Add support for time input/output in local timezone (#31)

DCDBLib/include/timestamp.h

@@ -67,6 +67,16 @@ public:
    */
   void setNow(void);
 
+  /**
+   * @brief Convert from local time to UTC
+   */
+  void convertFromLocal(void);
+
+  /**
+   * @brief Convert from UTC to local time
+   */
+  void convertToLocal(void);
+
   /**
    * @brief Returns the raw time stamp value.
    * @return The object's value as uint64_t.

DCDBLib/src/timestamp.cpp

@@ -9,9 +9,13 @@
 #include <cinttypes>
 
 #include "boost/date_time/posix_time/posix_time.hpp"
+#include "boost/date_time/local_time/local_time.hpp"
+#include "boost/date_time/c_local_time_adjustor.hpp"
 
 #include "timestamp.h"
 
+/* Use this as our local to utc adjustor */
+typedef boost::date_time::c_local_adjustor<boost::posix_time::ptime> local_adj;
 
 /**
  * This function parses a string and tries to do a best guess at the contained
@@ -90,6 +94,49 @@ void DCDBTimeStamp::setNow(void)
   raw = diff.total_nanoseconds();
 }
 
+/**
+ *
+ */
+void DCDBTimeStamp::convertFromLocal()
+{
+  /*
+   * Unfortunately BOOST c_local_adjustor doesn't support local-to-utc conversion.
+   * Therfore, we first check the offset of "raw" during utc-to-local conversion
+   * and then apply this offset in the other direction.
+   */
+
+  /* Construct ptime object t from raw */
+  boost::posix_time::ptime t(boost::gregorian::date(1970,1,1));
+  t += boost::posix_time::nanoseconds(raw);
+
+  /* Convert t to UTC */
+  boost::posix_time::ptime t2 = local_adj::utc_to_local(t);
+
+  /* Check the difference of the two times */
+  boost::posix_time::time_duration diff = t - t2;
+
+  /* Write back adjusted value to raw */
+  raw += diff.total_nanoseconds();
+}
+
+/**
+ *
+ */
+void DCDBTimeStamp::convertToLocal()
+{
+  /* Construct ptime object t from raw */
+  boost::posix_time::ptime t(boost::gregorian::date(1970,1,1));
+  t += boost::posix_time::nanoseconds(raw);
+
+  /* Convert t to Local */
+  t = local_adj::utc_to_local(t);
+
+  /* Write back to raw */
+  boost::posix_time::ptime epoch(boost::gregorian::date(1970,1,1));
+  boost::posix_time::time_duration diff = t - epoch;
+  raw = diff.total_nanoseconds();
+}
+
 /**
  *
  */

DCDBTools/dcdbquery/dcdbquery.cpp

@@ -21,7 +21,7 @@ void usage(void)
 {
   /*            0---------1---------2---------3---------4---------5---------6---------7--------- */
   std::cout << "Usage:" << std::endl
-            << "dcdbquery [-h <hostname>] [-r] <Sensor 1> [<Sensor 2> ...] <Start> <End>" << std::endl
+            << "dcdbquery [-h <hostname>] [-r] [-l] <Sensor 1> [<Sensor 2> ...] <Start> <End>" << std::endl
             << "where" << std::endl
             << "    <hostname> - the name of the DB server" << std::endl
             << "    <Sensor n> - a public sensor name" << std::endl
@@ -31,7 +31,9 @@ void usage(void)
             << "<Start> and <End> times should be supplied as 'yyyy-mm-dd hh:mm:ss' or unix" << std::endl
             << "timestamps." << std::endl
             << "When the -r option is specified, timestamps will be reported in internal (raw)" << std::endl
-            << "format (nanoseconds since epoch) insted of ISO human readable form." << std::endl;
+            << "format (nanoseconds since epoch) insted of ISO human readable form." << std::endl
+            << "When the -l option is specified, times for <Start>, <End>, and in the generated" << std::endl
+            << "output will be interpreted / printed in the local time zone." << std::endl;
   exit(EXIT_SUCCESS);
 }
 
@@ -46,7 +48,8 @@ int main(int argc, char* argv[])
   int ret;
   const char *host = "localhost";
   bool raw = false;
-  while ((ret=getopt(argc, argv, "+h:r"))!=-1) {
+  bool localtime = false;
+  while ((ret=getopt(argc, argv, "+h:rl"))!=-1) {
       switch(ret) {
           case 'h':
               host = optarg;
@@ -54,6 +57,9 @@ int main(int argc, char* argv[])
           case 'r':
               raw = true;
               break;
+          case 'l':
+              localtime = true;
+              break;
           default:
               usage();
               exit(EXIT_FAILURE);
@@ -65,6 +71,10 @@ int main(int argc, char* argv[])
   try {
       start = DCDBTimeStamp(argv[argc-2]);
       end   = DCDBTimeStamp(argv[argc-1]);
+      if (localtime) {
+          start.convertFromLocal();
+          end.convertFromLocal();
+      }
   }
   catch (std::exception& e) {
       std::cout << "Wrong time format." << std::endl;
@@ -83,7 +93,7 @@ int main(int argc, char* argv[])
       sensors.push_back(argv[arg]);
   }
 
-  DCDBQuery::doQuery(host, sensors, start, end, raw);
+  DCDBQuery::doQuery(host, sensors, start, end, raw, localtime);
 
   return 0;
 }

DCDBTools/dcdbquery/query.cpp

@@ -22,7 +22,7 @@
 #include "casshelper.h"
 
 /* Lovely spaghetti code coming up next. Be aware... */
-void DCDBQuery::doQuery(const char* hostname, std::list<std::string> sensors, DCDBTimeStamp start, DCDBTimeStamp end, bool raw)
+void DCDBQuery::doQuery(const char* hostname, std::list<std::string> sensors, DCDBTimeStamp start, DCDBTimeStamp end, bool raw, bool localtime)
 {
   /* Connect to db */
   CassCluster *cluster = CassHelper::create_cluster(hostname);
@@ -54,7 +54,7 @@ void DCDBQuery::doQuery(const char* hostname, std::list<std::string> sensors, DC
       }
 #endif
 
-      querySensorsCSV(session, *it, sidList, start, end, raw);
+      querySensorsCSV(session, *it, sidList, start, end, raw, localtime);
   }
 
   /* Clean up */
@@ -279,7 +279,7 @@ bool DCDBQuery::sidPatternMatch(SensorId& sid, std::string pattern)
   return true;
 }
 
-void DCDBQuery::querySensorsCSV(CassSession* session, std::string sensorName, std::list<SensorId>& sidList, DCDBTimeStamp& start, DCDBTimeStamp& end, bool raw)
+void DCDBQuery::querySensorsCSV(CassSession* session, std::string sensorName, std::list<SensorId>& sidList, DCDBTimeStamp& start, DCDBTimeStamp& end, bool raw, bool localtime)
 {
   /* Since everything has been mangled until here, we assume parameter safety and do a non-prepared statement... Oh oh... */
   std::stringstream query;
@@ -313,11 +313,14 @@ void DCDBQuery::querySensorsCSV(CassSession* session, std::string sensorName, st
           cass_value_get_int64(cass_row_get_column_by_name(row, "ts"), &ts);
           cass_value_get_int64(cass_row_get_column_by_name(row, "value"), &value);
 
+          DCDBTimeStamp t((uint64_t)ts);
+          if (localtime) {
+              t.convertToLocal();
+          }
           if (raw) {
-              std::cout << sensorName << "," << std::dec << ts << "," << std::dec << value << std::endl;
+              std::cout << sensorName << "," << std::dec << t.getRaw() << "," << std::dec << value << std::endl;
           }
           else {
-              DCDBTimeStamp t((uint64_t)ts);
               std::cout << sensorName << "," << t.getString() << "," << std::dec << value << std::endl;
           }
       }

DCDBTools/dcdbquery/query.h

@@ -20,7 +20,7 @@
 class DCDBQuery
 {
 public:
-  static void doQuery(const char* hostname, std::list<std::string> sensors, DCDBTimeStamp start, DCDBTimeStamp end, bool raw);
+  static void doQuery(const char* hostname, std::list<std::string> sensors, DCDBTimeStamp start, DCDBTimeStamp end, bool raw, bool localtime);
 
 protected:
   static void lookupPublishedSensorPattern(CassSession* session, std::string name, std::string& pattern);
@@ -28,7 +28,7 @@ protected:
   static bool topicToSid(SensorId& sid, std::string topic);
   static std::string sidConvert(SensorId& sid);
   static bool sidPatternMatch(SensorId& sid, std::string pattern);
-  static void querySensorsCSV(CassSession* session, std::string sensorName, std::list<SensorId>& sidList, DCDBTimeStamp& start, DCDBTimeStamp& end, bool raw);
+  static void querySensorsCSV(CassSession* session, std::string sensorName, std::list<SensorId>& sidList, DCDBTimeStamp& start, DCDBTimeStamp& end, bool raw, bool localtime);
 };