Handle tmp file deletion

Signed-off-by: Shreyansh Ray <[email protected]>

server/src/main/java/org/opensearch/index/store/CompositeDirectory.java

@@ -108,11 +108,15 @@ public String[] listAll() throws IOException {
     @Override
     public void deleteFile(String name) throws IOException {
         logger.trace("deleteFile() called {}", name);
-        /*
-        Not deleting from localDirectory directly since it causes a race condition when the localDirectory deletes a file, and it ends up in pendingDeletion state.
-        Meanwhile, fileCache on removal deletes the file directly via the Files class and later when the directory tries to delete the files pending for deletion (which happens before creating a new file), it causes NoSuchFileException and new file creation fails
-         */
-        fileCache.remove(localDirectory.getDirectory().resolve(name));
+        if (isTempFile(name)) {
+            localDirectory.deleteFile(name);
+        } else {
+            /*
+            Not deleting from localDirectory directly since it causes a race condition when the localDirectory deletes a file, and it ends up in pendingDeletion state.
+            Meanwhile, fileCache on removal deletes the file directly via the Files class and later when the directory tries to delete the files pending for deletion (which happens before creating a new file), it causes NoSuchFileException and new file creation fails
+            */
+            fileCache.remove(localDirectory.getDirectory().resolve(name));
+        }
     }
 
     /**

server/src/test/java/org/opensearch/index/store/CompositeDirectoryTests.java

@@ -28,6 +28,7 @@
 import java.util.Map;
 
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.ArgumentMatchers.startsWith;
 import static org.mockito.Mockito.mock;
@@ -60,9 +61,12 @@ public void testListAll() throws IOException {
     public void testDeleteFile() throws IOException {
         Path basePath = mock(Path.class);
         Path resolvedPath = mock(Path.class);
-        when(basePath.resolve("_0.si")).thenReturn(resolvedPath);
+        when(basePath.resolve(anyString())).thenReturn(resolvedPath);
         when(localDirectory.getDirectory()).thenReturn(basePath);
 
+        compositeDirectory.deleteFile("_0.tmp");
+        verify(localDirectory).deleteFile("_0.tmp");
+
         compositeDirectory.deleteFile("_0.si");
         verify(fileCache).remove(resolvedPath);
     }