Implements the changes required for ticket #14

The SensorID type now includes a Rsvd field that is filled
by DCDBLib when saving data to avoid overflowing a Cassandra
key with more than 2^32 columns.

DCDBLib/include/sensordatastore.h

@@ -62,7 +62,8 @@ typedef union {
  */
 typedef struct {
     uint64_t sensor_number    : 16;
-    uint64_t device_id        : 48;
+    uint64_t rsvd             : 16;
+    uint64_t device_id        : 32;
 } DeviceSensorId;
 
 /**

DCDBLib/src/cassandraBackend.cpp

@@ -120,7 +120,7 @@ void CassandraBackend::insert(string columnFamily, string key, uint64_t ts, uint
     try {
         ColumnParent cparent;
         Column c;
-        string key, name, cvalue;
+        string name, cvalue;
 
         cparent.column_family = columnFamily;
 

DCDBLib/src/sensordatastore.cpp

@@ -108,6 +108,11 @@ void SensorDataStoreImpl::init(string hostname, int port) {
 
 void SensorDataStoreImpl::insert(SensorId* sid, uint64_t ts, uint64_t value)
 {
+  /* Calculate and insert week number */
+  uint16_t week = ts / 604800000000;
+  sid->dsid.rsvd = week;
+
+  /* Insert into Cassandra */
   csBackend->insert(CF_SENSORDATA, sidConvert(sid), ts, value);
 }