ceph/src/librbd/cache/pwl/LogMap.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #ifndef CEPH_LIBRBD_CACHE_RWL_LOG_MAP_H
   5 #define CEPH_LIBRBD_CACHE_RWL_LOG_MAP_H
   6
   7 #include "librbd/BlockGuard.h"
   8 #include <list>
   9
  10 namespace librbd {
  11 namespace cache {
  12 namespace pwl {
  13
  14 /**
  15  * WriteLogMap: maps block extents to GenericWriteLogEntries
  16  *
  17  * A WriteLogMapEntry (based on LogMapEntry) refers to a portion of a GenericWriteLogEntry
  18  */
  19 template <typename T>
  20 class LogMapEntry {
  21 public:
  22   BlockExtent block_extent;
  23   std::shared_ptr<T> log_entry;
  24
  25   LogMapEntry(BlockExtent block_extent,
  26               std::shared_ptr<T> log_entry = nullptr);
  27   LogMapEntry(std::shared_ptr<T> log_entry);
  28
  29   template <typename U>
  30   friend std::ostream &operator<<(std::ostream &os,
  31                                   LogMapEntry<U> &e);
  32 };
  33
  34 template <typename T>
  35 using LogMapEntries = std::list<LogMapEntry<T>>;
  36
  37 template <typename T>
  38 class LogMap {
  39 public:
  40   LogMap(CephContext *cct);
  41   LogMap(const LogMap&) = delete;
  42   LogMap &operator=(const LogMap&) = delete;
  43
  44   void add_log_entry(std::shared_ptr<T> log_entry);
  45   void add_log_entries(std::list<std::shared_ptr<T>> &log_entries);
  46   void remove_log_entry(std::shared_ptr<T> log_entry);
  47   void remove_log_entries(std::list<std::shared_ptr<T>> &log_entries);
  48   std::list<std::shared_ptr<T>> find_log_entries(BlockExtent block_extent);
  49   LogMapEntries<T> find_map_entries(BlockExtent block_extent);
  50
  51 private:
  52   void add_log_entry_locked(std::shared_ptr<T> log_entry);
  53   void remove_log_entry_locked(std::shared_ptr<T> log_entry);
  54   void add_map_entry_locked(LogMapEntry<T> &map_entry);
  55   void remove_map_entry_locked(LogMapEntry<T> &map_entry);
  56   void adjust_map_entry_locked(LogMapEntry<T> &map_entry, BlockExtent &new_extent);
  57   void split_map_entry_locked(LogMapEntry<T> &map_entry, BlockExtent &removed_extent);
  58   std::list<std::shared_ptr<T>> find_log_entries_locked(const BlockExtent &block_extent);
  59   LogMapEntries<T> find_map_entries_locked(const BlockExtent &block_extent);
  60
  61   using LogMapEntryT = LogMapEntry<T>;
  62
  63   class LogMapEntryCompare {
  64   public:
  65     bool operator()(const LogMapEntryT &lhs,
  66                     const LogMapEntryT &rhs) const;
  67   };
  68
  69   using BlockExtentToLogMapEntries = std::set<LogMapEntryT,
  70                                               LogMapEntryCompare>;
  71
  72   CephContext *m_cct;
  73   ceph::mutex m_lock;
  74   BlockExtentToLogMapEntries m_block_to_log_entry_map;
  75 };
  76
  77 } //namespace pwl
  78 } //namespace cache
  79 } //namespace librbd
  80
  81 #endif //CEPH_LIBRBD_CACHE_RWL_LOG_MAP_H