factored out lock-file handling into LockFileFeature

arangod/CMakeLists.txt

@@ -247,6 +247,7 @@ add_executable(${BIN_ARANGOD}
   RestServer/FileDescriptorsFeature.cpp
   RestServer/FrontendFeature.cpp
   RestServer/InitDatabaseFeature.cpp
+  RestServer/LockfileFeature.cpp
   RestServer/QueryRegistryFeature.cpp
   RestServer/RestServerFeature.cpp
   RestServer/ScriptFeature.cpp

arangod/RestServer/DatabaseFeature.h

@@ -43,7 +43,7 @@ class DatabaseFeature final : public application_features::ApplicationFeature {
 
  public:
   TRI_vocbase_t* vocbase() const { return _vocbase; }
-
+  std::string databasePath() const { return _databasePath; }
   bool ignoreDatafileErrors() const { return _ignoreDatafileErrors; }
   bool isInitiallyEmpty() const { return _isInitiallyEmpty; }
 

arangod/RestServer/LockfileFeature.cpp

@@ -0,0 +1,82 @@
+////////////////////////////////////////////////////////////////////////////////
+/// DISCLAIMER
+///
+/// Copyright 2016 ArangoDB GmbH, Cologne, Germany
+///
+/// Licensed under the Apache License, Version 2.0 (the "License");
+/// you may not use this file except in compliance with the License.
+/// You may obtain a copy of the License at
+///
+///     http://www.apache.org/licenses/LICENSE-2.0
+///
+/// Unless required by applicable law or agreed to in writing, software
+/// distributed under the License is distributed on an "AS IS" BASIS,
+/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+/// See the License for the specific language governing permissions and
+/// limitations under the License.
+///
+/// Copyright holder is ArangoDB GmbH, Cologne, Germany
+///
+/// @author Jan Steemann
+////////////////////////////////////////////////////////////////////////////////
+
+#include "LockfileFeature.h"
+#include "Basics/Exceptions.h"
+#include "Basics/FileUtils.h"
+#include "Basics/files.h"
+#include "RestServer/DatabaseFeature.h"
+
+using namespace arangodb;
+using namespace arangodb::basics;
+
+LockfileFeature::LockfileFeature(
+    application_features::ApplicationServer* server)
+    : ApplicationFeature(server, "Lockfile") {
+  setOptional(false);
+  requiresElevatedPrivileges(false);
+  startsAfter("Logger");
+}
+
+void LockfileFeature::prepare() {
+  // build lockfile name
+  DatabaseFeature* database = application_features::ApplicationServer::getFeature<DatabaseFeature>("Database");
+  std::string databasePath = database->databasePath();
+  TRI_ASSERT(!databasePath.empty());
+  
+  _lockFilename = basics::FileUtils::buildFilename(databasePath, "LOCK");
+
+  TRI_ASSERT(!_lockFilename.empty());
+
+  int res = TRI_VerifyLockFile(_lockFilename.c_str());
+
+  if (res != TRI_ERROR_NO_ERROR) {
+    LOG(ERR) << "database is locked, please check the lock file '" << _lockFilename << "'";
+    THROW_ARANGO_EXCEPTION(TRI_ERROR_ARANGO_DATADIR_LOCKED);
+  }
+  
+  if (TRI_ExistsFile(_lockFilename.c_str())) {
+    TRI_UnlinkFile(_lockFilename.c_str());
+  }
+  
+  if (res != TRI_ERROR_NO_ERROR) {
+    LOG(ERR)
+        << "cannot lock the database directory, please check the lock file '"
+        << _lockFilename << "': " << TRI_errno_string(res);
+
+    THROW_ARANGO_EXCEPTION(TRI_ERROR_ARANGO_DATADIR_UNLOCKABLE);
+  }
+  
+  res = TRI_CreateLockFile(_lockFilename.c_str());
+
+  if (res != TRI_ERROR_NO_ERROR) {
+    LOG(ERR)
+        << "cannot lock the database directory, please check the lock file '"
+        << _lockFilename << "': " << TRI_errno_string(res);
+
+    THROW_ARANGO_EXCEPTION(TRI_ERROR_ARANGO_DATADIR_UNLOCKABLE);
+  }
+}
+
+void LockfileFeature::unprepare() {
+  TRI_DestroyLockFile(_lockFilename.c_str());
+}

arangod/RestServer/LockfileFeature.h

@@ -0,0 +1,42 @@
+////////////////////////////////////////////////////////////////////////////////
+/// DISCLAIMER
+///
+/// Copyright 2016 ArangoDB GmbH, Cologne, Germany
+///
+/// Licensed under the Apache License, Version 2.0 (the "License");
+/// you may not use this file except in compliance with the License.
+/// You may obtain a copy of the License at
+///
+///     http://www.apache.org/licenses/LICENSE-2.0
+///
+/// Unless required by applicable law or agreed to in writing, software
+/// distributed under the License is distributed on an "AS IS" BASIS,
+/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+/// See the License for the specific language governing permissions and
+/// limitations under the License.
+///
+/// Copyright holder is ArangoDB GmbH, Cologne, Germany
+///
+/// @author Jan Steemann
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef ARANGODB_APPLICATION_FEATURES_LOCK_FILE_FEATURE_H
+#define ARANGODB_APPLICATION_FEATURES_LOCL_FILE_FEATURE_H 1
+
+#include "ApplicationFeatures/ApplicationFeature.h"
+
+namespace arangodb {
+class LockfileFeature final : public application_features::ApplicationFeature {
+ public:
+  explicit LockfileFeature(application_features::ApplicationServer* server);
+
+ public:
+  void prepare() override final;
+  void unprepare() override final;
+
+ private:
+  std::string _lockFilename;
+};
+}
+
+#endif

arangod/RestServer/arangod.cpp

@@ -57,6 +57,7 @@
 #include "RestServer/FileDescriptorsFeature.h"
 #include "RestServer/FrontendFeature.h"
 #include "RestServer/InitDatabaseFeature.h"
+#include "RestServer/LockfileFeature.h"
 #include "RestServer/QueryRegistryFeature.h"
 #include "RestServer/RestServerFeature.h"
 #include "RestServer/ScriptFeature.h"
@@ -125,6 +126,7 @@ static int runServer(int argc, char** argv) {
   server.addFeature(new FrontendFeature(&server));
   server.addFeature(new InitDatabaseFeature(&server, nonServerFeatures));
   server.addFeature(new LanguageFeature(&server));
+  server.addFeature(new LockfileFeature(&server));
   server.addFeature(new LogfileManager(&server));
   server.addFeature(new LoggerBufferFeature(&server));
   server.addFeature(new LoggerFeature(&server, true));

arangod/StorageEngine/EngineSelectorFeature.cpp

@@ -38,7 +38,8 @@ EngineSelectorFeature::EngineSelectorFeature(
     : ApplicationFeature(server, "EngineSelector"), _engine(MMFilesEngine::EngineName) {
   setOptional(false);
   requiresElevatedPrivileges(false);
-  startsAfter("Logger");
+  startsAfter("Database");
+  startsAfter("LogfileManager");
 }
 
 void EngineSelectorFeature::collectOptions(std::shared_ptr<ProgramOptions> options) {

arangod/VocBase/server.cpp

@@ -306,19 +306,18 @@ static int CreateBaseApplicationDirectory(char const* basePath,
 /// @brief create app subdirectory for a database
 ////////////////////////////////////////////////////////////////////////////////
 
-static int CreateApplicationDirectory(char const* name, char const* basePath) {
+static int CreateApplicationDirectory(std::string const& name, std::string const& basePath) {
-  if (basePath == nullptr || strlen(basePath) == 0) {
+  if (basePath.empty()) {
     return TRI_ERROR_NO_ERROR;
   }
 
+  std::string const path = basics::FileUtils::buildFilename(basics::FileUtils::buildFilename(basePath, "db"), name);
   int res = TRI_ERROR_NO_ERROR;
-  char* path = TRI_Concatenate3File(basePath, "_db", name);
 
-  if (path != nullptr) {
+  if (!TRI_IsDirectory(path.c_str())) {
-    if (!TRI_IsDirectory(path)) {
     long systemError;
     std::string errorMessage;
-      res = TRI_CreateRecursiveDirectory(path, systemError, errorMessage);
+    res = TRI_CreateRecursiveDirectory(path.c_str(), systemError, errorMessage);
 
     if (res == TRI_ERROR_NO_ERROR) {
       if (arangodb::wal::LogfileManager::instance()->isInRecovery()) {
@@ -338,9 +337,6 @@ static int CreateApplicationDirectory(char const* name, char const* basePath) {
     }
   }
 
-    TRI_Free(TRI_CORE_MEM_ZONE, path);
-  }
-
   return res;
 }
 
@@ -520,7 +516,7 @@ static int OpenDatabases(TRI_server_t* server, bool isUpgrade) {
         ApplicationServer::getFeature<V8DealerFeature>("V8Dealer");
     auto appPath = dealer->appPath();
 
-    res = CreateApplicationDirectory(databaseName.c_str(), appPath.c_str());
+    res = CreateApplicationDirectory(databaseName, appPath);
 
     if (res != TRI_ERROR_NO_ERROR) {
       break;
@@ -1149,19 +1145,9 @@ int TRI_InitServer(TRI_server_t* server,
     return TRI_ERROR_OUT_OF_MEMORY;
   }
 
-  server->_lockFilename = TRI_Concatenate2File(server->_basePath, "LOCK");
-
-  if (server->_lockFilename == nullptr) {
-    TRI_Free(TRI_CORE_MEM_ZONE, server->_databasePath);
-    TRI_Free(TRI_CORE_MEM_ZONE, server->_basePath);
-
-    return TRI_ERROR_OUT_OF_MEMORY;
-  }
-
   server->_serverIdFilename = TRI_Concatenate2File(server->_basePath, "SERVER");
 
   if (server->_serverIdFilename == nullptr) {
-    TRI_Free(TRI_CORE_MEM_ZONE, server->_lockFilename);
     TRI_Free(TRI_CORE_MEM_ZONE, server->_databasePath);
     TRI_Free(TRI_CORE_MEM_ZONE, server->_basePath);
 
@@ -1208,11 +1194,8 @@ TRI_server_id_t TRI_GetIdServer() { return ServerId; }
 
 int TRI_StartServer(TRI_server_t* server, bool checkVersion,
                     bool performUpgrade) {
-  int res;
-
   if (!TRI_IsDirectory(server->_basePath)) {
-    LOG(ERR) << "database path '" << server->_basePath
+    LOG(ERR) << "database path '" << server->_basePath << "' is not a directory";
-             << "' is not a directory";
 
     return TRI_ERROR_ARANGO_DATADIR_INVALID;
   }
@@ -1225,33 +1208,6 @@ int TRI_StartServer(TRI_server_t* server, bool checkVersion,
     return TRI_ERROR_ARANGO_DATADIR_NOT_WRITABLE;
   }
 
-  // ...........................................................................
-  // check that the database is not locked and lock it
-  // ...........................................................................
-
-  res = TRI_VerifyLockFile(server->_lockFilename);
-
-  if (res != TRI_ERROR_NO_ERROR) {
-    LOG(ERR) << "database is locked, please check the lock file '"
-             << server->_lockFilename << "'";
-
-    return TRI_ERROR_ARANGO_DATADIR_LOCKED;
-  }
-
-  if (TRI_ExistsFile(server->_lockFilename)) {
-    TRI_UnlinkFile(server->_lockFilename);
-  }
-
-  res = TRI_CreateLockFile(server->_lockFilename);
-
-  if (res != TRI_ERROR_NO_ERROR) {
-    LOG(ERR)
-        << "cannot lock the database directory, please check the lock file '"
-        << server->_lockFilename << "': " << TRI_errno_string(res);
-
-    return TRI_ERROR_ARANGO_DATADIR_UNLOCKABLE;
-  }
-
   // ...........................................................................
   // read the server id
   // ...........................................................................
@@ -1421,8 +1377,6 @@ int TRI_StopServer(TRI_server_t* server) {
 
   CloseDatabases(server);
 
-  TRI_DestroyLockFile(server->_lockFilename);
-
   return res;
 }
 
@@ -1628,7 +1582,7 @@ int TRI_CreateDatabaseServer(TRI_server_t* server, TRI_voc_tick_t databaseId,
         ApplicationServer::getFeature<V8DealerFeature>("V8Dealer");
     auto appPath = dealer->appPath();
 
-    CreateApplicationDirectory(vocbase->_name, appPath.c_str());
+    CreateApplicationDirectory(vocbase->_name, appPath);
 
     if (!arangodb::wal::LogfileManager::instance()->isInRecovery()) {
       TRI_StartCompactorVocBase(vocbase);
@@ -2155,7 +2109,6 @@ TRI_server_t::TRI_server_t()
       _queryRegistry(nullptr),
       _basePath(nullptr),
       _databasePath(nullptr),
-      _lockFilename(nullptr),
       _serverIdFilename(nullptr),
       _disableReplicationAppliers(false),
       _disableCompactor(false),
@@ -2171,7 +2124,6 @@ TRI_server_t::~TRI_server_t() {
     delete p;
 
     TRI_Free(TRI_CORE_MEM_ZONE, _serverIdFilename);
-    TRI_Free(TRI_CORE_MEM_ZONE, _lockFilename);
     TRI_Free(TRI_CORE_MEM_ZONE, _databasePath);
     TRI_Free(TRI_CORE_MEM_ZONE, _basePath);
   }

arangod/VocBase/server.h

@@ -75,7 +75,6 @@ struct TRI_server_t {
 
   char* _basePath;
   char* _databasePath;
-  char* _lockFilename;
   char* _serverIdFilename;
 
   bool _disableReplicationAppliers;