From 4651dc105780d03f3426b83166afc767c18b6db7 Mon Sep 17 00:00:00 2001
From: Greg Farnum <gregf@hq.newdream.net>
Date: Thu, 8 Oct 2009 16:29:43 -0700
Subject: [PATCH] mon: Add MonmapMonitor source.

---
 src/mon/MonmapMonitor.cc | 104 +++++++++++++++++++++++++++++++++++++++
 src/mon/MonmapMonitor.h  |  69 ++++++++++++++++++++++++++
 2 files changed, 173 insertions(+)
 create mode 100644 src/mon/MonmapMonitor.cc
 create mode 100644 src/mon/MonmapMonitor.h

diff --git a/src/mon/MonmapMonitor.cc b/src/mon/MonmapMonitor.cc
new file mode 100644
index 0000000000000..a231ce080771c
--- /dev/null
+++ b/src/mon/MonmapMonitor.cc
@@ -0,0 +1,104 @@
+// -*- 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) 2009 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.
+ * 
+ */
+
+#include "MonmapMonitor.h"
+#include "Monitor.h"
+#include "MonitorStore.h"
+
+#include "messages/MMonAdd.h"
+#include "common/Timer.h"
+
+#include <sstream>
+#include "config.h"
+
+#define DOUT_SUBSYS mon
+#undef dout_prefix
+#define dout_prefix _prefix(mon)
+static ostream& _prefix(Monitor *mon) {
+  return *_dout << dbeginl
+		<< "mon" << mon->whoami
+		<< (mon->is_starting() ? (const char*)"(starting)":(mon->is_leader() ? (const char*)"(leader)":(mon->is_peon() ? (const char*)"(peon)":(const char*)"(?\?)")))
+		<< ".client v" << mon->monmap->epoch << " ";
+}
+
+void MonmapMonitor::create_initial(bufferlist& bl)
+{
+  //what is this function supposed to do?
+}
+
+bool MonmapMonitor::update_from_paxos()
+{
+  //check versions to see if there's an update
+  version_t paxosv = paxos->get_version();
+  if (paxosv == mon->monmap->epoch) return true;
+  assert(paxosv >= mon->monmap->epoch);
+
+  dout(10) << "update_from_paxos paxosv " << paxosv
+	   << ", my v " << mon->monmap->epoch << dendl;
+
+  //read and decode
+  monmap_bl.clear();
+  bool success = paxos->read(paxosv, monmap_bl);
+  assert(success);
+  dout(10) << "update_from_paxos got " << paxosv << dendl;
+  mon->monmap->decode(monmap_bl);
+
+  //save the bufferlist version in the paxos instance as well
+  paxos->stash_latest(paxosv, monmap_bl);
+
+  return true;
+}
+
+void MonmapMonitor::create_pending()
+{
+  pending_map = *mon->monmap;
+  pending_map.epoch++;
+  dout(10) << "create_pending monmap epoch " << pending_map.epoch << dendl;
+}
+
+void MonmapMonitor::encode_pending(bufferlist& bl)
+{
+  dout(10) << "encode_pending epoch " << pending_map.epoch << dendl;
+
+  assert(paxos->get_version() + 1 == pending_map.epoch);
+  pending_map.encode(bl);
+}
+
+bool MonmapMonitor::preprocess_query(PaxosServiceMessage *m)
+{
+  return false;
+}
+
+bool MonmapMonitor::prepare_update(PaxosServiceMessage *message)
+{
+  MMonAdd *m = (MMonAdd *) message;
+  pending_map.add(m->address);
+  return true;
+}
+
+bool MonmapMonitor::should_propose(double& delay)
+{
+  delay = 0.0;
+  return true;
+}
+
+void MonmapMonitor::committed()
+{
+  //Nothing useful to do here.
+}
+
+void MonmapMonitor::tick()
+{
+  update_from_paxos();
+}
diff --git a/src/mon/MonmapMonitor.h b/src/mon/MonmapMonitor.h
new file mode 100644
index 0000000000000..d8ff389e88726
--- /dev/null
+++ b/src/mon/MonmapMonitor.h
@@ -0,0 +1,69 @@
+// -*- 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) 2009 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.
+ * 
+ */
+
+/*
+ * The Monmap Monitor is used to track the monitors in the cluster.
+ */
+
+#ifndef __MONMAPMONITOR_H
+#define __MONMAPMONITOR_H
+
+#include <map>
+#include <set>
+
+using namespace std;
+
+#include "include/types.h"
+#include "msg/Messenger.h"
+
+#include "PaxosService.h"
+#include "MonMap.h"
+
+class MMonGetMap;
+class MMonMap;
+
+class MonmapMonitor : public PaxosService {
+ public:
+  MonmapMonitor(Monitor *mn, Paxos *p) : PaxosService(mn, p) {}
+  MonMap pending_map; //the pending map awaiting passage
+
+  void create_initial(bufferlist& bl);
+
+  bool update_from_paxos();
+
+  void create_pending();
+
+  void encode_pending(bufferlist& bl);
+
+
+  bool preprocess_query(PaxosServiceMessage *m);
+
+  bool prepare_update(PaxosServiceMessage *m);
+
+  /*
+   * Since monitors are pretty
+   * important, this implementation will just write 0.0.
+   */
+  bool should_propose(double& delay);
+
+  void committed();
+
+  void tick();
+
+ private:
+  bufferlist monmap_bl;
+};
+
+
+#endif
-- 
2.39.5