1 files changed, 92 insertions, 0 deletions
diff --git a/impl_core/src/main/java/io/opencensus/implcore/stats/StatsComponentImplBase.java b/impl_core/src/main/java/io/opencensus/implcore/stats/StatsComponentImplBase.java
new file mode 100644
index 00000000..741b399b
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+++ b/impl_core/src/main/java/io/opencensus/implcore/stats/StatsComponentImplBase.java
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2017, OpenCensus Authors
+ *
+ * Licensed 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 io.opencensus.implcore.stats;
+
+import com.google.common.base.Preconditions;
+import io.opencensus.common.Clock;
+import io.opencensus.implcore.internal.CurrentState;
+import io.opencensus.implcore.internal.CurrentState.State;
+import io.opencensus.implcore.internal.EventQueue;
+import io.opencensus.metrics.Metrics;
+import io.opencensus.metrics.export.MetricProducer;
+import io.opencensus.stats.StatsCollectionState;
+import io.opencensus.stats.StatsComponent;
+
+/** Base implementation of {@link StatsComponent}. */
+public class StatsComponentImplBase extends StatsComponent {
+  private static final State DEFAULT_STATE = State.ENABLED;
+
+  // The State shared between the StatsComponent, StatsRecorder and ViewManager.
+  private final CurrentState currentState = new CurrentState(DEFAULT_STATE);
+
+  private final ViewManagerImpl viewManager;
+  private final StatsRecorderImpl statsRecorder;
+
+  /**
+   * Creates a new {@code StatsComponentImplBase}.
+   *
+   * @param queue the queue implementation.
+   * @param clock the clock to use when recording stats.
+   */
+  public StatsComponentImplBase(EventQueue queue, Clock clock) {
+    StatsManager statsManager = new StatsManager(queue, clock, currentState);
+    this.viewManager = new ViewManagerImpl(statsManager);
+    this.statsRecorder = new StatsRecorderImpl(statsManager);
+
+    // Create a new MetricProducerImpl and register it to MetricProducerManager when
+    // StatsComponentImplBase is initialized.
+    MetricProducer metricProducer = new MetricProducerImpl(statsManager);
+    Metrics.getExportComponent().getMetricProducerManager().add(metricProducer);
+  }
+
+  @Override
+  public ViewManagerImpl getViewManager() {
+    return viewManager;
+  }
+
+  @Override
+  public StatsRecorderImpl getStatsRecorder() {
+    return statsRecorder;
+  }
+
+  @Override
+  public StatsCollectionState getState() {
+    return stateToStatsState(currentState.get());
+  }
+
+  @Override
+  @SuppressWarnings("deprecation")
+  public synchronized void setState(StatsCollectionState newState) {
+    boolean stateChanged =
+        currentState.set(statsStateToState(Preconditions.checkNotNull(newState, "newState")));
+    if (stateChanged) {
+      if (newState == StatsCollectionState.DISABLED) {
+        viewManager.clearStats();
+      } else {
+        viewManager.resumeStatsCollection();
+      }
+    }
+  }
+
+  private static State statsStateToState(StatsCollectionState statsCollectionState) {
+    return statsCollectionState == StatsCollectionState.ENABLED ? State.ENABLED : State.DISABLED;
+  }
+
+  private static StatsCollectionState stateToStatsState(State state) {
+    return state == State.ENABLED ? StatsCollectionState.ENABLED : StatsCollectionState.DISABLED;
+  }
+}