1 files changed, 150 insertions, 0 deletions
diff --git a/src/mds/SnapRealm.h b/src/mds/SnapRealm.h
new file mode 100644
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+++ b/src/mds/SnapRealm.h
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_SNAPREALM_H
+#define CEPH_MDS_SNAPREALM_H
+
+#include <string_view>
+
+#include "mdstypes.h"
+#include "snap.h"
+#include "include/xlist.h"
+#include "include/elist.h"
+#include "common/snap_types.h"
+#include "MDSContext.h"
+
+struct SnapRealm {
+public:
+  SnapRealm(MDCache *c, CInode *in);
+
+  bool exists(std::string_view name) const {
+    for (auto p = srnode.snaps.begin(); p != srnode.snaps.end(); ++p) {
+      if (p->second.name == name)
+	return true;
+    }
+    return false;
+  }
+
+  void prune_past_parent_snaps();
+  bool has_past_parent_snaps() const {
+    return !srnode.past_parent_snaps.empty();
+  }
+
+  void build_snap_set() const;
+  void get_snap_info(std::map<snapid_t, const SnapInfo*>& infomap, snapid_t first=0, snapid_t last=CEPH_NOSNAP);
+
+  const ceph::buffer::list& get_snap_trace() const;
+  void build_snap_trace() const;
+
+  std::string_view get_snapname(snapid_t snapid, inodeno_t atino);
+  snapid_t resolve_snapname(std::string_view name, inodeno_t atino, snapid_t first=0, snapid_t last=CEPH_NOSNAP);
+
+  const std::set<snapid_t>& get_snaps() const;
+  const SnapContext& get_snap_context() const;
+  void invalidate_cached_snaps() {
+    cached_seq = 0;
+  }
+  snapid_t get_last_created() {
+    check_cache();
+    return cached_last_created;
+  }
+  snapid_t get_last_destroyed() {
+    check_cache();
+    return cached_last_destroyed;
+  }
+  snapid_t get_newest_snap() {
+    check_cache();
+    if (cached_snaps.empty())
+      return 0;
+    else
+      return *cached_snaps.rbegin();
+  }
+  snapid_t get_newest_seq() {
+    check_cache();
+    return cached_seq;
+  }
+
+  snapid_t get_snap_following(snapid_t follows) {
+    check_cache();
+    const std::set<snapid_t>& s = get_snaps();
+    auto p = s.upper_bound(follows);
+    if (p != s.end())
+      return *p;
+    return CEPH_NOSNAP;
+  }
+
+  bool has_snaps_in_range(snapid_t first, snapid_t last) {
+    check_cache();
+    const auto& s = get_snaps();
+    auto p = s.lower_bound(first);
+    return (p != s.end() && *p <= last);
+  }
+
+  inodeno_t get_subvolume_ino() {
+    check_cache();
+    return cached_subvolume_ino;
+  }
+
+  void adjust_parent();
+
+  void split_at(SnapRealm *child);
+  void merge_to(SnapRealm *newparent);
+
+  void add_cap(client_t client, Capability *cap) {
+    auto client_caps_entry = client_caps.find(client);
+    if (client_caps_entry == client_caps.end())
+      client_caps_entry = client_caps.emplace(client,
+					      new xlist<Capability*>).first;
+    client_caps_entry->second->push_back(&cap->item_snaprealm_caps);
+  }
+  void remove_cap(client_t client, Capability *cap) {
+    cap->item_snaprealm_caps.remove_myself();
+    auto found = client_caps.find(client);
+    if (found != client_caps.end() && found->second->empty()) {
+      delete found->second;
+      client_caps.erase(found);
+    }
+  }
+
+  // realm state
+  sr_t srnode;
+
+  // in-memory state
+  MDCache *mdcache;
+  CInode *inode;
+
+  SnapRealm *parent = nullptr;
+  std::set<SnapRealm*> open_children;    // active children that are currently open
+
+  elist<CInode*> inodes_with_caps;             // for efficient realm splits
+  std::map<client_t, xlist<Capability*>* > client_caps;   // to identify clients who need snap notifications
+
+protected:
+  void check_cache() const;
+
+private:
+  bool global;
+
+  // cache
+  mutable snapid_t cached_seq;           // max seq over self and all past+present parents.
+  mutable snapid_t cached_last_created;  // max last_created over all past+present parents
+  mutable snapid_t cached_last_destroyed;
+  mutable std::set<snapid_t> cached_snaps;
+  mutable SnapContext cached_snap_context;
+  mutable ceph::buffer::list cached_snap_trace;
+  mutable inodeno_t cached_subvolume_ino = 0;
+};
+
+std::ostream& operator<<(std::ostream& out, const SnapRealm &realm);
+#endif