fix wrong property after restart (#82)

Signed-off-by: Connor1996 <zbk602423539@gmail.com>

src/db_impl.cc

@@ -256,6 +256,10 @@ Status TitanDBImpl::Open(const std::vector<TitanCFDescriptor>& descs,
   }
   if (!s.ok()) return s;
 
+  if (stats_.get()) {
+    stats_->Initialize(column_families);
+  }
+
   s = blob_file_set_->Open(column_families);
   if (!s.ok()) return s;
 
@@ -268,9 +272,6 @@ Status TitanDBImpl::Open(const std::vector<TitanCFDescriptor>& descs,
   s = DB::Open(db_options_, dbname_, base_descs, handles, &db_);
   if (s.ok()) {
     db_impl_ = reinterpret_cast<DBImpl*>(db_->GetRootDB());
-    if (stats_.get()) {
-      stats_->Initialize(column_families);
-    }
     ROCKS_LOG_INFO(db_options_.info_log, "Titan DB open.");
     ROCKS_LOG_HEADER(db_options_.info_log, "Titan git sha: %s",
                      titan_build_git_sha);

src/titan_db_test.cc

@@ -13,6 +13,7 @@
 #include "blob_file_size_collector.h"
 #include "db_impl.h"
 #include "db_iter.h"
+#include "monitoring/statistics.h"
 #include "titan/db.h"
 #include "titan_fault_injection_test_env.h"
 
@@ -38,6 +39,7 @@ class TitanDBTest : public testing::Test {
     options_.merge_small_file_threshold = 0;
     options_.disable_background_gc = true;
     options_.blob_file_compression = CompressionType::kLZ4Compression;
+    options_.statistics = CreateDBStatistics();
     DeleteDir(env_, options_.dirname);
     DeleteDir(env_, dbname_);
   }
@@ -129,6 +131,10 @@ class TitanDBTest : public testing::Test {
     }
   }
 
+  bool GetIntProperty(const Slice& property, uint64_t* value) {
+    return db_->GetIntProperty(property, value);
+  }
+
   std::weak_ptr<BlobStorage> GetBlobStorage(
       ColumnFamilyHandle* cf_handle = nullptr) {
     if (cf_handle == nullptr) {
@@ -367,6 +373,20 @@ TEST_F(TitanDBTest, DBIterSeek) {
   }
 }
 
+TEST_F(TitanDBTest, GetProperty) {
+  Open();
+  for (uint64_t k = 1; k <= 100; k++) {
+    Put(k);
+  }
+  Flush();
+  uint64_t value;
+  ASSERT_TRUE(GetIntProperty(TitanDB::Properties::kNumLiveBlobFile, &value));
+  ASSERT_EQ(value, 1);
+  Reopen();
+  ASSERT_TRUE(GetIntProperty(TitanDB::Properties::kNumLiveBlobFile, &value));
+  ASSERT_EQ(value, 1);
+}
+
 TEST_F(TitanDBTest, Snapshot) {
   Open();
   std::map<std::string, std::string> data;