From: Sage Weil <sage@inktank.com>
Date: Tue, 25 Jun 2013 23:12:39 +0000 (-0700)
Subject: mon/Paxos: simplify trim()
X-Git-Tag: v0.67-rc1~175^2~4
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=516445bebc1ddd390d789390c17408f69928b7d2;p=ceph.git

mon/Paxos: simplify trim()

Collapse all the trim methods into a single simple method.

Signed-off-by: Sage Weil <sage@inktank.com>
---

diff --git a/src/mon/Paxos.cc b/src/mon/Paxos.cc
index ce9f2952e2a..58c35d0305c 100644
--- a/src/mon/Paxos.cc
+++ b/src/mon/Paxos.cc
@@ -958,54 +958,44 @@ void Paxos::lease_renew_timeout()
 /*
  * trim old states
  */
-void Paxos::trim_to(MonitorDBStore::Transaction *t,
-		    version_t from, version_t to) {
-  dout(10) << __func__ << " from " << from << " to " << to << dendl;
-  assert(from < to);
+void Paxos::trim()
+{
+  assert(should_trim());
+  version_t end = MIN(get_version() - g_conf->paxos_max_join_drift,
+			get_first_committed() + g_conf->paxos_trim_max);
+
+  if (first_committed >= end)
+    return;
+
+  dout(10) << "trim to " << end << " (was " << first_committed << ")" << dendl;
 
-  for (version_t v = from; v < to; ++v) {
+  MonitorDBStore::Transaction t;
+
+  for (version_t v = first_committed; v < end; ++v) {
     dout(10) << "trim " << v << dendl;
-    t->erase(get_name(), v);
+    t.erase(get_name(), v);
   }
+  t.put(get_name(), "first_committed", end);
   if (g_conf->mon_compact_on_trim) {
     dout(10) << " compacting trimmed range" << dendl;
-    t->compact_range(get_name(), stringify(from - 1), stringify(to));
+    t.compact_range(get_name(), stringify(first_committed - 1), stringify(end));
   }
-}
-
-void Paxos::trim_to(MonitorDBStore::Transaction *t, version_t first)
-{
-  dout(10) << "trim_to " << first << " (was " << first_committed << ")"
-	   << dendl;
-
-  if (first_committed >= first)
-    return;
-  trim_to(t, first_committed, first);
-  t->put(get_name(), "first_committed", first);
-}
 
-void Paxos::trim_to(version_t first)
-{
-  MonitorDBStore::Transaction t;
-  
-  trim_to(&t, first);
-
-  if (!t.empty()) {
-    dout(30) << __func__ << " transaction dump:\n";
-    JSONFormatter f(true);
-    t.dump(&f);
-    f.flush(*_dout);
-    *_dout << dendl;
+  dout(30) << __func__ << " transaction dump:\n";
+  JSONFormatter f(true);
+  t.dump(&f);
+  f.flush(*_dout);
+  *_dout << dendl;
 
-    bufferlist bl;
-    t.encode(bl);
+  bufferlist bl;
+  t.encode(bl);
 
-    going_to_trim = true;
-    queue_proposal(bl, new C_Trimmed(this));
-  }
+  trimming = true;
+  queue_proposal(bl, new C_Trimmed(this));
 }
 
-void Paxos::trim_enable() {
+void Paxos::trim_enable()
+{
   trim_disabled_version = 0;
   // We may not be the leader when we reach this function. We sure must
   // have been the leader at some point, but we may have been demoted and
diff --git a/src/mon/Paxos.h b/src/mon/Paxos.h
index 810953c8101..9be4713a282 100644
--- a/src/mon/Paxos.h
+++ b/src/mon/Paxos.h
@@ -529,7 +529,7 @@ private:
    * Should be true if we have proposed to trim, or are in the middle of
    * trimming; false otherwise.
    */
-  bool going_to_trim;
+  bool trimming;
   /**
    * If we have disabled trimming our state, this variable should have a
    * value greater than zero, corresponding to the version we had at the time
@@ -616,7 +616,7 @@ private:
   public:
     C_Trimmed(Paxos *p) : paxos(p) { }
     void finish(int r) {
-      paxos->going_to_trim = false;
+      paxos->trimming = false;
     }
   };
   /**
@@ -1013,7 +1013,7 @@ public:
 		   lease_timeout_event(0),
 		   accept_timeout_event(0),
 		   clock_drift_warned(0),
-		   going_to_trim(false),
+		   trimming(false),
 		   trim_disabled_version(0) { }
 
   const string get_name() const {
@@ -1131,37 +1131,11 @@ public:
     waiting_for_active.push_back(c);
   }
 
-  /**
-   * Erase old states from stable storage.
-   *
-   * @param first The version we are trimming to
-   */
-  void trim_to(version_t first);
-  /**
-   * Erase old states from stable storage.
-   *
-   * @param t A transaction
-   * @param first The version we are trimming to
-   */
-  void trim_to(MonitorDBStore::Transaction *t, version_t first);
-  /**
-   * Auxiliary function to erase states in the interval [from, to[ from stable
-   * storage.
-   *
-   * @param t A transaction
-   * @param from Bottom limit of the interval of versions to erase
-   * @param to Upper limit, not including, of the interval of versions to erase
-   */
-  void trim_to(MonitorDBStore::Transaction *t, version_t from, version_t to);
   /**
    * Trim the Paxos state as much as we can.
    */
-  void trim() {
-    assert(should_trim());
-    version_t trim_to_version = MIN(get_version() - g_conf->paxos_max_join_drift,
-				    get_first_committed() + g_conf->paxos_trim_max);
-    trim_to(trim_to_version);
-  }
+  void trim();
+
   /**
    * Disable trimming
    *
@@ -1195,7 +1169,7 @@ public:
     int maximum_versions =
       (g_conf->paxos_max_join_drift + g_conf->paxos_trim_min);
 
-    if (going_to_trim || (available_versions <= maximum_versions))
+    if (trimming || (available_versions <= maximum_versions))
       return false;
 
     if (trim_disabled_version > 0) {