move context manager from Histogram class to metrics module

README.rst

@@ -70,11 +70,11 @@ and let's see the results::
     >>> metrics.get("test")
     {'arithmetic_mean': 0.41326093673706055, 'kind': 'histogram', 'skewness': 0.2739718270714368, 'harmonic_mean': 0.14326954591313346, 'min': 0.0613858699798584, 'standard_deviation': 0.4319169569113129, 'median': 0.2831099033355713, 'histogram': [(1.0613858699798584, 3), (2.0613858699798584, 0)], 'percentile': [(50, 0.2831099033355713), (75, 0.2831099033355713), (90, 0.895287036895752), (95, 0.895287036895752), (99, 0.895287036895752), (99.9, 0.895287036895752)], 'n': 3, 'max': 0.895287036895752, 'variance': 0.18655225766752892, 'geometric_mean': 0.24964828731906127, 'kurtosis': -2.3333333333333335}
 
-It is also possible to time specific sections of the code by using the ``time`` context manager::
+It is also possible to time specific sections of the code by using the ``timer`` context manager::
 
     >>> import time, random
     ... def my_worker():
-    ...     with metrics.metric("test").time():
+    ...     with metrics.timer("test"):
     ...         time.sleep(random.random())
     ...
 

appmetrics/histogram.py

@@ -21,7 +21,6 @@
 import time
 import operator
 import math
-from contextlib import contextmanager
 
 from . import statistics, exceptions, py3comp
 
@@ -350,14 +349,6 @@ def raw_data(self):
 
         return self.reservoir.values
 
-    @contextmanager
-    def time(self):
-        """A context manager which times execution of a piece of code"""
-        t1 = time.time()
-        yield
-        t2 = time.time()
-        self.notify(t2 - t1)
-
     def get(self):
         """Return the computed statistics over the gathered data"""
 

appmetrics/metrics.py

@@ -18,6 +18,7 @@
 Main interface module
 """
 
+from contextlib import contextmanager
 import functools
 import threading
 import time
@@ -240,6 +241,21 @@ def fun(*args, **kwargs):
     return wrapper
 
 
+@contextmanager
+def timer(name, reservoir_type="uniform", *reservoir_args, **reservoir_kwargs):
+    """
+    Time-measuring context manager: the time spent in the wrapped block
+    if measured and added to the named metric.
+    """
+
+    hmetric = get_or_create_histogram(name, reservoir_type, *reservoir_args, **reservoir_kwargs)
+
+    t1 = time.time()
+    yield
+    t2 = time.time()
+    hmetric.notify(t2 - t1)
+
+
 def tag(name, tag_name):
     """
     Tag the named metric with the given tag.

appmetrics/tests/test_histogram.py

@@ -361,13 +361,6 @@ def test_notify(self):
             [mock.call(1.2)])
         nt.assert_equal(result, self.reservoir.add.return_value)
 
-    def test_time(self):
-        self.histogram.notify = mock.Mock()
-        with self.histogram.time():
-            pass
-
-        nt.assert_equal(self.histogram.notify.call_count, 1)
-
     def test_raw_data(self):
         result = self.histogram.raw_data()
         nt.assert_equal(result, self.reservoir.values)

appmetrics/tests/test_metrics.py

@@ -372,6 +372,38 @@ def f2(v1, v2):
 
             return v1*v2
 
+    @mock.patch('appmetrics.histogram.Histogram.notify')
+    def test_timer(self, notify):
+        with mm.timer("test"):
+            pass
+
+        assert_equal(notify.call_count, 1)
+
+    @mock.patch('appmetrics.histogram.Histogram.notify')
+    def test_timer_multiple(self, notify):
+        with mm.timer("test"):
+            pass
+
+        with mm.timer("test"):
+            pass
+
+        assert_equal(notify.call_count, 2)
+
+    @raises(exceptions.DuplicateMetricError)
+    def test_timer_multiple_different_reservoir(self):
+        with mm.timer("test", reservoir_type="sliding_window"):
+            pass
+
+        with mm.timer("test"):
+            pass
+
+    @raises(exceptions.DuplicateMetricError)
+    def test_timer_multiple_different_type(self):
+        mm.new_gauge("test")
+
+        with mm.timer("test"):
+            pass
+
     @raises(exceptions.InvalidMetricError)
     def test_tag_invalid_name(self):
         mm.tag("test", "test")