1 files changed, 90 insertions, 0 deletions
diff --git a/impl_core/src/main/java/io/opencensus/implcore/stats/StatsManager.java b/impl_core/src/main/java/io/opencensus/implcore/stats/StatsManager.java
new file mode 100644
index 00000000..63fcd587
--- /dev/null
+++ b/impl_core/src/main/java/io/opencensus/implcore/stats/StatsManager.java
@@ -0,0 +1,90 @@
+/*
+ * 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 static com.google.common.base.Preconditions.checkNotNull;
+
+import io.opencensus.common.Clock;
+import io.opencensus.implcore.internal.EventQueue;
+import io.opencensus.stats.StatsCollectionState;
+import io.opencensus.stats.View;
+import io.opencensus.stats.ViewData;
+import io.opencensus.tags.TagContext;
+
+/** Object that stores all views and stats. */
+final class StatsManager {
+
+  private final EventQueue queue;
+
+  // clock used throughout the stats implementation
+  private final Clock clock;
+
+  private final CurrentStatsState state;
+  private final MeasureToViewMap measureToViewMap = new MeasureToViewMap();
+
+  StatsManager(EventQueue queue, Clock clock, CurrentStatsState state) {
+    checkNotNull(queue, "EventQueue");
+    checkNotNull(clock, "Clock");
+    checkNotNull(state, "state");
+    this.queue = queue;
+    this.clock = clock;
+    this.state = state;
+  }
+
+  void registerView(View view) {
+    measureToViewMap.registerView(view, clock);
+  }
+
+  ViewData getView(View.Name viewName) {
+    return measureToViewMap.getView(viewName, clock, state.getInternal());
+  }
+
+  void record(TagContext tags, MeasureMapInternal measurementValues) {
+    // TODO(songya): consider exposing No-op MeasureMap and use it when stats state is DISABLED, so
+    // that we don't need to create actual MeasureMapImpl.
+    if (state.getInternal() == StatsCollectionState.ENABLED) {
+      queue.enqueue(new StatsEvent(this, tags, measurementValues));
+    }
+  }
+
+  void clearStats() {
+    measureToViewMap.clearStats();
+  }
+
+  void resumeStatsCollection() {
+    measureToViewMap.resumeStatsCollection(clock.now());
+  }
+
+  // An EventQueue entry that records the stats from one call to StatsManager.record(...).
+  private static final class StatsEvent implements EventQueue.Entry {
+    private final TagContext tags;
+    private final MeasureMapInternal stats;
+    private final StatsManager statsManager;
+
+    StatsEvent(StatsManager statsManager, TagContext tags, MeasureMapInternal stats) {
+      this.statsManager = statsManager;
+      this.tags = tags;
+      this.stats = stats;
+    }
+
+    @Override
+    public void process() {
+      // Add Timestamp to value after it went through the DisruptorQueue.
+      statsManager.measureToViewMap.record(tags, stats, statsManager.clock.now());
+    }
+  }
+}