Reuse MetricData

sdk/common/src/main/java/io/opentelemetry/sdk/internal/PrimitiveLongList.java

@@ -30,6 +30,13 @@ public static List<Long> wrap(long[] values) {
     return new LongListImpl(values);
   }
 
+  /** Set the size. */
+  public static void setSize(List<Long> list, int size) {
+    if (list instanceof LongListImpl) {
+      ((LongListImpl) list).setSize(size);
+    }
+  }
+
   /**
    * Returns a primitive array with the values of the list. The list should generally have been
    * created with {@link PrimitiveLongList#wrap(long[])}.
@@ -49,13 +56,22 @@ public static long[] toArray(List<Long> list) {
   private static class LongListImpl extends AbstractList<Long> {
 
     private final long[] values;
+    private int size;
 
     LongListImpl(long[] values) {
       this.values = values;
+      this.size = values.length;
+    }
+
+    private void setSize(int size) {
+      this.size = size;
     }
 
     @Override
     public Long get(int index) {
+      if (index >= size) {
+        throw new IndexOutOfBoundsException("Index " + index + " out of bounds for length " + size);
+      }
       // If out of bounds, the array access will produce a perfectly fine IndexOutOfBoundsException.
       return values[index];
     }
@@ -75,7 +91,7 @@ public int hashCode() {
 
     @Override
     public int size() {
-      return values.length;
+      return size;
     }
   }
 

sdk/common/src/test/java/io/opentelemetry/sdk/internal/PrimitiveLongListTest.java

@@ -7,7 +7,6 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.assertj.core.api.Assertions.catchThrowable;
 
 import java.util.Arrays;
 import java.util.List;
@@ -27,12 +26,7 @@ void wrap() {
     assertThat(wrapped.hashCode()).isEqualTo(reference.hashCode());
     assertThat(wrapped.equals(PrimitiveLongList.wrap(array))).isTrue();
 
-    // Message can change between Java versions, so instead check it's the same as a normal List's
-    // exception.
-    Throwable referenceException = catchThrowable(() -> reference.get(3));
-    assertThatThrownBy(() -> wrapped.get(3))
-        .isInstanceOf(IndexOutOfBoundsException.class)
-        .hasMessage(referenceException.getMessage());
+    assertThatThrownBy(() -> wrapped.get(3)).isInstanceOf(IndexOutOfBoundsException.class);
 
     assertThat(PrimitiveLongList.toArray(wrapped)).isSameAs(array).containsExactly(1L, 2L);
   }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/SdkMeterProvider.java

@@ -162,6 +162,9 @@ private static class LeasedMetricProducer implements MetricProducer {
     private final MeterProviderSharedState sharedState;
     private final RegisteredReader registeredReader;
 
+    private final Object collectLock = new Object();
+    private final List<MetricData> results = new ArrayList<>();
+
     LeasedMetricProducer(
         ComponentRegistry<SdkMeter> registry,
         MeterProviderSharedState sharedState,
@@ -173,14 +176,16 @@ private static class LeasedMetricProducer implements MetricProducer {
 
     @Override
     public Collection<MetricData> collectAllMetrics() {
-      Collection<SdkMeter> meters = registry.getComponents();
-      List<MetricData> result = new ArrayList<>();
-      long collectTime = sharedState.getClock().now();
-      for (SdkMeter meter : meters) {
-        result.addAll(meter.collectAll(registeredReader, collectTime));
+      synchronized (collectLock) {
+        Collection<SdkMeter> meters = registry.getComponents();
+        results.clear();
+        long collectTime = sharedState.getClock().now();
+        for (SdkMeter meter : meters) {
+          results.addAll(meter.collectAll(registeredReader, collectTime));
+        }
+        registeredReader.setLastCollectEpochNanos(collectTime);
+        return Collections.unmodifiableCollection(results);
       }
-      registeredReader.setLastCollectEpochNanos(collectTime);
-      return Collections.unmodifiableCollection(result);
     }
   }
 }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/aggregator/AdaptingCircularBufferCounter.java

@@ -14,7 +14,7 @@
  *
  * <p>This class is NOT thread-safe. It is expected to be behind a synchronized incrementer.
  */
-final class AdaptingCircularBufferCounter {
+public final class AdaptingCircularBufferCounter {
   private static final int NULL_INDEX = Integer.MIN_VALUE;
   private int endIndex = NULL_INDEX;
   private int startIndex = NULL_INDEX;
@@ -41,7 +41,7 @@ final class AdaptingCircularBufferCounter {
    *
    * @return the first index with a recording.
    */
-  int getIndexStart() {
+  public int getIndexStart() {
     return startIndex;
   }
 
@@ -52,7 +52,7 @@ int getIndexStart() {
    *
    * @return The last index with a recording.
    */
-  int getIndexEnd() {
+  public int getIndexEnd() {
     return endIndex;
   }
 
@@ -95,7 +95,7 @@ boolean increment(int index, long delta) {
    *
    * @return the number of recordings for the index, or 0 if the index is out of bounds.
    */
-  long get(int index) {
+  public long get(int index) {
     if (index < startIndex || index > endIndex) {
       return 0;
     }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/aggregator/DoubleBase2ExponentialHistogramAggregator.java

@@ -13,9 +13,11 @@
 import io.opentelemetry.sdk.metrics.data.ExponentialHistogramBuckets;
 import io.opentelemetry.sdk.metrics.data.ExponentialHistogramPointData;
 import io.opentelemetry.sdk.metrics.data.MetricData;
-import io.opentelemetry.sdk.metrics.internal.data.ImmutableExponentialHistogramData;
-import io.opentelemetry.sdk.metrics.internal.data.ImmutableExponentialHistogramPointData;
-import io.opentelemetry.sdk.metrics.internal.data.ImmutableMetricData;
+import io.opentelemetry.sdk.metrics.data.MetricDataType;
+import io.opentelemetry.sdk.metrics.internal.data.MutableExponentialHistogramBuckets;
+import io.opentelemetry.sdk.metrics.internal.data.MutableExponentialHistogramData;
+import io.opentelemetry.sdk.metrics.internal.data.MutableExponentialHistogramPointData;
+import io.opentelemetry.sdk.metrics.internal.data.MutableMetricData;
 import io.opentelemetry.sdk.metrics.internal.descriptor.MetricDescriptor;
 import io.opentelemetry.sdk.metrics.internal.exemplar.ExemplarReservoir;
 import io.opentelemetry.sdk.resources.Resource;
@@ -39,6 +41,9 @@ public final class DoubleBase2ExponentialHistogramAggregator
   private final Supplier<ExemplarReservoir<DoubleExemplarData>> reservoirSupplier;
   private final int maxBuckets;
   private final int maxScale;
+  private final MutableMetricData metricData =
+      new MutableMetricData(MetricDataType.EXPONENTIAL_HISTOGRAM);
+  private final MutableExponentialHistogramData data = new MutableExponentialHistogramData();
 
   /**
    * Constructs an exponential histogram aggregator.
@@ -66,13 +71,15 @@ public MetricData toMetricData(
       MetricDescriptor metricDescriptor,
       Collection<ExponentialHistogramPointData> points,
       AggregationTemporality temporality) {
-    return ImmutableMetricData.createExponentialHistogram(
+    data.set(temporality, points);
+    metricData.set(
         resource,
         instrumentationScopeInfo,
         metricDescriptor.getName(),
         metricDescriptor.getDescription(),
         metricDescriptor.getSourceInstrument().getUnit(),
-        ImmutableExponentialHistogramData.create(temporality, points));
+        data);
+    return metricData;
   }
 
   static final class Handle
@@ -86,6 +93,10 @@ static final class Handle
     private double max;
     private long count;
     private int scale;
+    private final MutableExponentialHistogramPointData point =
+        new MutableExponentialHistogramPointData();
+    private final MutableExponentialHistogramBuckets mutablePositiveBuckets;
+    private final MutableExponentialHistogramBuckets mutableNegativeBuckets;
 
     Handle(ExemplarReservoir<DoubleExemplarData> reservoir, int maxBuckets, int maxScale) {
       super(reservoir);
@@ -96,6 +107,8 @@ static final class Handle
       this.max = -1;
       this.count = 0;
       this.scale = maxScale;
+      this.mutablePositiveBuckets = new MutableExponentialHistogramBuckets(maxBuckets);
+      this.mutableNegativeBuckets = new MutableExponentialHistogramBuckets(maxBuckets);
     }
 
     @Override
@@ -105,21 +118,20 @@ protected synchronized ExponentialHistogramPointData doAggregateThenMaybeReset(
         Attributes attributes,
         List<DoubleExemplarData> exemplars,
         boolean reset) {
-      ExponentialHistogramPointData point =
-          ImmutableExponentialHistogramPointData.create(
-              scale,
-              sum,
-              zeroCount,
-              this.count > 0,
-              this.min,
-              this.count > 0,
-              this.max,
-              resolveBuckets(this.positiveBuckets, scale, reset),
-              resolveBuckets(this.negativeBuckets, scale, reset),
-              startEpochNanos,
-              epochNanos,
-              attributes,
-              exemplars);
+      point.set(
+          scale,
+          sum,
+          zeroCount,
+          this.count > 0,
+          this.min,
+          this.count > 0,
+          this.max,
+          resolveBuckets(this.positiveBuckets, this.mutablePositiveBuckets, scale, reset),
+          resolveBuckets(this.negativeBuckets, this.mutableNegativeBuckets, scale, reset),
+          startEpochNanos,
+          epochNanos,
+          attributes,
+          exemplars);
       if (reset) {
         this.sum = 0;
         this.zeroCount = 0;
@@ -131,15 +143,18 @@ protected synchronized ExponentialHistogramPointData doAggregateThenMaybeReset(
     }
 
     private static ExponentialHistogramBuckets resolveBuckets(
-        @Nullable DoubleBase2ExponentialHistogramBuckets buckets, int scale, boolean reset) {
+        @Nullable DoubleBase2ExponentialHistogramBuckets buckets,
+        MutableExponentialHistogramBuckets mutableBuckets,
+        int scale,
+        boolean reset) {
       if (buckets == null) {
         return EmptyExponentialHistogramBuckets.get(scale);
       }
-      ExponentialHistogramBuckets copy = buckets.copy();
+      mutableBuckets.set(buckets);
       if (reset) {
         buckets.clear();
       }
-      return copy;
+      return mutableBuckets;
     }
 
     @Override

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/aggregator/DoubleBase2ExponentialHistogramBuckets.java

@@ -18,7 +18,7 @@
  * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
  * at any time.
  */
-final class DoubleBase2ExponentialHistogramBuckets implements ExponentialHistogramBuckets {
+public final class DoubleBase2ExponentialHistogramBuckets implements ExponentialHistogramBuckets {
 
   private AdaptingCircularBufferCounter counts;
   private int scale;
@@ -75,6 +75,10 @@ public int getOffset() {
     return counts.getIndexStart();
   }
 
+  public AdaptingCircularBufferCounter getCounts() {
+    return counts;
+  }
+
   @Override
   public List<Long> getBucketCounts() {
     if (counts.isEmpty()) {

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/data/MutableExponentialHistogramBuckets.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.metrics.internal.data;
+
+import io.opentelemetry.sdk.internal.PrimitiveLongList;
+import io.opentelemetry.sdk.metrics.data.ExponentialHistogramBuckets;
+import io.opentelemetry.sdk.metrics.internal.aggregator.AdaptingCircularBufferCounter;
+import io.opentelemetry.sdk.metrics.internal.aggregator.DoubleBase2ExponentialHistogramBuckets;
+import java.util.List;
+
+public class MutableExponentialHistogramBuckets implements ExponentialHistogramBuckets {
+
+  private int scale;
+  private int offset;
+  private final long[] bucketCounts;
+  private final List<Long> bucketCountsList;
+  private long totalCount;
+
+  public MutableExponentialHistogramBuckets(int maxBuckets) {
+    this.bucketCounts = new long[maxBuckets];
+    this.bucketCountsList = PrimitiveLongList.wrap(bucketCounts);
+  }
+
+  @Override
+  public int getScale() {
+    return scale;
+  }
+
+  @Override
+  public int getOffset() {
+    return offset;
+  }
+
+  @Override
+  public List<Long> getBucketCounts() {
+    return bucketCountsList;
+  }
+
+  @Override
+  public long getTotalCount() {
+    return totalCount;
+  }
+
+  /** Set the values. */
+  public void set(DoubleBase2ExponentialHistogramBuckets exponentialHistogramBuckets) {
+    this.scale = exponentialHistogramBuckets.getScale();
+    this.offset = exponentialHistogramBuckets.getOffset();
+    AdaptingCircularBufferCounter counts = exponentialHistogramBuckets.getCounts();
+    for (int i = 0; i < bucketCounts.length; i++) {
+      this.bucketCounts[i] = counts.get(i + counts.getIndexStart());
+    }
+    PrimitiveLongList.setSize(
+        this.bucketCountsList, counts.getIndexEnd() - counts.getIndexStart() + 1);
+    this.totalCount = exponentialHistogramBuckets.getTotalCount();
+  }
+}

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/data/MutableExponentialHistogramData.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.metrics.internal.data;
+
+import io.opentelemetry.sdk.metrics.data.AggregationTemporality;
+import io.opentelemetry.sdk.metrics.data.ExponentialHistogramData;
+import io.opentelemetry.sdk.metrics.data.ExponentialHistogramPointData;
+import java.util.Collection;
+import java.util.Collections;
+
+/**
+ * Auto value implementation of {@link ExponentialHistogramData}.
+ *
+ * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
+ * at any time.
+ */
+public class MutableExponentialHistogramData implements ExponentialHistogramData {
+
+  private AggregationTemporality temporality = AggregationTemporality.CUMULATIVE;
+  private Collection<ExponentialHistogramPointData> pointData = Collections.emptyList();
+
+  public MutableExponentialHistogramData() {}
+
+  @Override
+  public AggregationTemporality getAggregationTemporality() {
+    return temporality;
+  }
+
+  @Override
+  public Collection<ExponentialHistogramPointData> getPoints() {
+    return pointData;
+  }
+
+  /** Set the values. */
+  public void set(
+      AggregationTemporality temporality, Collection<ExponentialHistogramPointData> pointData) {
+    this.temporality = temporality;
+    this.pointData = pointData;
+  }
+}