From bb0dcd2cedeae65a0fb54e5a2a3e6498940da765 Mon Sep 17 00:00:00 2001
From: Greg Farnum <gregf@hq.newdream.net>
Date: Thu, 12 Aug 2010 14:11:17 -0700
Subject: [PATCH] mds: add SnapRealm projection methods

---
 src/mds/snap.cc | 20 ++++++++++++++++++++
 src/mds/snap.h  | 10 ++++++++++
 2 files changed, 30 insertions(+)

diff --git a/src/mds/snap.cc b/src/mds/snap.cc
index a04dafb2f29..992b45f3a75 100644
--- a/src/mds/snap.cc
+++ b/src/mds/snap.cc
@@ -530,3 +530,23 @@ void SnapRealm::prune_past_parents()
     }
   }
 }
+
+sr_t *SnapRealm::project_snaprealm()
+{
+  if (projected_srnode.empty())
+    projected_srnode.push_back(new sr_t(srnode));
+  else
+    projected_srnode.push_back(new sr_t(*projected_srnode.back()));
+  dout(0) << "project_snaprealm " << projected_srnode.back() << dendl;
+  return projected_srnode.back();
+}
+
+void SnapRealm::pop_projected_snaprealm()
+{
+  assert(!projected_srnode.empty());
+  dout(0) << "pop_projected_snaprealm " << projected_srnode.front()
+          << " seq" << projected_srnode.front()->seq << dendl;
+  srnode = *projected_srnode.front();
+  delete projected_srnode.front();
+  projected_srnode.pop_front();
+}
diff --git a/src/mds/snap.h b/src/mds/snap.h
index 0dac3438ee6..aec11747b7b 100644
--- a/src/mds/snap.h
+++ b/src/mds/snap.h
@@ -139,6 +139,7 @@ struct SnapRealm {
   // realm state
 
   sr_t srnode;
+  list<sr_t*> projected_srnode;
 
   void encode(bufferlist& bl) const {
     __u8 struct_v = 2;
@@ -273,6 +274,15 @@ struct SnapRealm {
     if (client_caps[client].empty())
       client_caps.erase(client);
   }
+
+  sr_t *get_projected_snaprealm() {
+    if (projected_srnode.empty())
+      return &srnode;
+    else
+      return projected_srnode.back();
+  }
+  sr_t *project_snaprealm();
+  void pop_projected_snaprealm();
 };
 WRITE_CLASS_ENCODER(SnapRealm)