[data-stats] Adds `buffer_utilization` statistics for PrefetchDataset.

RELNOTES: n/a
PiperOrigin-RevId: 211995741

2 files changed, 35 insertions, 0 deletions

diff --git a/tensorflow/contrib/data/python/kernel_tests/stats_dataset_ops_test.py b/tensorflow/contrib/data/python/kernel_tests/stats_dataset_ops_test.py
index 43067b4245..e25570c5ad 100644
--- a/tensorflow/contrib/data/python/kernel_tests/stats_dataset_ops_test.py
+++ b/tensorflow/contrib/data/python/kernel_tests/stats_dataset_ops_test.py
@@ -75,6 +75,31 @@ class StatsDatasetTest(stats_dataset_test_base.StatsDatasetTestBase):
         sess.run(next_element)
       self._assertSummaryHasCount(sess.run(summary_t), "record_latency", 100.0)
 
+  def testPrefetchBufferUtilization(self):
+    stats_aggregator = stats_ops.StatsAggregator()
+    dataset = dataset_ops.Dataset.range(100).map(
+        lambda x: array_ops.tile([x], ops.convert_to_tensor([x]))).prefetch(
+            -1).apply(stats_ops.set_stats_aggregator(stats_aggregator))
+    iterator = dataset.make_initializable_iterator()
+    next_element = iterator.get_next()
+    summary_t = stats_aggregator.get_summary()
+
+    with self.test_session() as sess:
+      sess.run(iterator.initializer)
+      for i in range(100):
+        self.assertAllEqual(
+            np.array([i] * i, dtype=np.int64), sess.run(next_element))
+        summary_str = sess.run(summary_t)
+        self._assertSummaryHasCount(summary_str, "Prefetch::buffer_utilization",
+                                    float(i + 1))
+        self._assertSummaryHasRange(summary_str, "Prefetch::buffer_utilization",
+                                    0, 1)
+      with self.assertRaises(errors.OutOfRangeError):
+        sess.run(next_element)
+      summary_str = sess.run(summary_t)
+      self._assertSummaryHasCount(summary_str, "Prefetch::buffer_utilization",
+                                  100)
+
   def testReinitialize(self):
     stats_aggregator = stats_ops.StatsAggregator()
     dataset = dataset_ops.Dataset.range(100).apply(
diff --git a/tensorflow/contrib/data/python/kernel_tests/stats_dataset_test_base.py b/tensorflow/contrib/data/python/kernel_tests/stats_dataset_test_base.py
index 9a13acf8f0..2f5a44408f 100644
--- a/tensorflow/contrib/data/python/kernel_tests/stats_dataset_test_base.py
+++ b/tensorflow/contrib/data/python/kernel_tests/stats_dataset_test_base.py
@@ -34,6 +34,16 @@ class StatsDatasetTestBase(test.TestCase):
         return
     self.fail("Expected tag %r not found in summary %r" % (tag, summary_proto))
 
+  def _assertSummaryHasRange(self, summary_str, tag, min_value, max_value):
+    summary_proto = summary_pb2.Summary()
+    summary_proto.ParseFromString(summary_str)
+    for value in summary_proto.value:
+      if tag == value.tag:
+        self.assertLessEqual(min_value, value.histo.min)
+        self.assertGreaterEqual(max_value, value.histo.max)
+        return
+    self.fail("Expected tag %r not found in summary %r" % (tag, summary_proto))
+
   def _assertSummaryHasSum(self, summary_str, tag, expected_value):
     summary_proto = summary_pb2.Summary()
     summary_proto.ParseFromString(summary_str)