From 172bab75c8549229b0ab468506feecb504923e34 Mon Sep 17 00:00:00 2001
From: Amogh Jahagirdar <amogh@tabular.io>
Date: Thu, 7 Sep 2023 11:06:09 -0700
Subject: [PATCH] Core: Add a validation API to DeleteFiles which validates
 files exist prior to attempting to deletion.

Simplify/improve the validation check

Use failMissingDeletePaths, more simplification
---
 .../java/org/apache/iceberg/DeleteFiles.java  | 11 +++++++
 .../org/apache/iceberg/StreamingDelete.java   | 15 +++++++++
 .../org/apache/iceberg/TestDeleteFiles.java   | 31 +++++++++++++++++++
 3 files changed, 57 insertions(+)

diff --git a/api/src/main/java/org/apache/iceberg/DeleteFiles.java b/api/src/main/java/org/apache/iceberg/DeleteFiles.java
index 74d31a6dad81..8a396920e03b 100644
--- a/api/src/main/java/org/apache/iceberg/DeleteFiles.java
+++ b/api/src/main/java/org/apache/iceberg/DeleteFiles.java
@@ -81,4 +81,15 @@ default DeleteFiles deleteFile(DataFile file) {
    * @return this for method chaining
    */
   DeleteFiles caseSensitive(boolean caseSensitive);
+
+  /**
+   * Enables validation that any files that are part of the deletion still exist when committing the
+   * operation.
+   *
+   * @return this for method chaining
+   */
+  default DeleteFiles validateFilesExist() {
+    throw new UnsupportedOperationException(
+        this.getClass().getName() + " doesn't implement validateFilesExist");
+  }
 }
diff --git a/core/src/main/java/org/apache/iceberg/StreamingDelete.java b/core/src/main/java/org/apache/iceberg/StreamingDelete.java
index 8ff7bb831ec9..df5a11bf31c5 100644
--- a/core/src/main/java/org/apache/iceberg/StreamingDelete.java
+++ b/core/src/main/java/org/apache/iceberg/StreamingDelete.java
@@ -28,6 +28,8 @@
  * CommitFailedException}.
  */
 public class StreamingDelete extends MergingSnapshotProducer<DeleteFiles> implements DeleteFiles {
+  private boolean validateFilesToDeleteExist = false;
+
   protected StreamingDelete(String tableName, TableOperations ops) {
     super(tableName, ops);
   }
@@ -60,9 +62,22 @@ public StreamingDelete deleteFromRowFilter(Expression expr) {
     return this;
   }
 
+  @Override
+  public DeleteFiles validateFilesExist() {
+    this.validateFilesToDeleteExist = true;
+    return this;
+  }
+
   @Override
   public StreamingDelete toBranch(String branch) {
     targetBranch(branch);
     return this;
   }
+
+  @Override
+  protected void validate(TableMetadata base, Snapshot parent) {
+    if (validateFilesToDeleteExist) {
+      failMissingDeletePaths();
+    }
+  }
 }
diff --git a/core/src/test/java/org/apache/iceberg/TestDeleteFiles.java b/core/src/test/java/org/apache/iceberg/TestDeleteFiles.java
index 4e4565306c00..63fc7010c49c 100644
--- a/core/src/test/java/org/apache/iceberg/TestDeleteFiles.java
+++ b/core/src/test/java/org/apache/iceberg/TestDeleteFiles.java
@@ -412,6 +412,37 @@ public void testDeleteWithCollision() {
         afterDeletePartitions);
   }
 
+  @Test
+  public void testDeleteValidateFileExistence() {
+    commit(table, table.newFastAppend().appendFile(FILE_B), branch);
+    Snapshot delete =
+        commit(table, table.newDelete().deleteFile(FILE_B).validateFilesExist(), branch);
+    validateManifestEntries(
+        Iterables.getOnlyElement(delete.allManifests(FILE_IO)),
+        ids(delete.snapshotId()),
+        files(FILE_B),
+        statuses(Status.DELETED));
+
+    Assertions.assertThatThrownBy(
+            () -> commit(table, table.newDelete().deleteFile(FILE_B).validateFilesExist(), branch))
+        .isInstanceOf(ValidationException.class);
+  }
+
+  @Test
+  public void testDeleteFilesNoValidation() {
+    commit(table, table.newFastAppend().appendFile(FILE_B), branch);
+    Snapshot delete1 = commit(table, table.newDelete().deleteFile(FILE_B), branch);
+    validateManifestEntries(
+        Iterables.getOnlyElement(delete1.allManifests(FILE_IO)),
+        ids(delete1.snapshotId()),
+        files(FILE_B),
+        statuses(Status.DELETED));
+
+    Snapshot delete2 = commit(table, table.newDelete().deleteFile(FILE_B), branch);
+    Assertions.assertThat(delete2.allManifests(FILE_IO).isEmpty()).isTrue();
+    Assertions.assertThat(delete2.removedDataFiles(FILE_IO).iterator().hasNext()).isFalse();
+  }
+
   private static ByteBuffer longToBuffer(long value) {
     return ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN).putLong(0, value);
   }