Minor refactor Tags (#602)

Author: reyang

contrib/opencensus-ext-postgresql/setup.py

@@ -40,7 +40,7 @@
     long_description=open('README.rst').read(),
     install_requires=[
         'opencensus >= 0.4.dev0, < 1.0.0',
-        'psycopg2 >= 2.7.3.1',
+        'psycopg2-binary >= 2.7.3.1',
     ],
     extras_require={},
     license='Apache-2.0',

opencensus/stats/measurement_map.py

@@ -15,7 +15,7 @@
 import logging
 
 from opencensus.common import utils
-from opencensus.tags import execution_context
+from opencensus.tags import TagContext
 
 
 logger = logging.getLogger(__name__)
@@ -90,13 +90,13 @@ def measure_put_attachment(self, key, value):
 
         self._attachments[key] = value
 
-    def record(self, tag_map_tags=None):
+    def record(self, tags=None):
         """records all the measures at the same time with a tag_map.
         tag_map could either be explicitly passed to the method, or implicitly
-        read from current execution context.
+        read from current runtime context.
         """
-        if tag_map_tags is None:
-            tag_map_tags = execution_context.get_current_tag_map()
+        if tags is None:
+            tags = TagContext.get()
         if self._invalid:
             logger.warning("Measurement map has included negative value "
                            "measurements, refusing to record")
@@ -112,7 +112,7 @@ def record(self, tag_map_tags=None):
                 return
 
         self.measure_to_view_map.record(
-                tags=tag_map_tags,
+                tags=tags,
                 measurement_map=self.measurement_map,
                 timestamp=utils.to_iso_str(),
                 attachments=self.attachments

opencensus/tags/__init__.py

@@ -12,9 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from opencensus.common.runtime_context import RuntimeContext
 from opencensus.tags.tag import Tag
 from opencensus.tags.tag_key import TagKey
 from opencensus.tags.tag_value import TagValue
 from opencensus.tags.tag_map import TagMap
 
-__all__ = ['Tag', 'TagKey', 'TagValue', 'TagMap']
+__all__ = ['Tag', 'TagContext', 'TagKey', 'TagValue', 'TagMap']
+
+TagContext = RuntimeContext.register_slot('tag_context', None)

opencensus/tags/execution_context.py

@@ -13,18 +13,25 @@
 # limitations under the License.
 
 from collections import namedtuple
+from opencensus.tags.tag_key import TagKey
+from opencensus.tags.tag_value import TagValue
 
 Tag_ = namedtuple('Tag', ['key', 'value'])
 
 
 class Tag(Tag_):
     """A tag, in the format [KEY]:[VALUE].
 
-    :type key: '~opencensus.tags.tag_key.TagKey'
-    :param key: Key in the tag
+    :type key: str
+    :param key: The name of the tag
 
-    :type value: '~opencensus.tags.tag_key.TagValue'
-    :param value: Value of the key in the tag.
+    :type value: str
+    :param value: The value of the tag
 
     """
-    pass
+    def __new__(cls, key, value):
+        return super(Tag, cls).__new__(
+            cls,
+            key=TagKey(key),
+            value=TagValue(value),
+        )

opencensus/tags/tag.py

@@ -29,6 +29,7 @@ def __new__(cls, name):
         :param name: The name of the key
         :return: TagKey
         """
-        if not is_valid_tag_name(name):
-            raise ValueError(_TAG_NAME_ERROR)
+        if not isinstance(name, cls):
+            if not is_valid_tag_name(name):
+                raise ValueError(_TAG_NAME_ERROR)
         return super(TagKey, cls).__new__(cls, name)

opencensus/tags/tag_key.py

@@ -29,6 +29,7 @@ def __new__(cls, value):
         :param value: A string representing the value of a key in a tag
         :return: TagValue
         """
-        if not is_valid_tag_value(value):
-            raise ValueError(_TAG_VALUE_ERROR)
+        if not isinstance(value, cls):
+            if not is_valid_tag_value(value):
+                raise ValueError(_TAG_VALUE_ERROR)
         return super(TagValue, cls).__new__(cls, value)

opencensus/tags/tag_value.py

@@ -16,7 +16,9 @@
 import unittest
 
 from opencensus.stats import measurement_map as measurement_map_module
-from opencensus.tags import execution_context
+from opencensus.tags import Tag
+from opencensus.tags import TagContext
+from opencensus.tags import TagMap
 
 logger_patch = mock.patch('opencensus.stats.measurement_map.logger')
 
@@ -130,16 +132,14 @@ def test_record_against_explicit_tag_map(self):
             measure_to_view_map=measure_to_view_map)
 
         tags = {'testtag1': 'testtag1val'}
-        measurement_map.record(tag_map_tags=tags)
+        measurement_map.record(tags=tags)
         self.assertTrue(measure_to_view_map.record.called)
 
     def test_record_against_implicit_tag_map(self):
         measure_to_view_map = mock.Mock()
         measurement_map = measurement_map_module.MeasurementMap(
             measure_to_view_map=measure_to_view_map)
-
-        tags = {'testtag1': 'testtag1val'}
-        execution_context.set_current_tag_map(tags)
+        TagContext.set(TagMap(tags=[Tag('testtag1', 'testtag1val')]))
         measurement_map.record()
         self.assertTrue(measure_to_view_map.record.called)
 

tests/unit/stats/test_measurement_map.py

@@ -13,15 +13,17 @@
 # limitations under the License.
 
 import unittest
-from opencensus.tags import Tag, TagKey, TagValue
+from opencensus.tags import Tag
 
 
 class TestTag(unittest.TestCase):
 
     def test_constructor(self):
         key = 'key1'
         value = 'value1'
-        tag = Tag(key=TagKey(key), value=TagValue(value))
+        tag = Tag(key=key, value=value)
 
         self.assertEqual(tag.key, key)
         self.assertEqual(tag.value, value)
+        self.assertRaises(ValueError, lambda: Tag(key='', value=value))
+        self.assertRaises(ValueError, lambda: Tag(key=key, value='\0'))