Make CompactionService derived from Customizable (facebook#8395)

Summary:
(1)Make CompactionService derived from Customizable by defining two extra functions that are needed, as described in customizable.h comment section
(2)Revise the MyTestCompactionService class in compaction_service_test.cc to satisfy the class inheritance requirement
(3)Specify namespace of ToString() in compaction_service_test.cc to avoid function collision with CompactionService's ancestor classes

Test did:
make -j24 compaction_service_test
./compaction_service_test

Pull Request resolved: facebook#8395

Reviewed By: jay-zhuang

Differential Revision: D29076068

Pulled By: hx235

fbshipit-source-id: c130100fa466939b3137e917f5fdc4b2ae8e37d4

db/compaction/compaction_service_test.cc

@@ -16,6 +16,10 @@ class MyTestCompactionService : public CompactionService {
                           std::shared_ptr<FileSystem> fs, Options& options)
       : db_path_(db_path), fs_(fs), options_(options) {}
 
+  static const char* kClassName() { return "MyTestCompactionService"; }
+
+  const char* Name() const override { return kClassName(); }
+
   CompactionServiceJobStatus Start(const std::string& compaction_service_input,
                                    int job_id) override {
     InstrumentedMutexLock l(&mutex_);
@@ -51,9 +55,9 @@ class MyTestCompactionService : public CompactionService {
     options_override.table_factory = options_.table_factory;
     options_override.sst_partitioner_factory = options_.sst_partitioner_factory;
 
-    Status s = DB::OpenAndCompact(db_path_, db_path_ + "/" + ToString(job_id),
-                                  compaction_input, compaction_service_result,
-                                  options_override);
+    Status s = DB::OpenAndCompact(
+        db_path_, db_path_ + "/" + ROCKSDB_NAMESPACE::ToString(job_id),
+        compaction_input, compaction_service_result, options_override);
     TEST_SYNC_POINT_CALLBACK("MyTestCompactionService::WaitForComplete::End",
                              compaction_service_result);
     compaction_num_.fetch_add(1);

include/rocksdb/options.h

@@ -20,6 +20,7 @@
 #include "rocksdb/advanced_options.h"
 #include "rocksdb/comparator.h"
 #include "rocksdb/compression_type.h"
+#include "rocksdb/customizable.h"
 #include "rocksdb/data_structure.h"
 #include "rocksdb/env.h"
 #include "rocksdb/file_checksum.h"
@@ -370,8 +371,13 @@ enum class CompactionServiceJobStatus : char {
   kUseLocal,  // TODO: Add support for use local compaction
 };
 
-class CompactionService {
+class CompactionService : public Customizable {
  public:
+  static const char* Type() { return "CompactionService"; }
+
+  // Returns the name of this compaction service.
+  virtual const char* Name() const = 0;
+
   // Start the compaction with input information, which can be passed to
   // `DB::OpenAndCompact()`.
   // job_id is pre-assigned, it will be reset after DB re-open.