leave closing iterators to GC again

Author: fm3

build.sbt

@@ -25,7 +25,7 @@ libraryDependencies ++= Seq(
   "io.grpc" % "grpc-netty" % scalapb.compiler.Version.grpcJavaVersion,
   "io.grpc" % "grpc-services" % scalapb.compiler.Version.grpcJavaVersion,
   "com.thesamet.scalapb" %% "scalapb-runtime-grpc" % scalapb.compiler.Version.scalapbVersion,
-  "org.rocksdb" % "rocksdbjni" % "7.9.2",
+  "org.rocksdb" % "rocksdbjni" % "5.11.3",
   "com.github.scopt" %% "scopt" % "3.7.0"
 )
 

src/main/scala/com/scalableminds/fossildb/db/RocksDBStore.scala

@@ -56,7 +56,7 @@ class RocksDBManager(dataDir: Path, columnFamilies: List[String], optionsFilePat
       Files.createDirectories(backupDir)
 
     RocksDB.loadLibrary()
-    val backupEngine = BackupEngine.open(Env.getDefault, new BackupEngineOptions(backupDir.toString))
+    val backupEngine = BackupEngine.open(Env.getDefault, new BackupableDBOptions(backupDir.toString))
     backupEngine.createNewBackup(db)
     backupEngine.purgeOldBackups(1)
     backupEngine.getBackupInfo.asScala.headOption.map(info => BackupInfo(info.backupId, info.timestamp, info.size))
@@ -66,7 +66,7 @@ class RocksDBManager(dataDir: Path, columnFamilies: List[String], optionsFilePat
     logger.info("Restoring from backup. RocksDB temporarily unavailable")
     close()
     RocksDB.loadLibrary()
-    val backupEngine = BackupEngine.open(Env.getDefault, new BackupEngineOptions(backupDir.toString))
+    val backupEngine = BackupEngine.open(Env.getDefault, new BackupableDBOptions(backupDir.toString))
     backupEngine.restoreDbFromLatestBackup(dataDir.toString, dataDir.toString, new RestoreOptions(true))
     logger.info("Restoring from backup complete. Reopening RocksDB")
   }
@@ -85,7 +85,6 @@ class RocksDBManager(dataDir: Path, columnFamilies: List[String], optionsFilePat
     newManager.columnFamilyHandles.foreach { case (name, handle) =>
       val dataIterator = getStoreForColumnFamily(name).get.scan("", None)
       dataIterator.foreach(el => newManager.db.put(handle, el.key.getBytes, el.value))
-      dataIterator.close()
     }
     logger.info("Writing data completed. Start compaction")
     newManager.db.compactRange()
@@ -112,8 +111,6 @@ class RocksDBKeyIterator(it: RocksIterator, prefix: Option[String]) extends Iter
     new String(it.key().map(_.toChar))
   }
 
-  def close(): Unit = it.close()
-
 }
 
 class RocksDBIterator(it: RocksIterator, prefix: Option[String]) extends Iterator[KeyValuePair[Array[Byte]]] {
@@ -126,8 +123,6 @@ class RocksDBIterator(it: RocksIterator, prefix: Option[String]) extends Iterato
     value
   }
 
-  def close(): Unit = it.close()
-
 }
 
 class RocksDBStore(db: RocksDB, handle: ColumnFamilyHandle) extends LazyLogging {

src/main/scala/com/scalableminds/fossildb/db/VersionedKeyValueStore.scala

@@ -52,8 +52,6 @@ class VersionFilterIterator(it: RocksDBIterator, version: Option[Long]) extends
     value
   }
 
-  def close(): Unit = it.close()
-
 }
 
 class KeyOnlyIterator[T](underlying: RocksDBStore, startAfterKey: Option[String]) extends Iterator[String] {
@@ -116,12 +114,9 @@ class VersionedKeyValueStore(underlying: RocksDBStore) {
   private def scanVersionValuePairs(key: String, version: Option[Long] = None): Iterator[VersionedKeyValuePair[Array[Byte]]] = {
     requireValidKey(key)
     val prefix = s"$key@"
-    val it = underlying.scan(version.map(VersionedKey(key, _).toString).getOrElse(prefix), Some(prefix))
-    val res = it.flatMap { pair =>
+    underlying.scan(version.map(VersionedKey(key, _).toString).getOrElse(prefix), Some(prefix)).flatMap { pair =>
       VersionedKey(pair.key).map(VersionedKeyValuePair(_, pair.value))
     }
-    it.close()
-    res
   }
 
   private def scanVersionsOnly(key: String, version: Option[Long] = None): Iterator[VersionedKey] = {
@@ -137,7 +132,6 @@ class VersionedKeyValueStore(underlying: RocksDBStore) {
     prefix.foreach{ p => requireValidKey(p)}
     val iterator: VersionFilterIterator = scanKeys(key, prefix, version)
     val asSequence = iterator.take(limit.getOrElse(Int.MaxValue)).toSeq
-    iterator.close()
     val keys = asSequence.map(_.key)
     val values = asSequence.map(_.value)
     val versions = asSequence.map(_.version)

src/test/scala/com/scalableminds/fossildb/FossilDBSuite.scala

@@ -24,7 +24,6 @@ class FossilDBSuite extends FlatSpec with BeforeAndAfterEach with TestHelpers wi
   private val healthClient = HealthGrpc.newBlockingStub(channel)
   private val collectionA = "collectionA"
   private val collectionB = "collectionB"
-  private val collectionC = "collectionC"
 
   private val testData1 = ByteString.copyFromUtf8("testData1")
   private val testData2 = ByteString.copyFromUtf8("testData2")