Partial Revert of powercap API update

Previous commit 0c93ce6a broke the
sample code used by the daemon, by reverting the sample function to a
json message generator. This is due to inconsistencies between the coolr
code and the NRM import: we removed json generation from coolr, to push
it on the messaging side, while upstream still does it on sensor
reading.

This commit fixes that, but doesn't touch the new test code embedded in
clr_rapl.py
We will move that the test infrastructure later.

nrm/coolr/clr_rapl.py

@@ -214,7 +214,7 @@ class rapl_reader:
         e = self.read_energy_acc()
         self.stop_time = time.time()
 
-    def sample_and_json(self, label = "", accflag = False, node = ""):
+    def sample(self, accflag=False):
         if not self.initialized():
             return
 
@@ -226,55 +226,32 @@ class rapl_reader:
             if k != 'time':
                 if accflag:
                     self.totalenergy[k] += de[k]
-                self.lastpower[k] = de[k]/de['time']/1000.0/1000.0;
+                self.lastpower[k] = de[k]/de['time']/1000.0/1000.0
         self.prev_e = e
 
-        # constructing a json output
-        s  = '{"sample":"energy","time":%.3f' % (e['time'])
-        if len(node) > 0:
-            s += ',"node":"%s"' % node
-        if len(label) > 0:
-            s += ',"label":"%s"' % label
-        s += ',"energy":{'
-        firstitem = True
+        ret = dict()
+        ret['energy'] = dict()
         for k in sorted(e.keys()):
             if k != 'time':
-                if firstitem:
-                    firstitem = False
-                else:
-                    s+=','
-                s += '"%s":%d' % (self.shortenkey(k), e[k])
-        s += '},'
-        s += '"power":{'
+                ret['energy'][self.shortenkey(k)] = e[k]
 
+        ret['power'] = dict()
         totalpower = 0.0
-        firstitem = True
         for k in sorted(self.lastpower.keys()):
             if k != 'time':
-                if firstitem:
-                    firstitem = False
-                else:
-                    s+=','
-                s += '"%s":%.1f' % (self.shortenkey(k), self.lastpower[k])
-                # this is a bit ad hoc way to calculate the total. needs to be fixed later
+                ret['power'][self.shortenkey(k)] = self.lastpower[k]
+                # this is a bit ad hoc way to calculate the total.
+                # needs to be fixed later
                 if k.find("core") == -1:
                     totalpower += self.lastpower[k]
-        s += ',"total":%.1f' % (totalpower)
-        s += '},'
+        ret['power']['total'] = totalpower
 
-        s += '"powercap":{'
+        ret['powercap'] = dict()
         rlimit = self.readpowerlimitall()
-        firstitem = True
         for k in sorted(rlimit.keys()):
-            if firstitem:
-                firstitem = False
-            else:
-                s+=','
-            s += '"%s":%.1f' % (self.shortenkey(k), rlimit[k]['curW'])
-        s += '}'
+            ret['powercap'][self.shortenkey(k)] = rlimit[k]['curW']
 
-        s += '}'
-        return s
+        return ret
 
     def total_energy_json(self):
         if not self.initialized():