Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 141 insertions, 0 deletions

diff --git a/src/rocksdb/file/delete_scheduler.h b/src/rocksdb/file/delete_scheduler.h
new file mode 100644
index 000000000..60948480a
--- /dev/null
+++ b/src/rocksdb/file/delete_scheduler.h
@@ -0,0 +1,141 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#ifndef ROCKSDB_LITE
+
+#include <map>
+#include <queue>
+#include <string>
+#include <thread>
+
+#include "monitoring/instrumented_mutex.h"
+#include "port/port.h"
+
+#include "rocksdb/file_system.h"
+#include "rocksdb/status.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class Env;
+class Logger;
+class SstFileManagerImpl;
+
+// DeleteScheduler allows the DB to enforce a rate limit on file deletion,
+// Instead of deleteing files immediately, files are marked as trash
+// and deleted in a background thread that apply sleep penlty between deletes
+// if they are happening in a rate faster than rate_bytes_per_sec,
+//
+// Rate limiting can be turned off by setting rate_bytes_per_sec = 0, In this
+// case DeleteScheduler will delete files immediately.
+class DeleteScheduler {
+ public:
+  DeleteScheduler(Env* env, FileSystem* fs, int64_t rate_bytes_per_sec,
+                  Logger* info_log, SstFileManagerImpl* sst_file_manager,
+                  double max_trash_db_ratio, uint64_t bytes_max_delete_chunk);
+
+  ~DeleteScheduler();
+
+  // Return delete rate limit in bytes per second
+  int64_t GetRateBytesPerSecond() { return rate_bytes_per_sec_.load(); }
+
+  // Set delete rate limit in bytes per second
+  void SetRateBytesPerSecond(int64_t bytes_per_sec) {
+    rate_bytes_per_sec_.store(bytes_per_sec);
+  }
+
+  // Mark file as trash directory and schedule it's deletion. If force_bg is
+  // set, it forces the file to always be deleted in the background thread,
+  // except when rate limiting is disabled
+  Status DeleteFile(const std::string& fname, const std::string& dir_to_sync,
+      const bool force_bg = false);
+
+  // Wait for all files being deleteing in the background to finish or for
+  // destructor to be called.
+  void WaitForEmptyTrash();
+
+  // Return a map containing errors that happened in BackgroundEmptyTrash
+  // file_path => error status
+  std::map<std::string, Status> GetBackgroundErrors();
+
+  uint64_t GetTotalTrashSize() { return total_trash_size_.load(); }
+
+  // Return trash/DB size ratio where new files will be deleted immediately
+  double GetMaxTrashDBRatio() {
+    return max_trash_db_ratio_.load();
+  }
+
+  // Update trash/DB size ratio where new files will be deleted immediately
+  void SetMaxTrashDBRatio(double r) {
+    assert(r >= 0);
+    max_trash_db_ratio_.store(r);
+  }
+
+  static const std::string kTrashExtension;
+  static bool IsTrashFile(const std::string& file_path);
+
+  // Check if there are any .trash filse in path, and schedule their deletion
+  // Or delete immediately if sst_file_manager is nullptr
+  static Status CleanupDirectory(Env* env, SstFileManagerImpl* sfm,
+                                 const std::string& path);
+
+ private:
+  Status MarkAsTrash(const std::string& file_path, std::string* path_in_trash);
+
+  Status DeleteTrashFile(const std::string& path_in_trash,
+                         const std::string& dir_to_sync,
+                         uint64_t* deleted_bytes, bool* is_complete);
+
+  void BackgroundEmptyTrash();
+
+  Env* env_;
+  FileSystem* fs_;
+
+  // total size of trash files
+  std::atomic<uint64_t> total_trash_size_;
+  // Maximum number of bytes that should be deleted per second
+  std::atomic<int64_t> rate_bytes_per_sec_;
+  // Mutex to protect queue_, pending_files_, bg_errors_, closing_
+  InstrumentedMutex mu_;
+
+  struct FileAndDir {
+    FileAndDir(const std::string& f, const std::string& d) : fname(f), dir(d) {}
+    std::string fname;
+    std::string dir;  // empty will be skipped.
+  };
+
+  // Queue of trash files that need to be deleted
+  std::queue<FileAndDir> queue_;
+  // Number of trash files that are waiting to be deleted
+  int32_t pending_files_;
+  uint64_t bytes_max_delete_chunk_;
+  // Errors that happened in BackgroundEmptyTrash (file_path => error)
+  std::map<std::string, Status> bg_errors_;
+
+  bool num_link_error_printed_ = false;
+  // Set to true in ~DeleteScheduler() to force BackgroundEmptyTrash to stop
+  bool closing_;
+  // Condition variable signaled in these conditions
+  //    - pending_files_ value change from 0 => 1
+  //    - pending_files_ value change from 1 => 0
+  //    - closing_ value is set to true
+  InstrumentedCondVar cv_;
+  // Background thread running BackgroundEmptyTrash
+  std::unique_ptr<port::Thread> bg_thread_;
+  // Mutex to protect threads from file name conflicts
+  InstrumentedMutex file_move_mu_;
+  Logger* info_log_;
+  SstFileManagerImpl* sst_file_manager_;
+  // If the trash size constitutes for more than this fraction of the total DB
+  // size we will start deleting new files passed to DeleteScheduler
+  // immediately
+  std::atomic<double> max_trash_db_ratio_;
+  static const uint64_t kMicrosInSecond = 1000 * 1000LL;
+};
+
+}  // namespace ROCKSDB_NAMESPACE
+
+#endif  // ROCKSDB_LITE