feat:

1. rename app class
2. cli supports 'state' command, and print data dir & config file path
3. fix redundant WAL files remaining bug

src/main/scala/io/github/leibnizhu/tinylsm/LsmStorageInner.scala

@@ -26,7 +26,7 @@ object LsmStorageInner {
     val nextSstId = AtomicInteger(0)
     val blockCache = BlockCache.apply(128)
     val compactionController = CompactionController(options.compactionOptions)
-    val manifestFile = new File(path, "MANIFEST")
+    val manifestFile = new File(path, Manifest.fileName)
     val manifest = new Manifest(manifestFile, options.targetManifestSize)
     var lastCommitTs = 0L;
     if (manifestFile.exists()) {
@@ -70,17 +70,27 @@ object LsmStorageInner {
       log.info("{} SST opened", sstCnt)
 
       val newMemtableId = nextSstId.incrementAndGet()
+
       if (options.enableWal) {
         // 从 wal 恢复Memtable,到了这里，memTables 里面是从Manifest恢复的、没flush的Memtable
         var walCnt = 0
         for (mtId <- memTables) {
-          val memTable = MemTable.recoverFromWal(mtId, fileOfWal(path, mtId))
-          if (memTable.nonEmpty) {
-            state.immutableMemTables = memTable :: state.immutableMemTables
-            val memTableMaxTs = memTable.map.keySet().asScala.map(_.ts).max
-            lastCommitTs = lastCommitTs.max(memTableMaxTs)
-            walCnt += 1
+          val walFile = fileOfWal(path, mtId)
+          if (walFile.exists()) {
+            val memTable = MemTable.recoverFromWal(mtId, walFile)
+            if (memTable.nonEmpty) {
+              state.immutableMemTables = memTable :: state.immutableMemTables
+              val memTableMaxTs = memTable.map.keySet().asScala.map(_.ts).max
+              lastCommitTs = lastCommitTs.max(memTableMaxTs)
+              walCnt += 1
+            } else {
+              // 如果wal为空，那么对应的memtable不会加入到immutableMemTables，在下次flush的时候也不会被处理，所以wal可以删除
+              // 一般来说wal为空有两种情况：1.最新的Memtable，没有数据  2.手动强制flush了，flush的时候Memtable里没有数据
+              val deletedWal = walFile.delete()
+              log.info("Deleted empty wal file {} success: {}", walFile, deletedWal)
+            }
           }
+          // 有manifest记录，但没有wal文件，一般是wal文件为空、在上一次启动恢复的时候删除了
         }
         log.info("{} MemTable recovered from wal", walCnt)
         state.memTable = MemTable(newMemtableId, Some(fileOfWal(path, newMemtableId)))
@@ -516,7 +526,10 @@ private[tinylsm] case class LsmStorageInner(
     println()
   }
 
-  def dumpState(): String = state.dumpState()
+  def dumpState(): String =
+    s"""Data dir:\t${path.getAbsolutePath}
+Config file path:\t${Config.configFilePath}
+${state.dumpState()}"""
 
   def triggerFlush(): Unit = {
     val (memtableNum, numLimit) = state.read(st => (st.immutableMemTables.length, options.numMemTableLimit))

src/main/scala/io/github/leibnizhu/tinylsm/Manifest.scala

@@ -88,6 +88,10 @@ class Manifest(file: File, targetSize: Int = 1024) {
   }
 }
 
+object Manifest {
+  val fileName = "MANIFEST"
+}
+
 @JsonTypeInfo(
   use = JsonTypeInfo.Id.NAME,
   include = JsonTypeInfo.As.PROPERTY,

src/main/scala/io/github/leibnizhu/tinylsm/app/ApiCommands.scala

@@ -5,10 +5,9 @@ import akka.actor.typed.{ActorRef, Behavior}
 import akka.http.scaladsl.server.Directives.complete
 import akka.http.scaladsl.server.StandardRoute
 import io.github.leibnizhu.tinylsm.app.BizCode.*
-import io.github.leibnizhu.tinylsm.iterator.StorageIterator
 import io.github.leibnizhu.tinylsm.mvcc.Transaction
 import io.github.leibnizhu.tinylsm.utils.Bound
-import io.github.leibnizhu.tinylsm.{Key, MemTableEntry, MemTableValue, RawKey, TinyLsm}
+import io.github.leibnizhu.tinylsm.{Key, MemTableValue, TinyLsm}
 
 import java.util.StringJoiner
 

src/main/scala/io/github/leibnizhu/tinylsm/app/TinyLsmRpcServiceImpl.scala → src/main/scala/io/github/leibnizhu/tinylsm/app/GrpcServiceImpl.scala

@@ -3,18 +3,16 @@ package io.github.leibnizhu.tinylsm.app
 import akka.actor.typed.ActorSystem
 import com.google.protobuf.ByteString
 import io.github.leibnizhu.tinylsm.app.ApiCommands.*
-import io.github.leibnizhu.tinylsm.app.BizCode.{Success, TransactionInvalid, TransactionNotExists}
+import io.github.leibnizhu.tinylsm.app.BizCode.Success
 import io.github.leibnizhu.tinylsm.grpc.*
-import io.github.leibnizhu.tinylsm.iterator.StorageIterator
 import io.github.leibnizhu.tinylsm.mvcc.Transaction
 import io.github.leibnizhu.tinylsm.utils.Bound
-import io.github.leibnizhu.tinylsm.{Key, MemTableValue, RawKey, TinyLsm}
+import io.github.leibnizhu.tinylsm.{Key, MemTableValue, TinyLsm}
 
-import scala.collection.mutable.ArrayBuffer
 import scala.concurrent.Future
 
-class TinyLsmRpcServiceImpl(state: ApiCommands.InnerState,
-                            system: ActorSystem[_]) extends TinyLsmRpcService {
+class GrpcServiceImpl(state: ApiCommands.InnerState,
+                      system: ActorSystem[_]) extends TinyLsmRpcService {
 
   override def getKey(in: GetKeyRequest): Future[ValueReply] = {
     val response = GetByKey(in.key.toByteArray, in.tid, null).wrapBehavior(state)
@@ -86,7 +84,7 @@ class TinyLsmRpcServiceImpl(state: ApiCommands.InnerState,
   }
 }
 
-object TinyLsmRpcServiceImpl {
-  def apply(storage: TinyLsm, transactions: java.util.Map[Int, Transaction], system: ActorSystem[_]): TinyLsmRpcServiceImpl =
-    new TinyLsmRpcServiceImpl(ApiCommands.InnerState(storage, transactions), system)
+object GrpcServiceImpl {
+  def apply(storage: TinyLsm, transactions: java.util.Map[Int, Transaction], system: ActorSystem[_]): GrpcServiceImpl =
+    new GrpcServiceImpl(ApiCommands.InnerState(storage, transactions), system)
 }

src/main/scala/io/github/leibnizhu/tinylsm/app/TinyLsmHttpRoutes.scala → src/main/scala/io/github/leibnizhu/tinylsm/app/HttpRoutes.scala

@@ -7,13 +7,12 @@ import akka.http.scaladsl.server.Route
 import akka.util.Timeout
 import io.github.leibnizhu.tinylsm.app.ApiCommands.*
 import io.github.leibnizhu.tinylsm.utils.Bound
-import io.github.leibnizhu.tinylsm.{Key, MemTableValue}
 
 import java.time.Duration
 import scala.concurrent.Future
 
-class TinyLsmHttpRoutes(registry: ActorRef[ApiCommands.Command])
-                       (implicit val system: ActorSystem[_]) {
+class HttpRoutes(registry: ActorRef[ApiCommands.Command])
+                (implicit val system: ActorSystem[_]) {
 
   //#user-routes-class
 

src/main/scala/io/github/leibnizhu/tinylsm/app/TinyLsmCli.scala

@@ -64,7 +64,7 @@ object TinyLsmCli {
       case "commit" => cliContext.commitCurrentTxn()
       case "rollback" => cliContext.rollbackCurrentTxn()
       case "flush" => cliContext.flush()
-      case "status" => cliContext.status()
+      case "status" | "state" => cliContext.status()
       case _ => println(s"Unsupported command: '${words.head}', you can type :help for more information or <TAB> for auto complete")
   }
 
@@ -79,11 +79,11 @@ object TinyLsmCli {
       |  -p: TinyLSM port, default value is 9527.
       |Commands:
       |  get <key> : Get value by key.
-      |  delete <key> : Delete a key.
+      |  del|delete <key> : Delete a key.
       |  put <key> <value> : Put value by key.
       |  scan <Unbound|Excluded|Included> <fromKey> <Unbound|Excluded|Included> <toKey> : Scan by key range.
       |  flush : Force flush MemTable to SST.
-      |  status : Show TinyLSM status.
+      |  state|status : Show TinyLSM status.
       |  txn: Start a new transaction
       |  commit: Commit current transaction
       |  rollback: rollback current transaction

src/main/scala/io/github/leibnizhu/tinylsm/app/TinyLsmServer.scala

@@ -33,7 +33,7 @@ class TinyLsmServer(storage: TinyLsm, host: String, httpPort: Int, rpcPort: Int)
       val httpRegistry = TinyLsmHttpRegistry(storage, transactions).registry()
       val tinyLsmActor = context.spawn(httpRegistry, "TinyLsmActor")
       context.watch(tinyLsmActor)
-      val routes = new TinyLsmHttpRoutes(tinyLsmActor)(context.system)
+      val routes = new HttpRoutes(tinyLsmActor)(context.system)
       startHttpServer(routes.routes)(context.system)
       startRpcServer()(context.system)
       Behaviors.empty
@@ -63,7 +63,7 @@ class TinyLsmServer(storage: TinyLsm, host: String, httpPort: Int, rpcPort: Int)
     implicit val ec: ExecutionContext = system.executionContext
 
     val service: HttpRequest => Future[HttpResponse] =
-      TinyLsmRpcServiceHandler(TinyLsmRpcServiceImpl(storage, transactions, system))
+      TinyLsmRpcServiceHandler(GrpcServiceImpl(storage, transactions, system))
 
     val bound: Future[Http.ServerBinding] = Http()
       .newServerAt(host, rpcPort)

src/main/scala/io/github/leibnizhu/tinylsm/utils/Config.scala

@@ -83,17 +83,22 @@ object Config {
   }
 
   private def loadConfigFile(): Properties = {
-    val configFileEnvName = "TINY_LSM_CONFIG_FILE"
-    val configFileSysPropName = toPropertyName("CONFIG_FILE")
-    val configFile = System.getProperty(configFileSysPropName,
-      System.getenv().getOrDefault(configFileEnvName, "/etc/tinylsm/tinylsm.conf"))
+    val configFile: String = configFilePath
     val prop = Properties()
     if (new File(configFile).exists()) {
       prop.load(new FileInputStream(configFile))
     }
     prop
   }
 
+  def configFilePath = {
+    val configFileEnvName = "TINY_LSM_CONFIG_FILE"
+    val configFileSysPropName = toPropertyName("CONFIG_FILE")
+    val configFile = System.getProperty(configFileSysPropName,
+      System.getenv().getOrDefault(configFileEnvName, "/etc/tinylsm/tinylsm.conf"))
+    configFile
+  }
+
   def print(): Unit = {
     println("TinyLsm configurations:")
     Config.values.foreach(c => println(s"\t${c.sysPropName} => ${c.get()}"))