Make SecondaryCache Customizable (#8480)

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8480

Reviewed By: zhichao-cao

Differential Revision: D29528740

Pulled By: mrambacher

fbshipit-source-id: fd0f70d15f66611c8498257a9973f7e98ca13839

HISTORY.md

@@ -17,6 +17,7 @@
 
 ### Public API change
 * Added APIs to the Customizable class to allow developers to create their own Customizable classes.  Created the utilities/customizable_util.h file to contain helper methods for developing new Customizable classes.
+* Change signature of SecondaryCache::Name().  Make SecondaryCache customizable and add SecondaryCache::CreateFromString method.
 ## 6.22.0 (2021-06-18)
 ### Behavior Changes
 * Added two additional tickers, MEMTABLE_PAYLOAD_BYTES_AT_FLUSH and MEMTABLE_GARBAGE_BYTES_AT_FLUSH. These stats can be used to estimate the ratio of "garbage" (outdated) bytes in the memtable that are discarded at flush time.

cache/cache.cc

@@ -10,6 +10,8 @@
 #include "rocksdb/cache.h"
 
 #include "cache/lru_cache.h"
+#include "rocksdb/secondary_cache.h"
+#include "rocksdb/utilities/customizable_util.h"
 #include "rocksdb/utilities/options_type.h"
 #include "util/string_util.h"
 
@@ -34,6 +36,13 @@ static std::unordered_map<std::string, OptionTypeInfo>
 };
 #endif  // ROCKSDB_LITE
 
+Status SecondaryCache::CreateFromString(
+    const ConfigOptions& config_options, const std::string& value,
+    std::shared_ptr<SecondaryCache>* result) {
+  return LoadSharedObject<SecondaryCache>(config_options, value, nullptr,
+                                          result);
+}
+
 Status Cache::CreateFromString(const ConfigOptions& config_options,
                                const std::string& value,
                                std::shared_ptr<Cache>* result) {

cache/cache_bench_tool.cc

@@ -13,11 +13,11 @@
 #include "monitoring/histogram.h"
 #include "port/port.h"
 #include "rocksdb/cache.h"
+#include "rocksdb/convenience.h"
 #include "rocksdb/db.h"
 #include "rocksdb/env.h"
 #include "rocksdb/secondary_cache.h"
 #include "rocksdb/system_clock.h"
-#include "rocksdb/utilities/object_registry.h"
 #include "table/block_based/cachable_entry.h"
 #include "util/coding.h"
 #include "util/gflags_compat.h"
@@ -233,9 +233,8 @@ class CacheBench {
       LRUCacheOptions opts(FLAGS_cache_size, FLAGS_num_shard_bits, false, 0.5);
 #ifndef ROCKSDB_LITE
       if (!FLAGS_secondary_cache_uri.empty()) {
-        Status s =
-            ObjectRegistry::NewInstance()->NewSharedObject<SecondaryCache>(
-                FLAGS_secondary_cache_uri, &secondary_cache);
+        Status s = SecondaryCache::CreateFromString(
+            ConfigOptions(), FLAGS_secondary_cache_uri, &secondary_cache);
         if (secondary_cache == nullptr) {
           fprintf(
               stderr,

cache/lru_cache_test.cc

@@ -224,7 +224,7 @@ class TestSecondaryCache : public SecondaryCache {
   }
   ~TestSecondaryCache() override { cache_.reset(); }
 
-  std::string Name() override { return "TestSecondaryCache"; }
+  const char* Name() const override { return "TestSecondaryCache"; }
 
   void InjectFailure() { inject_failure_ = true; }
 

db_stress_tool/db_stress_test_base.cc

@@ -119,6 +119,7 @@ StressTest::~StressTest() {
 
 std::shared_ptr<Cache> StressTest::NewCache(size_t capacity,
                                             int32_t num_shard_bits) {
+  ConfigOptions config_options;
   if (capacity <= 0) {
     return nullptr;
   }
@@ -136,8 +137,8 @@ std::shared_ptr<Cache> StressTest::NewCache(size_t capacity,
 #ifndef ROCKSDB_LITE
     std::shared_ptr<SecondaryCache> secondary_cache;
     if (!FLAGS_secondary_cache_uri.empty()) {
-      Status s = ObjectRegistry::NewInstance()->NewSharedObject<SecondaryCache>(
-          FLAGS_secondary_cache_uri, &secondary_cache);
+      Status s = SecondaryCache::CreateFromString(
+          config_options, FLAGS_secondary_cache_uri, &secondary_cache);
       if (secondary_cache == nullptr) {
         fprintf(stderr,
                 "No secondary cache registered matching string: %s status=%s\n",

include/rocksdb/secondary_cache.h

@@ -10,6 +10,7 @@
 #include <string>
 
 #include "rocksdb/cache.h"
+#include "rocksdb/customizable.h"
 #include "rocksdb/slice.h"
 #include "rocksdb/statistics.h"
 #include "rocksdb/status.h"
@@ -42,13 +43,14 @@ class SecondaryCacheResultHandle {
 //
 // Cache interface for caching blocks on a secondary tier (which can include
 // non-volatile media, or alternate forms of caching such as compressed data)
-class SecondaryCache {
+class SecondaryCache : public Customizable {
  public:
   virtual ~SecondaryCache() {}
 
-  virtual std::string Name() = 0;
-
-  static const std::string Type() { return "SecondaryCache"; }
+  static const char* Type() { return "SecondaryCache"; }
+  static Status CreateFromString(const ConfigOptions& config_options,
+                                 const std::string& id,
+                                 std::shared_ptr<SecondaryCache>* result);
 
   // Insert the given value into this cache. The value is not written
   // directly. Rather, the SaveToCallback provided by helper_cb will be

options/customizable_test.cc

@@ -18,6 +18,7 @@
 #include "options/options_helper.h"
 #include "options/options_parser.h"
 #include "rocksdb/convenience.h"
+#include "rocksdb/secondary_cache.h"
 #include "rocksdb/utilities/customizable_util.h"
 #include "rocksdb/utilities/object_registry.h"
 #include "rocksdb/utilities/options_type.h"
@@ -870,6 +871,27 @@ TEST_F(CustomizableTest, MutableOptionsTest) {
 }
 #endif  // !ROCKSDB_LITE
 
+class TestSecondaryCache : public SecondaryCache {
+ public:
+  const char* Name() const override { return kClassName(); }
+  static const char* kClassName() { return "Test"; }
+  Status Insert(const Slice& /*key*/, void* /*value*/,
+                const Cache::CacheItemHelper* /*helper*/) override {
+    return Status::NotSupported();
+  }
+  std::unique_ptr<SecondaryCacheResultHandle> Lookup(
+      const Slice& /*key*/, const Cache::CreateCallback& /*create_cb*/,
+      bool /*wait*/) override {
+    return nullptr;
+  }
+  void Erase(const Slice& /*key*/) override {}
+
+  // Wait for a collection of handles to become ready
+  void WaitAll(std::vector<SecondaryCacheResultHandle*> /*handles*/) override {}
+
+  std::string GetPrintableOptions() const override { return ""; }
+};
+
 #ifndef ROCKSDB_LITE
 // This method loads existing test classes into the ObjectRegistry
 static int RegisterTestObjects(ObjectLibrary& library,
@@ -898,6 +920,13 @@ static int RegisterLocalObjects(ObjectLibrary& library,
                                 const std::string& /*arg*/) {
   size_t num_types;
   // Load any locally defined objects here
+  library.Register<SecondaryCache>(
+      TestSecondaryCache::kClassName(),
+      [](const std::string& /*uri*/, std::unique_ptr<SecondaryCache>* guard,
+         std::string* /* errmsg */) {
+        guard->reset(new TestSecondaryCache());
+        return guard->get();
+      });
   return static_cast<int>(library.GetFactoryCount(&num_types));
 }
 #endif  // !ROCKSDB_LITE
@@ -941,6 +970,18 @@ TEST_F(LoadCustomizableTest, LoadTableFactoryTest) {
   }
 }
 
+TEST_F(LoadCustomizableTest, LoadSecondaryCacheTest) {
+  std::shared_ptr<SecondaryCache> result;
+  ASSERT_NOK(SecondaryCache::CreateFromString(
+      config_options_, TestSecondaryCache::kClassName(), &result));
+  if (RegisterTests("Test")) {
+    ASSERT_OK(SecondaryCache::CreateFromString(
+        config_options_, TestSecondaryCache::kClassName(), &result));
+    ASSERT_NE(result, nullptr);
+    ASSERT_STREQ(result->Name(), TestSecondaryCache::kClassName());
+  }
+}
+
 TEST_F(LoadCustomizableTest, LoadComparatorTest) {
   const Comparator* bytewise = BytewiseComparator();
   const Comparator* reverse = ReverseBytewiseComparator();

tools/db_bench_tool.cc

@@ -2869,9 +2869,8 @@ class Benchmark {
       }
 #ifndef ROCKSDB_LITE
       if (!FLAGS_secondary_cache_uri.empty()) {
-        Status s =
-            ObjectRegistry::NewInstance()->NewSharedObject<SecondaryCache>(
-                FLAGS_secondary_cache_uri, &secondary_cache);
+        Status s = SecondaryCache::CreateFromString(
+            ConfigOptions(), FLAGS_secondary_cache_uri, &secondary_cache);
         if (secondary_cache == nullptr) {
           fprintf(
               stderr,