Modify old formatter to match rocket's formatting style

nilmdb/server/layout.pyx

@@ -43,9 +43,13 @@ class Layout:
             self.parse = self.parse_uint16
             self.format_str = "%.6f" + " %d" * self.count
             self.format = self.format_generic
-        elif datatype == 'float32' or datatype == 'float64':
+        elif datatype == 'float32':
             self.parse = self.parse_float64
-            self.format_str = "%.6f" + " %f" * self.count
+            self.format_str = "%.6f" + " %.6e" * self.count
+            self.format = self.format_generic
+        elif datatype == 'float64':
+            self.parse = self.parse_float64
+            self.format_str = "%.6f" + " %.16e" * self.count
             self.format = self.format_generic
         else:
             raise KeyError("invalid type")

nilmdb/server/pyrocket.py

@@ -2,7 +2,7 @@
 # This interface translates between the binary format on disk
 # and the ASCII format used when communicating with clients.
 
-# This is slow!
+# This is slow!  Use the C version instead.
 
 import struct
 import layout as _layout

tests/test_layout.py

@@ -151,10 +151,12 @@ class TestLayouts(object):
                  [ 1234567890.100000, 1.1, 2.2, 3.3, 4.4, 5.5, 6.6, 7.7, 8.8 ] ]
         text = formatter.format(data)
         eq_(text,
-            "1234567890.000000 1.100000 2.200000 3.300000 4.400000 " +
-            "5.500000 6.600000 7.700000 8.800000\n" +
-            "1234567890.100000 1.100000 2.200000 3.300000 4.400000 " +
-            "5.500000 6.600000 7.700000 8.800000\n")
+            "1234567890.000000 1.100000e+00 2.200000e+00 3.300000e+00 "
+            "4.400000e+00 5.500000e+00 6.600000e+00 7.700000e+00 "
+            "8.800000e+00\n" +
+            "1234567890.100000 1.100000e+00 2.200000e+00 3.300000e+00 "
+            "4.400000e+00 5.500000e+00 6.600000e+00 7.700000e+00 "
+            "8.800000e+00\n")
 
         # try uint16_6 too
         formatter = Formatter(name_raw)
@@ -208,7 +210,7 @@ class TestLayouts(object):
                 eq_(parser1.data, parser2.data)
 
         def datagen():
-            return [ sprintf("%f", random.uniform(-1000,1000))
+            return [ sprintf("%.6e", random.uniform(-1000,1000))
                      for x in range(8) ]
         do_roundtrip(name_prep, datagen)
 
@@ -256,7 +258,7 @@ class TestLayoutSpeed:
 
         print ""
         def datagen():
-            return [ sprintf("%f", random.uniform(-1000,1000))
+            return [ sprintf("%.6e", random.uniform(-1000,1000))
                      for x in range(10) ]
         do_speedtest("float32_10", datagen)