1 files changed, 95 insertions, 0 deletions
diff --git a/impl_core/src/main/java/io/opencensus/implcore/stats/IntervalBucket.java b/impl_core/src/main/java/io/opencensus/implcore/stats/IntervalBucket.java
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+/*
+ * 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.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.collect.Maps;
+import io.opencensus.common.Duration;
+import io.opencensus.common.Timestamp;
+import io.opencensus.stats.Aggregation;
+import io.opencensus.stats.Measure;
+import io.opencensus.tags.TagValue;
+import java.util.List;
+import java.util.Map;
+
+/*>>>
+import org.checkerframework.checker.nullness.qual.Nullable;
+*/
+
+/** The bucket with aggregated {@code MeasureValue}s used for {@code IntervalViewData}. */
+final class IntervalBucket {
+
+  private static final Duration ZERO = Duration.create(0, 0);
+
+  private final Timestamp start;
+  private final Duration duration;
+  private final Aggregation aggregation;
+  private final Measure measure;
+  private final Map<List</*@Nullable*/ TagValue>, MutableAggregation> tagValueAggregationMap =
+      Maps.newHashMap();
+
+  IntervalBucket(Timestamp start, Duration duration, Aggregation aggregation, Measure measure) {
+    this.start = checkNotNull(start, "Start");
+    this.duration = checkNotNull(duration, "Duration");
+    checkArgument(duration.compareTo(ZERO) > 0, "Duration must be positive");
+    this.aggregation = checkNotNull(aggregation, "Aggregation");
+    this.measure = checkNotNull(measure, "measure");
+  }
+
+  Map<List</*@Nullable*/ TagValue>, MutableAggregation> getTagValueAggregationMap() {
+    return tagValueAggregationMap;
+  }
+
+  Timestamp getStart() {
+    return start;
+  }
+
+  // Puts a new value into the internal MutableAggregations, based on the TagValues.
+  void record(
+      List</*@Nullable*/ TagValue> tagValues,
+      double value,
+      Map<String, String> attachments,
+      Timestamp timestamp) {
+    if (!tagValueAggregationMap.containsKey(tagValues)) {
+      tagValueAggregationMap.put(
+          tagValues, RecordUtils.createMutableAggregation(aggregation, measure));
+    }
+    tagValueAggregationMap.get(tagValues).add(value, attachments, timestamp);
+  }
+
+  /*
+   * Returns how much fraction of duration has passed in this IntervalBucket. For example, if this
+   * bucket starts at 10s and has a duration of 20s, and now is 15s, then getFraction() should
+   * return (15 - 10) / 20 = 0.25.
+   *
+   * This IntervalBucket must be current, i.e. the current timestamp must be within
+   * [this.start, this.start + this.duration).
+   */
+  double getFraction(Timestamp now) {
+    Duration elapsedTime = now.subtractTimestamp(start);
+    checkArgument(
+        elapsedTime.compareTo(ZERO) >= 0 && elapsedTime.compareTo(duration) < 0,
+        "This bucket must be current.");
+    return ((double) elapsedTime.toMillis()) / duration.toMillis();
+  }
+
+  void clearStats() {
+    tagValueAggregationMap.clear();
+  }
+}