From d53f7ff69ac728f3080e71f0adceac27ee53db60 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=81=82=E4=BD=A9=E8=BD=A9?= <niepeixuan@bytedance.com>
Date: Thu, 17 Jun 2021 15:59:53 -0700
Subject: [PATCH] Add DeteleRange support for DBWithTTL (#8384)

Summary:
This commit is for enabling `DBWithTTL` to use `DeteleRange` which it cannot before.
As (int32_t)Timestamp is suffixed to values in `DBWithTTL`, there is no reason that it
cannot use the common used api. I added `DeleteRangeCF` in `DBWithTTLImpl::Write`
so that we can use `DeteleRange` normally. When we run code like
`dbWithTtl->DeleteRange(start, end)`, it executes`WriteBatchInternal::DeleteRange`
internally. Intended to fix https://github.com/facebook/rocksdb/issues/7218

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8384

Test Plan: added corresponded testing logic to existing unit test

Reviewed By: jay-zhuang

Differential Revision: D29176734

fbshipit-source-id: 6874ed979fc08e1d138149d03653e43a75f0e0e6
---
 HISTORY.md                   |  3 +++
 utilities/ttl/db_ttl_impl.cc |  5 +++++
 utilities/ttl/ttl_test.cc    | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/HISTORY.md b/HISTORY.md
index f7249818e..bcccc546c 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -10,6 +10,9 @@
 ### New Features
 * Marked the Ribbon filter and optimize_filters_for_memory features as production-ready, each enabling memory savings for Bloom-like filters. Use `NewRibbonFilterPolicy` in place of `NewBloomFilterPolicy` to use Ribbon filters instead of Bloom, or `ribbonfilter` in place of `bloomfilter` in configuration string.
 
+### New Features
+* Allow `DBWithTTL` to use `DeleteRange` api just like other DBs. `DeleteRangeCF()` which executes `WriteBatchInternal::DeleteRange()` has been added to the handler in `DBWithTTLImpl::Write()` to implement it.
+
 ## 6.21.0 (2021-05-21)
 ### Bug Fixes
 * Fixed a bug in handling file rename error in distributed/network file systems when the server succeeds but client returns error. The bug can cause CURRENT file to point to non-existing MANIFEST file, thus DB cannot be opened.
diff --git a/utilities/ttl/db_ttl_impl.cc b/utilities/ttl/db_ttl_impl.cc
index 0463025f8..917130ca1 100644
--- a/utilities/ttl/db_ttl_impl.cc
+++ b/utilities/ttl/db_ttl_impl.cc
@@ -304,6 +304,11 @@ Status DBWithTTLImpl::Write(const WriteOptions& opts, WriteBatch* updates) {
     Status DeleteCF(uint32_t column_family_id, const Slice& key) override {
       return WriteBatchInternal::Delete(&updates_ttl, column_family_id, key);
     }
+    Status DeleteRangeCF(uint32_t column_family_id, const Slice& begin_key,
+                         const Slice& end_key) override {
+      return WriteBatchInternal::DeleteRange(&updates_ttl, column_family_id,
+                                             begin_key, end_key);
+    }
     void LogData(const Slice& blob) override { updates_ttl.PutLogData(blob); }
 
    private:
diff --git a/utilities/ttl/ttl_test.cc b/utilities/ttl/ttl_test.cc
index 099ed6859..8e60fbc76 100644
--- a/utilities/ttl/ttl_test.cc
+++ b/utilities/ttl/ttl_test.cc
@@ -186,6 +186,18 @@ class TtlTest : public testing::Test {
     }
   }
 
+  // Runs a DeleteRange
+  void MakeDeleteRange(std::string start, std::string end,
+                       ColumnFamilyHandle* cf = nullptr) {
+    ASSERT_TRUE(db_ttl_);
+    static WriteOptions wops;
+    WriteBatch wb;
+    ASSERT_OK(cf == nullptr
+                  ? wb.DeleteRange(db_ttl_->DefaultColumnFamily(), start, end)
+                  : wb.DeleteRange(cf, start, end));
+    ASSERT_OK(db_ttl_->Write(wops, &wb));
+  }
+
   // checks the whole kvmap_ to return correct values using KeyMayExist
   void SimpleKeyMayExistCheck() {
     static ReadOptions ropts;
@@ -684,6 +696,29 @@ TEST_F(TtlTest, ChangeTtlOnOpenDb) {
   CloseTtl();
 }
 
+// Test DeleteRange for DBWithTtl
+TEST_F(TtlTest, DeleteRangeTest) {
+  OpenTtl();
+  ASSERT_OK(db_ttl_->Put(WriteOptions(), "a", "val"));
+  MakeDeleteRange("a", "b");
+  ASSERT_OK(db_ttl_->Put(WriteOptions(), "c", "val"));
+  MakeDeleteRange("b", "d");
+  ASSERT_OK(db_ttl_->Put(WriteOptions(), "e", "val"));
+  MakeDeleteRange("d", "e");
+  // first iteration verifies query correctness in memtable, second verifies
+  // query correctness for a single SST file
+  for (int i = 0; i < 2; i++) {
+    if (i > 0) {
+      ASSERT_OK(db_ttl_->Flush(FlushOptions()));
+    }
+    std::string value;
+    ASSERT_TRUE(db_ttl_->Get(ReadOptions(), "a", &value).IsNotFound());
+    ASSERT_TRUE(db_ttl_->Get(ReadOptions(), "c", &value).IsNotFound());
+    ASSERT_OK(db_ttl_->Get(ReadOptions(), "e", &value));
+  }
+  CloseTtl();
+}
+
 }  // namespace ROCKSDB_NAMESPACE
 
 // A black-box test for the ttl wrapper around rocksdb