From 177ff0c9cbcb5f56766678fb1b49ad52f0b59f3a Mon Sep 17 00:00:00 2001
From: Maciej Szeszko <mszeszko@meta.com>
Date: Wed, 22 Jan 2025 13:11:56 -0800
Subject: [PATCH] WIP

---
 .../java/org/rocksdb/EventListenerTest.java   | 71 +++++++++++++++----
 1 file changed, 57 insertions(+), 14 deletions(-)

diff --git a/java/src/test/java/org/rocksdb/EventListenerTest.java b/java/src/test/java/org/rocksdb/EventListenerTest.java
index 8e36a230298f..7a32beb885ec 100644
--- a/java/src/test/java/org/rocksdb/EventListenerTest.java
+++ b/java/src/test/java/org/rocksdb/EventListenerTest.java
@@ -73,23 +73,66 @@ public void onFlushBegin(final RocksDB rocksDb, final FlushJobInfo flushJobInfo)
     flushDb(onFlushBeginListener, wasCbCalled);
   }
 
+
+  // TODO(mszeszko): This is just a temporary copy-pasta from RocksDBTest.java
+  // to see if we can trigger on file table deletion callback. If it works,
+  // we'll use similar but simpler approach in the final version.
   void deleteTableFile(final AbstractEventListener el, final AtomicBoolean wasCbCalled)
       throws RocksDBException {
-    try (final Options opt =
-             new Options().setCreateIfMissing(true).setListeners(Collections.singletonList(el));
+    final int KEY_SIZE = 20;
+    final int VALUE_SIZE = 1000;
+    final int FILE_SIZE = 64000;
+    final int NUM_FILES = 10;
+
+    final int KEY_INTERVAL = 10000;
+    /*
+     * Intention of these options is to end up reliably with 10 files
+     * we will be deleting using deleteFilesInRange.
+     * It is writing roughly number of keys that will fit in 10 files (target size)
+     * It is writing interleaved so that files from memory on L0 will overlap
+     * Then compaction cleans everything, and we should end up with 10 files
+     */
+    try (final Options opt = new Options()
+                                 .setCreateIfMissing(true)
+                                 .setCompressionType(CompressionType.NO_COMPRESSION)
+                                 .setTargetFileSizeBase(FILE_SIZE)
+                                 .setWriteBufferSize(FILE_SIZE / 2)
+                                 .setDisableAutoCompactions(true)
+                                 .setLevelCompactionDynamicLevelBytes(false);
          final RocksDB db = RocksDB.open(opt, dbFolder.getRoot().getAbsolutePath())) {
-      assertThat(db).isNotNull();
-      final byte[] value = new byte[24];
-      rand.nextBytes(value);
-      db.put("testKey".getBytes(), value);
-      final RocksDB.LiveFiles liveFiles = db.getLiveFiles();
-      assertThat(liveFiles).isNotNull();
-      assertThat(liveFiles.files).isNotNull();
-      assertThat(liveFiles.files.isEmpty()).isFalse();
-      db.delete("testKey".getBytes());
-      final FlushOptions flushOptions = new FlushOptions();
-      db.flush(flushOptions);
-      db.compactRange("testKey".getBytes(), null);
+      final int records = FILE_SIZE / (KEY_SIZE + VALUE_SIZE);
+
+      // fill database with key/value pairs
+      final byte[] value = new byte[VALUE_SIZE];
+      int key_init = 0;
+      for (int o = 0; o < NUM_FILES; ++o) {
+        int int_key = key_init++;
+        for (int i = 0; i < records; ++i) {
+          int_key += KEY_INTERVAL;
+          rand.nextBytes(value);
+
+          db.put(String.format("%020d", int_key).getBytes(), value);
+        }
+      }
+      try (final FlushOptions flushOptions = new FlushOptions().setWaitForFlush(true)) {
+        db.flush(flushOptions);
+      }
+      db.compactRange();
+      // Make sure we do create one more L0 files.
+      assertThat(db.getProperty("rocksdb.num-files-at-level0")).isEqualTo("0");
+
+      // Should be 10, but we are OK with asserting +- 2
+      int files = Integer.parseInt(db.getProperty("rocksdb.num-files-at-level1"));
+      assertThat(files).isBetween(8, 12);
+
+      // Delete lower 60% (roughly). Result should be 5, but we are OK with asserting +- 2
+      // Important is that we know something was deleted (JNI call did something)
+      // Exact assertions are done in C++ unit tests
+      db.deleteFilesInRanges(null,
+          Arrays.asList(null, String.format("%020d", records * KEY_INTERVAL * 6 / 10).getBytes()),
+          false);
+      files = Integer.parseInt(db.getProperty("rocksdb.num-files-at-level1"));
+      assertThat(files).isBetween(3, 7);
       assertThat(wasCbCalled.get()).isTrue();
     }
   }