File bz561413-09-Add-cache-to-ClusterMonitor-objects.patch of Package clustermon

From 65be5031d05a7367fc3e1b1388f8fbc66b1a2a11 Mon Sep 17 00:00:00 2001
From: Lon Hohberger <lhh@redhat.com>
Date: Thu, 13 May 2010 13:16:33 -0400
Subject: [PATCH 09/16] modclusterd: Add cache to ClusterMonitor objects

Signed-off-by: Lon Hohberger <lhh@redhat.com>
---
 .../cluster/clumon/src/common/ClusterMonitor.cpp   |   49 ++++++++++++++++++-
 ricci/modules/cluster/clumon/src/daemon/Makefile   |    2 +-
 .../cluster/clumon/src/include/ClusterMonitor.h    |    9 ++++
 .../modules/cluster/clumon/src/snmp-agent/Makefile |    2 +-
 4 files changed, 57 insertions(+), 5 deletions(-)

diff --git a/ricci/modules/cluster/clumon/src/common/ClusterMonitor.cpp b/ricci/modules/cluster/clumon/src/common/ClusterMonitor.cpp
index 15779e4..eff8de2 100644
--- a/ricci/modules/cluster/clumon/src/common/ClusterMonitor.cpp
+++ b/ricci/modules/cluster/clumon/src/common/ClusterMonitor.cpp
@@ -26,19 +26,45 @@
 
 #include <errno.h>
 #include <sys/poll.h>
+#include <sys/types.h>
+#include <sys/time.h>
 
 using namespace ClusterMonitoring;
 
 ClusterMonitor::ClusterMonitor(const String& socket_path) :
 	_sock_path(socket_path)
-{}
+{
+	last_update.tv_sec = 0;
+	last_update.tv_nsec = 0;
+	cache_lifetime = 0;
+}
 
 ClusterMonitor::~ClusterMonitor()
 {}
 
+unsigned int
+ClusterMonitor::expire_cache(unsigned int age)
+{
+	unsigned int ret;
+
+	ret = cache_lifetime;
+	cache_lifetime = age;
+	return ret;
+}
+
 counting_auto_ptr<Cluster>
-ClusterMonitor::get_cluster()
+ClusterMonitor::get_cluster(unsigned int age)
 {
+	struct timespec ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	if (age > 0 && last_update.tv_sec) {
+		if ((ts.tv_nsec - last_update.tv_nsec) < 0)
+			--(ts.tv_sec);
+		if ((ts.tv_sec - last_update.tv_sec) < age)
+			return cached_copy;
+	}
+
 	try {
 		ClientSocket sock(_sock_path);
 
@@ -81,8 +107,25 @@ ClusterMonitor::get_cluster()
 			if (poll_data.revents & (POLLERR | POLLHUP | POLLNVAL))
 				throw String("get_cluster(): socket error");
 		}
-		return xml2cluster(xml);
+
+		last_update.tv_sec = ts.tv_sec;
+		last_update.tv_nsec = ts.tv_nsec;
+
+		cached_copy = xml2cluster(xml);
+		return cached_copy;
 	} catch ( ... ) {
 		return counting_auto_ptr<Cluster>();
 	}
 }
+
+counting_auto_ptr<Cluster>
+ClusterMonitor::get_cluster()
+{
+	return get_cluster(cache_lifetime);
+}
+
+counting_auto_ptr<Cluster>
+ClusterMonitor::get_cache()
+{
+	return cached_copy;
+}
diff --git a/ricci/modules/cluster/clumon/src/daemon/Makefile b/ricci/modules/cluster/clumon/src/daemon/Makefile
index 908c65f..08217c4 100644
--- a/ricci/modules/cluster/clumon/src/daemon/Makefile
+++ b/ricci/modules/cluster/clumon/src/daemon/Makefile
@@ -22,7 +22,7 @@ OBJECTS = main.o \
 
 INCLUDE += -I../include
 CXXFLAGS += -DPARANOIA=$(PARANOID)
-LDFLAGS += ../common/*.o
+LDFLAGS += ../common/*.o -lrt
 
 ifeq ($(PARANOID), 1)
 	LDFLAGS += ${top_srcdir}/common/paranoid/*.o
diff --git a/ricci/modules/cluster/clumon/src/include/ClusterMonitor.h b/ricci/modules/cluster/clumon/src/include/ClusterMonitor.h
index e011709..dc96a94 100644
--- a/ricci/modules/cluster/clumon/src/include/ClusterMonitor.h
+++ b/ricci/modules/cluster/clumon/src/include/ClusterMonitor.h
@@ -39,10 +39,19 @@ class ClusterMonitor
 		ClusterMonitor(const String& socket_path=MONITORING_CLIENT_SOCKET);
 		virtual ~ClusterMonitor();
 
+		// Set cache expiration to age seconds.  0 means 
+		// always refresh when we call get_cluster()
+		unsigned int expire_cache(unsigned int age);
+
 		counting_auto_ptr<Cluster> get_cluster();
+		counting_auto_ptr<Cluster> get_cluster(unsigned int age);
+		counting_auto_ptr<Cluster> get_cache();
 
 	private:
 		String _sock_path;
+		struct timespec last_update;
+		counting_auto_ptr<Cluster> cached_copy;
+		unsigned int cache_lifetime;
 
 		ClusterMonitor(const ClusterMonitor&);
 		ClusterMonitor& operator= (const ClusterMonitor&);
diff --git a/ricci/modules/cluster/clumon/src/snmp-agent/Makefile b/ricci/modules/cluster/clumon/src/snmp-agent/Makefile
index 483aa13..159a9d2 100644
--- a/ricci/modules/cluster/clumon/src/snmp-agent/Makefile
+++ b/ricci/modules/cluster/clumon/src/snmp-agent/Makefile
@@ -19,7 +19,7 @@ SNMP_LDLAGS = `net-snmp-config --libs`
 INCLUDE += -I ../include
 CFLAGS += -fPIC $(SNMP_CFLAGS) -DPARANOIA=$(PARANOID)
 CXXFLAGS += -fPIC $(SNMP_CFLAGS) -DPARANOIA=$(PARANOID)
-LDFLAGS += -fPIC -shared $(SNMP_LDLAGS)
+LDFLAGS += -fPIC -shared $(SNMP_LDLAGS) -lrt
 
 ifeq ($(PARANOID), 1)
 	LDFLAGS += ${top_srcdir}/common/paranoid/*.o
-- 
1.6.2.5