initial snapshot of dmucs svn

1 files changed, 84 insertions, 0 deletions

diff --git a/dmucs_hosts_file.h b/dmucs_hosts_file.h
new file mode 100644
index 0000000..9b94166
--- /dev/null
+++ b/dmucs_hosts_file.h
@@ -0,0 +1,84 @@
+#ifndef _DMUCS_HOST_FILE_H_
+#define _DMUCS_HOST_FILE_H_ 1
+
+/*
+ * dmucs_hosts_file.h: code to read the hosts-info configuration file.
+ *
+ * Copyright (C) 2005, 2006  Victor T. Norman
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <map>
+#include <string>
+
+#ifdef PKGDATADIR
+const std::string HOSTS_INFO_FILE = std::string(PKGDATADIR) + \
+	std::string("/") + std::string("hosts-info");
+#else
+const std::string HOSTS_INFO_FILE = "hosts-info";
+#endif
+
+
+class DmucsHostsFile
+{
+public:
+
+    static DmucsHostsFile *getInstance(const std::string &hostsInfoFile);
+    void getDataForHost(const struct in_addr &ipAddr, int *numCpus,
+			int *powerIndex) const;
+
+    /*
+     * This class implements the singleton pattern, as only one instance of
+     * it needs to exist, and it should take care to re-read the hostsfile,
+     * etc., when necessary.
+     */
+
+private:
+    // this is private so that it cannot be used (this is a Singleton).
+    DmucsHostsFile(const std::string &hostsInfoFile);	
+    ~DmucsHostsFile();
+
+    struct info_t {
+	int numCpus_;
+	int powerIndex_;
+	info_t(int ncpus, int pindex) :
+	    numCpus_(ncpus), powerIndex_(pindex) {};
+    };
+
+    static DmucsHostsFile *instance_;
+    std::string hostsInfoFile_;
+
+    /*
+     * This maps an IP address (in 32-bit format) to the pair of values:
+     * numCpus and powerIndex.
+     */
+    typedef std::map<unsigned int, info_t> host_info_db_t;
+    typedef host_info_db_t::iterator host_info_db_iter_t;
+
+    mutable host_info_db_t db_;
+    mutable time_t lastFileChangeTime_;
+
+    void readFileIntoDb() const;
+
+    /* If the file modification time has changed since the last time this
+       was called, then return true AND update lastFileChangeTime_ to the
+       new modification time. */
+    bool hasFileChanged() const;
+
+};
+
+#endif
+