test commit

runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/RemoveSafeDeltaCounterCell.java

@@ -0,0 +1,94 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.beam.runners.dataflow.worker;
+
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicLong;
+import org.apache.beam.runners.core.metrics.CounterCell;
+import org.apache.beam.runners.core.metrics.DirtyState;
+import org.apache.beam.runners.core.metrics.MetricCell;
+import org.apache.beam.sdk.metrics.Counter;
+import org.apache.beam.sdk.metrics.MetricName;
+
+/**
+ * Version of {@link CounterCell} supporting multi-thread safe mutations and extraction of delta
+ * values.
+ */
+public class RemoveSafeDeltaCounterCell implements Counter, MetricCell<Long> {
+
+  private final MetricName metricName;
+  private final ConcurrentHashMap<MetricName, Long> countersMap;
+
+  public RemoveSafeDeltaCounterCell(MetricName metricName, ConcurrentHashMap<MetricName, Long> countersMap) {
+    this.metricName = metricName;
+    this.countersMap = countersMap;
+  }
+
+  @Override
+  public void reset() {
+    countersMap.computeIfPresent(name, (unusedName, unusedValue) -> 0L);
+  }
+
+  @Override
+  public void inc(long n) {
+    countersMap.compute(name, (name, value) -> {
+        if (value == null) {
+            return n;
+        }
+        return value + n;
+    });
+  }
+
+  @Override
+  public void inc() {
+    inc(1);
+  }
+
+  @Override
+  public void dec() {
+    inc(-1);
+  }
+
+  @Override
+  public void dec(long n) {
+    inc(-1 * n);
+  }
+
+  @Override
+  public MetricName getName() {
+    return metricName;
+  }
+
+  @Override
+  public DirtyState getDirty() {
+    throw new UnsupportedOperationException(
+        String.format("%s doesn't support the getDirty", getClass().getSimpleName()));
+  }
+
+  @Override
+  public Long getCumulative() {
+    throw new UnsupportedOperationException("getCumulative is not supported by Streaming Metrics");
+  }
+
+  public void deleteIfZero() {
+    if (metricName == null) {
+      return;
+    }
+    countersMap.remove(metricName, 0L);
+  }
+}

runners/google-cloud-dataflow-java/worker/src/test/java/org/apache/beam/runners/dataflow/worker/RemoveSafeDeltaCounterCellTest.java

@@ -0,0 +1,59 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+*/
+
+package org.apache.beam.runners.dataflow.worker;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.nullValue;
+import static org.hamcrest.Matchers.is;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.apache.beam.sdk.metrics.MetricName;
+
+/** Tests for {@link RemoveSafeDeltaCounterCell}. */
+@RunWith(JUnit4.class)
+public class RemoveSafeDeltaCounterCellTest {
+
+  @Test
+  public void testRemoveSafeDeltaCounterCell_safeDeletes() throws Exception {
+    ConcurrentHashMap<MetricName, Long> metric_map = new ConcurrentHashMap<>();
+    MetricName metric1 = MetricName.named("namespace", "name_1");
+
+    RemoveSafeDeltaCounterCell cell_1 = new RemoveSafeDeltaCounterCell(metric1, metric_map);
+    RemoveSafeDeltaCounterCell cell_2 = new RemoveSafeDeltaCounterCell(metric1, metric_map);
+
+    cell_2.inc(10);
+    assertThat(metric_map.get(metric1), equalTo(10L));
+
+    cell_2.reset();
+    assertThat(metric_map.get(metric1), equalTo(0L));
+    cell_2.deleteIfZero();
+
+    assertThat(metric_map.get(metric1), is(nullValue()));
+
+    // Incrementing a deleted counter will recreate it.
+    cell_1.inc(20);
+    assertThat(metric_map.get(metric1), equalTo(20L));
+  }
+
+}