1 files changed, 81 insertions, 0 deletions
diff --git a/src/librbd/cache/pwl/LogMap.h b/src/librbd/cache/pwl/LogMap.h
new file mode 100644
index 000000000..a05307896
--- /dev/null
+++ b/src/librbd/cache/pwl/LogMap.h
@@ -0,0 +1,81 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_CACHE_RWL_LOG_MAP_H
+#define CEPH_LIBRBD_CACHE_RWL_LOG_MAP_H
+
+#include "librbd/BlockGuard.h"
+#include <list>
+
+namespace librbd {
+namespace cache {
+namespace pwl {
+
+/**
+ * WriteLogMap: maps block extents to GenericWriteLogEntries
+ *
+ * A WriteLogMapEntry (based on LogMapEntry) refers to a portion of a GenericWriteLogEntry
+ */
+template <typename T>
+class LogMapEntry {
+public:
+  BlockExtent block_extent;
+  std::shared_ptr<T> log_entry;
+
+  LogMapEntry(BlockExtent block_extent,
+              std::shared_ptr<T> log_entry = nullptr);
+  LogMapEntry(std::shared_ptr<T> log_entry);
+
+  template <typename U>
+  friend std::ostream &operator<<(std::ostream &os,
+                                  LogMapEntry<U> &e);
+};
+
+template <typename T>
+using LogMapEntries = std::list<LogMapEntry<T>>;
+
+template <typename T>
+class LogMap {
+public:
+  LogMap(CephContext *cct);
+  LogMap(const LogMap&) = delete;
+  LogMap &operator=(const LogMap&) = delete;
+
+  void add_log_entry(std::shared_ptr<T> log_entry);
+  void add_log_entries(std::list<std::shared_ptr<T>> &log_entries);
+  void remove_log_entry(std::shared_ptr<T> log_entry);
+  void remove_log_entries(std::list<std::shared_ptr<T>> &log_entries);
+  std::list<std::shared_ptr<T>> find_log_entries(BlockExtent block_extent);
+  LogMapEntries<T> find_map_entries(BlockExtent block_extent);
+
+private:
+  void add_log_entry_locked(std::shared_ptr<T> log_entry);
+  void remove_log_entry_locked(std::shared_ptr<T> log_entry);
+  void add_map_entry_locked(LogMapEntry<T> &map_entry);
+  void remove_map_entry_locked(LogMapEntry<T> &map_entry);
+  void adjust_map_entry_locked(LogMapEntry<T> &map_entry, BlockExtent &new_extent);
+  void split_map_entry_locked(LogMapEntry<T> &map_entry, BlockExtent &removed_extent);
+  std::list<std::shared_ptr<T>> find_log_entries_locked(const BlockExtent &block_extent);
+  LogMapEntries<T> find_map_entries_locked(const BlockExtent &block_extent);
+
+  using LogMapEntryT = LogMapEntry<T>;
+
+  class LogMapEntryCompare {
+  public:
+    bool operator()(const LogMapEntryT &lhs,
+                    const LogMapEntryT &rhs) const;
+  };
+
+  using BlockExtentToLogMapEntries = std::set<LogMapEntryT,
+                                              LogMapEntryCompare>;
+
+  CephContext *m_cct;
+  ceph::mutex m_lock;
+  BlockExtentToLogMapEntries m_block_to_log_entry_map;
+};
+
+} //namespace pwl
+} //namespace cache
+} //namespace librbd
+
+#endif //CEPH_LIBRBD_CACHE_RWL_LOG_MAP_H