibernate.fetchSize", 1000)
-                        .getResultList());
-
-    ImmutableList<String[]> formattedRecords =
-        queryResult.stream().map(r -> r.split(",")).collect(toImmutableList());
     printer.printRecord(
         ImmutableList.of("Domain Name", "Creation Time", "Expiration Time", "Domain Statuses"));
-    printer.printRecords(formattedRecords);
+
+    tm().transact(
+            () -> {
+              try (var resultStream =
+                  tm().getEntityManager()
+                      .createNativeQuery(sql, String.class)
+                      .setParameter("registrarId", registrarId)
+                      .setHint("org.hibernate.fetchSize", 1000)
+                      .getResultStream()) {
+
+                resultStream.forEach(
+                    row -> {
+                      try {
+                        printer.printRecord((Object[]) ((String) row).split(","));
+                      } catch (IOException e) {
+                        throw new RuntimeException(e);
+                      }
+                    });
+              }
+            });
   }
 }