ceph/src/rocksdb/include/rocksdb/sst_file_manager.h

   1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under the BSD-style license found in the
   3 //  LICENSE file in the root directory of this source tree. An additional grant
   4 //  of patent rights can be found in the PATENTS file in the same directory.
   5
   6 #pragma once
   7
   8 #include <memory>
   9 #include <string>
  10 #include <unordered_map>
  11
  12 #include "rocksdb/status.h"
  13
  14 namespace rocksdb {
  15
  16 class Env;
  17 class Logger;
  18
  19 // SstFileManager is used to track SST files in the DB and control there
  20 // deletion rate.
  21 // All SstFileManager public functions are thread-safe.
  22 class SstFileManager {
  23  public:
  24   virtual ~SstFileManager() {}
  25
  26   // Update the maximum allowed space that should be used by RocksDB, if
  27   // the total size of the SST files exceeds max_allowed_space, writes to
  28   // RocksDB will fail.
  29   //
  30   // Setting max_allowed_space to 0 will disable this feature, maximum allowed
  31   // space will be infinite (Default value).
  32   //
  33   // thread-safe.
  34   virtual void SetMaxAllowedSpaceUsage(uint64_t max_allowed_space) = 0;
  35
  36   // Return true if the total size of SST files exceeded the maximum allowed
  37   // space usage.
  38   //
  39   // thread-safe.
  40   virtual bool IsMaxAllowedSpaceReached() = 0;
  41
  42   // Return the total size of all tracked files.
  43   // thread-safe
  44   virtual uint64_t GetTotalSize() = 0;
  45
  46   // Return a map containing all tracked files and there corresponding sizes.
  47   // thread-safe
  48   virtual std::unordered_map<std::string, uint64_t> GetTrackedFiles() = 0;
  49
  50   // Return delete rate limit in bytes per second.
  51   // thread-safe
  52   virtual int64_t GetDeleteRateBytesPerSecond() = 0;
  53
  54   // Update the delete rate limit in bytes per second.
  55   // zero means disable delete rate limiting and delete files immediately
  56   // thread-safe
  57   virtual void SetDeleteRateBytesPerSecond(int64_t delete_rate) = 0;
  58 };
  59
  60 // Create a new SstFileManager that can be shared among multiple RocksDB
  61 // instances to track SST file and control there deletion rate.
  62 //
  63 // @param env: Pointer to Env object, please see "rocksdb/env.h".
  64 // @param info_log: If not nullptr, info_log will be used to log errors.
  65 //
  66 // == Deletion rate limiting specific arguments ==
  67 // @param trash_dir: Path to the directory where deleted files will be moved
  68 //    to be deleted in a background thread while applying rate limiting. If this
  69 //    directory dont exist, it will be created. This directory should not be
  70 //    used by any other process or any other SstFileManager, Set to "" to
  71 //    disable deletion rate limiting.
  72 // @param rate_bytes_per_sec: How many bytes should be deleted per second, If
  73 //    this value is set to 1024 (1 Kb / sec) and we deleted a file of size 4 Kb
  74 //    in 1 second, we will wait for another 3 seconds before we delete other
  75 //    files, Set to 0 to disable deletion rate limiting.
  76 // @param delete_existing_trash: If set to true, the newly created
  77 //    SstFileManager will delete files that already exist in trash_dir.
  78 // @param status: If not nullptr, status will contain any errors that happened
  79 //    during creating the missing trash_dir or deleting existing files in trash.
  80 extern SstFileManager* NewSstFileManager(
  81     Env* env, std::shared_ptr<Logger> info_log = nullptr,
  82     std::string trash_dir = "", int64_t rate_bytes_per_sec = 0,
  83     bool delete_existing_trash = true, Status* status = nullptr);
  84
  85 }  // namespace rocksdb