Add is-file-deletions-enabled property

Summary:
Add property 'rocksdb.is-file-deletions-enable'
	 which equals disable_delete_obsole_file_

Test Plan: make all check

Reviewers: sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22119

db/db_filesnapshot.cc

@@ -66,6 +66,10 @@ Status DBImpl::EnableFileDeletions(bool force) {
   return Status::OK();
 }
 
+int DBImpl::IsFileDeletionsEnabled() const {
+  return disable_delete_obsolete_files_;
+}
+
 Status DBImpl::GetLiveFiles(std::vector<std::string>& ret,
                             uint64_t* manifest_file_size,
                             bool flush_memtable) {

db/db_impl.cc

@@ -4468,7 +4468,7 @@ bool DBImpl::GetIntPropertyInternal(ColumnFamilyHandle* column_family,
 
   if (!need_out_of_mutex) {
     MutexLock l(&mutex_);
-    return cfd->internal_stats()->GetIntProperty(property_type, value);
+    return cfd->internal_stats()->GetIntProperty(property_type, value, this);
   } else {
     SuperVersion* sv = GetAndRefSuperVersion(cfd);
 

db/db_impl.h

@@ -127,6 +127,7 @@ class DBImpl : public DB {
 #ifndef ROCKSDB_LITE
   virtual Status DisableFileDeletions();
   virtual Status EnableFileDeletions(bool force);
+  virtual int IsFileDeletionsEnabled() const;
   // All the returned filenames start with "/"
   virtual Status GetLiveFiles(std::vector<std::string>&,
                               uint64_t* manifest_file_size,

db/db_test.cc

@@ -1149,6 +1149,31 @@ TEST(DBTest, Empty) {
 
     ASSERT_EQ("v1", Get(1, "foo"));
     env_->delay_sstable_sync_.Release_Store(nullptr);   // Release sync calls
+
+    ASSERT_OK(db_->DisableFileDeletions());
+    ASSERT_TRUE(
+        dbfull()->GetProperty("rocksdb.is-file-deletions-enabled", &num));
+    ASSERT_EQ("1", num);
+
+    ASSERT_OK(db_->DisableFileDeletions());
+    ASSERT_TRUE(
+        dbfull()->GetProperty("rocksdb.is-file-deletions-enabled", &num));
+    ASSERT_EQ("2", num);
+
+    ASSERT_OK(db_->DisableFileDeletions());
+    ASSERT_TRUE(
+        dbfull()->GetProperty("rocksdb.is-file-deletions-enabled", &num));
+    ASSERT_EQ("3", num);
+
+    ASSERT_OK(db_->EnableFileDeletions(false));
+    ASSERT_TRUE(
+        dbfull()->GetProperty("rocksdb.is-file-deletions-enabled", &num));
+    ASSERT_EQ("2", num);
+
+    ASSERT_OK(db_->EnableFileDeletions());
+    ASSERT_TRUE(
+        dbfull()->GetProperty("rocksdb.is-file-deletions-enabled", &num));
+    ASSERT_EQ("0", num);
   } while (ChangeOptions());
 }
 

db/internal_stats.cc

@@ -11,6 +11,7 @@
 #include <inttypes.h>
 #include <vector>
 #include "db/column_family.h"
+#include "db/db_impl.h"
 
 namespace rocksdb {
 
@@ -133,6 +134,8 @@ DBPropertyType GetPropertyType(const Slice& property, bool* is_int_property,
   } else if (in == "estimate-table-readers-mem") {
     *need_out_of_mutex = true;
     return kEstimatedUsageByTableReaders;
+  } else if (in == "is-file-deletions-enabled") {
+    return kIsFileDeletionEnabled;
   }
   return kUnknown;
 }
@@ -215,7 +218,7 @@ bool InternalStats::GetStringProperty(DBPropertyType property_type,
 }
 
 bool InternalStats::GetIntProperty(DBPropertyType property_type,
-                                   uint64_t* value) const {
+                                   uint64_t* value, DBImpl* db) const {
   Version* current = cfd_->current();
 
   switch (property_type) {
@@ -254,6 +257,9 @@ bool InternalStats::GetIntProperty(DBPropertyType property_type,
                cfd_->imm()->current()->GetTotalNumEntries() +
                current->GetEstimatedActiveKeys();
       return true;
+    case kIsFileDeletionEnabled:
+      *value = db->IsFileDeletionsEnabled();
+      return true;
     default:
       return false;
   }

db/internal_stats.h

@@ -42,6 +42,8 @@ enum DBPropertyType : uint32_t {
                                    // the immutable mem tables.
   kEstimatedNumKeys,  // Estimated total number of keys in the database.
   kEstimatedUsageByTableReaders,  // Estimated memory by table readers.
+  kIsFileDeletionEnabled,         // Equals disable_delete_obsolete_files_,
+                                  // 0 means file deletions enabled
 };
 
 extern DBPropertyType GetPropertyType(const Slice& property,
@@ -197,7 +199,8 @@ class InternalStats {
   bool GetStringProperty(DBPropertyType property_type, const Slice& property,
                          std::string* value);
 
-  bool GetIntProperty(DBPropertyType property_type, uint64_t* value) const;
+  bool GetIntProperty(DBPropertyType property_type, uint64_t* value,
+                      DBImpl* db) const;
 
   bool GetIntPropertyOutOfMutex(DBPropertyType property_type, Version* version,
                                 uint64_t* value) const;